CN114073224B

CN114073224B - Avocado water culture method

Info

Publication number: CN114073224B
Application number: CN202111163465.5A
Authority: CN
Inventors: 王甲水; 刘远征; 张贺; 李艳霞; 马蔚红
Original assignee: Hainan Rezuo Liangyuan Seed Industry Technology Co ltd; Haikou Experimental Station of Chinese Academy of Tropical Agricultural Sciences
Current assignee: Hainan Rezuo Liangyuan Seed Industry Technology Co ltd; Haikou Experimental Station of Chinese Academy of Tropical Agricultural Sciences
Priority date: 2021-09-30
Filing date: 2021-09-30
Publication date: 2022-09-23
Anticipated expiration: 2041-09-30
Also published as: CN114073224A

Abstract

The invention provides a avocado water culture method which comprises seed germination water culture or tissue culture rooting seedling water culture, wherein the seed germination water culture comprises the steps of seed treatment, cleaning, primary culture, water culture and the like, and the tissue culture rooting seedling water culture comprises the steps of seedling hardening, pre-culture, cleaning of tissue culture seedlings, primary culture, water culture and the like of the tissue culture rooting seedlings. The invention establishes the hydroponic culture system of the avocado seeds and the tissue culture seedlings by utilizing the avocado hydroponic culture solution formula, the culture technology and the matched equipment thereof and by methods of staged culture and the like, improves the rooting efficiency, the seed germination rate, the seedling rate and the survival rate of the avocado, and reduces the root rotting rate.

Description

Avocado water culture method

Technical Field

The invention relates to the technical field of plant water culture, in particular to a avocado water culture method.

Background

Avocados (Persea americana Mill), also known as avocados, etc., native to the Central America and Mexico wet regions, are well-known tropical and subtropical fruits and are also one of the woody oil tree species. China is suitable for cultivation in Hainan province, Guizhou province, Guangdong province, Guangxi province, Yunnan province and other provinces. The avocado is a fruit with extremely high nutritive value, contains a plurality of vitamins, fatty acids, proteins and mineral elements, wherein 80 percent of the fatty acids are unsaturated fatty acids such as linoleic acid, linolenic acid and the like which are necessary for human bodies, the human body absorption rate is up to 93.7 percent, and the avocado is reputed to be forest butter. Avocados are also high-energy food products, which have been called "fruit-grains".

The avocados have the nutritional and health-care values and are eager and sought after by consumers. In recent decades, the growing area and yield of the world avocados have been rapidly increased, the consumption has been increasing day by day, and the world avocados are in a short supply and demand state in the international market for a long time. Two main important factors for restricting the development of the avocado industry are root diseases such as avocado root rot and the like, and the rapid propagation of healthy seedlings. At present, no report is found about the hydroponic method of the avocados, so that the effective hydroponic method of the avocados has important significance for the development of the avocado industry.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a hydroponic method for avocados.

The technical scheme of the invention mainly comprises the following contents:

a water culture method for avocado comprises water culture for germination of seeds or water culture of rooting seedlings;

the seed germination water culture comprises the following steps:

s1-1, seed treatment: disinfecting and cleaning seeds for later use;

s1-2, preparation of water culture facilities: a culture plate is arranged in the incubator, and is provided with a planting hole, and a planting device is arranged on the planting hole; the incubator body is provided with a humidifying vent hole which is externally connected with a humidifier, the bottom of the incubator is provided with a water inlet and water outlet, a culture solution storage tank is arranged outside the incubator, a moisturizing cover is arranged above the incubator, and the moisturizing cover is provided with a humidifying vent hole;

s1-3, seed germination culture: planting the cleaned and aired seeds in a planting device for germination culture;

s1-4, primary culture: after the seeds are germinated and cultured for 10-20 days, replacing the primary culture nutrient solution, enabling the part with the root of less than 0.5-1 cm to completely enter the primary culture nutrient solution, and ventilating and supplying oxygen to the primary culture nutrient solution; when the root system main root is 10-12 cm long, the area of the seed cotyledon 1/2 is cut off, and when the root system main root is more than or equal to 20cm long, the area of the seed cotyledon 3/4 is cut off, and then the water culture stage can be carried out;

the primary culture nutrient solution comprises the following components: 500-550 mg/L of calcium nitrate tetrahydrate, 500-550 mg/L of potassium nitrate, 35-40 mg/L of ammonium nitrate, 700-750 mg/L of monopotassium phosphate, 250-300 mg/L of magnesium sulfate, 1.10-1.25 mL of iron salt solution and 5-7 mL of trace element solution;

according to the pair K in the growth process of the avocados ⁺ Required amount, and Cl susceptibility ^- And (4) screening the nutrient solution most suitable for the growth of the avocado in the seedling stage by the stress characteristic. When the root system main root grows for about 10cm, the seed cotyledon 1/2 is cut off, and when the root system main root grows for more than 20cm, the seed cotyledon 3/4 is cut off, so that the effect is optimal. Because the root system growth is basically improved by the self nutrition of the seeds, the root absorbs less nutrition, the size of seed cotyledons is reduced by the length of the root system, the function of the root for absorbing nutrition can be stimulated to be improved, the root is rotten along with the reduction of nutrient substances of the seeds if the root system is not treated, and the problem of dead seedlings caused by the fact that the root cannot absorb or absorbs insufficient nutrition can be caused if the root system is completely removed.

S1-5, water culture:

replacing the primary culture nutrient solution in the incubator with a hydroponic culture solution, enabling the part below 0.5-1 cm of the root to completely enter the hydroponic culture solution, and ventilating and supplying oxygen; emptying the hydroponic culture solution to a nutrient solution storage tank every 30-45 min, injecting the hydroponic culture solution into the incubator again after 30-45 min intervals, and keeping the roots wet through a humidifying vent hole on the incubator body during the period of discharging the culture solution;

the root system of the tissue culture seedling of the avocado is relatively crisp and easy to break, and meanwhile, when the avocado root absorbs nutrition, the root beneficial bacteria are needed to assist in absorption, so that the root system of the avocado is relatively weak in adaptability. A set of water culture technical method of the tissue culture seedlings of the avocados is developed according to the characteristics and the characteristics of the root systems of the avocados.

The water culture of the tissue culture rooted seedlings comprises the following steps:

s2-1, hardening off the tissue culture rooted seedlings;

s2-2, preculture: opening the seal of the culture bottle, injecting a rooting culture solution into the culture bottle, ventilating and supplying oxygen, wherein the culture time is more than or equal to 5 d; the rooting culture solution comprises the following components: 1800-1900 mg/L potassium nitrate, 1600-1650 mg/L ammonium nitrate, 150-170 mg/L potassium dihydrogen phosphate, 350-370 mg/L magnesium sulfate, 420-440 mg/L calcium chloride, 0.83-1.0 mg/L potassium iodide, 6.0-6.2 mg/L boric acid, 22.0-22.3 mg/L manganese sulfate, 8.2-8.6 mg/L zinc sulfate, 0.25-0.28 mg/L sodium molybdate, 0.025-0.028 mg/L of copper sulfate, 0.025-0.030 mg/L of cobalt chloride, 35.00-37.25 mg/L of disodium ethylenediamine tetraacetate, 27.85-29.00 mg/L of ferrous sulfate, 100-110 mg/L of inositol, 2-3 mg/L of glycine, 0.1-0.15 mg/L of thiamine hydrochloride, 0.5-0.7 mg/L of pyridoxine hydrochloride, 0.5-0.6 mg/L, IBA 1.0.0-1.2 mg/L of nicotinic acid and 10-12 wt% of coconut water;

when the direct water planting of the rooting tissue culture seedling of avocado, change the culture medium and can cause root system to be inadaptable, change into liquid nutrient medium by solid-state culture medium and also can have the problem of adaptation, all can cause the root system to be inadaptable and the problem of dead root appears above, serious meeting causes the death of tissue culture seedling. This technique is through increasing the preculture before the hydroponics, firstly imitates the water planting through group's tissue culture bottle, puts in culture solution and leads to oxygen, can improve the water planting adaptability on next step of tissue culture seedling, secondly can provide vegetative growth through the culture solution of taking root, can improve the root system adaptability again in the root system growth of simulation water culture and the sprouting of new root.

S2-3, cleaning the tissue culture rooted seedlings;

s2-4, preparation of water culture facilities: a culture plate is arranged in the incubator, and is provided with a planting hole, and a planting device is arranged on the planting hole; the incubator is provided with a humidifying vent hole which is externally connected with a humidifier, the bottom of the incubator is provided with a water inlet and water outlet, a culture solution storage tank is arranged outside the incubator, a moisturizing cover is arranged above the incubator, and the moisturizing cover is provided with a humidifying vent hole;

s2-5, primary culture: taking the clean tissue culture rooted seedlings, then planting the seedlings in a field planting device, adding a primary culture nutrient solution into an incubator, enabling the part below 0.5-1 cm of the root to completely enter the primary culture nutrient solution, ventilating and supplying oxygen in the culture solution, and stopping ventilating for 5-10 min every 30-45 min;

the primary culture nutrient solution comprises the following components: 1800-1900 mg/L of potassium nitrate, 1600-1650 mg/L of ammonium nitrate, 150-170 mg/L of monopotassium phosphate, 350-370 mg/L of magnesium sulfate, 420-440 mg/L of calcium chloride, 0.83-1.0 mg/L of potassium iodide, 6.0-6.2 mg/L of boric acid, 22.0-22.3 mg/L of manganese sulfate, 8.2-8.6 mg/L of zinc sulfate, 0.25-0.28 mg/L of sodium molybdate, 0.025-0.028 mg/L of copper sulfate, 0.025-0.030 mg/L of cobalt chloride, 35.00-37.25 mg/L of disodium ethylenediaminetetraacetate, 27.85-29.00 mg/L of ferrous sulfate, 100-110 mg/L of inositol, 2-3 mg/L of glycine, 0.1-0.15 mg/L of thiamine hydrochloride, 0.5-0.7 mg/L of pyridoxine hydrochloride, 0.5-0.6 mg/L of nicotinic acid and 0.5-0.5 mg/L of BA;

the transplanting of the tissue culture seedlings can generate the adaptation process of the root system, although the adaptation time can be reduced by pre-culture, the adaptation period of the tissue culture seedlings still can be generated, the invention further improves the adaptability of the root system and shortens the adaptation time by water culture initial culture. The primary culture has the following characteristics: firstly, moisturizing and humidifying functions are added, so that the moisture of the leaves of the tissue culture seedlings can be kept, the influence of moisture evaporation on the seedlings is reduced, the survival rate of the seedlings is improved, and the seedling revival period is shortened; and secondly, the initial culture nutrient solution can improve the root adaptability and promote the germination of new roots, and the seedling revival period is shortened.

S2-6, water culture: after the initial culture is carried out for 10-15 days, the culture is converted into water culture; when water culture is carried out, uncovering the moisturizing cover; replacing the initial culture nutrient solution in the incubator with a hydroponic culture solution, enabling the part with root of less than 0.5-1 cm to completely enter the hydroponic culture solution, and ventilating and supplying oxygen; emptying the hydroponic culture solution into the storage box every 30-45 min, injecting the hydroponic culture solution into the culture box again after 30-45 min, and keeping the root moist through the humidifying vent holes during the culture solution discharge period;

firstly, according to the K pair in the growing process of the avocado ⁺ Required amount, and is susceptible to Cl ^- StressScreening out the nutrient solution most suitable for the growth of the avocado in the seedling stage. And secondly, according to the characteristics that the avocados are used as woody fruits and the roots of the avocados grow in the seedling stage, the optimal nutrient solution supply mode and related parameters are screened out through experiments, and because the avocados are woody fruit trees, the roots of the avocados are found to be soaked in water or nutrient solution for a long time in the water culture process, although oxygen is continuously introduced, the roots of the avocados can suffer from root rot, the nutrient solution supply mode is improved through the experiments, the intermittent circulation supply is changed, the liquid is emptied in 30-45 min during the root liquid soaking, and the liquid is kept moist by a humidifier instead. Thus, root rot can be improved.

In the step S1-5 and the step S2-6, the hydroponic culture solution comprises the following components: 900-945 mg/L of calcium nitrate tetrahydrate, 506-1000 mg/L of potassium nitrate, 80-90 mg/L of ammonium nitrate, 136-150 mg/L of monopotassium phosphate, 493-510 mg/L of magnesium sulfate, 2.5-2.8 mL of iron salt solution and 5-8 mL of trace element solution.

The water culture of the tissue culture seedlings can provide root culture of the tissue culture seedlings of the avocado on one hand, improve the seedling rate, and provide an ideal root system for root researches, such as seedling-stage nutrition supply research, root disease research and the like.

Preferably, the sterilization is: after the seeds are cleaned, 300 times diluted liquid of 50% carbendazim wettable powder and 70% mancozeb wettable powder is used as a disinfectant for disinfection for 20 min.

Preferably, the aeration and oxygen supply rate is 90L/min.

Preferably, in step S2-1, the hardening off of the tissue-cultured rooted plantlets is: taking out the tissue culture rooted seedlings from the culture room, placing the tissue culture rooted seedlings in the room temperature, closing the bottle, exercising for at least 3d, moving the tissue culture rooted seedlings to a water culture temperature environment, and closing the bottle, exercising for more than 5 d. The seedlings are trained by using the temperature of the environment twice, the adaptation of the avocado seedlings to the environment can be ensured, and the survival rate of the avocado seedlings after subsequent water planting and uncovering is facilitated.

Preferably, step S2-3, cleaning the tissue culture rooted seedlings: taking out the tissue culture rooted seedling after pre-culture, washing the easy-to-fall culture medium attached to the root with clear water, then placing the tissue culture seedling in a container, filling the container with rooting culture solution, ventilating and supplying oxygen, and washing the residual culture medium with clear water after the culture medium falls off. In this link, utilize the mode of continuous logical oxygen, can effectively clear away root culture medium, but the furthest simultaneously reduces the root damage, also can furthest keep the root through the adaptability of preculture.

Preferably, step S1-3, seed germination culture: planting the cleaned and aired seeds in a planting device, and adding water with the pH value of 5.0-7.0 into an incubator to enable the tips of the seeds to be downward and enable the seeds not to completely enter the water; during the culture period, the moisture-preserving cover is covered, the seeds are internally humidified through the humidifying vent holes on the moisture-preserving cover, the seeds are prevented from losing water, and the seeds are humidified every 30-45 min for 5-10 min.

Experiments show that the bottom of the avocado seeds enters the culture solution for 0.5-1 cm optimally when the avocado seeds germinate, the seeds are easily rotted if the avocado seeds are too deep, and water loss is easily caused if the avocado seeds are too shallow. The bottom of the avocado seeds enters the culture solution for 0.5-1 cm, so that the seeds can be promoted to germinate; secondly, experiments show that the avocado seed coat influences seed germination, the seed germination time can be delayed, the seed coat is required to be removed for accelerating seed germination, the seed dehydration can be caused when the seed is removed, particularly, the seed dehydration phenomenon can occur within 2-3 days after the seed coat is removed, and the seed germination is directly influenced or the seed embryo is dead and cannot germinate along with the serious dehydration. This scheme has increased moisturizing device and humidification method, can ensure that the seed can not appear the desiccation, and cause unable germination.

Preferably, the iron salt solution comprises the following components: 2.78g of ferrous sulfate heptahydrate, 3.73g of disodium ethylene diamine tetraacetate and 500mL of distilled water.

Preferably, the trace element liquid comprises the following components: potassium iodide 0.83mg/L, boric acid 6.2mg/L, manganese sulfate 22.3mg/L, zinc sulfate 8.6mg/L, sodium molybdate 0.25mg/L, copper sulfate 0.025mg/L, and cobalt chloride 0.025 mg/L.

The invention has the following effects:

according to the invention, a water culture medium formula, a culture technology and supporting equipment of the avocado are researched, and a water culture system of the avocado is established by a staged culture method and the like, so that a system for researching a needed healthy root system and a system for researching the root disease of the avocado is provided, a water culture technology is innovatively utilized to establish an external nutrition rooting technology of the avocado, and the rooting efficiency of the avocado is improved; by utilizing the water culture system, the germination rate and the survival rate of seeds are improved, and the rotten root rate is reduced.

Drawings

FIG. 1: the invention discloses a structural schematic diagram of a water culture system.

FIG. 2: partial schematic diagram of structure of water culture system

Detailed Description

In order that the technical contents of the invention may be better understood, specific examples are provided below to further illustrate the invention.

The aeration oxygen supply rate described in the following examples and comparative examples was 90L/min.

Example 1 hydroponic method for germination of avocado seeds

1. Seed treatment

Cleaning fresh avocado seeds, soaking the fresh avocado seeds in a disinfectant solution which is 300 times of 50% carbendazim wettable powder and 70% mancozeb wettable powder for 20min, then washing the seeds with running water, and washing seed coats;

2. incubator preparation

The cultivation box is 30cm in depth, 100cm in width and 100cm in length, a cultivation plate is designed on the cultivation box, planting holes 15-20 cm apart are formed in the cultivation plate, and planting devices are arranged on the planting holes; the incubator box is equipped with the humidification air vent apart from bottom 28cm department, can external humidifier humidification internally. The incubator bottom is equipped with water inlet and delivery port, is equipped with the culture solution bin outside the incubator, and the accessible water pump carries out hydrologic cycle. The incubator is provided with a moisturizing cover with the height of at least 10cm, wherein the moisturizing cover is provided with a humidifying vent hole, and can be externally connected with a humidifier to humidify the inside.

3. Seed germination

Planting cleaned and aired avocado seeds in a planting device, adding 25cm high water with the pH value of 5.1 into an incubator, adjusting the height of the seeds by the planting device to enable the tips of the seeds to face downwards, enabling the avocado seeds to enter water with the length of 0.5cm, and enabling other parts to be above the water surface; during the culture period, the moisture-preserving cover is covered, the seeds are internally humidified through the humidifying vent holes of the moisture-preserving cover, the seeds are prevented from losing water, and the seeds are humidified every 30min for 5 min. The average temperature in the daytime is 33-35 ℃, and the average temperature at night is 26-28 ℃;

4. initial culture

After 10 days of culture, most seeds germinate and root, and the germination rate is 96%. After the seeds germinate, water in an incubator is replaced by initial culture nutrient solution with the height of 25cm and the pH value of 6.8, and the height of the roots of the tissue culture seedlings is adjusted by a planting device, so that the parts of the roots below 0.5cm are all put into the initial culture nutrient solution; and is connected with the air stone through an air pump and a hose, and the culture solution is aerated and supplied with oxygen. When the root system main root grows for 10-12 cm, the area of the seed cotyledon 1/2 is cut off, and when the root system main root grows for more than or equal to 20cm, the area of the seed cotyledon 3/4 is cut off. The average temperature in the daytime is 33-35 ℃, and the average temperature at night is 26-28 ℃.

The primary culture nutrient solution comprises the following components: 500mg/L of calcium nitrate tetrahydrate, 500mg/L of potassium nitrate, 40mg/L of ammonium nitrate, 750mg/L of monopotassium phosphate, 250mg/L of magnesium sulfate, 1.25mL of iron salt solution and 5mL of trace element solution;

iron salt solution: 2.78g of ferrous sulfate heptahydrate, 3.73g of disodium ethylene diamine tetraacetate (EDTA.Na) and 500mL of distilled water, wherein the pH value is 5.5;

trace element liquid: potassium iodide 0.83mg/L, boric acid 6.2mg/L, manganese sulfate 22.3mg/L, zinc sulfate 8.6mg/L, sodium molybdate 0.25mg/L, copper sulfate 0.025mg/L, and cobalt chloride 0.025 mg/L.

5. Hydroponic culture

Replacing the primary culture nutrient solution in the incubator with a pH7.0 water culture solution, wherein the height of the water culture solution is 25cm, and adjusting the height of the roots of the tissue culture seedlings through a field planting device to enable the parts below 0.5cm of the roots to completely enter the water culture solution; and is connected with the air stone through an air pump and a hose, and the culture solution is aerated and supplied with oxygen.

Emptying the culture solution to the nutrient solution culture storage tank every 30min, and re-injecting water culture nutrient solution with height of 25cm after 30min interval. During the period of discharging the culture solution, the external humidifier keeps the root part moist by utilizing the humidifying vent hole at the position of the incubator body, which is 28cm away from the bottom. The average temperature in the daytime is 33-35 ℃, and the average temperature at night is 26-28 ℃. Changing the culture solution every 7 days;

the hydroponic culture solution comprises the following components: 945mg/L calcium nitrate tetrahydrate, 1000mg/L potassium nitrate, 80mg/L ammonium nitrate, 150mg/L monopotassium phosphate, 493mg/L magnesium sulfate, 2.5mL iron salt solution and 5mL trace element solution.

Example 2 hydroponic method for germination of avocado seeds

1. Seed treatment

2. incubator preparation

The depth of the incubator is 30cm, the width of the incubator is 100cm, the length of the incubator is 100cm, an incubator plate is designed on the incubator, planting holes which are 15-20 cm away from each other are formed in the incubator plate, and planting devices are arranged on the planting holes; the incubator body is provided with a humidifying vent hole at a position 28cm away from the bottom, and the external humidifier humidifies the inside. The bottom of the incubator is provided with a water inlet and a water outlet, a culture solution storage tank is arranged outside the incubator, and water circulation is carried out through a water pump. The incubator is provided with a moisturizing cover with the height of at least 10cm, wherein the moisturizing cover is provided with a humidifying vent hole and can be externally connected with a humidifier for internal humidification.

3. Seed germination

Planting cleaned and aired avocado seeds in a planting device, adding 25 cm-high water with the pH value of 7.0 into an incubator, adjusting the height of the seeds by the planting device to enable the tips of the seeds to face downwards, enabling the avocado seeds to enter water with the length of 1.0cm, and enabling other parts to be above the water surface; during the culture period, the moisture-preserving cover is covered, the seeds are internally humidified through the humidifying vent holes of the moisture-preserving cover, the seeds are prevented from losing water, and the seeds are humidified every 30min for 5 min. The average temperature in the daytime is 33-35 ℃, and the average temperature at night is 26-28 ℃;

4. initial culture

After 20 days of culture, most seeds germinate and root, the germination rate is 95 percent, water in an incubator after the seeds germinate is replaced by a primary culture nutrient solution with the pH of 5.3 and the height of the roots of the tissue culture seedlings is adjusted by a planting device, and the parts of the roots below 1.0cm are all put into the primary culture nutrient solution; and is connected with the air stone through an air pump and a hose, and the culture solution is aerated and supplied with oxygen. When the root system main root grows for 10-12 cm, the area of the seed cotyledon 1/2 is cut off, and when the root system main root grows for more than or equal to 20cm, the area of the seed cotyledon 3/4 is cut off. The average temperature in the daytime is 33-35 ℃, and the average temperature at night is 26-28 ℃.

The primary culture nutrient solution comprises the following components: 550mg/L of calcium nitrate tetrahydrate, 550mg/L of potassium nitrate, 35mg/L of ammonium nitrate, 700mg/L of monopotassium phosphate, 300mg/L of magnesium sulfate, 1.10mL of iron salt solution and 7mL of trace element solution;

5. Hydroponic culture

Replacing the primary culture nutrient solution in the incubator with a pH5.0 water culture solution with a height of 25cm, and adjusting the height of the roots of the tissue culture seedlings through a field planting device to enable the parts below 1.0cm of the roots to completely enter the water culture solution; and is connected with the air stone through an air pump and a hose, and the culture solution is aerated and supplied with oxygen.

Emptying the culture solution to the nutrient solution culture storage tank every 45min, and re-injecting water culture nutrient solution with the height of 25cm after the interval of 45 min. During the period of discharging the culture solution, the external humidifier keeps the root part moist by utilizing the humidifying vent hole at the position of the incubator body, which is 28cm away from the bottom. The average temperature in the daytime is 33-35 ℃, and the average temperature at night is 26-28 ℃. Changing the culture solution every 7 days;

the hydroponic culture solution comprises the following components: 900mg/L of calcium nitrate tetrahydrate, 506mg/L of potassium nitrate, 90mg/L of ammonium nitrate, 136mg/L of monopotassium phosphate, 510mg/L of magnesium sulfate, 2.8mL of iron salt solution and 8mL of trace element solution.

Example 3 hydroponic method for tissue culture rooting seedlings of avocados

1. Training the tissue culture rooted seedlings:

taking out the tissue culture seedling which is subjected to rooting culture and meets the transplanting standard from the culture room, placing the tissue culture seedling in the room temperature, closing the bottle for exercise for 3 days, then transferring the tissue culture seedling to the temperature environment for water culture, and closing the bottle for exercise for 5 days.

2. Tissue culture rooting seedling water culture pre-culture:

taking the tissue culture rooted seedlings after seedling training, opening a culture bottle for sealing, injecting a rooting culture solution with the height of 1cm into the bottle, introducing oxygen into a rubber hose through an air pump, culturing for 5 days, and then carrying out water culture;

the rooting culture solution comprises the following components: potassium nitrate (KNO) ₃ )1900mg/L of ammonium Nitrate (NH) ₄ NO ₃ )1650mg/L of monopotassium phosphate (KH) ₂ PO ₄ )170mg/L magnesium sulfate (MgSO) ₄ ·7H ₂ O)370mg/L calcium chloride (CaCl) ₂ ·2H ₂ O)440mg/L, potassium iodide (KI)0.83mg/L, boric acid (H) ₃ BO ₃ )6.2mg/L manganese sulfate (MnSO4 & 4H) ₂ O)22.3mg/L, zinc sulfate (ZnSO) ₄ ·7H ₂ O)8.6mg/L, sodium molybdate (Na) ₂ MoO ₄ ·2H ₂ O)0.25mg/L, copper sulfate (CuSO) ₄ ·5H ₂ O)0.025mg/L, cobalt chloride (CoCl) ₂ ·6H ₂ O)0.025mg/L, disodium edetate (Na) ₂ EDTA)37.25mg/L, ferrous sulfate (FeSO) ₄ ·7H ₂ O)27.85mg/L, inositol 100mg/L, glycine 2mg/L, thiamine hydrochloride (VB) ₁ )0.1mg/L of pyridoxine hydrochloride (VB) ₆ )0.5mg/L, nicotinic acid (VB) ₅ )0.5mg/L, IBA 1.0.0 mg/L, 10 wt% coconut water (pH 5.7).

3. Cleaning of tissue culture seedlings

After the tissue culture rooting seedling is initially cultured in water, the culture medium at the root of the tissue culture seedling falls off or partially falls off. Gently taking out the tissue culture seedling from the bottle by using tweezers, washing the culture medium which is attached to the root and is easy to fall off by using clear water, then placing the tissue culture seedling into a container with the depth of 20cm, filling the tissue culture seedling into a rooting culture solution, wherein the rooting culture solution just overflows the root of the tissue culture seedling, then inoculating a rubber hose, introducing oxygen through an air pump, and connecting an air stone at the front section of the rubber hose. Through the continuous oxygen suppliment of ventilating, can effectively clear up root culture medium, and reach the effect of damage. After the culture medium falls off, the residual culture medium attached to the roots, stems and leaves is washed with clear water.

4. Preparation of hydroponic facilities

The cultivation box is 30cm in depth, 100cm in width and 100cm in length, a cultivation plate is designed on the cultivation box, planting holes 15-20 cm apart are formed in the cultivation plate, and planting devices are arranged on the planting holes; the incubator box is equipped with the humidification air vent apart from bottom 28cm department, can external humidifier humidification internally. After the water inlet and the water outlet are arranged at the bottom of the incubator, a culture solution storage tank is arranged outside the incubator, and water circulation can be performed through a water pump. The incubator is provided with a moisturizing cover with the height of at least 10cm, wherein the moisturizing cover is provided with a humidifying vent hole, and can be externally connected with a humidifier to humidify the inside.

5. Hydroponic initial culture of tissue culture seedlings

Taking cleaned and dried tissue culture rooted seedlings of the avocados, planting the seedlings in a field planting device, adding a primary culture nutrient solution with the pH value of 5.2 and the height of 25cm into an incubator, and adjusting the height of the roots of the tissue culture seedlings through the field planting device to enable the parts below 0.5cm of the roots to be completely put into the culture solution; and connecting air stone with air pump and hose, introducing oxygen in the culture solution, and stopping 5min every 30 min. During the culture, cover the cover of moisturizing on the incubator, through the cover humidification air vent of moisturizing, internal humidification guarantees that the blade does not lose water, humidifies 5min every half an hour. The average temperature in the daytime is 33-35 ℃, and the average temperature at night is 26-28 ℃.

The primary culture nutrient solution comprises the following components: potassium nitrate (KNO) ₃ )1900mg/L of ammonium Nitrate (NH) ₄ NO ₃ )1650mg/L of monopotassium phosphate (KH) ₂ PO ₄ )170mg/L magnesium sulfate (MgSO) ₄ ·7H ₂ O)370mg/L calcium chloride (CaCl) ₂ ·2H ₂ O)440mg/L, potassium iodide (KI)0.83mg/L, boric acid (H) ₃ BO ₃ )6.2mg/L manganese sulfate (MnSO) ₄ ·4H ₂ O)22.3mg/L, zinc sulfate (ZnSO) ₄ ·7H ₂ O)8.6mg/L, sodium molybdate (Na) ₂ MoO ₄ ·2H ₂ O)0.25mg/L, copper sulfate (CuSO) ₄ ·5H ₂ O)0.025mg/L, cobalt chloride (CoCl) ₂ ·6H ₂ O)0.025mg/L, disodium edetate (Na) ₂ EDTA)37.25mg/L, ferrous sulfate (FeSO) ₄ ·7H ₂ O)27.85mg/L, inositol 100mg/L, glycine 2mg/L, thiamine hydrochloride (VB) ₁ )0.1mg/L of pyridoxine hydrochloride (VB) ₆ )0.5mg/L, nicotinic acid (VB) ₅ )0.5mg/L、6-BA 0.5mg/L。

6. Hydroponic culture of tissue culture seedlings

And (5) carrying out water culture for 10 days, and converting to water culture. When water culture is carried out, the moisture-preserving cover is uncovered, and the blade humidification is changed into air humidification. Changing the initial culture nutrient solution in the incubator into a water culture nutrient solution with the pH value of 5.0, adding the water culture nutrient solution with the height of 25cm into the incubator, adjusting the height of the roots of the tissue culture seedlings through a field planting device, and enabling the parts of the roots below 0.5cm to completely enter the culture solution; and is connected with the air stone through an air pump and a hose, and the culture solution is aerated for supplying oxygen.

Emptying the culture solution to the nutrient solution culture storage tank every 30min, and refilling the nutrient solution into the culture tank at an interval of 30min and adding the water culture nutrient solution with the height of 25 cm. During the period of discharging the culture solution, a humidifying vent hole is arranged at the position of the incubator body, which is 28cm away from the bottom, and an external humidifier is used for keeping the root part moist. The average temperature in the daytime is 33-35 ℃, and the average temperature at night is 26-28 ℃. The culture medium was changed every 7 days.

The culture nutrient solution comprises the following components: 945mg/L calcium nitrate tetrahydrate, 1000mg/L potassium nitrate, 80mg/L ammonium nitrate, 150mg/L monopotassium phosphate, 493mg/L magnesium sulfate, 2.5mL ferric salt solution and 5mL trace element solution;

iron salt solution: ferrous sulfate heptahydrate 2.78g, disodium ethylene diamine tetraacetate 3.73g and distilled water 500ml, wherein the pH value is 5.5;

Example 4 hydroponic method for tissue culture rooting seedlings of avocados

1. Training the tissue culture rooted seedlings:

2. Culturing tissue culture rooting seedlings before water culture:

taking tissue culture rooted seedlings after seedling training, opening a culture bottle for sealing, injecting a rooting culture solution with the height of 1cm into the bottle, introducing oxygen into a rubber hose through an air pump, culturing for 5 days, and then carrying out water culture;

the rooting culture solution comprises the following components: 1800mg/L potassium nitrate, 1600mg/L ammonium nitrate, 150mg/L potassium dihydrogen phosphate, 350mg/L magnesium sulfate, 420mg/L calcium chloride, 1.0mg/L potassium iodide, 6.0mg/L boric acid, 22.0mg/L manganese sulfate, 8.2mg/L zinc sulfate, 0.28mg/L sodium molybdate, 0.028mg/L copper sulfate, 0.030mg/L cobalt chloride, 35.00mg/L disodium edetate, 29.00mg/L ferrous sulfate, 110mg/L inositol, 3mg/L glycine, 0.15mg/L thiamine hydrochloride, 0.7mg/L pyridoxine hydrochloride, 0.6mg/L, IBA 1.2.2 mg/L nicotinic acid and 12 wt% coconut water; (pH5.7)

3. Cleaning of tissue culture seedlings

After the rooting seedling is cultured in water, the culture medium at the root of the tissue culture seedling falls off or partially falls off. Gently taking out the tissue culture seedling from the bottle by using tweezers, washing the culture medium which is attached to the root and is easy to fall off by using clear water, then placing the tissue culture seedling into a container with the depth of 20cm, filling the tissue culture seedling into a rooting culture solution, wherein the rooting culture solution just overflows the root of the tissue culture seedling, then inoculating a rubber hose, introducing oxygen through an air pump, and connecting an air stone at the front section of the rubber hose. Through the continuous oxygen suppliment of ventilating, can effectively clear up root culture medium, and reach the effect of damage. After the culture medium falls off, the residual culture medium attached to the roots, stems and leaves is washed with clear water.

4. Preparation of hydroponic facilities

The depth of the incubator is 30cm, the width of the incubator is 100cm, the length of the incubator is 100cm, an incubator plate is designed on the incubator, planting holes which are 15-20 cm away from each other are formed in the incubator plate, and planting devices are arranged on the planting holes; the incubator body is provided with a humidifying vent hole at a position 28cm away from the bottom, and the incubator body can be internally humidified by an external humidifier. After the bottom of the incubator is provided with a water inlet and water outlet, a culture solution storage tank is arranged outside the incubator, and water circulation is carried out through a water pump. The incubator is provided with a moisturizing cover with the height of at least 10cm, wherein the moisturizing cover is provided with a humidifying vent hole, and can be externally connected with a humidifier to humidify the inside.

5. Hydroponic initial culture of tissue culture seedlings

Taking cleaned and dried tissue culture rooted seedlings of the avocados, planting the seedlings in a field planting device, adding a primary culture nutrient solution with the pH value of 6.0 and the height of 25cm into an incubator, and adjusting the height of the roots of the tissue culture seedlings through the field planting device to enable the parts below 1cm of the roots to completely enter the culture solution; and connecting air stone with air pump and hose, introducing oxygen in the culture solution, and stopping introducing air every 30min for 10 min. During the culture, cover the cover of moisturizing on the incubator, through the cover humidification air vent of moisturizing, internal humidification guarantees that the blade does not lose water, humidifies 10min every half an hour. The average temperature in the daytime is 33-35 ℃, and the average temperature at night is 26-28 ℃.

The primary culture nutrient solution comprises the following components: 1800mg/L of potassium nitrate, 1600mg/L of ammonium nitrate, 150mg/L of monopotassium phosphate, 350mg/L of magnesium sulfate, 420mg/L of calcium chloride, 1.0mg/L of potassium iodide, 6.0mg/L of boric acid, 22.0mg/L of manganese sulfate, 8.2mg/L of zinc sulfate, 0.28mg/L of sodium molybdate, 0.028mg/L of copper sulfate, 0.030mg/L of cobalt chloride, 35.00mg/L of disodium ethylenediamine tetraacetic acid, 29.00mg/L of ferrous sulfate, 110mg/L of inositol, 3mg/L of glycine, 0.15mg/L of thiamine hydrochloride, 0.7mg/L of pyridoxine hydrochloride, 0.6mg/L of nicotinic acid and 0.7mg/L of 6-BA.

6. Hydroponic culture of tissue culture seedlings

And (5) carrying out water culture for 15d, and converting to water culture. When water culture is carried out, the moisture-preserving cover is uncovered, and the blade humidification is changed into air humidification. Changing the initial culture nutrient solution in the incubator into a water culture nutrient solution with the pH value of 7.0, adding the water culture nutrient solution with the height of 25cm into the incubator, adjusting the height of the roots of the tissue culture seedlings through a field planting device, and enabling the parts of the roots below 1.0cm to completely enter the culture solution; and is connected with the air stone through an air pump and a hose, and the culture solution is aerated for supplying oxygen.

Emptying the culture solution to the nutrient solution culture storage box every 45min, and refilling the nutrient solution culture storage box with the culture solution with the height of 25cm after the interval of 45 min. During the period of discharging the culture solution, a humidifying vent hole at the position of 28cm on the bottom of the incubator body is utilized, and an external humidifier keeps the root part moist. The average temperature in the daytime is 33-35 ℃, and the average temperature at night is 26-28 ℃. The culture medium was changed every 7 days.

The culture nutrient solution comprises the following components: 900mg/L of calcium nitrate tetrahydrate, 506mg/L of potassium nitrate, 90mg/L of ammonium nitrate, 136mg/L of monopotassium phosphate, 510mg/L of magnesium sulfate, 2.8mL of iron salt solution and 8mL of trace element solution;

iron salt solution: 2.78g of ferrous sulfate heptahydrate, 3.73g of disodium ethylene diamine tetraacetate and 500mL of distilled water, wherein the pH value is 5.5;

Comparative example 1 hydroponic method for germination of avocado seeds

The main differences between this example and example 1 are: no initial culture was performed.

1. Seed treatment

Cleaning fresh avocado seeds, soaking in a disinfectant solution which is 300 times of 50% carbendazim wettable powder and 70% mancozeb wettable powder for 20min, then washing with running water, and cleaning seed coats;

2. incubator preparation

The cultivation box is 30cm in depth, 100cm in width and 100cm in length, a cultivation plate is designed on the cultivation box, planting holes 15-20 cm apart are formed in the cultivation plate, and planting devices are arranged on the planting holes; the incubator body is provided with a humidifying vent hole at a position 28cm away from the bottom, and the incubator body can be internally humidified by an external humidifier. The bottom of the incubator is provided with a water inlet and a water outlet, the incubator is externally provided with a culture solution storage box, and water circulation can be carried out through a water pump. The incubator is provided with a moisturizing cover with the height of at least 10cm, wherein the moisturizing cover is provided with a humidifying vent hole, and can be externally connected with a humidifier to humidify the inside.

3. Seed germination

Planting cleaned and aired avocado seeds in a planting device, adding 25 cm-high water with the pH value of 5.1 into an incubator, adjusting the height of the seeds by the planting device to enable the tips of the seeds to face downwards, enabling the avocado seeds to enter water with the length of 0.5cm, and enabling other parts to be above the water surface; during the culture period, the moisturizing cover is covered, the seeds are humidified internally through the humidifying vent holes of the moisturizing cover, the seeds are prevented from losing water, and the seeds are humidified every 30min for 5 min. The average temperature in the daytime is 33-35 ℃, and the average temperature at night is 26-28 ℃;

4. hydroponic culture

After the seeds are germinated and cultured for 10 days, replacing water in the incubator with a water culture solution with the pH of 7.0, wherein the height of the water culture solution is 25cm, and adjusting the height of the roots of the tissue culture seedlings through a field planting device to enable the parts of the roots below 0.5cm to completely enter the water culture solution; and is connected with the air stone through an air pump and a hose, and the culture solution is aerated and supplied with oxygen.

Emptying the culture solution to the nutrient solution culture storage tank every 30min, and re-injecting water culture nutrient solution with height of 25cm after 30min interval. During the period of discharging the culture solution, the external humidifier keeps the root part moist by utilizing the humidifying vent hole at the position of the incubator body, which is 28cm away from the bottom. The average temperature in the daytime is 33-35 ℃, and the average temperature at night is 26-28 ℃. Changing the culture solution every 7 d;

the hydroponic culture solution comprises the following components: 945mg/L of calcium nitrate tetrahydrate, 1000mg/L of potassium nitrate, 80mg/L of ammonium nitrate, 150mg/L of monopotassium phosphate, 493mg/L of magnesium sulfate, 2.5mL of iron salt solution and 5mL of trace element solution.

Comparative example 2 hydroponic culture method for germination of avocado seeds

The main differences between this example and example 1 are: the water culture adopts a primary culture nutrient solution.

1. Seed treatment

2. incubator preparation

The depth of the incubator is 30cm, the width of the incubator is 100cm, the length of the incubator is 100cm, an incubator plate is designed on the incubator, planting holes which are 15-20 cm away from each other are formed in the incubator plate, and planting devices are arranged on the planting holes; the incubator body is provided with a humidifying vent hole at a position 28cm away from the bottom, and the incubator body can be internally humidified by an external humidifier. The bottom of the incubator is provided with a water inlet and a water outlet, the incubator is externally provided with a culture solution storage box, and water circulation can be carried out through a water pump. The incubator is provided with a moisturizing cover with the height of at least 10cm, wherein the moisturizing cover is provided with a humidifying vent hole and can be externally connected with a humidifier for internal humidification.

3. Seed germination

4. initial culture

After the seeds are germinated and cultured for 10 days, water in an incubator is replaced by initial culture nutrient solution with the height of 25cm and the pH value of 6.8, and the height of the roots of the tissue culture seedlings is adjusted through a field planting device, so that the parts below 0.5cm of the roots are all put into the initial culture nutrient solution; and is connected with the air stone through an air pump and a hose, and the culture solution is aerated and supplied with oxygen. When the root system main root grows for 10-12 cm, the area of the seed cotyledon 1/2 is cut off, and when the root system main root grows for more than or equal to 20cm, the area of the seed cotyledon 3/4 is cut off. The average temperature in the daytime is 33-35 ℃, and the average temperature at night is 26-28 ℃.

5. Hydroponic culture

Replacing a new primary culture nutrient solution, wherein the height of the culture solution is 25cm, and adjusting the height of the roots of the tissue culture seedlings through a field planting device to enable the parts below 0.5cm of the roots to completely enter the culture solution; and is connected with the air stone through an air pump and a hose, and the culture solution is aerated and supplied with oxygen.

Emptying the culture solution to the nutrient solution culture storage tank every 30min, and re-injecting the nutrient solution with the height of 25cm after 30 min. During the period of discharging the culture solution, a humidifying vent hole at the position of 28cm on the bottom of the incubator body is utilized, and an external humidifier is used for keeping the root part moist. The average temperature in the daytime is 33-35 ℃, and the average temperature at night is 26-28 ℃. The culture medium was changed every 7 days.

Comparative example 3 hydroponic method for tissue culture rooted seedlings of avocados

The main differences between this example and example 3 are: the water culture nutrient solution is a primary culture nutrient solution.

1. Training the tissue culture rooted seedlings:

2. Tissue culture rooting seedling water culture pre-culture:

the rooting culture solution comprises the following components: potassium nitrate (KNO) ₃ )1900mg/L of ammonium Nitrate (NH) ₄ NO ₃ )1650mg/L of monopotassium phosphate (KH) ₂ PO ₄ )170mg/L magnesium sulfate (MgSO) ₄ ·7H ₂ O)370mg/L calcium chloride (CaCl) ₂ ·2H ₂ O)440mg/L, potassium iodide (KI)0.83 mg/L; boric acid (H) ₃ BO ₃ )6.2 mg/L; manganese sulfate (MnSO4 & 4H) ₂ O)22.3mg/L, zinc sulfate (ZnSO) ₄ ·7H ₂ O)8.6mg/L, sodium molybdate (Na) ₂ MoO ₄ ·2H ₂ O)0.25mg/L, copper sulfate (CuSO) ₄ ·5H ₂ O)0.025 mg/L; cobalt chloride (CoCl) ₂ ·6H ₂ O)0.025mg/L, disodium edetate (Na) ₂ EDTA)37.25mg/L, ferrous sulfate (FeSO) ₄ ·7H ₂ O)27.85mg/L, inositol 100mg/L, glycine 2mg/L, thiamine hydrochloride (VB) ₁ )0.1mg/L, pyridoxine hydrochloride (VB) ₆ )0.5mg/L, nicotinic acid (VB) ₅ )0.5mg/L, IBA 1.0.0 mg/L, 10 wt% coconut water (pH 5.7).

3. Cleaning of tissue culture seedlings

4. Preparation of hydroponic facilities

The cultivation box is 30cm in depth, 100cm in width and 100cm in length, a cultivation plate is designed on the cultivation box, planting holes 15-20 cm apart are formed in the cultivation plate, and planting devices are arranged on the planting holes; a28 cm position on the bottom of the incubator body is provided with a humidifying vent hole, and the incubator can be externally connected with a humidifier to humidify the inside. After the water inlet and the water outlet are arranged at the bottom of the incubator, a culture solution storage tank is arranged outside the incubator, and water circulation can be performed through a water pump. The incubator is provided with a moisturizing cover with the height of at least 10cm, wherein the moisturizing cover is provided with a humidifying vent hole, and can be externally connected with a humidifier to humidify the inside.

5. Hydroponic initial culture of tissue culture seedlings

The primary culture nutrient solution comprises the following components: potassium nitrate (KNO) ₃ )1900mg/L of ammonium Nitrate (NH) ₄ NO ₃ )1650mg/L of monopotassium phosphate (KH) ₂ PO ₄ )170mg/L magnesium sulfate (MgSO) ₄ ·7H ₂ O)370mg/L calcium chloride (CaCl) ₂ ·2H ₂ O)440 mg/L. Potassium iodide (KI)0.83mg/L, boric acid (H) ₃ BO ₃ )6.2mg/L manganese sulfate (MnSO) ₄ ·4H ₂ O)22.3mg/L, zinc sulfate (ZnSO) ₄ ·7H ₂ O)8.6mg/L, sodium molybdate (Na) ₂ MoO ₄ ·2H ₂ O)0.25mg/L, copper sulfate (CuSO) ₄ ·5H ₂ O)0.025mg/L, cobalt chloride (CoCl) ₂ ·6H ₂ O)0.025mg/L, disodium edetate (Na) ₂ EDTA)37.25mg/L, ferrous sulfate (FeSO) ₄ ·7H ₂ O)27.85mg/L, inositol 100mg/L, glycine 2mg/L, thiamine hydrochloride (VB) ₁ )0.1mg/L of pyridoxine hydrochloride (VB) ₆ )0.5mg/L, nicotinic acid (VB) ₅ )0.5mg/L、6-BA 0.5mg/L。

6. Hydroponic culture of tissue culture seedlings

And (5) carrying out water culture for 10 days, and converting to water culture. When water culture is carried out, the moisture-preserving cover is uncovered, and the blade humidification is changed into air humidification. Taking the primary culture nutrient solution as a water culture nutrient solution, adding a nutrient solution with the height of 25cm into an incubator, and adjusting the height of the roots of the tissue culture seedlings through a field planting device to enable the parts with the root length less than 0.5cm to completely enter the culture solution; and is connected with the air stone through an air pump and a hose, and the culture solution is aerated for supplying oxygen.

Emptying the culture solution to the nutrient solution culture storage tank every 30min, and refilling the nutrient solution into the nutrient tank at an interval of 30min and adding the nutrient solution with the height of 25 cm. During the period of discharging the culture solution, a humidifying vent hole at the position of 28cm on the bottom of the incubator body is utilized, and an external humidifier keeps the root part moist. The average temperature in the daytime is 33-35 ℃, and the average temperature at night is 26-28 ℃. The culture medium was changed every 7 days.

Comparative example 4 hydroponic method for tissue culture rooted seedlings of avocados

The main differences between this example and example 3 are: no initial culture was performed.

1. Training the tissue culture rooted seedlings:

2. Tissue culture rooting seedling water culture pre-culture:

the rooting culture solution comprises the following components: potassium nitrate (KNO) ₃ )1900mg/L of ammonium Nitrate (NH) ₄ NO ₃ )1650mg/L of monopotassium phosphate (KH) ₂ PO ₄ )170mg/L magnesium sulfate (MgSO) ₄ ·7H ₂ O)370mg/L calcium chloride (CaCl) ₂ ·2H ₂ O)440mg/L, potassium iodide (KI)0.83mg/L, boric acid (H) ₃ BO ₃ )6.2mg/L manganese sulfate (MnSO4 & 4H) ₂ O)22.3mg/L, zinc sulfate (ZnSO) ₄ ·7H ₂ O)8.6mg/L, sodium molybdate (Na) ₂ MoO ₄ ·2H ₂ O)0.25mg/L, copper sulfate (CuSO) ₄ ·5H ₂ O)0.025 mg/L; cobalt chloride (CoCl) ₂ ·6H ₂ O)0.025mg/L, disodium edetate (Na) ₂ EDTA)37.25mg/L, ferrous sulfate (FeSO) ₄ ·7H ₂ O)27.85mg/L, inositol 100mg/L, glycine 2mg/L, thiamine hydrochloride (VB) ₁ )0.1mg/L, pyridoxine hydrochloride (VB) ₆ )0.5mg/L, nicotinic acid (VB) ₅ )0.5mg/L, IBA 1.0.0 mg/L, 10 wt% coconut water, (pH 5.7).

3. Cleaning of tissue culture seedlings

After the tissue culture rooting seedling is initially cultured in water, the culture medium at the root of the tissue culture seedling falls off or partially falls off. Gently taking out the tissue culture seedling from the bottle by using tweezers, washing the culture medium which is attached to the root and is easy to fall off by using clear water, then placing the tissue culture seedling into a container with the depth of 20cm, filling a rooting culture solution of the tissue culture seedling, wherein the rooting culture solution just overflows the root of the tissue culture seedling, then connecting a rubber hose, introducing oxygen by using an air pump, and connecting an air stone at the front section of the rubber hose. Through the continuous oxygen suppliment of ventilating, can effectively clear up root culture medium, and reach the effect of damage. After the culture medium falls off, the residual culture medium attached to the roots, stems and leaves is washed with clear water.

4. Preparation of hydroponic facilities

The cultivation box is 30cm in depth, 100cm in width and 100cm in length, a cultivation plate is designed on the cultivation box, planting holes 15-20 cm apart are formed in the cultivation plate, and planting devices are arranged on the planting holes; the incubator body is provided with a humidifying vent hole at a position 28cm away from the bottom, and the incubator body can be internally humidified by an external humidifier. After the water inlet and the water outlet are arranged at the bottom of the incubator, a culture solution storage tank is arranged outside the incubator, and water circulation can be performed through a water pump. The incubator is provided with a moisturizing cover with the height of at least 10cm, wherein the moisturizing cover is provided with a humidifying vent hole, and can be externally connected with a humidifier to humidify the inside.

5. Hydroponic culture of tissue culture seedlings

And (4) taking the cleaned and dried tissue culture rooted seedlings of the avocados, and planting the rooted seedlings in a planting device for water culture. When water culture is carried out, the moisture-preserving cover is uncovered, and the blade humidification is changed into air humidification. Adding a water culture nutrient solution with the height of 25cm into the incubator, and adjusting the height of the roots of the tissue culture seedlings through a planting device to enable the parts below 0.5cm of the roots to completely enter the culture solution; and is connected with the air stone through an air pump and a hose, and the culture solution is aerated for supplying oxygen.

Emptying the culture solution to the nutrient solution culture storage tank every 30min, and refilling the nutrient solution into the culture tank at an interval of 30min and adding the water culture nutrient solution with the height of 25 cm. During the period of discharging the culture solution, a humidifying vent hole at the position of 28cm on the bottom of the incubator body is utilized, and an external humidifier keeps the root part moist. The average temperature in the daytime is 33-35 ℃, and the average temperature at night is 26-28 ℃. The culture medium was changed every 7 days.

Comparative example 5: water culture method for tissue culture rooting seedlings of avocados

The main differences between this example and example 3 are: without preculture

1. Training the tissue culture rooted seedlings:

2. Cleaning of tissue culture seedlings

Gently taking out the tissue culture seedling from the bottle by using tweezers, washing the culture medium which is attached to the root and is easy to fall off by using clear water, then placing the tissue culture seedling into a container with the depth of 20cm, filling the tissue culture seedling into a rooting culture solution, wherein the rooting culture solution just overflows the root of the tissue culture seedling, then inoculating a rubber hose, introducing oxygen through an air pump, and connecting an air stone at the front section of the rubber hose. Through the continuous oxygen suppliment of ventilating, can effectively clear up root culture medium, and reach the effect of damage. After the culture medium falls off, the residual culture medium attached to the roots, stems and leaves is washed with clear water.

3. Preparation of hydroponic facilities

The depth of the incubator is 30cm, the width of the incubator is 100cm, the length of the incubator is 100cm, an incubator plate is designed on the incubator, planting holes which are 15-20 cm away from each other are formed in the incubator plate, and planting devices are arranged on the planting holes; the incubator body is provided with a humidifying vent hole at a position 28cm away from the bottom, and the incubator body can be internally humidified by an external humidifier. After the bottom of the incubator is provided with a water inlet and water outlet, a culture solution storage tank is arranged outside the incubator, and water circulation can be performed through a water pump. The incubator is provided with a moisturizing cover with the height of at least 10cm, wherein the moisturizing cover is provided with a humidifying vent hole, and can be externally connected with a humidifier to humidify the inside.

4. Hydroponic initial culture of tissue culture seedlings

5. Hydroponic culture of tissue culture seedlings

And (5) carrying out water culture for 10 days, and converting to water culture. When water culture is carried out, the moisture-preserving cover is uncovered, and the blade humidification is changed into air humidification. Replacing the initial culture nutrient solution in the incubator with a water culture nutrient solution with the pH value of 5.0, adding the water culture nutrient solution with the height of 25cm into the incubator, and adjusting the height of the roots of the tissue culture seedlings through a field planting device to enable the parts below 0.5cm of the roots to completely enter the culture solution; and is connected with the air stone through an air pump and a hose, and the culture solution is aerated for supplying oxygen.

Emptying the culture solution to the nutrient solution culture storage tank every 30min, and refilling the culture tank with the culture solution with a height of 25cm after 30min interval. During the period of discharging the culture solution, a humidifying vent hole at the position of 28cm on the bottom of the incubator body is utilized, and an external humidifier keeps the root part moist. The average temperature in the daytime is 33-35 ℃, and the average temperature at night is 26-28 ℃. The culture medium was changed every 7 days.

The culture nutrient solution comprises the following components: 945mg/L of calcium nitrate tetrahydrate, 1000mg/L of potassium nitrate, 80mg/L of ammonium nitrate, 150mg/L of monopotassium phosphate, 493mg/L of magnesium sulfate, 2.5mL of iron salt solution and 5mL of trace element solution;

Comparative example 6 hydroponic method for tissue culture rooting seedlings of avocados

The main differences between this example and example 3 are: the nutrient solution supply mode is not an intermittent circulation.

1. Training the tissue culture rooted seedlings:

2. Tissue culture rooting seedling water culture pre-culture:

3. Cleaning of tissue culture seedlings

After the rooting seedling is cultured in water, the culture medium at the root of the tissue culture seedling falls off or partially falls off. Gently taking out the tissue culture seedling from the bottle by using tweezers, washing the culture medium which is attached to the root and is easy to fall off by using clear water, then placing the tissue culture seedling into a container with the depth of 20cm, filling a rooting culture solution of the tissue culture seedling, wherein the rooting culture solution just overflows the root of the tissue culture seedling, then connecting a rubber hose, introducing oxygen by using an air pump, and connecting an air stone at the front section of the rubber hose. Through continuous ventilation and oxygen supply, the root culture medium can be effectively cleaned, and the injury effect is achieved. After the culture medium falls off, the residual culture medium attached to the roots, stems and leaves is washed with clear water.

4. Preparation of hydroponic facilities

The depth of the incubator is 30cm, the width of the incubator is 100cm, the length of the incubator is 100cm, an incubator plate is designed on the incubator, planting holes which are 15-20 cm away from each other are formed in the incubator plate, and planting devices are arranged on the planting holes; the incubator box is equipped with the humidification air vent apart from bottom 28cm department, can external humidifier humidification internally. After the bottom of the incubator is provided with a water inlet and water outlet, a culture solution storage tank is arranged outside the incubator, and water circulation can be performed through a water pump. The incubator is provided with a moisturizing cover with the height of at least 10cm, wherein the moisturizing cover is provided with a humidifying vent hole, and can be externally connected with a humidifier to humidify the inside.

5. Hydroponic initial culture of tissue culture seedlings

Taking cleaned and dried tissue culture rooted seedlings of the avocados, planting the seedlings in a field planting device, adding a primary culture nutrient solution with the pH value of 5.2 and the height of 25cm into an incubator, and adjusting the height of the roots of the tissue culture seedlings through the field planting device to enable the parts below 0.5cm of the roots to be completely put into the culture solution; and connecting air stone with air pump and hose, introducing oxygen in the culture solution, and stopping 5min every 30 min. During the cultivation, cover the cover of moisturizing on the incubator, through the cover humidification air vent, internal humidification guarantees that the blade does not lose water, humidification 5min every half an hour. The average temperature in the daytime is 33-35 ℃, and the average temperature at night is 26-28 ℃.

6. Hydroponic culture of tissue culture seedlings

The average temperature in the daytime is 33-35 ℃, and the average temperature at night is 26-28 ℃. The culture medium was changed every 7 days.

Comparative example 7 hydroponic culture method for germination of avocado seeds

The main differences between this example and example 1 are: no seed cotyledon excision was performed during the initial culture period.

1. Seed treatment

2. incubator preparation

3. Seed germination

4. initial culture

After 10 days of culture, most seeds germinate and root, and the germination rate is 96%. After the seeds germinate, water in an incubator is replaced by initial culture nutrient solution with the height of 25cm and the pH value of 6.8, and the height of the roots of the tissue culture seedlings is adjusted by a planting device, so that the parts of the roots below 0.5cm are all put into the initial culture nutrient solution; and is connected with the air stone through an air pump and a hose, and the culture solution is aerated and supplied with oxygen. The average temperature in the daytime is 33-35 ℃, and the average temperature at night is 26-28 ℃.

5. Hydroponic culture

Emptying the culture solution to the nutrient solution culture storage tank every 30min, and re-injecting water culture nutrient solution with height of 25cm after 30min interval. During discharging the culture solution, the root part is kept moist by utilizing a humidifying vent hole at the position of the incubator body, which is 28cm away from the bottom part, and an external humidifier. The average temperature in the daytime is 33-35 ℃, and the average temperature at night is 26-28 ℃. Changing the culture solution every 7 days;

Iron salt solution: ferrous sulfate heptahydrate 2.78g, disodium ethylene diamine tetraacetate (EDTA.Na)3.73g, distilled water 500mL, pH 5.5;

And (4) after 30 days of water culture, calculating the survival rate and the rotten root rate (100 plants in each test and taking the average value in 3 tests), wherein the rotten root rate is the rotten root number/total root number of each water culture seedling. The results are shown in Table 1.

TABLE 1

	Survival rate	Root rot rate
			Example 1	96％	3.6％
Example 2	98％	4.3％
			Example 3	99％	4.0％
Example 4	97％	4.7％
			Comparative example 1	15％	80％
Comparative example 2	88％	8.9％
			Comparative example 3	86％	10.1％
Comparative example 4	75％	13.7％
			Comparative example 5	80％	8.0％
Comparative example 6	75％	25％
			Comparative example 7	15％	82％

The results show that: the survival rate of the examples 1-4 is higher than that of the comparative example, and the root rot rate is lower than that of the comparative example. The results of the examples and the comparative examples 1-5 show that the initial culture and the pre-culture stage are indispensable, and in addition, the nutrient solution in the initial culture, the pre-culture and the water culture stage must be reasonably configured to effectively reduce the rotten root rate and improve the survival rate. The results of comparative example 6 and example 3 show that the invention changes the nutrient solution supply mode into intermittent circulation supply, and the liquid is emptied in 30-45 min after 30-45 min of root liquid immersion, and is moisturized and moistened by a humidifier. Thus, the root rotting phenomenon can be effectively improved, the root rotting rate is reduced, and the survival rate is improved. The results of comparative example 7 and example 1 show that the seed cotyledon 1/2 is cut off when the root system main root grows for 10cm in the initial culture stage, and the seed cotyledon 3/4 is cut off when the root system main root grows for more than 20cm, so that the root can be stimulated to absorb nutrition, the rotten root rate is reduced, and the survival rate is improved.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that are within the spirit and principle of the present invention are intended to be included in the scope of the present invention.

Claims

1. A water culture method of avocados is characterized by comprising seed germination water culture or tissue culture rooting seedling water culture;

the seed germination water culture comprises the following steps:

s1-1, seed treatment: disinfecting and cleaning seeds for later use;

s1-2, preparation of water culture facilities: a culture plate is arranged in the incubator, and is provided with a planting hole, and a planting device is arranged on the planting hole; the incubator body is provided with a humidifying vent hole which is externally connected with a humidifier, the bottom of the incubator is provided with a water inlet and a water outlet, a culture solution storage tank is arranged outside the incubator, a moisturizing cover is arranged above the incubator, and the moisturizing cover is provided with a humidifying vent hole;

s1-5, water culture:

the hydroponic culture solution comprises the following components: 900-945 mg/L of calcium nitrate tetrahydrate, 506-1000 mg/L of potassium nitrate, 80-90 mg/L of ammonium nitrate, 136-150 mg/L of monopotassium phosphate, 493-510 mg/L of magnesium sulfate, 2.5-2.8 mL of iron salt solution and 5-8 mL of trace element solution;

s2-1, hardening off the tissue culture rooted seedlings;

s2-2, preculture: opening the seal of the culture bottle, injecting rooting culture solution into the culture bottle, ventilating and supplying oxygen, and culturing for more than or equal to 5 d;

the rooting culture solution comprises the following components: 1800-1900 mg/L potassium nitrate, 1600-1650 mg/L ammonium nitrate, 150-170 mg/L potassium dihydrogen phosphate, 350-370 mg/L magnesium sulfate, 420-440 mg/L calcium chloride, 0.83-1.0 mg/L potassium iodide, 6.0-6.2 mg/L boric acid, 22.0-22.3 mg/L manganese sulfate, 8.2-8.6 mg/L zinc sulfate, 0.25-0.28 mg/L sodium molybdate, 0.025-0.028 mg/L copper sulfate, 0.025-0.030 mg/L cobalt chloride, 35.00-37.25 mg/L disodium ethylenediamine tetraacetate, 27.85-29.00 mg/L ferrous sulfate, 100-110 mg/L inositol, 2-3 mg/L glycine, 0.1-0.15 mg/L thiamine hydrochloride, 0.5-0.7 mg/L pyridoxine hydrochloride, 0.5-0.6 mg/L, IBA 1.0.0-1.2 mg/L nicotinic acid and 10-12 wt% coconut water;

s2-3, cleaning the tissue culture rooted seedlings;

s2-4, preparation of water culture facilities: a culture plate is arranged in the incubator, a planting hole is formed in the culture plate, and a planting device is arranged on the planting hole; the incubator is provided with a humidifying vent hole, the vent hole is externally connected with a humidifier, the bottom of the incubator is provided with a water inlet and a water outlet, a culture solution storage box is arranged outside the incubator, a moisturizing cover is arranged above the incubator, and the moisturizing cover is provided with a humidifying vent hole;

s2-5, primary culture: taking the clean tissue culture rooted seedlings, then planting the seedlings in a field planting device, adding a primary culture nutrient solution into an incubator, enabling all parts below 0.5-1 cm of roots to enter the primary culture nutrient solution, ventilating and supplying oxygen in the culture solution, and stopping ventilating for 5-10 min every 30-45 min;

the primary culture nutrient solution comprises the following components: 1800-1900 mg/L of potassium nitrate, 1600-1650 mg/L of ammonium nitrate, 150-170 mg/L of monopotassium phosphate, 350-370 mg/L of magnesium sulfate, 420-440 mg/L of calcium chloride, 0.83-1.0 mg/L of potassium iodide, 6.0-6.2 mg/L of boric acid, 22.0-22.3 mg/L of manganese sulfate, 8.2-8.6 mg/L of zinc sulfate, 0.25-0.28 mg/L of sodium molybdate, 0.025-0.028 mg/L of copper sulfate, 0.025-0.030 mg/L of cobalt chloride, 35.00-37.25 mg/L of disodium ethylenediaminetetraacetate, 27.85-29.00 mg/L of ferrous sulfate, 100-110 mg/L of inositol, 2-3 mg/L of glycine, 0.1-0.15 mg/L of thiamine hydrochloride, 0.5-0.7 mg/L of pyridoxine hydrochloride, 0.5-0.6 mg/L of nicotinic acid and 0.5-0.7 mg/L of BA;

s2-6, water culture: after the initial culture is carried out for 10-15 days, the culture is changed into water culture; when water culture is carried out, uncovering the moisturizing cover; replacing the primary culture nutrient solution in the incubator with a hydroponic culture solution, and introducing the part of the root of less than 0.5-1 cm into the hydroponic culture solution for ventilation and oxygen supply; emptying the hydroponic culture solution into the storage box every 30-45 min, injecting the hydroponic culture solution into the culture box again after 30-45 min intervals, and keeping the root wet through the humidifying vent hole during the culture solution discharge period;

the iron salt solution comprises the following components: 2.78g of ferrous sulfate heptahydrate, 3.73g of disodium ethylene diamine tetraacetate and 500mL of distilled water;

the trace element liquid comprises the following components: potassium iodide 0.83mg/L, boric acid 6.2mg/L, manganese sulfate 22.3mg/L, zinc sulfate 8.6mg/L, sodium molybdate 0.25mg/L, copper sulfate 0.025mg/L, and cobalt chloride 0.025 mg/L.

2. The avocado hydroponic culture method according to claim 1, characterized in that said disinfection is: after the seeds are cleaned, 300 times diluted liquid of 50% carbendazim wettable powder and 70% mancozeb wettable powder is used as a disinfectant for disinfection for 20 min.

3. The avocado hydroponic method according to claim 1, wherein in step S2-1, the hardening off of the tissue-cultured rooted seedlings is: taking out the tissue culture rooted seedlings from the culture room, placing the seedlings in the room temperature, closing the bottles for exercise for at least 3 days, then moving the seedlings to a temperature environment for water culture, and closing the bottles for exercise for more than 5 days.

4. The avocado hydroponic culture method according to claim 1, characterized in that, in step S2-3, the cleaning of the tissue-cultured rooted seedlings: taking out the tissue culture rooted seedling after pre-culture, washing the easy-to-fall culture medium attached to the root with clear water, then placing the tissue culture seedling in a container, filling the container with rooting culture solution, ventilating and supplying oxygen, and washing the residual culture medium with clear water after the culture medium falls off.

5. The avocado hydroponic method according to claim 1, characterized in that, in step S1-3, the seed germination culture: planting the cleaned and aired seeds in a planting device, and adding water with the pH value of 5.0-7.0 into an incubator to enable the tips of the seeds to be downward and enable the seeds not to completely enter the water; during the culture period, the moisturizing cover is covered, the seeds are internally humidified through the humidifying vent holes on the moisturizing cover, the seeds are prevented from losing water, and the seeds are humidified every 30-45 min for 5-10 min.

6. The avocado hydroponic culture method according to claim 1, wherein the aeration and oxygen supply rate is 90L/min.