CN109105171B

CN109105171B - A kind of efficient propagation method of perennial forage corn

Info

Publication number: CN109105171B
Application number: CN201811166108.2A
Authority: CN
Inventors: 唐祈林; 吴子周; 李影正; 严旭; 杨春燕; 李晓锋; 何如钰; 李杨; 赵艳丽; 温小冬; 张萍; 周阳; 张磊; 张翔
Original assignee: Sichuan Agricultural University
Current assignee: Sichuan Agricultural University
Priority date: 2018-10-08
Filing date: 2018-10-08
Publication date: 2021-01-01
Anticipated expiration: 2038-10-08
Also published as: CN109105171A

Abstract

The invention belongs to the field of breeding methods of perennial forage corn, and particularly relates to a high-efficiency propagation method of perennial forage corn. The method is to cut off the upper part of the stem from the end of vegetative growth to the beginning of tasseling of perennial forage maize, cover the incision with talcum powder, and remove the leaves and leaf sheaths on the stem to promote the germination of axillary buds in the middle and lower parts of the stem; Cut diagonally in the middle of each internode into stem segments as seedlings; soak the seedlings in water, naphthalene acetic acid solution and carbendazim solution; then plant the stem segments in the nursery, and do arching before the first frost In the early spring, when the ground temperature is stable at ≥10 °C, the seedlings are hardened for 7 days, and the obtained seedlings can be transplanted or sold. The method of the invention eliminates the apical dominance and utilizes the nutrition of the mother plant to promote the development of axillary buds, so the propagation coefficient of a single plant is high, which is 40% higher than that of the cutting method; secondly, the seedling rate of the method of the invention is higher than that of the cutting method by 20%; In addition, the method of the present invention has low cost of raising seedlings.

Description

Efficient propagation method for perennial forage maize

Technical Field

The invention belongs to the field of propagation methods of perennial forage maize, and particularly relates to an efficient propagation method of perennial forage maize.

Background

China lives 22% of people in cultivated land which accounts for 7% of the world, and with the continuous increase of the population and the reduction of the cultivated land, the food problem increasingly becomes the focus of people's attention. Particularly, in each province of south China, people are more and less, the area of the mountain land accounts for about 70%, and the grain problem is more prominent. The grain problem is the problem of feed grains to a great extent, along with the improvement of the living standard of people in China, the demand of meat and milk foods is remarkably increased, correspondingly, the demand of the feed grains is further increased, and the problem of the shortage of the feed grains is more prominent. The climate and ecological conditions in the southwest region of China are special, and the method is very suitable for producing high-quality forage grass with the purpose of harvesting nutriments. Perennial forage maize cultivated by the creative new species maize allohexaploid of Sichuan agricultural university provides an important way for solving the problem of feed in southern China due to the advantages of perennial, more tillers, strong stress resistance, fast growth, multiple times of mowing in one year, high biological yield and the like.

Corn allophexaploid (tripazea Cramericaze T.) is an intergeneric hybrid F between tetraploid corn (Zea mays L., 2 n. about.40) and tetraploid Murashia dactyloides (or Tripsacum dactyloides L., 2 n. about.72) introduced into the United states by the Sichuan university of agriculture₁An intergeneric hybrid, which is bred by crossing a tetraploid perennial maize (Zea perennis, 2n ═ 40) as a female parent and comprises a complete set of maize chromosomes (20), a dactylicapnos paniculata chromosome (36) and a tetraploid perennial maize chromosome (20), is a new species that does not exist in nature (suyue, university of agriculture, sikawa, 2009). The corn allophexaploid has 76 chromosomes, has the characteristics of perennial growth, more tillering, fertile female part, high sterility of pollen and the like,corn, triploid or tetraploid perennial corn is used as a male parent to pollinate the male parent, and hybrid offspring can be obtained, so that the corn allophexaploid can be used as a bridge material, and excellent genes such as waterlogging resistance, cold resistance and the like in corn related species such as triploid or tetraploid perennial corn are transferred into the corn, so that the germplasm basis of the corn is widened; the perennial forage maize can also be cultivated by utilizing the characteristics of perennial forage maize, more tillering and reclinable for many times in one year.

Perennial forage maize is maize allohexaploid MTF-1(Tripsazea Creammaize T.) originally invented by corn research of Sichuan university of agriculture or a derivative thereof serving as a female parent, and a brand new perennial forage crop which is bred by hybridization with common cultivated corn (Zeamays L.), tetraploid perennial maize (Zea perennis) or tripsacum dactyloides L and aims at harvesting stalk and leaf nutrients, such as Yucaao No. 5 (variety registration: 2016007) and Yucaao No. 6 (variety registration: 2017001), namely perennial forage maize which is bred by hybridization with MTF-1 serving as a female parent and tetraploid perennial maize serving as a male parent, has high biological yield and the cold resistance, tillering capacity, high rapid growth, high yield and perennial characteristics of the maize, and the triploid and the perennial grass which have developed root system, high tillering capacity, rapid growth, high growing speed, high yield and perennial characteristics, The perennial forage maize can naturally overwinter in southwest area (5 ℃ below zero) for many years, and benefits from planting for many years. Therefore, the method is popular with farmers, and the planting area of the method is increased year by year.

Because chromosomes of cultivated corn, tripsacum digitatum and tetraploid perennial teosintes are aggregated, the chromosomes of perennial forage maize are constructed into aneuploid, so meiosis is disordered, pollen is fertility-free and hard to seed, and the perennial forage maize cannot be propagated through seeds but only can be propagated in asexual propagation modes such as cutting propagation or stump propagation, and both propagation methods are used for seedling raising and transplanting in spring. The division and propagation is to select the overwintering old stump with green stem or more tillering buds in spring, separate into single plants, and transplant the seedlings to the field (or directly transplant). When the root is separated in spring, the root is larger, the root layer is staggered, the artificial root separation is more difficult particularly when the land is dry, and even if the root is separated into single plants, the survival rate is greatly reduced because the root systems of the single plants are damaged, and the like. The cutting propagation has strict requirements on axillary buds, the axillary buds are easy to rot and freeze when being processed improperly after being buried in pits or stored in cellars in winter, the emergence rate of cut seedlings dug out in spring of the next year is low, a large amount of land, manpower and material resources are wasted, the seedling rate of the two methods is low, the seedling supply of perennial forage maize seedlings is short, the seedlings are expensive, the high seedlings limit the popularization and utilization of the perennial forage maize, and the large-scale and commercial process of the perennial forage maize is hindered. How to obtain high-quality seedlings and reduce the seedling cost becomes a problem which needs to be solved urgently in perennial forage maize industrialization.

Disclosure of Invention

Aiming at the problems of low seedling rate, high cost and the like of the current perennial forage maize cutting propagation and stump division propagation, the invention aims to provide a high-efficiency propagation method of perennial forage maize.

The invention is realized by the following technical scheme:

a method for efficiently propagating perennial forage maize comprises the following steps:

(1) removing stem tops and promoting axillary buds: in the last ten days of 8 months to the last ten days of 9 months, in the late vegetative growth stage to the initial stage of castration of perennial forage maize, the upper parts of the stalks which are more than 100-150 cm away from the ground surface are cut off by a sickle or a pruner, and then the cuts are uniformly covered by talcum powder, so that the moisture loss of the stalks is reduced; leaving the stem without obvious plant diseases and insect pests, and removing leaves and leaf sheaths on the stem;

(2) seedling treatment: under the field condition, axillary buds at the middle and lower parts of the stem in the step (1) germinate for 2-4 weeks, and then are obliquely cut into stem segments serving as seedlings in the middle of each internode by using pruning shears; classifying according to the development state of axillary buds to ensure the consistent growth vigor of the seedlings; the seedling classification standard is as follows: a type: axillary buds have developed into a complete plant with roots, stems and leaves; b type: axillary buds have formed stems and leaves; class C: axillary buds do not sprout; bundling the A-type seedlings, soaking the A-type seedlings in water for 12-24 hours, and directly transplanting and growing the seedlings; soaking the B-type seedlings in water for 8-16h, then soaking the B-type seedlings in a naphthylacetic acid solution with the concentration of 100-150 mg/L for 4-8 h, and soaking the B-type seedlings in a 1000-fold liquid of 50% carbendazim wettable powder for 3-5 min for disinfection; the depth of the seedling soaking is that the stem section of the parent body is submerged on the water surface; discarding the C-type seedlings;

(3) applying enough base fertilizer, preparing soil and dividing compartments: selecting a plot with loose and fertile soil, sunny appearance and good drainage performance as a nursery garden, applying a compound fertilizer to the ground surface of the nursery garden according to the proportion of 150-300 kg/hectare, and deeply ploughing the soil by a rotary cultivator for 20-30 cm; then, making the compartment according to the width of 1.5-2 m, wherein the width of a furrow is 40-50 cm, and the depth of the furrow is 20-30 cm;

(4) transplanting seedlings: planting furrows with the depth of 10-15cm are formed in the compartment in the step (3), and the distance between every two adjacent planting furrows is 15 cm; before transplanting seedlings, spreading chlorpyrifos granules in the planting furrows according to the proportion of 18 kg/hectare of the chlorpyrifos granules for preventing and controlling underground pests such as mole cricket, grub, cutworms and the like; according to the planting density of 5cm multiplied by 15cm, the A, B seedlings in the step (2) are planted in a compartment mode, so that seedlings with consistent growth vigor can be obtained conveniently, and root fixing water is poured immediately after the seedlings are transplanted; spraying herbicide for preventing and controlling field weeds; before blooming, a glass fiber rod with the diameter of 7mm and the length of 2-3 m is used as an arch frame, a plastic film with the width of 2-3 m is covered to build an arch shed, and heat preservation and overwintering are carried out;

(5) hardening seedlings: opening one side of the film for hardening seedlings at 8:00 in the morning of fine days when the ground temperature is stabilized to be more than or equal to 10 ℃ in early spring, and covering the plastic film at the evening; hardening seedlings for 7 days, and then removing all plastic films; the obtained seedlings can be transplanted or sold; wherein 2/3-3/4 of the length of the seedling leaves are cut off before transplanting, and 1/2-2/3 of the length of the roots are cut off.

The perennial forage maize in the step (1) of the method is the perennial forage maize which is bred by hybridization by taking a maize allohexaploid (Tripsazea Creammaize T.) as a female parent and taking a cultivated maize (Zea mays L.), a tripsacanthyloides L or a tetraploid perennial maize (Zea perennis) as a male parent and aims at harvesting a stem and leaf nutrient.

The perennial forage maize in the step (1) of the method is jade grass No. 5 or jade grass No. 6 and the like. The No. 5 jade grass or No. 6 jade grass is perennial forage grass corn which is bred by hybridization by taking MTF-1(Tripsazea Creammaize T.) as a female parent and tetraploid perennial corn as a male parent.

Yucaocao No. 5 and Yucaocao No. 6 have both been registered by the Sichuan province grass variety approval Committee, and the variety registration number for Yucaocao No. 5 is 2016007, and the variety registration number for Yucaocao No. 6 is 2017001. Yucaocao No. 5 and Yucaocao No. 6 are popularized and applied in the market, and the biological materials can be purchased from the market or Sichuan agriculture university.

The corn allophexaploid refers to MTF-1 or a derivative line thereof.

The step (1) of uniformly covering the incision with the talcum powder is to wrap the absorbent cotton with gauze to prepare a cotton ball with the size of a thumb, and slightly flap the cotton ball on the incision by dipping a little talcum powder, so that the talcum powder can cover the incision. The incision is convenient to accelerate healing, so that the water loss of the stem is reduced.

The herbicide spraying in the step (4) of the method is to weed after seedlings are transplanted when new leaves of the seedlings are spread; for example, the propagule/atrazine suspension 23% 1500-1800 mL/ha, the propagule/plowland 1500-2250 mL/ha, or the atrazine suspension 40% 2550-3000 mL/ha is used for controlling broad leaf weeds or grassy weeds.

Compared with the existing cuttage propagation method, the method has the advantages and beneficial effects that: (1) the method has high propagation coefficient of single plant. The axillary buds of the cutting slips in the cutting method used at present are easily affected by mechanical damage, the robustness of the cutting slips, the infection of sundry bacteria on the cutting slip sections and other factors to germinate, so that the seedling rate of the stem nodes at the lower part of the stems is below 50%. The method provided by the invention can remove the top advantages of the plant by cutting the upper part of the stem, and promote the axillary buds at the stem nodes to germinate into seedlings under the nutrition supply of the matrix, so that the seedling rate of the stem nodes is improved, and the propagation coefficient of a single plant is further improved. The stem node seedling rate of the invention is improved by more than 20 percent compared with the cuttage method, and the single plant propagation expansion coefficient is improved by at least 40 percent. (2) The seedlings propagated by the method of the invention are more robust. Compared with the cuttage method, the seedling obtained by the method of the invention has the advantages of 28 days earlier seedling emergence, long growth time, high plant height, thick and strong stem, more leaves and 1-2 tillers existing in the plant during early spring transplantation. (3) The method of the invention has small seedling-raising occupied area and effectively reduces the seedling-raising cost. The axillary buds of the stem nodes germinate into seedlings on the parent body, the transplanting purpose of the seedlings is strong, and the seedlings are transplanted into a seedling nursery only by shearing the stem sections of the seedlings. Generally, 1998000 seedlings can be cultured per hectare, so that the occupied area for seedling culture is reduced, and the land utilization rate is improved. (4) The method has low seedling raising cost. The method has high stem node seedling rate and propagation expansion coefficient, reduces the investment of manpower and financial resources, and reduces the seedling cost. The application of the invention can effectively relieve the problem of seedling shortage when perennial forage maize is introduced and popularized in southwest areas, and is beneficial to large-scale planting and popularization of perennial forage maize.

Drawings

FIG. 1 is a field photograph of a mother stem seedling after the top end of the stem is removed from Yucao No. 5.

Detailed Description

The present invention is further illustrated by, but is not limited to, the following examples. Unless otherwise specified, the methods used in the following examples are conventional methods

Example 1 comparison test of perennial forage grass maize seedlings for efficient propagation

The method comprises the following steps:

(1) removing stem tops and promoting axillary buds: 6 Yucaao 5, which was planted in 2016, was randomly marked at 31.9.2016 in Chongzhou modern agriculture research and development base of Sichuan agriculture university. 3 of the single plants are selected to be provided as seedlings, the upper parts of the stems 100cm away from the ground surface are cut by using a pair of pruning shears, the middle and lower parts of the stems without obvious plant diseases and insect pests and damage to axillary buds are left, leaves and leaf sheaths on the stems are manually removed, and 300 stem nodes are reserved for each single plant. The absorbent cotton is wrapped by gauze to prepare a cotton ball with the size of a thumb, a little talcum powder is dipped and lightly flapped on the cut, and the cut is convenient to heal quickly so as to reduce the water loss of the stalks. And the other 3 single plants grow normally in the field and provide cutting slips for a conventional cutting method, wherein each cutting slip has 1 stem node.

(2) Seedling treatment: preparing seedlings (see figure 1) after axillary buds at the middle and lower parts of the stem germinate for 28 days, obliquely shearing single plants adopting the method of the invention into stem segments at the middle parts of all sections of the stem by using branch scissors as seedlings, and classifying the stem segments according to the growth state of the axillary buds to ensure that the seedlings grow uniformly; . The seedling classification standard is as follows: a type: axillary buds have developed into a complete plant with roots, stems and leaves; b type: axillary buds have formed stems and leaves; class C: axillary buds are not germinated. Bundling A-type seedlings by using nylon ropes, then placing the A-type seedlings in water for soaking for 12 hours, and directly transplanting and raising the seedlings; soaking the B-type seedlings in water for 8h, then soaking the B-type seedlings in a naphthylacetic acid solution containing 150mg/L for 4h, and then disinfecting the B-type seedlings for 5min by using 1000 times of 50% carbendazim wettable powder, wherein the soaking depth of the B-type seedlings is that stems are submerged on the water surface. Discarding the C-type seedlings. Meanwhile, the other 3 single plants are treated with the cutting slips by a conventional method of a cutting method, and 300 cutting slips are selected from each single plant.

(3) Applying enough base fertilizer, preparing soil and dividing compartments: in 2016, 10 months and 25 days, a land block with loose and fertile soil, sunny exposure and good drainage performance is selected as a nursery in Chongzhou modern agriculture research and development base of Sichuan agriculture university, 300kg of nitrogen-phosphorus-potassium ternary compound fertilizer is applied to the ground surface of the nursery per hectare, and a rotary cultivator is used for deeply ploughing the soil by 25-30 cm. The ridge making compartment is formed according to the width of 1.5m, the width of the ridge and the furrow is 50cm, and the depth of the furrow is 30 cm. The nursery garden is provided with 6 cells, and the area of each cell is 1.5m multiplied by 1.5 m. The random block design of the cutting slips of the seedlings and the cutting method is realized by planting 3 cells in various ways, and 300 cutting slips are planted in each cell by the cutting method, and the seedling number of each cell is the actual seedling number of 300 stem nodes on a single plant in the steps (1) and (2).

(4) Transplanting seedlings: and (4) planting furrows with the depth of 5-10 cm are formed in the cells of the compartment in the step (3), and the distance between every two adjacent planting furrows is 15 cm. Before transplanting seedlings, the chlorpyrifos granules are scattered into planting ditches according to the proportion of 18 kg/hectare of the chlorpyrifos granules, and are used for preventing and controlling underground pests such as mole cricket, grub, cutworms and the like. Placing the A, B seedlings and the cuttings in the step (2) in a ditch according to the density of the row spacing of 5cm multiplied by 15cm, covering soil and compacting, and immediately watering once root fixing water after the seedlings are transplanted. In 2016, 11 months and 5 days, weeding is carried out after seedlings have new leaves spread, and broad-leaved weeds and gramineous weeds are prevented and removed by 23 percent of nicosulfuron and atrazine with the concentration of 1500-. When the temperature is lower than 5 ℃, the film is covered to keep warm and overwinter, a glass fiber rod with the diameter of 7mm and the length of 2m is used as an arch frame in 2016, 11 and 20 days, and a 3m wide film is covered to build an arch shed to keep warm and overwinter.

(5) Hardening seedlings: in early spring, when the ground temperature is stabilized above 10 deg.C, the hardening off and transplanting can be carried out. In 2017, 2, 15 days, 8:00 in the morning of a sunny day, the thin film side is uncovered for hardening seedlings, and 6:00 in the evening is covered with the thin film. The above cycle was repeated every day with increasing film removal every other day, and all films were removed in 2017, 2 and 22. Before transplanting, 2/3 of the length of the main stem and leaf of the seedling and 1/2 of the length of the root are cut off by using a pair of scissors, so that excessive water loss in the process of transporting the seedling is reduced, and the seedling revival and new root quick-growing after the seedling is transplanted are facilitated.

On 23/2/2017, the stem node seedling rate and the individual plant propagation coefficient of each plot were investigated, where the stem node seedling rate (%) is (number of stem nodes of seedling/total number of stem nodes) × 100, and the individual plant propagation coefficient is the number of single plant stem node seedling. Meanwhile, the agronomic characters of the seedlings in each cell, such as plant height, stem thickness, tillering number, main stem leaf number and the like, are counted to represent the robust degree of the seedlings.

The results (see table 1) show that the conventional cuttage propagation coefficient of a single plant is 140-147, while the propagation coefficient of the invention is 200-213, which is 1.4 times of the propagation coefficient of the conventional cuttage method; the seedling rate of the method is obviously higher than that of the conventional cuttage method. The high-definition conventional cuttage method with obvious propagation coefficient and seedling rate is demonstrated.

As can be seen from Table 2, the seedlings obtained by the method of the present invention have higher average plant height, stem thickness, tillering number and main stem leaf number than those obtained by the cutting method. The method of the invention is proved that the robustness of the obtained seedlings is obviously higher than that of the seedlings obtained by the conventional cuttage method.

TABLE 1 comparative test results of the survival rate of the No. 5 stem node of Yucaao and the propagation coefficient of each plant

The "-" in the table indicates that the data need not be counted.

TABLE 2 comparison test result of agronomic characters of No. 5 Yucao seedlings

Claims

1. a kind of efficient propagation method of perennial forage corn, is characterized in that comprising the steps:

(1) Remove the top of the stem and promote axillary buds: From late August to early September, from the end of vegetative growth to the beginning of tasseling of perennial forage corn, use a sickle or branch shears to cut off the upper part of the stalk 100cm above the surface, and then use talc. The powder evenly covers the incision to reduce the water loss of the stalk; leave the stalk without obvious pests and diseases, and remove the leaves and leaf sheaths on the stalk; the perennial forage maize refers to the maize allohexaploid as the female parent , the perennial forage maize with cultivated maize, rubbing grass or tetraploid perennial maize as the male parent cross-bred, with the goal of harvesting stem, leaf vegetative body; Described maize allohexaploid refers to MTF-1 Or its derivative line; Described perennial forage corn refers to Yucao No. 5 or Yucao No. 6;

(2) Seedling treatment: under field conditions, the axillary buds in the middle and lower parts of the stem described in step (1) germinate for 2 to 4 weeks, and then use branch shears to cut diagonally into stem segments in the middle of each internode as seedlings; and Classification according to the development status of axillary buds to ensure consistent growth of seedlings; classification criteria for seedlings: Class A: Axillary buds have developed into complete plants with roots, stems and leaves; Class B: Axillary buds have formed stems and leaves; Class C: Axillary buds No germination; bundle the A seedlings, then soak them in water for 12-24 hours, and then directly transplant the seedlings; soak the B seedlings in water for 8-16 hours, and then immerse them in a concentration of 100-150 mg/L Soak in naphthalene acetic acid solution for 4 to 8 hours, and then soak in 1000 times 50% carbendazim wettable powder for 3 to 5 minutes for disinfection; the depth of immersion of the seedlings is that the water surface submerges the stem of the mother; discard the C-type seedlings;

(3) Apply enough basal fertilizer and prepare the land and compartments: Choose a plot with loose and fertile soil, sunny and good drainage performance as the nursery, and apply compound fertilizer to the surface of the nursery at a rate of 150-300kg/ha, and use rotary tillage. Deeply plough the soil 20-30cm; then make a box with a width of 1.5-2m, the width of the ditch is 40-50cm, and the depth of the ditch is 20-30cm;

(4) Seedling transplanting: open a planting ditch with a depth of 10-15 cm in the compartment described in step (3), and the spacing between adjacent planting ditches is 15 cm; The proportion of chlorpyrifos granules is spread in the planting ditch, for preventing and controlling mole crickets, grubs, cutworms; according to the planting density of 5cm × 15cm according to the row spacing, the A and B seedlings described in step (2) are divided into Box planting is convenient for obtaining seedlings with consistent growth. After the seedlings are transplanted, water for rooting is poured immediately; herbicides are sprayed to control weeds in the field; Fiber rods are used as arch frames, covered with 2-3m wide plastic film to build arch sheds to keep warm and overwinter;

(5) Seedling hardening: When the ground temperature is stable at ≥10°C in early spring, open the side of the film for hardening at 8:00 in the morning on a sunny day, and cover it with plastic film in the evening; harden the seedlings for 7 days, and then remove all plastic films; Transplanting or selling; before transplanting, cut off 2/3 to 3/4 of the leaf length of the seedling, and cut off 1/2 to 2/3 of the root length.

2. The method according to claim 1, wherein the step (1) of covering the incision with talc powder evenly refers to wrapping absorbent cotton with gauze to make a thumb-sized cotton ball, dipping a little talc powder and gently. Tap on the incision until the talc can cover the incision.

3. The method according to claim 1, characterized in that the herbicide spraying described in step (4) refers to the use of herbicide to carry out post-emergence weeding when the seedlings have new leaves after transplanting; 23% Nicotinine and atrazine 1500-1800 mL/ha, or Gengjie 1500-2250 mL/ha, or 40% atrazine suspension 2550-3000 mL/ha to control broadleaf weeds or grass weeds.