CN113575315B - Planting method for promoting tomato growth and development and fruit quality based on calcium-zinc application - Google Patents

Abstract

The invention discloses a planting method for promoting tomato growth and development and fruit quality based on calcium-zinc dispensing, which comprises the following steps: culturing tomato seedlings; before field planting, the culture medium coco coir is subjected to zinc fertilizer base application treatment, and the concentration is set into two groups according to the volume ratio of the coco coir to the culture medium: 0 and 0.1g/L; carrying out exogenous calcium solution spraying treatment on the 1 st to 2 nd fully developed functional leaves under the growing points of the tomatoes in the initial flowering and initial fruiting period, wherein the total concentration of the exogenous calcium solution is four groups: 0. 0.25%, 0.5% and 1.0% CaCl ₂ The water solution is uniformly sprayed on the front and back sides of the blade, and the spraying is carried out once a week for three weeks continuously; after field planting, irrigating with 1/2 concentration Hoagland nutrient solution every 1-2d, wherein each plant is about 500ml at a time; when tomatoes grow to a fruit expanding period, the irrigation amount of each plant of tomatoes is increased to 1000ml; the invention sprays 0.5 percent CaCl on the leaf surface under the condition of 0.1g/L zinc fertilizer base application ₂ The solution has the best effect of improving the quality of tomatoes.

Description

A planting method based on calcium and zinc combined application to promote tomato growth and fruit quality

Technical field

The invention relates to the technical field of plant planting and cultivation, and specifically relates to a planting method based on calcium and zinc combined application to promote tomato growth and fruit quality.

Background technique

Tomato (Solanum lycopersicum L.) is one of the vegetable crops with the largest cultivated area at home and abroad. It is also an important model crop for genetic improvement of solanaceous vegetable quality. Cherry tomatoes are a variety of cultivated tomatoes. Due to their short plants, short growth cycle, and strong adaptability, they are widely used in genetic improvement of tomato quality and physiological and biochemical research. Compared with other varieties, ‘Zhe Ying Fen No. 1’ has the advantages of parthenocarpy and adaptability to high temperature and high humidity environments in greenhouses. Calcium and zinc are essential mineral elements for plant growth and development. They also play key roles in the growth and development of the human body. Daily diet is an effective way for the human body to absorb calcium and zinc elements. At present, in the process of tomato cultivation and management, there is a common problem of calcium and zinc nutritional deficiencies, which seriously restricts the sustainable development of tomato production. Existing technical research mostly focuses on the effect of a single factor (calcium or zinc) on tomato growth and development, but has poor effect on improving tomato quality.

Contents of the invention

The purpose of the present invention is to solve the deficiencies in the prior art and provide a planting method based on calcium and zinc combined application to promote tomato growth and fruit quality.

In order to achieve the above objects, the present invention provides the following technical solutions:

A planting method based on the application of calcium and zinc to promote tomato growth, development and fruit quality, including the following steps:

S1. Medium preparation: Before planting tomato seedlings, the coconut bran bricks are fully soaked in distilled water, fully disinfected using sunlight, dried and mixed with zinc fertilizer, and then put into the prepared nutrient bowl for later use;

S2. Cultivation of tomato seedlings: Tomato seeds are sown in plug trays after germination and whitening. When the tomato seedlings grow to have three leaves and one center, they are planted in a nutrient pot for matrix cultivation;

S3. Fertilization: When the tomatoes enter the first flowering and first fruiting stage, set several control groups when the 1-2 functional leaves from the lower growth point of the tomato plant are fully expanded. Spray fertilizer on each control group once a week for three consecutive days. week;

S4: After planting, irrigate with Hoagland's nutrient solution every 1-2 days, 500ml per plant at a time. The Hoagland's nutrient solution is diluted with water to a volume concentration of 50%;

S5: When the tomatoes grow to the fruit expansion stage, irrigate with Hoagland's nutrient solution every 1-2 days, 1000ml per plant at a time. The Hoagland's nutrient solution is diluted to 50% volume concentration with water.

Further, the coconut bran bricks in step S1 are Petermann coconut bricks, produced in India, unit weight is 5-5.5kg/block, EC value ≤ 0.6MS/CM, pH value between 5.5-6.8, fiber ≤ 2%.

Further, in step S1, the zinc fertilizer content in the coconut bran bricks is 0.1g/L.

Further, the tomato variety in step S2 is "Zheying Fen No. 1".

Further, in step S2, the solar greenhouse is a reinforced concrete structure greenhouse, the temperature of the solar greenhouse is maintained in the range of 15°C-35°C, and the light is sufficient.

Further, in step S3, the control group is sprayed with CaCl ₂ aqueous solution, and the volume concentration of the CaCl 2 solution sprayed in each control group is not greater than 1.0%.

Further, the spraying method in step S3 is: spray evenly on the front and back of the leaves. After spraying, the standard is that the leaves are covered with water droplets and do not drip.

Further, four groups of control groups are set up in step S3. The volume concentrations of CaCl2 aqueous solution sprayed on the tomato plants in the four groups of control groups are 0, 0.25%, 0.5% and 1.0% respectively.

Compared with the prior art, the beneficial effects of the present invention are:

1. The plant height, stem diameter, node spacing and number of fruits per panicle of tomato plants increased significantly under zinc fertilizer application. Foliar spraying of calcium chloride at low, medium and high concentrations (0.25%, 0.5%, 1.0%) has a significant promotion effect on the physiological characteristics of tomatoes, and the 0.5% calcium chloride spraying treatment has the most significant promotion effect. Compared with pure zinc or calcium treatment, there was no further increase trend in tomato plant height, stem diameter, node spacing and number of fruits per panicle under different concentrations of calcium and zinc combined.

2. Zinc fertilizer basal application can significantly promote the accumulation of chlorophyll in tomato leaves and enhance photosynthesis, in which the net photosynthetic rate, stomatal conductance and transpiration rate are all significantly increased. Foliar spraying of calcium chloride at different concentrations effectively increased various types of chlorophyll content and photosynthesis; 0.5% calcium chloride treatment had the best effect. The combined application of 0.5% concentration calcium and zinc fertilizer can further promote the photosynthesis of tomatoes.

3. Zinc fertilizer basal application or calcium chloride spraying increased the biomass of fruits, promoted the accumulation of soluble solids, lycopene, free amino acids, soluble sugars, etc., while effectively inhibiting organic acids and nitrate nitrogen. content increased. Appropriate concentrations of calcium and zinc can further promote the accumulation of lycopene, vitamin C, soluble protein and soluble sugar content in fruits. Zinc treatment did not increase the content of Ca, Mg, K, Na and Zn elements in the fruit; while low and medium concentration calcium treatments could effectively promote the accumulation of Ca and Zn elements in the fruit; the Ca and Zn elements of the fruit further increased under the combination of appropriate concentrations of calcium and zinc. high. At the same time, both zinc and calcium treatments can inhibit the accumulation of phytic acid in fruits and increase the effective zinc and calcium contents in fruits.

4. Basal application of zinc fertilizer can significantly increase the activities of SOD, POD and CAT in fruits. Foliar spraying of calcium chloride increased the activity of antioxidant enzymes to varying degrees; the treatment with 1.0% concentration of calcium chloride had the best effect. At the same time, the activity of some antioxidant enzymes and the content of antioxidant substances (vitamin C) in the fruits further increased after the application of appropriate concentrations of calcium and zinc.

5. Basic application of zinc fertilizer significantly increased the reducing sugar and sucrose content of the fruit, and promoted the significant increase in the activities of acid invertase and neutral invertase. Foliar spraying of calcium chloride increased reducing sugar content and acid invertase activity to varying degrees, and inhibited sucrose synthase activity. The combination of low and medium concentrations of calcium and zinc can further promote sucrose accumulation and increase the activities of acid invertase, neutral invertase and sucrose phosphate synthase.

6. Basic application of zinc fertilizer can significantly increase the content of various amino acids in tomato fruits, among which the contents of essential amino acids for humans, essential amino acids for children, sweet amino acids and aromatic amino acids are all significantly increased. Low and medium concentration calcium spraying promoted the increase in the contents of various amino acids to varying degrees, and the contents of many types of amino acids increased significantly. However, the contents of various amino acids showed a significant downward trend under high concentration calcium treatment. Compared with pure zinc or calcium treatment, the combination of calcium and zinc at different concentrations did not further promote the increase in amino acid content, but effectively regulated the ratio of various amino acids to the total amount.

7. Zinc fertilizer base application promotes the significant increase of various volatile flavor substances such as aldehydes, esters, ketones, alcohols and hydrocarbons in the fruit, among which hexanal, trans-2-vinyl aldehyde, trans-2 -The contents of large proportions of flavor substances such as pentenol and linalool increased significantly. Foliar spraying of calcium chloride also promoted the increase in the content of various volatile flavor substances in the fruit to varying degrees, but the increasing trend of the content of various flavor substances significantly decreased under the combined application of calcium and zinc at different concentrations.

Picture description:

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without exerting creative efforts.

Figure 1 is a flow chart of the present invention;

Figure 2 shows the effect of calcium and zinc application on the growth characteristics of tomato plants;

Figure 3 shows the effect of calcium and zinc application on photosynthesis of tomato plants (net photosynthetic rate, intercellular carbon dioxide, transpiration rate and stomatal conductance);

Figure 4 shows the effect of calcium and zinc application on the light response curve of tomato plants;

Figure 5 shows the effect of calcium and zinc on tomato fruit quality (soluble solids, nitrate nitrogen, free amino acids, soluble protein, soluble sugar, organic acid, soluble pectin and sugar-acid ratio, etc.);

Figure 6 shows the effect of calcium and zinc on the reducing sugar and sucrose content of tomato fruits;

Figure 7 shows the effect of calcium and zinc on the sucrose metabolic enzyme activities of tomato fruits (acid invertase, neutral invertase, sucrose synthase and sucrose phosphate synthase).

Detailed ways:

In order to make it easy to understand the technical means, creative features, objectives and effects of the present invention, the present invention will be further elaborated below in conjunction with the specific implementation modes:

Accordingly, the following detailed description of the embodiments of the invention provided in the appended drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the invention based on which embodiments are disclosed. All other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

It should be noted that similar reference numerals and letters represent similar items in the following figures, therefore, once an item is defined in one figure, it does not need further definition and explanation in subsequent figures.

The terms "first", "second", "third", etc. are used for descriptive purposes only and are not to be understood as indicating or implying relative importance.

In the description of the present invention, it should also be noted that, unless otherwise clearly stated and limited, the terms "set", "installation", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, It can also be a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two components. For ordinary people in this field For those skilled in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

Please refer to Figure 1-Figure 7,

A planting method based on the application of calcium and zinc to promote tomato growth, development and fruit quality, including the following steps:

S1. Medium preparation: Before planting tomato seedlings, the coconut bran bricks are fully soaked in distilled water, fully disinfected using sunlight, dried and mixed with zinc fertilizer, and then put into the prepared nutrient bowl for later use;

S2. Cultivation of tomato seedlings: Tomato seeds are sown in plug trays after germination and whitening. When the tomato seedlings grow to have three leaves and one center, they are planted in a nutrient pot for matrix cultivation;

S3. Fertilization: When the tomatoes enter the first flowering and first fruiting stage, set several control groups when the 1-2 functional leaves from the lower growth point of the tomato plant are fully expanded. Spray fertilizer on each control group once a week for three consecutive days. week;

S4: After planting, irrigate with Hoagland's nutrient solution every 1-2 days, 500ml per plant at a time. The Hoagland's nutrient solution is diluted with water to a volume concentration of 50%;

S5: When the tomatoes grow to the fruit expansion stage, irrigate with Hoagland's nutrient solution every 1-2 days, 1000ml per plant at a time, and the Hoagland's nutrient solution is diluted to 50% volume concentration with water;

S6: Measure various parameters of the fruit after the fruit matures, and then perform data analysis on the parameters.

In this embodiment, the coconut bran bricks in step S1 are Petermann coconut bricks, origin is India, unit weight is 5-5.5kg/block, EC value ≤ 0.6MS/CM, pH value is between 5.5-6.8, Fiber ≤ 2%.

In this embodiment, the zinc fertilizer content in the coconut bran bricks in step S1 is 0.1g/L.

In this embodiment, the tomato variety in step S2 is "Zheying Fen No. 1".

In this embodiment, the solar greenhouse in step S2 is a reinforced concrete structure greenhouse, the temperature of the solar greenhouse is maintained in the range of 15°C-35°C, and the light is sufficient.

In this embodiment, in the step S3, the control group is sprayed with CaCl ₂ aqueous solution, and the volume concentration of the CaCl 2 solution sprayed in each control group is not greater than 1.0%.

In this embodiment, the spraying method in step S3 is: spray evenly on the front and back of the leaves. After spraying, the standard is that the leaves are covered with water droplets and do not drip.

In this embodiment, four groups of control groups are set up in step S3. The volume concentrations of CaCl ₂ aqueous solution sprayed on tomato plants in the four groups of control groups are 0, 0.25%, 0.5% and 1.0% respectively.

The experimental treatment is as follows: the four control groups are combined with zinc fertilizer basal application or set alone to form the following experimental groups:

(1)CK: Spray with distilled water;

(2) Zn: Zinc fertilizer base application + distilled water spray;

(3)0.25Ca: Spray CaCl ₂ at a concentration of 0.25%;

(4) 0.25Ca+Zn: Zinc fertilizer base application + 0.25% concentration CaCl ₂ spraying;

(5)0.5Ca: 0.5% concentration CaCl ₂ spraying;

(6) 0.5Ca+Zn: Zinc fertilizer base application + 0.5% CaCl ₂ spraying;

(7)1.0Ca: 1.0% CaCl ₂ spray;

(8) 1.0Ca+Zn: Zinc fertilizer base application + 1.0% CaCl ₂ spraying.

After conducting the experiment according to the above experimental group, samples were taken after the first ear of fruit has completed color change. One part was stored in a -80°C ultra-low temperature refrigerator for later use, and the other part was dried and stored in a dry test tube for determination of mineral elements.

Measurement items and methods:

Tomato growth characteristics;

Tomato plant height and node spacing were measured using a ruler with an accuracy of 1 mm; tomato stem thickness was measured with a vernier caliper with an accuracy of 0.01 mm.

The horizontal and vertical diameters of tomato fruits were measured using vernier calipers with an accuracy of 0.01 mm; the weight of individual fruits was measured using an electronic balance with an accuracy of 0.001 g.

Photosynthetic pigment content and photosynthetic parameters of tomato leaves:

When the tomato fruits enter the color change period, choose a sunny day and use an L-6800 photosynthetic instrument (L-6800, Beijing Ligaotai Technology Co., Ltd.) to measure the photosynthetic parameters (net photosynthetic rate) between 9:00 and 11:00 am. , transpiration rate, intercellular CO2 concentration and stomatal conductance, etc.) and measurement of light response curves. Settings when measuring photosynthetic parameters: built-in light source 400 μmol-1·m-2·s-1, flow rate 500 μmol·s-1, leaf temperature 25°C; measuring light response curve parameters: flow rate 500 μmol·s-1, leaf temperature 25°C, 12 photosynthetically active radiation intensity gradients: 1500, 1200, 1000, 800, 600, 400, 200, 150, 100, 50, 25, 0 μmol-1·m-2·s-1, recording the photosynthesis of tomato leaves under different light intensities Parameters and draw the light response curve, record data every 180s, repeat 10 times.

Tomato fruit supplements:

The soluble solid content was measured using a sugar refractometer (WYT-1, Quanzhou Optical Instrument Factory). Fruit hardness was measured using a durometer (GY-3, Zhejiang Top Instrument Co., Ltd.). The soluble sugar content is measured by the phenol colorimetric method, and the titratable acid is measured by the acid-base titration method. The sugar-acid ratio = soluble sugar/titratable acid. Soluble protein content was determined using the Coomassie Brilliant Blue G-250 method. Vitamin C content was determined using the molybdenum blue colorimetric method.

Lycopene was measured using the petroleum ether extraction method. Refer to the method of Zhang Lianfu et al. and modify it. Weigh 1.0g of tomato pulp, grind it thoroughly, filter it with 20ml of absolute ethanol four times, and then filter it with 30ml methanol six times until it is filtered. The liquid that comes out is transparent and colorless. Discard the filtrate and keep the filter residue; react the filter residue with petroleum ether (98% petroleum ether + 2% methylene chloride). The filtrate will be orange-yellow. Filter several times until the filter residue turns white. ; Adjust the volume of the filtrate to 50ml, measure the color with a UV spectrophotometer at 502nm, read the absorbance value and calculate the lycopene content.

Phytic acid content was measured using the ferric chloride fading method with slight modifications. Phytic acid extraction: Weigh 0.5g of fresh tomato fruit sample, add 15ml of 1.2% HCl and 10% Na2SO4, stir and extract at room temperature for 2 hours, centrifuge (4000r/min, 30min), take the supernatant and store it in a 4°C refrigerator for later use. Determination of phytic acid content: Take 2 ml of phytic acid extract, add 2 ml of 15% trichloroacetic acid (TCA), mix evenly in a 10 ml centrifuge tube and place it in a 4°C refrigerator for 2 hours. After centrifugation, take 2 ml of the supernatant and mix it with 0.75 mol/LNaOH to adjust the pH to 6.0, then add distilled water to adjust the volume to 30ml, take 3ml of diluent and add 1ml of 0.3% sulfosalicylic acid and 0.03% ferric chloride (FeCl ₃ ·6H ₂ O), mix well and add Colorimetrically measure at 505nm, read the absorbance value and calculate the content according to the phytic acid standard curve.

Tomato fruit sucrose metabolism enzyme activity:

Weigh 0.05g of fresh tomato samples, and measure the fruit sucrose synthase (SS), sucrose phosphate synthase (SPS), acid invertase (AI), and neutral invertase (NI) activities using corresponding enzyme activity detection kits (Beijing) Solebao Technology Co., Ltd.). Each treatment was repeated 3 times.

Tomato mineral element content:

After picking the fruit, separate the roots, stems, and leaves of the plant, wash and dry them, place them in an oven at 105°C for 15 minutes, and then dry them at 80°C for 48 hours to prepare dry samples. Weigh 2.0g of dried samples of tomato roots, stems, leaves and fruits respectively, and prepare machine samples by H ₂ SO ₄ -H ₂ O ₂ digestion method, using a flame atomic absorption spectrophotometer (AA-6200, SHIMADZU, Japan) Determine the content of K, Ca, Mg, Zn, Fe, and Mn elements in different organs. Each treatment was repeated 3 times.

Tomato antioxidant enzyme activity:

Enzyme liquid extraction: Weigh an appropriate amount of tomato fruit homogenate, add pre-cooled potassium phosphate buffer (50mM, pH7.8), grind in an ice bath until homogenized, then transfer to a 10ml centrifuge tube for centrifugation (4°C, 6500r/min) , 15min), extract the supernatant for testing.

SOD activity was measured using the nitroblue tetrazolium (NBT) method. Take 150μl of the enzyme solution to be tested and add it to the SOD reaction solution (1.5ml 50mM phosphate buffer (pH 7.8), 0.3ml 13mM methionine solution, 0.3ml 75mM NBT, 0.3ml 0.1mM EDTA-Na2, 0.3ml 4mM riboflavin and 0.5ml distilled water) , after reacting under light for 20 minutes, the color was measured at a wavelength of 560nm.

For POD and CAT activity, refer to the method of Gao Junfeng et al. Take 100 μl of the enzyme solution to be tested and add it to the POD reaction solution (10mM guaiacol, 50mM H2O2 and 0.2mM phosphate buffer (pH 6.0)), and quickly place it at a wavelength of 470nm for kinetic colorimetry; add an appropriate amount of the enzyme solution to be tested. CAT reaction solution (15mM phosphate buffer (pH 7.0) and 10mM H ₂ O ₂ ) was quickly placed at a wavelength of 240nm for kinetic colorimetry.

Tomato fruit amino acid composition:

Weigh 0.1g of dried tomato fruit sample, soak it in 1.5mL 2% 5-sulfosalicylic acid, fully extract for 24 hours, and centrifuge at 12000rpm at 4℃ low temperature, take 800μL of the supernatant and use 0.02mmol·L ^-1 Dilute HCl to 5mL. The sample was filtered through a 0.45 μm filter membrane and placed in a 1.5 mL injection bottle. An amino acid analyzer (L-8800, HITACHI) was used to measure the content of different amino acid components. The injection volume was set to 20 μL. Each treatment was repeated 4 times. The total amount of amino acids is represented by TAA (Total amino acid, TAA); the essential amino acids for the human body are represented by EAA (Essential amino acid, EAA), including threonine, valine, isoleucine, leucine, and phenylalanine , lysine, methionine; human non-essential amino acids are represented by NEAA (Non-essentialamino acid, NEAA), including aspartic acid, serine, glutamic acid, glycine, alanine, tyrosine, histidine, and sperm. Amino acid and proline; essential amino acids for children are represented by CEAA (Essential amino acid for children, CEAA), including histidine and arginine; umami amino acids are represented by FAA (Fresh amino acid, FAA), including aspartic acid Acid and glutamic acid; sweet amino acids are represented by SAA (Sweet amino acid, SAA), including alanine, glycine, serine and proline; aromatic amino acids are represented by AAA (Aromatic amino acid, AAA), including phenylpropanine amino acids and tyrosine. Based on the tomato amino acid measurement results, calculate the proportion of various human amino acids to total amino acids (EAA/TAA, NEAA/TAA, CEAA/TAA), and the proportion of flavor amino acids to total amino acids (FAA/TAA, SAA/TAA, AAA/TAA).

Sample preparation for determination of flavor substances: Weigh 5.0g of fresh tomato fruit homogenate into a headspace bottle, add 1.5g NaCl and 25μl 2-nonanone standard solution (0.25mg/L) in sequence, and cap the headspace bottle. After sealing, mix the sample thoroughly with a shaker and place it in a 50°C water bath for 10 minutes, then take it out for later use. Determination: The prepared samples were placed on a gas chromatograph-mass spectrometer (Trace ISQ, Thermo) for determination of flavor substances, and then based on the characteristics of various flavor substances, aldehydes, esters, ketones, alcohols and Classify volatile flavor substances such as hydrocarbons.

data analysis:

The experimental data were analyzed using SPSS 21.1 for variance analysis and Excel 2019 for graphing. results and analysis:

Effects of calcium and zinc combined fertilization on the growth characteristics of tomato plants:

As shown in Figure 2, compared with CK, tomato plant height, stem diameter, node spacing and number of fruits per panicle increased significantly by 26.84%, 11.33%, 40.93% and 32.26% respectively under Zn treatment; 0.25Ca, 0.5Ca and 1.0 Under Ca treatment, tomato plant height, stem diameter, node spacing, and number of fruits per panicle all increased significantly, with the spacing between nodes significantly increasing by 44.73%, 31.22%, and 40.93%, respectively; and the number of fruits per panicle significantly increasing by 19.36%, 25.81% and 16.13%; under the 0.25Ca, 0.5Ca and 1.0Ca treatments combined with zinc, the plant height, stem diameter, node spacing and number of fruits per panicle all increased significantly, among which the plant height, node spacing and number under the 0.5Ca+Zn treatment The number of fruits per panicle increased significantly by 29.63%, 37.55% and 38.71% respectively.

Effects of calcium and zinc combined fertilization on photosynthetic characteristics and mineral element content of tomato leaves:

Effects of calcium and zinc combined fertilization on tomato chlorophyll content:

It can be seen from Table 1 that compared with CK, chlorophyll b, carotenoids, total chlorophyll content and chlorophyll a/b were significantly increased under Zn treatment, and the carotenoid content increased by as much as 26.10%; tomato plant leaves under 0.25Ca treatment Chlorophyll b, carotenoids, total chlorophyll content and chlorophyll a/b were all significantly increased, among which the carotenoid content increased by as much as 35.69%; the chlorophyll a, chlorophyll b, carotenoid and total chlorophyll contents of leaves increased significantly under 0.5Ca treatment. 54.28%, 45.89%, 50.73% and 51.94%; under 1.0Ca treatment, leaf carotenoids, total chlorophyll content and chlorophyll a/b were significantly increased, among which carotenoids increased by as much as 42.91%; 0.25Ca, 0.5Ca and 1.0 Chlorophyll a, chlorophyll b, carotenoids, total chlorophyll content and chlorophyll a/b all increased significantly under Ca treatment and zinc treatment, among which the chlorophyll a content increased significantly under 0.5Ca+Zn and 1.0Ca+Zn treatments respectively. 30.90% and 38.47%, the chlorophyll b content increased significantly by 23.47% and 28.26% respectively, the carotenoids increased significantly by 40.29% and 91.59% respectively, and the total chlorophyll content increased significantly by 29.80% and 40.05% respectively.

Table 1. Effects of different treatments on tomato chlorophyll content

Table 1.Effects of different treatments on chlorophyll content oftomato

Effects of calcium and zinc combined application on mineral element content in tomato leaves:

It can be seen from Table 2 that compared with CK, the Mg and K element contents of tomato leaves under Zn treatment significantly decreased by 20.88% and 48.98% respectively; the Zn element contents in leaves under 0.25Ca, 0.5Ca and 1.0Ca treatments significantly increased by 42.44% respectively. %, 49.17% and 83.91%; among them, the Mg element content of leaves significantly decreased under the 0.5Ca treatment; the Mg and K element contents significantly decreased by 25.08% and 32.66% respectively under the 1.0Ca treatment; the Zn content increased significantly under the 0.5Ca+Zn treatment. 69.97%; under 1.0Ca+Zn treatment, the Zn content increased significantly by 82.38%, and the K content decreased significantly by 51.02%.

Table 2. Effects of different treatments on element content in tomato leaves

Table 2.Effects of different treatments on element content in tomatoes

Effects of calcium and zinc combined application on photosynthetic parameters of tomato seedlings:

Compared with CK, the net photosynthetic rate, stomatal conductance and transpiration rate of tomatoes under Zn treatment were significantly increased by 0.39 times, 1.14 times and 1.19 times respectively; under the 0.25Ca treatment, the net photosynthetic rate, transpiration rate and stomatal conductance were significantly increased respectively. increased by 0.79 times, 2.05 times and 1.20 times; the net photosynthetic rate, intercellular CO2 concentration and transpiration rate increased significantly by 0.49 times, 3.31 times and 2.87 times respectively under 0.5Ca treatment; the stomatal conductance and transpiration rate under 1.0Ca treatment Significantly increased by 1.08 times and 0.79 times respectively; net photosynthetic rate, intercellular CO2 concentration, stomatal conductance and transpiration rate increased to varying degrees after 0.25Ca, 0.5Ca and 1.0Ca treatments and zinc were applied, among which Under 0.5Ca+Zn treatment, the net photosynthetic rate, stomatal conductance and transpiration rate significantly increased by 0.93 times, 7.03 times and 5.43 times respectively.

Effects of calcium and zinc combined application on the light response curve of tomato seedlings:

As shown in Figure 3, compared with CK, the net photosynthetic rate at the light saturation point of plants increased significantly under Zn treatment; the photosynthetic rate at the light saturation point under low, medium and high concentration calcium treatments showed a trend of promotion at low concentrations and inhibition at high concentrations. , the most significant effect of increasing the photosynthetic rate at the light saturation point was treated with 0.5Ca. At the same time, the net photosynthetic rate at the light saturation point further increased under the 0.5Ca, 1.0Ca treatments and zinc application.

Effects of calcium and zinc combined fertilization on tomato fruit quality and antioxidant enzyme activity:

Effects of calcium and zinc combined application on fruit appearance and quality:

Compared with CK, the horizontal and vertical diameters of tomato fruits increased significantly under Zn treatment, and the single fruit weight increased significantly by 53.78%; the horizontal and vertical diameters of tomato fruits increased significantly under 0.25Ca, 0.5Ca, and 1.0Ca treatments, and the single fruit weight increased significantly. Significantly increased by 53.63%, 52.18% and 48.46% respectively; under 0.25Ca, 0.5Ca and 1.0Ca treatments and combined with zinc application, the fruit transverse and longitudinal diameters were significantly increased, and the single fruit weight was significantly increased by 35.39% and 69.27% respectively. and 70.41%.

Table 3. Effects of different treatments on tomato fruit growth and physiological characteristics

Table3.Effects of different treatments on horizontal and vertical diameter, soluble solids, Hardness and single ftuit weight of tomato

Effects of calcium and zinc combined fertilization on the nutritional quality of tomatoes:

As shown in Figure 4, compared with CK, the soluble solids, lycopene, free amino acids, soluble protein and soluble sugar contents of tomato fruits increased significantly under Zn treatment, among which the sugar-acid ratio increased significantly by 29.36%, and flavonoids , organic acid and soluble pectin contents all significantly decreased, and the nitrate nitrogen content significantly decreased by 47.41%; under 0.25Ca and 0.5Ca treatments, the soluble solids, lycopene and soluble sugar contents of the fruit all significantly increased, and the sugar-acid ratio respectively It increased significantly by 53.65% and 72.94%, and the total phenolic, free amino acid, organic acid and soluble pectin contents all decreased significantly. Among them, the nitrate nitrogen content significantly decreased by 43.22% under the 0.5Ca treatment; the fruit soluble protein and soluble pectin under the 1.0Ca treatment. The sugar-acid ratio increased significantly by 22.48% and 61.96% respectively, the contents of vitamin C, total phenols, flavonoids and free amino acids all decreased significantly, and the nitrate nitrogen and organic acid contents decreased significantly by 43.99% and 33.66% respectively; 0.25Ca, 0.5 Under the treatments of Ca and 1.0Ca combined with zinc, the soluble solids, lycopene, vitamin C, soluble protein, soluble sugar content and sugar-to-acid ratio of fruits all increased significantly, and nitrate nitrogen, free amino acids, organic acids and soluble pectin increased significantly. The contents decreased significantly; among them, under the 0.5Ca+Zn treatment, fruit lycopene, soluble protein, soluble sugar content and sugar-acid ratio significantly increased by 33.35%, 23.33%, 21.27% and 64.91% respectively, and nitrate nitrogen and organic acids increased significantly. The content dropped significantly by 55.67% and 22.52% respectively.

Effects of calcium and zinc combined fertilization on tomato fruit antioxidant enzymes:

It can be seen from Table 4 that compared with CK, the SOD, POD and CAT enzyme activities of tomato fruits under Zn treatment were significantly increased by 0.59 times, 0.40 times and 6.28 times respectively; under 0.25Ca treatment, the POD of the fruit was significantly increased, and the CAT enzyme activity was significantly increased. Increased 3.91 times; SOD and CAT enzyme activities significantly increased 0.16 times and 4.22 times respectively under 0.5Ca treatment; SOD and CAT enzyme activities significantly increased 0.35 times and 4.78 times respectively under 1.0Ca treatment; 0.25Ca, 0.5Ca , 1.0Ca treatment and zinc combined application significantly increased the CAT activity of the fruit by 4.44 times, 3.77 times and 5.93 times respectively, among which the SOD activities under the 0.5Ca+Zn and 1.0Ca+Zn treatments significantly increased by 47.93% and 26.49% respectively. .

Table 4. Effects of different treatments on antioxidant enzyme activity of tomato fruits

Table4.Effeets of different treatments on antioxidant enzyme activities in tomato fruits

Effects of calcium and zinc combined fertilization on tomato element content:

Effects of calcium and zinc combined fertilization on potassium, sodium, magnesium, zinc and phytic acid contents in tomato fruits:

Compared with CK, the phytic acid content of fruits under Zn treatment significantly decreased by 34.41%; the phytic acid content of fruits under 0.25Ca, 0.5Ca and 1.0Ca treatments significantly decreased by 61.49%, 47.88% and 50.96% respectively. Among them, the phytic acid content under 1.0Ca treatment decreased significantly. The content decreased significantly; the phytic acid content of fruits under the 0.25Ca, 0.5Ca and 1.0Ca treatments and zinc application significantly decreased by 1.30 times, 0.89 times and 0.33 times respectively, among which the Zn content under the 0.25Ca+Zn and 0.5Ca+Zn treatments was the same. It increased significantly, and the K content under 0.5Ca+Zn treatment and the Na content under 1.0Ca+Zn treatment both decreased significantly.

Table 5. Effects of different treatments on elemental content of tomato fruits

Table5.Effects of different treatments on element content in tomatofruits

Effects of calcium and zinc combined application on calcium component content of tomato fruits:

As shown in the figure, compared with CK, the soluble calcium content of fruits under Zn treatment significantly increased by 33.05%; the Ca element, soluble calcium and calcium phosphate contents of fruits under 0.5Ca treatment significantly increased by 188.24%, 23.05% and 83.80% respectively. ; Under the 1.0Ca treatment, the fruit calcium phosphate content significantly increased by 54.86%; under the 0.25Ca, 0.5Ca and 1.0Ca treatments and zinc combined application, the calcium phosphate content significantly increased by 69.51%, 73.96% and 47.33%, respectively, of which 0.25Ca+ The soluble calcium content increased significantly under Zn and 1.0Ca+Zn treatments.

Table 6. Effects of different treatments on soluble calcium and calcium phosphate content in tomato fruits

Table6.Effects of different treatments on the contents of solublecalcium and calcium phosphate in tomato fruits

Effects of calcium and zinc combined fertilization on tomato fruit sugar content and related enzyme activities:

Effects of calcium and zinc combined application on sucrose and reducing sugar content in tomato fruits:

Compared with CK, the reducing sugar and sucrose contents of fruits increased significantly under Zn treatment; the reducing sugar contents increased significantly by 23.80% and 20.39% under 0.25Ca and 0.5Ca treatments, respectively. The reducing sugar content of fruits increased significantly under the combination of zinc and calcium at different concentrations. The reducing sugar content of 0.25Ca+Zn, 0.5Ca+Zn and 1.0Ca+Zn significantly increased by 12.58%, 19.55% and 16.72% respectively. The sucrose content increased significantly. There were no significant differences in the content changes. Effects of calcium and zinc combined fertilization on the activity of sucrose metabolic enzymes in tomato fruits.

Compared with CK, the AI and NI activities of tomato fruits under Zn treatment were significantly increased, and the SS activity was significantly decreased by 25.77%; under 0.25Ca treatment, the AI activity was significantly increased by 20.51%, and the SS activity was significantly decreased by 48.09%; under 0.5Ca treatment Under 1.0Ca treatment, AI activity significantly increased, SPS activity increased significantly by 1.11 times, and SS activity decreased significantly; AI, NI and SPS activities increased significantly by 0.36 times, 0.51 times and 1.19 times respectively under 1.0Ca treatment; zinc was combined with different concentrations of calcium The AI activity increased significantly under the application of 0.25Ca+Zn. The SS activity significantly decreased by 51.77% under the 0.25Ca+Zn treatment. The NI and SPS activities significantly increased by 0.25 times and 1.52 times respectively under the 0.5Ca+Zn treatment, while the SS activity decreased significantly. , SPS activity significantly increased by 1.06 times under 1.0Ca+Zn treatment. Effects of calcium and zinc combined application on the amino acid composition of tomato fruits:

Effects of calcium and zinc combined fertilization on the total amino acid content of tomato fruits:

As can be seen from Table 6, a total of 15 amino acids were identified in tomato fruits, including 5 essential amino acids (EAA): valine, isoleucine, leucine, phenylalanine, and lysine; 8 essential amino acids (NEAA): histidine, arginine, aspartic acid, glutamic acid, alanine, tyrosine, glycine, serine; 2 essential amino acids (CEAA) for children: histidine, Arginine. Compared with CK, isoleucine, leucine, phenylalanine, histidine, arginine, glutamic acid, tyrosine and glycine were significantly increased in tomato fruits under Zn treatment; under 0.25Ca treatment The contents of five essential amino acids, serine and glycine, all increased significantly under 0.5Ca treatment. The contents of serine, glycine, alanine, valine, leucine and isoleucine all increased significantly under 0.5Ca treatment; under 1.0Ca treatment, various The amino acid contents all decreased to varying degrees; the amino acid contents measured under the 0.25Ca+Zn treatment all decreased to varying degrees; the contents of essential amino acids except lysine for the human body increased significantly under the 0.5Ca+Zn treatment. The content of aspartic acid in essential amino acids decreased significantly, and the contents of serine, alanine and glycine increased significantly; under 1.0Ca+Zn treatment, the five essential amino acids for human body, aspartic acid, serine, glutamic acid, alanine, Both lysine and proline contents decreased significantly.

Table 7. Effects of different treatments on different amino acid contents of tomato fruits

Table7.Effects of different treatments on different amino acidcontents in tomato fruits

Effects of calcium and zinc combined fertilization on the content and proportion of amino acids required by different human bodies in tomatoes:

Compared with CK, the contents of essential amino acids, non-essential amino acids and children's essential amino acids in fruits increased significantly under Zn treatment, while the ratios of various amino acid contents to the total decreased significantly; under 0.25Ca treatment, the contents of essential amino acids, non-essential amino acids and essential amino acids for children increased significantly. The content and ratio of non-essential amino acids to the total amount increased significantly, and the content and ratio of essential amino acids to the total amount in children significantly decreased; under 0.5Ca treatment, the content of essential amino acids, non-essential amino acids, and essential amino acids for children accounted for The ratios of the total amounts all decreased significantly; under the 1.0Ca treatment, the contents of essential amino acids, non-essential amino acids for the human body and children's essential amino acids and their ratios to the total amount all decreased significantly; under the 0.25Ca+Zn treatment, the essential amino acids for the human body and the essential amino acids for children The content and the ratio of the total amount decreased significantly; under the 0.5Ca+Zn treatment, the content of essential amino acids and the ratio of the total amount increased significantly. The content of non-essential amino acids for the human body and the essential amino acids for children and the proportion of the total The ratios all decreased significantly; under the 1.0Ca+Zn treatment, the contents of essential amino acids for humans, non-essential amino acids for humans and essential amino acids for children, as well as their ratio to the total amount, all decreased significantly.

Table 8. Effects of different treatments on the content and proportion of various amino acids in tomato fruits

Table8.Effects of different treatments on contents and proportions ofvarious amino acids in tomato fruits

Effects of calcium and zinc combined fertilization on the content and proportion of tomato flavor amino acids:

Compared with CK, the ratio of sweet amino acids to the total amount of fruits under Zn treatment significantly decreased, and the content of umami amino acids and aromatic amino acids and the ratio to the total amount increased significantly; the content of sweet amino acids under 0.25Ca treatment The ratio of umami amino acids to the total amount increased significantly by 47.12% and 48.72% respectively, the ratio of umami amino acids to the total amount significantly decreased, and the content of aromatic amino acids and the ratio of the total amount to total amount increased significantly; under 0.5Ca treatment The content of sweet amino acids in the fruit and its ratio to the total amount increased significantly by 26.04% and 19.19% respectively, and the ratio of the total amount of umami amino acids decreased significantly. The content and ratio of sweet amino acids and aromatic amino acids in the fruit under the 1.0Ca treatment The ratio of the total amount decreased significantly, and the content of umami amino acids decreased significantly. Under the 0.25Ca+Zn treatment, the content of sweet amino acids and the ratio of the total amount both decreased significantly, and the ratio of umami and aromatic amino acids to the total amount decreased significantly. were significantly increased; under the 0.5Ca+Zn treatment, the content and the ratio of the total amount of sweet and aromatic amino acids were significantly increased, and the ratio of the total amount of umami amino acids was significantly decreased; under the 1.0Ca+Zn treatment, the sweetness The ratio of aromatic amino acids and aromatic amino acids to the total amount was significantly increased, and the content of umami amino acids and the ratio to the total amount were significantly decreased.

Table 9. Effects of different treatments on the content and proportion of flavor amino acids in tomato fruits

Table9.Effects of different treatments on the content and proportion of amino acids in tomato fruit flavor

Effects of Calcium and Zinc Fertilization on the Content of Tomato Flavor Substances:

As shown in Table 10, a total of 44 tomato flavor substances were measured in the test, mainly including volatile substances such as aldehydes, alcohols, ketones, hydrocarbons and esters.

The main components of aldehydes are hexanal, trans-2-hexenal, trans-2-zincenal and 2-heptenal, among which the contents of hexanal and trans-2-hexenal are significantly higher than Other aldehydes. Compared with CK, the contents of hexanal and trans-2-hexenal in fruits were significantly increased by 1.05 times and 2.05 times respectively under Zn treatment; they were significantly increased by 1.19 times and 1.65 times respectively under 0.25Ca treatment; and they were significantly increased respectively under 0.5Ca treatment. Increased by 73.35% and 66.26%; significantly increased by 68.40% and 90.32% respectively under 1.0Ca treatment; significantly increased hexanal and trans-2-hexenal contents by 22.42% and 35.89% respectively under 0.25Ca+Zn treatment ; Under the treatment of 0.5Ca+Zn, they increased significantly by 23.30% and 46.91% respectively; under the treatment of 1.0Ca+Zn, they increased significantly by 40.39% and 74.92%, respectively.

Four types of alcohols were detected, namely trans-2-pentenol, linalool, phenylethyl alcohol and 1-nonanol. Among them, phenylethyl alcohol was only detected in Zn treatment, and 1-nonanol was only detected in 0.5Ca and detected under 1.0Ca treatment. Compared with CK treatment, trans-2-pentenol and linalool increased significantly by 2.12 times and 2.09 times respectively under Zn treatment; significantly increased by 1.54 times and 2.76 times under 0.25Ca treatment; and significantly increased respectively under 0.5Ca treatment. 1.07 times and 50.86% higher; significantly increased by 1.08 times and 1.22 times respectively under 1.0Ca treatment; trans-2-pentenol content increased significantly by 42.71% under 0.25Ca+Zn treatment; trans-2-pentenol content under 0.5Ca+Zn treatment The contents of -2-pentenol and linalool increased significantly by 78.39% and 51.43% respectively; the contents of trans-2-pentenol and linalool increased significantly by 1.00 times and 1.10 times respectively under 1.0Ca+Zn treatment.

Five types of ketones were detected, namely 1-penten-3-one, 1-octen-3-one, geranylacetone, methylheptenone and damascenone, while methylheptenone Appears only under Zn treatment. Compared with CK, the 1-penten-3-one content increased significantly by 1.90 times under Zn treatment; significantly increased by 72.00%, 69.89% and 89.73% under 0.25Ca, 0.5Ca and 1.0Ca treatments; 0.5Ca+Zn and Under 1.0Ca+Zn treatment, the 1-penten-3-one content increased significantly by 57.98% and 57.50% respectively.

The content of each substance in hydrocarbons and esters is very low, and the content of valeric acid in other categories is relatively high. Compared with CK, the valeric acid content significantly decreased by 2.42 times under Zn treatment; significantly increased by 1.23 times, 1.01 times and 1.26 times under 0.25Ca, 0.5Ca and 1.0Ca treatments respectively; 0.25Ca, 0.5Ca and 1.0Ca were combined with zinc. The valeric acid content increased significantly by 26.71%, 57.38% and 86.54% respectively.

Table 10. Effects of different treatments on tomato fruit flavor compounds

Table10.Effects of different treatments on tomato fruit flavors

Continue the above table

Comprehensive evaluation of the effects of calcium and zinc combined application on tomato fruit quality:

Principal component analysis of main quality traits:

Table 10 shows a principal component analysis of 23 indicators such as tomato single fruit weight, multiple fruit quality indicators, mineral elements and amino acid components. Among them, organic acid, phytic acid and nitrate nitrogen content are inversely proportional to fruit quality. The indicators are reciprocated. It can be divided into 5 principal components according to the contribution rate. The contribution rate of main component 1 is 33.03%, mainly aromatic amino acids, total amino acid content and total phenolic content. The contribution rate of main component 2 is 25.90%, mainly lycopene, nitrate nitrogen (reciprocal), soluble sugar, soluble protein and vitamin C content. The contribution rate of main component 3 is 14.46%, mainly the proportion of essential amino acids for human body and the content of umami amino acids. The contribution rate of principal component 4 is 10.72%, mainly based on single fruit weight and Ca content. The contribution rate of main component 5 is 6.89%, mainly soluble protein content. The cumulative contribution rate of the five principal components is 91.10%, which can effectively reflect the influence of the above 23 indicators in the formation of fruit quality.

According to the comprehensive scores in Table 11, compared with CK, the comprehensive scores of the Zn, 0.25Ca and 0.5Ca treatments were significantly higher, but the scores of the 1.0Ca treatment showed a downward trend. At the same time, the comprehensive scores of 0.25Ca+Zn and 0.5Ca+Zn were further increased compared with those treated with Zn or Ca alone. According to the comprehensive score, the ranking order of each treatment is as follows: 0.5Ca+Zn>0.25Ca+Zn>Zn>0.5Ca>0.25Ca>1.0Ca+Zn>CK>1.0Ca.

Table 11. Eigenvectors, eigenroots, variance contribution rates and cumulative contribution rates of the five principal components

Table 11.The characteristic vectors, characteristic roots, variancecontribution rate and cumulative contribution rate of the five principalcomponents were analyzed

Table 12 Principal component scores and comprehensive scores

Table12.principal component score and comprehensive score

Correlation analysis between fruit calcium and zinc content and main quality traits:

In Table 12, the fruit Zn content showed a significant positive correlation with the soluble solids, lycopene and vitamin C content; the Ca content showed a significant positive correlation with the soluble sugar. Soluble solids showed a significant positive correlation with lycopene and vitamin C. There is a significant positive correlation between lycopene and vitamin C. Free amino acids showed significant and extremely significant positive correlations with total phenols and organic acids respectively. Soluble protein and nitrate nitrogen showed a significant negative correlation. Total phenols showed significant and extremely significant positive correlations with organic acids and flavonoids respectively.

Table 13. Correlation between tomato fruit Zn and Ca content and fruit quality

Tablel3.Correlation between Zn, Ca content and fruit quality of Tomato

Through the above experiments, the following conclusions are drawn:

1. The plant height, stem diameter, node spacing and number of fruits per panicle of tomato plants significantly increased by 26.84%, 11.33%, 40.93% and 32.26% respectively under zinc fertilizer application. Foliar spraying of calcium chloride at low, medium and high concentrations (0.25%, 0.5%, 1.0%) has a significant promoting effect on the physiological characteristics of tomatoes. The 0.5% calcium chloride spraying treatment has the most significant promotion effect. Compared with In the blank control, plant height, node spacing and number of fruits per panicle increased significantly by 28.62%, 31.22% and 25.81% respectively. Compared with pure zinc or calcium treatment, there was no further increase trend in tomato plant height, stem diameter, node spacing and number of fruits per panicle under different concentrations of calcium and zinc combined.

2. Zinc fertilizer-based fertilization can significantly promote the accumulation of chlorophyll in tomato leaves and enhance photosynthesis. The net photosynthetic rate, stomatal conductance and transpiration rate significantly increased by 0.40 times, 1.14 times and 1.19 times respectively. Foliar spraying of calcium chloride at different concentrations effectively increased the content of various chlorophylls and photosynthesis; the treatment with 0.5% calcium chloride had the best effect. Compared with the blank control, the contents of chlorophyll a, chlorophyll b and carotenoids increased significantly. 54.28%, 45.89% and 50.73% higher, and the net photosynthetic rate, stomatal conductance and transpiration rate increased significantly by 0.49 times, 3.31 times and 2.87 times respectively. The combined application of 0.5% calcium and zinc fertilizer can further promote the photosynthesis of tomatoes. Compared with the blank control, the net photosynthetic rate, stomatal conductance and transpiration rate were significantly increased by 0.93 times, 7.03 times and 5.43 times respectively.

3. Zinc fertilizer basal application or calcium chloride spraying increased the biomass of fruits, promoted the accumulation of soluble solids, lycopene, free amino acids, soluble sugars, etc., while effectively inhibiting organic acids and nitrate nitrogen. content increased. Appropriate concentrations of calcium and zinc can further promote the accumulation of lycopene, vitamin C, soluble protein and soluble sugar content in fruits. Zinc treatment did not increase the content of Ca, Mg, K, Na and Zn elements in the fruit; while low and medium concentration calcium treatments could effectively promote the accumulation of Ca and Zn elements in the fruit; the Ca and Zn elements of the fruit further increased under the combination of appropriate concentrations of calcium and zinc. high. At the same time, both zinc and calcium treatments can inhibit the accumulation of phytic acid in fruits and increase the effective zinc and calcium contents in fruits.

4. Basal application of zinc fertilizer significantly increased fruit SOD, POD and CAT activities by 59.39%, 40.14% and 6.27 times respectively. Foliar spraying of calcium chloride increased the activity of antioxidant enzymes to varying degrees; the 1.0% concentration of calcium chloride treatment had the best effect. Compared with the blank control, its SOD and CAT activities were significantly increased by 34.60% and 4.78 times respectively. . At the same time, the activity of some antioxidant enzymes and the content of antioxidant substances (vitamin C) in the fruits further increased after the application of appropriate concentrations of calcium and zinc.

5. Basic application of zinc fertilizer significantly increased the reducing sugar and sucrose content of the fruit, and promoted the significant increase in the activities of acid invertase and neutral invertase. Foliar spraying of calcium chloride increased reducing sugar content and acid invertase activity to varying degrees, and inhibited sucrose synthase activity. The combination of low and medium concentrations of calcium and zinc can further promote sucrose accumulation and increase the activities of acid invertase, neutral invertase and sucrose phosphate synthase.

6. Basic application of zinc fertilizer can significantly increase the content of various amino acids in tomato fruits, among which the contents of essential amino acids for humans, essential amino acids for children, sweet amino acids and aromatic amino acids are all significantly increased. Low and medium concentration calcium spraying promoted the increase in the contents of various amino acids to varying degrees, and the contents of many types of amino acids increased significantly. However, the contents of various amino acids showed a significant downward trend under high concentration calcium treatment. Compared with pure zinc or calcium treatment, the combination of calcium and zinc at different concentrations did not further promote the increase in amino acid content, but effectively regulated the ratio of various amino acids to the total amount.

7. Zinc fertilizer base application promotes the significant increase of various volatile flavor substances such as aldehydes, esters, ketones, alcohols and hydrocarbons in the fruit, among which hexanal, trans-2-vinyl aldehyde, trans-2 -The contents of major flavor substances such as pentenol and linalool increased significantly by 1.05 times, 2.05 times, 2.12 times and 2.09 times respectively. Foliar spraying of calcium chloride also promoted the increase in the content of various volatile flavor substances in the fruit to varying degrees, but the increasing trend of the content of various flavor substances significantly decreased under the combined application of calcium and zinc at different concentrations.

8. Through the correlation analysis of 23 quality indicators such as fruit weight, soluble solids, lycopene content and amino acid components, the comprehensive score of fruit quality for each treatment was calculated. The ranking is as follows: 0.5Ca+Zn>0.25 Ca+Zn>Zn>0.5Ca>0.25Ca>1.0Ca+Zn>CK>1.0Ca.

It is obvious to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be regarded as illustrative and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is therefore intended that all claims falling within the claims All changes within the meaning and scope of equivalent elements are included in the present invention. Any reference signs in the claims shall not be construed as limiting the claim in question.

Claims (1)

1. A planting method based on the application of calcium and zinc to promote tomato growth and fruit quality, which is characterized by including the following steps: S1. Medium preparation: Before planting tomato seedlings, the coconut bran bricks are fully soaked in distilled water, fully disinfected using sunlight, dried and mixed with zinc fertilizer, and then put into the prepared nutrient bowl for later use; The coconut bran bricks are Petermann coconut bricks, the unit weight is 5-5.5kg/block, the EC value is ≤0.6MS/CM, the pH value is between 5.5-6.8, the fiber is ≤2%, and the zinc fertilizer content in the coconut bran bricks is is 0.1g/L; S2. Cultivation of tomato seedlings: Tomato seeds are sown in plug trays after germination and whitening. When the tomato seedlings grow to have three leaves and one center, they are planted in a nutrient pot for matrix cultivation. The tomato variety is "Zheyingfen No. 1"; S3. Fertilization: When the tomatoes enter the first flowering and first fruiting stage, spray fertilizer on the 1-2 fully expanded functional leaves from the lower growth point of the tomato plant. Spray CaCl ₂ aqueous solution once a week for three consecutive weeks. Spraying method Spray evenly on the front and back of the leaves. After spraying, the leaves should be covered with water droplets and not dripping. The volume concentration of the CaCl ₂ aqueous solution is 0.25%-1.0%; S4: After planting, irrigate with Hoagland nutrient solution every 1-2 days, 500ml per plant at a time. The Hoagland nutrient solution is diluted with water to a volume concentration of 50%; S5: When the tomatoes grow to the fruit expansion stage, irrigate with Hoagland's nutrient solution every 1-2 days, 1000ml per plant at a time. The Hoagland's nutrient solution is diluted to 50% volume concentration with water.