Exercise planting method for improving salt tolerance of wheat in seedling stage

Abstract

The invention belongs to the technical field of wheat planting, and particularly relates to an exercise planting method for improving the salt tolerance of wheat in the seedling stage, which comprises the following steps: S1, planting first-generation wheat seeds in soil, performing water treatment in the planting period into dry farming and rain culture treatment, harvesting second-generation wheat seeds after the wheat seeds are mature, and setting the first-generation wheat seeds in groups; s2, putting the second-generation wheat seeds into a culture dish, culturing by using a NaCl solution, observing the germination rate and the fresh bud weight or the dry bud weight in the bud stage, and screening the seeds with the emergence rate of more than or equal to 90% and the fresh bud weight or the dry bud weight ranked in the first 30% of the group in the same group. According to the method, the wheat grows in the drought and saline-alkali environment, the salt tolerance of the next generation of wheat is improved through trans-generation stress exercise, meanwhile, the memory ability of seeds is improved through contemporary initiation treatment, and the drought and saline-alkali trans-generation stress exercise is matched with the contemporary initiation treatment to generate a synergistic effect, so that the salt tolerance of the wheat is further improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of wheat cultivation, and particularly relates to a training cultivation method for improving the salt tolerance of wheat seedlings. Background Art

[0002] Saline-alkali land is an important reserve cultivated land resource in China. The national saline-alkali land area is about 1.5 billion mu, of which 500 million mu has the potential for development and utilization. Due to population growth and the shortage of cultivated land resources, the improvement and utilization of saline-alkali land have become the key to ensuring food security. For example, through soil improvement in Dongying, Shandong, the wheat yield per mu has increased from 265.48 kg to 444.97 kg; through the selection of salt-tolerant varieties of dryland saline-alkali wheat in Huanghua, Hebei, the yield per mu reaches 250 kg, significantly improving the productivity of saline-alkali land. In addition, the wheat grown on saline-alkali land can form quality advantages such as a strong wheat fragrance due to its unique metabolic stress response, and has market differentiation value.

[0003] However, there is less rainfall during the wheat growing season, and the fresh water irrigation conditions in saline-alkali land are limited. Under drought and saline-alkali stress, the growth of wheat in saline-alkali land is greatly restricted. Especially, the drought and salt tolerance of wheat seedlings are weak, and it is easy to have the situation of seedling breakage and death, which seriously restricts the improvement of wheat production capacity. Therefore, how to improve the salt tolerance of wheat seedlings is of great significance for increasing the wheat yield in saline-alkali land. The traditional methods for improving the salt tolerance of crops mainly have two categories: one is to select salt-tolerant varieties; the other is to improve saline-alkali soil. Although both methods can improve the salt tolerance of wheat, these methods have a long cycle, high cost and low universality, and are difficult to be popularized and applied in a short time. Therefore, there is an urgent need to develop a new type of method for improving the salt tolerance of crop seedlings that is easy to operate, can be promoted and has quick results. Summary of the Invention

[0004] In order to solve the problems existing in the above-mentioned prior art, the present invention provides a training cultivation method for improving the salt tolerance of wheat seedlings, which improves the resistance of wheat to saline-alkali environment through cross-generation training plus contemporary induction. The first-generation salt-tolerant wheat or drought-resistant wheat is planted in the soil, and during this period, it is managed in a dry farming and rain-fed mode without additional water irrigation, so that the wheat grows in saline-alkali, drought and only drought environments, and the salt tolerance of the next generation of wheat is improved through stress training.

[0005] The specific technical solution adopted by the present invention is as follows:

[0006] A training cultivation method for improving the salt tolerance of wheat seedlings, comprising the following steps:

[0007] S1. Plant the first-generation wheat seeds in the soil, and the water treatment during the planting period is dry farming and rain-fed treatment. After maturity, harvest the second-generation wheat seeds. The first-generation wheat seeds are set in groups;

[0008] S2. Place the second-generation wheat seeds in a petri dish and culture them using an NaCl solution with a salt concentration of 3 - 5 g / L. Observe the germination rate, fresh weight of buds, or dry weight of buds at the germination stage, and screen the seeds with a seedling emergence rate ≥ 90% in the same group and a numerical ranking of fresh weight of buds or dry weight of buds in the top 30% of the group. These seeds are the highly salt-tolerant wheat seeds.

[0009] The first-generation wheat seeds are drought-resistant wheat seeds.

[0010] In step S1, the salt content of the soil is 2.5 - 3.5 g / kg, and the first-generation wheat seeds are salt-tolerant wheat seeds.

[0011] In step S2, the second-generation wheat seeds are placed in a petri dish after being primed. The priming treatment specifically includes the following steps:

[0012] A. Soak the seeds in 65 - 75% alcohol for 20 - 40 s, then disinfect them with 20% sodium hypochlorite solution, and then wash them with sterile water and air-dry for later use;

[0013] B. Soak the air-dried seeds in the priming agent for 10 - 16 h, and then air-dry the soaked seeds to restore the water content of the seeds to the state before soaking, thus completing the priming treatment.

[0014] The priming agent is a PEG - 6000 solution with a mass ratio of 18 - 22% or a CaCl2 solution with a concentration of 40 - 60 mmol / L.

[0015] The mass ratio of the seeds to the priming agent is 1:4 - 6.

[0016] The beneficial effects of the present invention are as follows:

[0017] 1. The present invention improves the resistance of wheat to subsequent saline-alkali environments through cross-generation stress exercise. The previous generation of wheat is planted in saline-alkali soil and managed using a dry farming and rain-fed mode during the period, so that the wheat grows in a drought and saline-alkali environment, and the salt tolerance of the next generation of wheat is improved through stress exercise; at the same time, through priming treatment, the memory ability of the seeds is improved, and their salt tolerance is further enhanced.

[0018] 2. It can be seen from the variety screening test in the present invention that the salt tolerance of salt-tolerant winter wheat varieties is always higher than that of drought-resistant winter wheat varieties. Among the salt-tolerant winter wheat varieties, Jiemai 19 has relatively high salt tolerance, and among the drought-resistant winter wheat varieties, Jimai 22 has relatively high salt tolerance.

[0019] 3. In the present invention, through the cross-generation adversity exercise test, it can be seen that the germination rate and dry weight of buds of winter wheat varieties subjected to cross-generation drought exercise are significantly higher than those of winter wheat varieties treated with normal irrigation, indicating that cross-generation drought exercise can improve the salt tolerance of winter wheat, and simultaneously conducting cross-generation drought and saline-alkali exercise can better improve the salt tolerance of winter wheat.

[0020] 4. In the present invention, by priming the wheat seeds subjected to cross-generation adversity exercise, the salt tolerance of wheat can be further improved, and the salt tolerance of salt-tolerant wheat varieties subjected to cross-generation drought and saline-alkali exercise and priming treatment is the strongest.

[0021] 5. The wheat seeds obtained by the method in the present invention have higher yields under the same sowing rate and water application amount. When the water application amount is reduced, compared with the first-generation wheat seeds, the yield remains unchanged, and it is more suitable for planting in arid saline-alkali areas.

[0022] Description of the Drawings

[0023] Figure 1 It is a bar chart showing the effect of different salt concentrations on the germination rate of salt-tolerant winter wheat varieties;

[0024] Figure 2 It is a bar chart showing the effect of different salt concentrations on the dry weight of buds of salt-tolerant winter wheat varieties;

[0025] Figure 3 It is a photo showing the effect of different salt concentrations on the growth of salt-tolerant winter wheat varieties at the bud stage;

[0026] Figure 4 It is a bar chart showing the germination rate of different salt-tolerant winter wheat varieties under the same salt concentration condition;

[0027] Figure 5 It is a bar chart showing the dry weight of buds of different salt-tolerant winter wheat varieties under the same salt concentration condition;

[0028] Figure 6 It is a bar chart showing the effect of different salt concentrations on the germination rate of drought-resistant winter wheat varieties;

[0029] Figure 7 It is a photo showing the effect of different salt concentrations on the germination rate of drought-resistant winter wheat varieties;

[0030] Figure 8 It is a bar chart showing the effect of different salt concentrations on the dry weight of buds of drought-resistant winter wheat varieties;

[0031] Figure 9 It is a photo showing the effect of different salt concentrations on the growth of drought-resistant winter wheat varieties at the bud stage;

[0032] Figure 10 It is a bar chart showing the germination rate of different drought-resistant winter wheat varieties under the same salt concentration condition;

[0033] Figure 11 Bar graph of the dry shoot weight of different drought-resistant winter wheat varieties under the same salt concentration condition;

[0034] Figure 12 Germination rate of winter wheat seeds harvested from transgenerational drought hardening and normal irrigation treatment in 0 g / L saline solution;

[0035] Figure 13 Germination rate of winter wheat seeds harvested from transgenerational drought hardening and normal irrigation treatment in 3 g / L saline solution;

[0036] Figure 14 Germination rate of winter wheat seeds harvested from transgenerational drought hardening and normal irrigation treatment in 5 g / L saline solution;

[0037] Figure 15 Dry shoot weight of winter wheat seeds harvested from transgenerational drought hardening and normal irrigation treatment in 0 g / L saline solution;

[0038] Figure 16 Dry shoot weight of winter wheat seeds harvested from transgenerational drought hardening and normal irrigation treatment in 3 g / L saline solution;

[0039] Figure 17 Dry shoot weight of winter wheat seeds harvested from transgenerational drought hardening and normal irrigation treatment in 5 g / L saline solution;

[0040] Figure 18 Germination rate of winter wheat seeds with transgenerational saline-alkali and drought hardening and without transgenerational saline-alkali and drought hardening in 0 g / L saline solution;

[0041] Figure 19 Germination rate of winter wheat seeds with transgenerational saline-alkali and drought hardening and without transgenerational saline-alkali and drought hardening in 3 g / L saline solution;

[0042] Figure 20 Germination rate of winter wheat seeds with transgenerational saline-alkali and drought hardening and without transgenerational saline-alkali and drought hardening in 5 g / L saline solution;

[0043] Figure 21 Fresh shoot weight of winter wheat seeds with transgenerational saline-alkali and drought hardening and without transgenerational saline-alkali and drought hardening in 0 g / L saline solution;

[0044] Figure 22 Fresh shoot weight of winter wheat seeds with transgenerational saline-alkali and drought hardening and without transgenerational saline-alkali and drought hardening in 3 g / L saline solution;

[0045] Figure 23 Fresh shoot weight of winter wheat seeds with transgenerational saline-alkali and drought hardening and without transgenerational saline-alkali and drought hardening in 5 g / L saline solution;

[0046] Figure 24 Photographs of the effects of different salt concentrations on the growth of winter wheat seeds at the germination stage with and without transgenerational saline-alkali and drought priming;

[0047] Figure 25 Bar graph of the effect of CaCl2 solution priming on the germination rate of winter wheat seeds with transgenerational stress priming under different salt concentrations;

[0048] Figure 26 Bar graph of the effect of CaCl2 solution priming on the fresh weight of buds of winter wheat seeds with transgenerational stress priming under different salt concentrations;

[0049] Figure 27 Photographs of the effects of CaCl2 solution priming on the germination rate and fresh weight of buds of winter wheat seeds with transgenerational stress priming under different salt concentrations;

[0050] Figure 28 Bar graph of the effect of different transgenerational stress priming and contemporary CaCl2 solution priming on the germination rate of winter wheat seeds under the same salt concentration;

[0051] Figure 29 Bar graph of the effect of different transgenerational stress priming and contemporary CaCl2 solution priming on the fresh weight of buds of winter wheat seeds under the same salt concentration;

[0052] Figure 30 Bar graph of the difference in germination rate between different transgenerational stress priming and contemporary priming of two winter wheat varieties under different salt concentrations;

[0053] Figure 31 Bar graph of the difference in fresh weight of buds between different transgenerational stress priming and contemporary priming of two winter wheat varieties under different salt concentrations;

[0054] Figure 32 Photographs of the differences in germination rate and fresh weight of buds between different transgenerational stress priming and contemporary priming of two winter wheat varieties under different salt concentrations;

[0055] Figure 33 Bar graph of the germination potential on the 6th day after sowing contemporary seeds primed with PEG-6000. Detailed implementation manner

[0056] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. I. Specific embodiments

[0058] A method for exercising and planting to improve the salt tolerance of wheat seedlings at the seedling stage includes the following steps:

[0059] S1. Plant the first-generation wheat seeds in the soil. During the planting period, the water treatment is dry farming with rainfed conditions. After maturity, harvest the second-generation wheat seeds. The first-generation wheat seeds are set in groups.

[0060] S2. Place the second-generation wheat seeds in a petri dish and culture them using an NaCl solution with a salt concentration of 3 - 5 g / L. Observe the germination rate, bud fresh weight, or bud dry weight at the germination stage. Screen the seeds with a germination rate ≥ 90% in the same group and a numerical ranking of bud fresh weight or bud dry weight in the top 30% of the group. These seeds are the highly salt-tolerant wheat seeds.

[0061] There are mainly two types of traditional methods to improve the salt tolerance of crops: one is to select salt-tolerant varieties; the other is to improve saline-alkali soil. Although both methods can improve the salt tolerance of wheat, these methods have a long cycle, high cost, and low universality, and are difficult to be popularized and applied in a short time.

[0062] In the present invention, the resistance of wheat to subsequent saline-alkali environments is improved by cross-generation stress exercise and contemporary seed priming. Plant the first-generation wheat, and during this period, manage it in a dry farming with rainfed mode without additional water irrigation. The wheat grows in a drought environment to improve the salt tolerance of the next generation of wheat.

[0063] The first-generation wheat seeds are drought-resistant wheat seeds. In order to ensure the survival of the first-generation wheat seeds under drought conditions, drought-resistant wheat seeds are required.

[0064] In step S1, the salt content of the soil is 2.5 - 3.5 g / kg, and the first-generation wheat seeds are salt-tolerant wheat seeds. Conducting cross-generation drought and saline-alkali stress exercises simultaneously can better improve the salt tolerance of winter wheat. In order to ensure the survival of the first-generation wheat seeds in saline-alkali land, salt-tolerant wheat seeds are required.

[0065] II. Salt-tolerant Variety Screening Test

[0066] 1. Prepare the test wheat seeds

[0067] Salt-tolerant winter wheat varieties subjected to cross-generation saline-alkali and drought stress: Jiemai 19, Jiemai 20, Cangmai 6002, Cangmai 6005, Xiaoyan 155, Xiangmai 517, Xiangmai 518, Xiangmai 519, Huaihan 115, Baimai;

[0068] Drought-resistant winter wheat varieties subjected to cross-generation drought stress: Heng 4399, Nongda 212, Xinmai 28, Shimai 15, Chang 8744, Shannong 28, Shimai 22, Jimai 418, Jimai 22, Zhongmai 36, Luohan 7;

[0069] 2. Test steps

[0070] (1) Take 50 seeds of each variety. Soak the seeds in 70% alcohol for 30 s, then disinfect them with 20% sodium hypochlorite solution for 20 min, and then wash them 3 - 4 times with sterile water and air dry for later use;

[0071] (2) Place the air - dried seeds in a petri dish. Put two layers of filter paper at the bottom of the petri dish with the seeds facing the same direction;

[0072] (3) Soak them in deionized water (0 g / L), 3 g / L NaCl solution, and 5 g / L NaCl solution respectively; then, according to the growth of the seeds, add a certain amount of solution every day to ensure normal germination of the seeds;

[0073] (4) Place all the treated seeds in an incubator for cultivation with 12 h of light and 12 h of darkness;

[0074] (5) Record the number of germinated seeds when the seeds start to germinate, investigate once a day until no new seeds germinate.

[0075] 3. Measurement indicators

[0076] (1) Record the germination rate three times for each group of experiments, that is, from the start of germination to complete germination;

[0077] (2) When harvesting each group of experiments, record the fresh weight and dry weight of the buds;

[0078] (3) Finally, use the final germination rate and dry weight of the buds as indicators to screen salt - tolerant varieties;

[0079] (4) Germination rate (Gr) = (the number of all normally germinated seeds at the end of germination) / (the number of tested seeds) × 100%.

[0080] 4. Experimental results

[0081] Figure 1 shows the effects of different salt concentrations on the germination rate of salt - tolerant winter wheat varieties (different letters in the figure indicate significant differences under different salts for the same variety). It can be seen that for winter wheat after cross - generation saline - alkali and drought hardening, the germination rate shows no obvious change with the increase in the salt concentration of the irrigation water.

[0082] Figures 2-3 shows the effects of different salt concentrations on the dry weight of buds of salt - tolerant winter wheat varieties (different letters in the figure indicate significant differences under different salts for the same variety). It can be seen that irrigation water with different salt concentrations has a significant effect on the dry weight of buds of winter wheat after cross - generation saline - alkali and drought hardening, and the dry weight of buds of winter wheat decreases significantly with the increase in the salt concentration of the irrigation water.

[0083] Figure 4Germination rates of different salt-tolerant winter wheat varieties under the same salt concentration conditions (different letters in the figure indicate significant differences among different varieties under the same salt condition). It can be seen that under the same salt condition, the differences among different varieties are not obvious, and almost all can reach over 97%. However, under the condition of 5 g / L, the germination rate of Jiemai 20 is significantly lower than that of other varieties, being 92.5%.

[0084] Figure 5 For the dry weight of buds of different salt-tolerant winter wheat varieties under the same salt concentration conditions (different letters in the figure indicate significant differences among different varieties under the same salt condition), the dry weight of buds of Jiemai 19 is the highest under different salt concentrations; while the dry weights of buds of Jiemai 20 and Baimai are significantly lower than those of other varieties.

[0085] In summary, the germination stage experiments of salt-tolerant winter wheat varieties show that Jiemai 19 has relatively high salt tolerance, followed by Xiangmai 519 and Cangmai 6002, while Jiemai 20 and Baimai have poor salt tolerance.

[0086] Figures 6-7 For the effects of different salt concentrations on the germination rates of drought-resistant winter wheat varieties (different letters in the figure indicate significant differences among different salts of the same variety), the germination rates of different drought-resistant wheat varieties show different trends with the increase in the salt concentration of irrigation water; among them, the germination rates of Jimai 418, Shimai 22, Xinmai 28, and Chang 8744 decrease significantly with the increase in salt concentration, while the changing trends of other varieties are not obvious.

[0087] Figures 8-9 For the effects of different salt concentrations on the dry weight of buds of drought-resistant winter wheat varieties (different letters in the figure indicate significant differences among different salts of the same variety), it can be seen that the dry weight of buds of winter wheat after cross-generation drought exercise decreases significantly with the increase in the salt concentration of irrigation water, and the decreasing amplitude is significantly greater than that of salt-tolerant winter wheat varieties after cross-generation saline-alkali and drought exercise.

[0088] Figure 10 For the germination rates of different drought-resistant winter wheat varieties under the same salt concentration conditions (different letters in the figure indicate significant differences among different varieties under the same salt condition), it can be seen that with the increase in salt concentration, the germination rates of Jimai 418 and Shimai 22 decrease significantly. Under the condition of 5 g / L, the germination rates of Heng 4399 and Shannong 28 are higher than those of other varieties, reaching over 95%; however, the overall germination rate of drought-resistant winter wheat varieties after cross-generation drought exercise is lower than that of salt-tolerant winter wheat varieties after saline-alkali and drought exercise.

[0089] Figure 11The dry weight of buds of different drought-resistant winter wheat varieties under the same salt concentration condition (different letters in the figure indicate significant differences among different varieties under the same salt condition). It can be seen that under different salt concentrations, the dry weight of buds of Jimai 22 reaches the highest, significantly higher than that of other varieties. Therefore, the bud stage test of drought-resistant winter wheat varieties shows that Jimai 22, which has undergone transgenerational drought hardening, has higher salt tolerance, followed by Shimai 15 and Chang 8744. In addition, the dry weight of buds of drought-resistant winter wheat varieties that have undergone transgenerational drought hardening is generally lower than that of salt-tolerant winter wheat varieties that have undergone transgenerational saline-alkali and drought hardening.

[0090] III. Transgenerational drought hardening test

[0091] 1. Prepare experimental wheat seeds

[0092] Drought-resistant winter wheat varieties that have undergone transgenerational drought hardening: Heng 4399, Nongda 212, Xinmai 28, Shimai 15, Chang 8744, Shannong 28, Shimai 22, Jimai 418, Jimai 22, Zhongmai 36, Luohan 7;

[0093] Drought-resistant winter wheat varieties under normal irrigation treatment: Heng 4399, Nongda 212, Xinmai 28, Shimai 15, Chang 8744, Shannong 28, Shimai 22, Jimai 418, Jimai 22, Zhongmai 36, Luohan 7;

[0094] 2. Experimental steps

[0095] (1) Take 50 seeds of each variety, soak the seeds in 70% alcohol for 30S, then disinfect them with 20% sodium hypochlorite solution for 20 min, and wash them 3 - 4 times with sterile water, and dry them for later use;

[0096] (2) Place the dried seeds in a petri dish, with two layers of filter paper placed at the bottom of the petri dish, and the seeds facing the same direction;

[0097] (3) Soak them in deionized water (0 g / L), 3 g / L NaCl solution and 5 g / L NaCl solution respectively; then add a certain amount of solution every day to ensure the normal germination of the seeds;

[0098] (4) Place all the seed treatments in an incubator for cultivation, with 12 h of light and dark treatment each;

[0099] (5) Record the number of germinated seeds when the seeds start to germinate, and investigate once a day until no new seeds germinate.

[0100] 3. Measurement indicators

[0101] (1) Record the germination rate three times for each group of experiments, that is, from the start of germination to complete germination;

[0102] (2) When harvesting each group of experiments, record the fresh weight and dry weight of the buds;

[0103] (3) Finally, the salt tolerance was compared with the final germination rate and dry weight of the buds of the seeds as indicators;

[0104] (4) Germination rate (Gr) = the number of all normally germinated seeds at the end of germination / the number of tested seeds × 100%.

[0105] 4. Test results

[0106] The drought-resistant winter wheat varieties treated with transgenerational drought exercise and normal irrigation were compared, and the comparison results are shown in Figures 12-17 (In the figure, different letters indicate significant differences between the same variety with or without transgenerational drought exercise), among which Figures 12-14 is the germination rate of winter wheat varieties treated with transgenerational drought exercise and normal irrigation under different salt concentrations, Figures 15-17 is the dry weight of the buds of winter wheat varieties treated with transgenerational drought exercise and normal irrigation under different salt concentrations. It can be seen that the germination rate and dry weight of the buds of winter wheat varieties treated with transgenerational drought exercise are significantly higher than those of winter wheat varieties treated with normal irrigation, indicating that drought exercise can improve the salt tolerance of winter wheat.

[0107] IV. Transgenerational saline-alkali and drought exercise test

[0108] 1. Prepare test wheat seeds

[0109] Salt-tolerant winter wheat varieties treated with transgenerational saline-alkali and drought exercise: Jiemai 19, Xiaoyan 155, Cangmai 6002, Cangmai 6005; Salt-tolerant winter wheat varieties not treated with transgenerational saline-alkali and drought exercise: Jiemai 19, Xiaoyan 155, Cangmai 6002, Cangmai 6005;

[0110] 2. Test steps

[0111] (1) Take 40 seeds of each variety, soak the seeds in 70% alcohol for 30S, then disinfect them with 20% sodium hypochlorite solution for 20 min, and wash them 3 - 4 times with sterile water and dry them for later use;

[0112] (2) Place the dried seeds in a petri dish, place two layers of filter paper at the bottom of the petri dish, and keep the seeds facing the same direction;

[0113] (3) Soak them in deionized water (0 g / L), 3 g / L NaCl solution and 5 g / L NaCl solution respectively; then, according to the growth of the seeds, add a certain amount of solution every day to ensure the normal germination of the seeds;

[0114] (4) Place all the treated seeds in an incubator for cultivation, with 12 h of light and dark treatment each;

[0115] (5) Record the number of germinated seeds when the seeds start to germinate, investigate once a day until no new seeds germinate.

[0116] 3. Measurement indicators

[0117] (1) Record the germination rate three times for each group of experiments, that is, from the start of germination to complete germination;

[0118] (2) When harvesting each group of experiments, record the fresh weight of the buds. Since the fresh weight of the buds is relatively low and the dry weight of the buds after drying is almost 0, only the fresh weight of the buds is recorded in the experiment;

[0119] (3) Finally, use the final germination rate and fresh weight of the buds as indicators to compare the salt tolerance;

[0120] (4) Germination rate (Gr) = number of all normally germinated seeds at the end of germination / number of tested seeds × 100%.

[0121] 4. Experimental results

[0122] Compare the winter wheat varieties that have undergone cross - generation saline - alkali and drought stress with those that have not. The comparison results are shown in Figures 18-24 (in the figure, different letters indicate significant differences between the same variety with and without cross - generation saline - alkali and drought stress), among which Figures 18-20 is the comparison of the germination rate between the winter wheat varieties that have undergone cross - generation saline - alkali and drought stress and those that have not, Figures 21-24 is the comparison of the fresh weight of the buds between the winter wheat varieties that have undergone cross - generation saline - alkali and drought stress and those that have not. The germination rate and fresh weight of the buds of the winter wheat varieties that have undergone cross - generation saline - alkali and drought stress are significantly higher than those of the winter wheat varieties that have not, indicating that cross - generation saline - alkali stress and drought stress can significantly improve the salt tolerance of winter wheat.

[0123] In summary, cross - generation saline - alkali stress and drought stress can improve the salt tolerance of winter wheat.

[0124] IV. Experiment on priming contemporary seeds with cross - generation stress and CaCl₂ solution

[0125] The second - generation wheat seeds described in step S2 are placed in a culture dish after priming treatment. The priming treatment specifically includes the following steps:

[0126] A. Soak the seeds in 65 - 75% alcohol for 20 - 40 s, then disinfect them with 20% sodium hypochlorite solution, and then wash them with sterile water and air - dry for later use;

[0127] B. Soak the air - dried seeds in the priming agent for 10 - 16 h, and then air - dry the soaked seeds to restore the seed moisture content to the state before soaking, thus completing the priming treatment.

[0128] The priming agent is a CaCl₂ solution with a concentration of 40 - 60 mmol / L.

[0129] The mass ratio of the seeds to the initiator is 1:4 - 6.

[0130] Through priming treatment, the memory ability of the seeds can be improved, and their salt tolerance can be further enhanced. In the present invention, two varieties with relatively high salt tolerance are selected. By soaking the seeds with the initiator, seed germination is promoted, the stability rate and the evenness rate of the germination time are increased, the standard deviation of the germination time is reduced, the drought and salt tolerance resistance and quality of wheat seedlings are improved, and the nutritional status is improved.

[0131] The specific operation is as follows:

[0132] 1. Prepare experimental wheat, namely Cangmai 6002 (without cross-generation saline-alkali and drought hardening), Cangmai 6002 (with cross-generation saline-alkali and drought hardening), Jimai 22 (without cross-generation drought hardening), Jimai 22 (with cross-generation drought hardening); prepare the initiator: 50 mmol / L CaCl2 solution.

[0133] 2. Experimental steps

[0134] (1) Soak the wheat seeds of Cangmai 6002 (without cross-generation saline-alkali and drought hardening), Cangmai 6002 (with cross-generation saline-alkali and drought hardening), Jimai 22 (without cross-generation drought hardening), and Jimai 22 (with cross-generation drought hardening) in 50 mmol / L CaCl2 solution for 12 h respectively, and then air-dry the soaked seeds to restore the seed moisture content to the state before soaking, obtaining the primed varieties. Use the varieties of Cangmai 6002 (without cross-generation saline-alkali and drought hardening), Cangmai 6002 (with cross-generation saline-alkali and drought hardening), Jimai 22 (without cross-generation drought hardening), and Jimai 22 (with cross-generation drought hardening) without priming as controls;

[0135] (2) Soak each group of wheat in deionized water (0 g / L), 3 g / L NaCl solution, and 5 g / L NaCl solution respectively, and then add a certain amount of solution every day to ensure the normal germination of the seeds;

[0136] (3) Place all the seed treatments in an incubator for cultivation, with 12 h of light and dark treatment each;

[0137] (4) Record the number of germinated seeds when the seeds start to germinate, and conduct an investigation once a day until no new seeds germinate.

[0138] Among them, CM6002-1: Cangmai 6002 (without contemporary induction + without cross-generation saline-alkali and drought hardening); CM6002-2: Cangmai 6002 (without contemporary induction + cross-generation saline-alkali and drought hardening); CM6002-3: Cangmai 6002 (contemporary induction + without cross-generation saline-alkali and drought hardening); CM6002-4: Cangmai 6002 (contemporary induction + cross-generation saline-alkali and drought hardening); JM22-1: Jimai 22 (without contemporary induction + without cross-generation drought hardening); JM22-2: Jimai 22 (without contemporary induction + cross-generation drought hardening); JM22-3: Jimai 22 (contemporary induction + without cross-generation drought hardening); JM22-4: Jimai 22 (contemporary induction + cross-generation drought hardening).

[0139] 3. Test results

[0140] Figure 25 This shows the effects of different salt concentrations on the germination rate of winter wheat (different letters in the figure indicate significant differences among the same seeds under different salts). Among them, Cangmai 6002 (CM6002-4) treated with cross-generation saline-alkali and drought hardening plus contemporary induction and Jimai 22 (JM22-4) treated with cross-generation drought hardening plus contemporary induction performed better.

[0141] Figures 26-27 This shows the effects of different salt concentrations on the fresh weight of winter wheat sprouts (different letters in the figure indicate significant differences among the same seeds under different salts). The fresh weight of winter wheat sprouts decreased significantly with the increase in the salt concentration of irrigation water. The fresh weight of Cangmai 6002 sprouts was the highest after cross-generation saline-alkali and drought hardening and induction treatment.

[0142] Figure 28 This shows the germination rates of different winter wheat varieties under the condition of the same salt concentration (different letters in the figure indicate significant differences among different seeds under the same salt condition). It can be seen that under the condition of 5 g / L salt concentration, the germination rate of drought-resistant varieties was significantly lower than that of salt-tolerant varieties, and the germination rate of wheat seeds after contemporary induction treatment was higher than that without induction treatment.

[0143] Figure 29 This shows the fresh weights of sprouts of different winter wheat varieties under the condition of the same salt concentration (different letters in the figure indicate significant differences among different seeds under the same salt condition). It can be seen that under the condition of 5 g / L salt concentration, the fresh weight of sprouts of drought-resistant varieties was significantly lower than that of salt-tolerant varieties, indicating that the salt tolerance of salt-tolerant varieties was always higher than that of drought-resistant varieties; and the fresh weight of wheat seeds after contemporary induction treatment was higher than that without induction treatment, indicating that induction treatment could improve the salt tolerance of seeds.

[0144] Figure 30For the difference in germination rate among four different pre-seeding treatments of two winter wheat varieties (different letters in the figure indicate significant differences among different cross-generational hardening and priming treatments for the same salt concentration and the same variety; Pre-treatment 1: no current priming + no cross-generational stress hardening, Pre-treatment 2: no current priming + cross-generational stress hardening, Pre-treatment 3: current priming + no cross-generational stress hardening, Pre-treatment 4: current priming + cross-generational stress hardening), under the condition of 5 g / L salt concentration, the effect of current seed priming treatment is the most obvious; the germination rate results show that the order of the four pre-seeding treatments in enhancing salt tolerance is: current priming + cross-generational stress hardening > only cross-generational stress hardening > only current priming > no cross-generational stress hardening + no priming.

[0145] Figures 31-32 For the difference in fresh weight of buds among four different pre-seeding treatments of two winter wheat varieties (different letters in the figure indicate significant differences among different cross-generational hardening and priming treatments for the same salt concentration and the same variety), it can be seen that the order of the four pre-seeding treatments in enhancing salt tolerance is: current priming + cross-generational stress hardening > only cross-generational stress hardening > only current priming > no cross-generational stress hardening + no priming.

[0146] The seed priming experiment shows that current seed priming treatment can improve the salt tolerance of seeds, and the effect is more obvious under the condition of higher salt content. The salt tolerance of seeds with cross-generational stress hardening plus current priming treatment is the strongest, higher than that of seeds only with cross-generational stress hardening and only with current priming treatment, and the salt tolerance of seeds without cross-generational stress hardening and current priming treatment is the worst.

[0147] V. Experiment on current seeds at the seedling stage with cross-generational drought hardening plus PEG-6000 priming

[0148] 1. Prepare experimental wheat, namely Jimai 22 (without cross-generational hardening) and Jimai 22 (drought cross-generational hardening); prepare the priming agent: PEG-6000 with a concentration of 20%.

[0149] 2. Experimental steps

[0150] (1) Immerse the wheat seeds of Jimai 22 (normal irrigation treatment) and Jimai 22 (drought cross-generational hardening) in a 20% PEG-6000 solution for 12 h respectively, and then air-dry the soaked seeds to restore the seed moisture content to the state before soaking, obtaining the primed varieties, and using the seeds of Jimai 22 (normal irrigation treatment) and Jimai 22 (drought cross-generational hardening) without current priming as the controls;

[0151] (2) Select seeds of similar size and plant them in buckets made of PVC pipes (20 cm in diameter and 100 cm in depth) with the radicles facing downwards. Seal the bottom with plastic film and tape. Fill each bucket with surface (0 - 20 cm) soil collected from nearby farmland to form a soil column 95 cm high, keeping the soil bulk density at 1.4 g / cm³ and the initial soil water content at 0.33 v / v.

[0152] (3) Sow 15 seeds in each pipe and thin out to 10 plants during the three - leaf stage. To reduce the influence of edge effects, sow a 0.5 - m - wide protected area around the bucket cultivation. During rainy and snowy weather, a movable rain shelter will cover the experimental area to ensure that the bucket cultivation experiment is not affected by rain.

[0153] 3. Experimental results

[0154] Figure 33 shows the germination of wheat (different letters in the figure indicate significant differences among different seed treatments). Among them, W0 is Jimai 22 (no priming + no trans - generational drought hardening), W0PEG is Jimai 22 (priming + no trans - generational drought hardening), W2 is Jimai 22 (no priming + trans - generational drought hardening), and W2PEG is Jimai 22 (priming + trans - generational drought hardening). It can be seen that PEG priming significantly improves the seed germination.

Claims

1. An exercise planting method for improving the salt tolerance of wheat seedlings, characterized in that, It includes the following steps: S1. Plant the first-generation wheat seeds in the soil. During the planting period, the water treatment is dry farming with rain-fed cultivation. After maturity, harvest the second-generation wheat seeds. The first-generation wheat seeds are set in groups. S2. Place the second-generation wheat seeds in a culture dish and culture them with an NaCl solution with a salt concentration of 3 - 5 g / L. Observe the germination rate, bud fresh weight or bud dry weight at the germination stage. Screen the seeds with a emergence rate ≥ 90% in the same group and the numerical ranking of bud fresh weight or bud dry weight in the top 30% of the group. These seeds are the highly salt-tolerant wheat seeds.

2. The exercise planting method for improving the salt tolerance of wheat seedlings according to claim 1, characterized in that, The first-generation wheat seeds are drought-resistant wheat seeds.

3. A method for cultivating and exercising wheat seedlings to improve their salt tolerance according to claim 1, characterized in that, In step S1, the salt content of the soil is 2.5 - 3.5 g / kg, and the first-generation wheat seeds are salt-tolerant wheat seeds.

4. A training and planting method for improving the salt tolerance of wheat seedlings according to claim 1, characterized in that In step S2, the second-generation wheat seeds are placed in a culture dish after being primed. The priming treatment specifically includes the following steps: A. Soak the seeds in 65 - 75% alcohol for 20 - 40 s, then disinfect them with 20% sodium hypochlorite solution, and then wash them with sterile water and air-dry for later use. B. Soak the air-dried seeds in the priming agent for 10 - 16 h, and then air-dry the soaked seeds to restore the seed moisture content to the state before soaking, thus completing the priming treatment.

5. A training and planting method for improving the salt tolerance of wheat seedlings according to claim 4, characterized in that, The priming agent is a PEG-6000 solution with a mass ratio of 18 - 22% or a CaCl2 solution with a concentration of 40 - 60 mmol / L.

6. The exercise planting method for improving the salt tolerance of wheat seedlings according to claim 4, characterized in that, The mass ratio of the seeds to the priming agent is 1:4 - 6.

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