Evaluation method for waterlogging tolerance of eggplant rootstock

Abstract

The invention relates to the technical field of plant cultivation and stress resistance identification, in particular to an eggplant rootstock waterlogging tolerance evaluation method which comprises the following steps: sowing and raising seedlings until 4-5 leaf stages of seedlings, cutting off top ends, and retaining lower rhizomes and 2-3 true leaves; the water surface is higher than the top ends of the seedlings in the flooding treatment process, the seedlings are fished out after flooding treatment is completed, growth is recovered, and the flooding tolerance of the eggplant rootstocks is evaluated according to the growth recovery condition. The problems that eggplant rootstock waterlogging tolerance evaluation seriously depends on experience, deviation is large, operation is complex, and cost is high can be solved.

Description

Technical Field

[0001] The invention relates to the technical field of plant cultivation and stress resistance identification, and in particular to a method for evaluating waterlogging resistance of eggplant rootstock. Background Art

[0002] Eggplant (Solanum melongena L.) is a plant of the genus Solanum in the Solanaceae family. It is widely planted in various parts of my country. Due to the increasing severity of soil-borne diseases and continuous cropping obstacles, the area of ​​grafted eggplant cultivation has exceeded the area of ​​traditional seedling cultivation, and the screening of multi-resistant rootstock eggplant has emerged. In the Yangtze River Basin and its southern regions in my country, due to seasonal rainfall, eggplant is very susceptible to rain and waterlogging stress, and its growth, yield and quality are seriously affected.

[0003] The Chinese patent with publication number CN107155666A discloses a method for rapid identification of waterlogging resistance of eggplant, comprising the following steps: Step 1: Flooding the four-leaf and one-heart eggplant seedlings, with the water level 2 cm above the soil surface, for 14 days; Step 2: Perform waterlogging recovery treatment after 14 days of flooding, and observe the phenotype of the eggplant seedlings after 7 days of recovery, selecting leaf color and shedding, and stem morphology as two evaluation indicators for evaluation; Step 3: Use leaf color and shedding, and stem morphology as two evaluation indicators for evaluation Carry out quantitative grading and formulate grade scoring standards; Step 4: Use the grade scoring standards to evaluate the grade score of the eggplant seedlings in each material, and calculate the average score of each material; Step 5: Use the calculated average score of each material to calculate the waterlogging resistance membership function value, and add up the two waterlogging resistance membership function values ​​of each material to calculate the average membership function value of the material. Use the average membership function value to compare the waterlogging resistance between different eggplant materials. If the comprehensive membership function value is higher, it indicates that the eggplant has stronger waterlogging resistance. This waterlogging resistance evaluation method is based on the color and morphology of the roots, stems, and leaves, and the operator makes subjective judgments, which is heavily dependent on the experience of the operator. The results of different operators have large deviations, and the waterlogging resistance of eggplant cannot be effectively judged. In order to more effectively evaluate waterlogging resistance, the existing technology evaluates by changes in the ultrastructure of leaf cells under waterlogging stress, but this judgment method is highly professional, complicated to operate, and has high evaluation costs, and cannot be applied to evaluation in complex and changeable environments in the field. Summary of the invention

[0004] The invention aims to provide a method for evaluating the waterlogging resistance of eggplant rootstock, which can solve the problems that the waterlogging resistance evaluation of eggplant rootstock is heavily dependent on experience, has large deviation, is complicated to operate and has high cost.

[0005] This application provides the following technical solutions:

[0006] A method for evaluating the waterlogging resistance of eggplant rootstocks comprises the following steps: sowing and raising seedlings, cutting off the tops of the seedlings when they reach the 4-5 leaf stage, retaining the lower rhizomes and 2-3 true leaves; performing a waterlogging treatment, during which the water level is higher than the tops of the seedlings, fishing out the seedlings after the waterlogging treatment is completed, resuming growth, and evaluating the waterlogging resistance of the eggplant rootstocks according to the resumption of growth.

[0007] Beneficial effects: This technical solution is based on the rootstock characteristics of the eggplant rootstock and is operated during the 4-5 leaf stage of the seedlings. At this time, the root system of the seedlings is coordinated with the growth of the aboveground part and can sensitively show the ability to adapt to waterlogging, highlighting the rootstock's own potential for waterlogging resistance. Cutting off the top removes the apical advantage and avoids interference with the waterlogging resistance evaluation due to differences in the growth height of the top main stems of different germplasms. Compared with the existing technology, when evaluating the waterlogging resistance of seedlings, the top will be retained. After the seedlings are treated with stress, the roots and stems at the lower end of some seedlings will rot and other damage, but the top will remain upright and the leaves will be relatively intact, thus affecting the overall waterlogging resistance evaluation of the seedlings. As the underground part of the grafted seedling, the eggplant rootstock only retains the roots after grafting and removes the top to simulate the actual application of eggplant rootstock in production, making the evaluation results more accurate. During the flooding process, the water level is higher than the top of the seedlings, simulating deep flooding conditions such as severe waterlogging and excessive waterlogging that may be encountered in the field. This can comprehensively evaluate the tolerance limit of eggplant rootstocks in extreme hypoxia and long-term deep flooding environments, increase damage to plants, and intuitively distinguish the waterlogging resistance of different eggplant rootstocks. Even if it is severely damaged in floods, if the rootstock can quickly recover, regrow branches and leaves, and restore root function, it can ensure the subsequent growth and yield formation of eggplant scions. From the perspective of long-term production benefits, screening out rootstocks with strong resilience can reduce the risk of reduced production and total crop failure due to waterlogging and stabilize the economic benefits of the eggplant planting industry.

[0008] Furthermore, the flooding treatment temperature is 20-30°C, and the flooding treatment time is 7-10 days.

[0009] Beneficial effects: When the temperature is 20-30℃ and the waterlogging treatment is carried out for 7-10 days, the degree of damage to the eggplant germplasm has reached the evaluation standard. If the waterlogging treatment time is less than 7 days, the degree of damage to the eggplant germplasm is insufficient and the true waterlogging resistance cannot be accurately reflected. If the waterlogging treatment time is more than 10 days, the eggplant germplasm is over-damaged, resulting in blurred individual differences and large errors in the evaluation results.

[0010] Furthermore, in the waterlogging treatment, a sensitive waterlogging control group is set, and the leaf shedding rate of the sensitive waterlogging control group is ≥90%, and the waterlogging treatment is completed.

[0011] Beneficial effects: A sensitive waterlogging control group was set up, and the leaf shedding rate of the sensitive waterlogging control group was ≥90% as the end of the treatment, which objectively quantified the stress intensity of waterlogging. Relying on the clear response of the sensitive waterlogging control group (leaf shedding) rather than a fixed time setting reduced human judgment errors and improved the objectivity of the experimental results.

[0012] Furthermore, in the sowing and seedling raising, seeds with full grains are selected, soaked in 0.5 g / L gibberellic acid at a temperature of 10-35° C. for 16-24 hours, dried, sown in plug trays, and managed in the field normally until the seedlings reach 4-5 leaf stage.

[0013] Beneficial effects: Gibberellic acid breaks the dormancy of eggplant seeds, ensuring rapid and uniform emergence after sowing. Normal field management refers to normal temperature, light and other conditions suitable for eggplant seed germination and emergence, as well as management measures such as water and fertilizer. Seedlings in the 4-5 leaf stage have relatively strong rhizomes, which have a certain ability to absorb and transport water and nutrients, and are more sensitive to environmental stress, and can more accurately reflect the differences in waterlogging resistance of eggplant rootstocks. If the seedlings are too small and have weak growth potential, their own growth and adaptability are limited, and they cannot accurately reflect the waterlogging resistance characteristics of eggplant rootstocks. If the seedlings are too large, the field management and time costs are high, which increases the cost of waterlogging resistance evaluation.

[0014] Furthermore, after the sowing and seedling raising, the seedlings are screened to retain normal, healthy seedlings with similar growth status.

[0015] Beneficial effects: ensuring that the growth and health status of the seedlings being evaluated for waterlogging resistance are basically consistent, ensuring the accuracy of the waterlogging resistance evaluation.

[0016] Furthermore, in the flooding treatment, the water surface is 10-15 cm higher than the top of the seedlings.

[0017] Beneficial effects: Maintaining a certain water layer depth can more realistically simulate this severe waterlogging scenario, ensure that the environment around the seedlings is in a relatively stable hypoxic state, and ensure the accuracy of waterlogging resistance evaluation.

[0018] Furthermore, the time for recovery growth is 15-20 days.

[0019] Beneficial effects: 15-20 days is sufficient time for eggplant rootstock seedlings to fully demonstrate their ability to recover after experiencing waterlogging stress.

[0020] Further, the method for evaluating the waterlogging resistance of eggplant rootstock according to the recovery growth situation is as follows:

[0021] Calculate the survival rate of plants after waterlogging: the survival rate of plants after waterlogging = the number of plants that recovered / the total number of plants in the waterlogging treatment;

[0022] The waterlogging resistance was evaluated according to the survival rate of plants after waterlogging: strong: P ≥ 65%; medium: 35% ≤ P < 65%; weak: P < 35%.

[0023] Beneficial effects: By simulating waterlogging stress, the judgment of waterlogging resistance is based only on the survival rate after recovery of growth, which greatly reduces the difficulty of judging different levels and has the advantages of simple operation, good repeatability and strong reliability. DETAILED DESCRIPTION

[0024] The following is further described in detail through specific implementation methods:

[0025] Embodiment 1

[0026] A method for evaluating waterlogging resistance of rootstock eggplant comprises the following steps:

[0027] (1) Seeding and seedling raising: Select seeds with full grains, soak them in 0.5 g / L gibberellic acid at a temperature of 10-35°C for 16-24 hours, dry them, sow them in plug trays, and carry out normal field management until the seedlings reach 4-5 leaves.

[0028] (2) Heading treatment: Screen the seedlings and remove those with signs of death, leaf shedding, yellowing and wilting leaves, and retain normal and healthy seedlings. Make a comprehensive judgment based on the number of leaves, stem thickness and plant height of the seedlings, select seedlings with basically the same growth status, cut off the top with a blade, and retain the lower rhizome, 2-3 true leaves and 2 cotyledons.

[0029] (3) Flooding treatment: Spread a layer of millet soil on the surface of the plug tray substrate. The millet soil is used to ensure the stability of the seedlings after water injection. Place the seedling plug tray with the head removed in a flooding pool or basket, add water until the water surface is 10-15 cm higher than the top of the seedlings, and keep the water level stable. The water surface is always higher than the top of the seedlings during the flooding treatment. Flooding treatment is carried out for 7-10 days at a temperature of 20-30℃, and a sensitive flooding control group can be set up at the same time. When the flooding treatment lasts for 7-10 days, the leaf shedding rate of the sensitive flooding control group is ≥90%, and the time when the leaf shedding rate of the sensitive flooding control group is ≥90% is used as the time when the flooding treatment is completed. When the flooding treatment time is ≤6 days, the leaf shedding rate of the sensitive flooding control group is ≥90%, and the flooding treatment is terminated when the leaf shedding rate of the sensitive flooding control group is ≥90%; confirm whether there are any abnormal conditions during the flooding treatment, such as large temperature fluctuations; if so, repeat the experiment; if not, proceed to the next step and replace the sensitive flooding control group for re-experimentation for verification. When the flooding treatment time is ≥11 days, and the leaf shedding rate of the sensitive control group is still not ≥90%, confirm whether there are any abnormal conditions during the flooding treatment; if so, repeat the experiment; if not, continue the flooding treatment until the leaf shedding rate of the sensitive control group is ≥90%, then end the flooding treatment and proceed to the next step, and replace the sensitive control group with a new one for verification.

[0030] The sensitive control group selected eggplant germplasm with low waterlogging resistance, such as "March Eggplant" and other eggplant germplasm with extremely low waterlogging resistance recognized by technicians in the field. The sowing and seedling raising, head removal and flooding treatment processes of the sensitive control group were the same as those of the group to be evaluated. The leaf shedding rate of the sensitive control group can be obtained by direct observation, including leaves that naturally fall off due to leaf corruption after long-term deep water flooding, and leaves that easily fall off when manually scooping out residual leaves and garbage.

[0031] (4) Resume growth management: After flooding treatment is completed, remove the plug tray from the flooding pool or basket and resume normal field management for 15-20 days.

[0032] (5) Recovery investigation: When new buds or leaves grow on the main stem of the seedling, it is judged that growth has resumed.

[0033] The survival rate of plants after waterlogging (P) = the number of plants that recovered / the number of plants that were treated with waterlogging resistance. Waterlogging resistance was evaluated based on the survival rate of the plants: strong: P ≥ 65%; medium: 35% ≤ P < 65%; weak: P < 35%.

[0034] Experiment 1

[0035] Experimental method: Using "March Eggplant" as the sensitive control group of eggplant rootstock germplasm, the waterlogging resistance of 6 eggplant rootstock germplasms was evaluated.

[0036] The sowing and seedling raising method of Example 1 was adopted to sow and raise seedlings for 6 eggplant rootstock germplasms and a sensitive waterlogging control group. 150 seedlings were cultivated for each eggplant germplasm. When the seedlings reached the 4-5 leaf stage, 90 seedlings with basically the same growth were selected and divided into three groups, each with 30 seedlings. The first group was managed according to the method of Example 1. When the waterlogging treatment was carried out, "March eggplant" was used as the sensitive waterlogging control group. After 8 days of waterlogging treatment, the leaf shedding rate of the sensitive waterlogging control group reached 100%; the second group was managed according to the method of Example 1, except that the head removal treatment was not carried out. When the waterlogging treatment was carried out, "March eggplant" was used as the sensitive waterlogging control group. After 13 days of waterlogging treatment, the leaf shedding rate of the sensitive waterlogging control group reached 100%; the third group was managed according to the method of Example 1, except that when the waterlogging treatment was carried out, the water injection surface was 2-3 cm higher than the top of the seedling, and "March eggplant" was used as the sensitive waterlogging control group. After 20 days of waterlogging treatment, the leaf shedding rate of the sensitive waterlogging control group reached 100%. The evaluation results of waterlogging tolerance of 6 eggplant rootstock germplasms and the waterlogging-sensitive control group are shown in Table 1.

[0037] Experiment 2

[0038] The waterlogging resistance of 7 eggplant germplasms including "March Eggplant" was evaluated by existing methods. Experimental method: Water normally during the seedling raising process to keep the soil moist; keep a 1-2 cm water layer on the soil surface at the 4-leaf stage and observe the growth of the plants. When 40% of all the test germplasms wilted and recovered slowly, all seedlings were managed normally in the field. After 5 days, the recovery of all the test germplasm plants was investigated, and the recovery level was divided into 5 levels according to the recovery and death of the plants.

[0039] Level 0: All leaves are basically recovered, or only the leaf tips are slightly yellowed;

[0040] Level 1: No dead leaves, no more than 3 yellow leaves;

[0041] Level 2: Growth is basically restored, with no more than 2 dead leaves;

[0042] Level 3: 3 to 4 completely dead leaves, with new leaves growing

[0043] Level 4: Plants are basically dead

[0044] The recovery index is calculated based on the recovery level. The calculation formula is:

[0045]

[0046] Where: RI is the recovery index, x i is the number of trees damaged by waterlogging at each level, n i is the value of each waterlogging damage level, and N is the total number of surveyed plants.

[0047] The waterlogging resistance of seedlings was divided into three levels according to the waterlogging damage index: strong (recovery index < 35%), medium (35% ≤ recovery index < 65%), and weak (recovery index ≥ 65%). The evaluation results of waterlogging resistance of 7 eggplant germplasms are shown in Table 1.

[0048] Table 1

[0049]

[0050]

[0051] As shown in Table 1, when evaluating the waterlogging tolerance of the seedlings in the third group of each germplasm in Experiment 1, the water level of the flooding treatment was 2-3 cm higher than the top of the seedlings. During the flooding treatment, some seedlings continued to grow. After the flooding treatment was completed, some seedlings had grown above the water surface. The waterlogging tolerance evaluation results of the third group were closest to those of Experiment 2. It can be seen that the evaluation method of the third group did not adequately damage the seedlings by flooding, and could not accurately reflect the true waterlogging tolerance of the germplasm. The seedlings in the second group of each germplasm in Experiment 1 had a higher water level than the seedlings in the third group. During the flooding process, the seedlings were always below the water surface, which increased the flooding damage to the seedlings. After the growth management was restored, the survival rate was low, which still could not accurately reflect the true waterlogging tolerance of the germplasm. Compared with the seedlings in the first group, the sensitive control group took longer to fall off its leaves because no head removal treatment was performed, which increased the flooding damage to the seedlings. After the growth management was restored, the survival rate was low, which could not accurately reflect the true waterlogging tolerance of the germplasm. In Experiment 1, the seedlings of the first group of each germplasm in the sensitive control group fell off leaves faster than those in the second group, and the flooding treatment time was shortened. After the growth management was restored, the survival rate was improved, highlighting the differences between different germplasms. It can be seen that after the head removal treatment, the interference of the growth difference of the main stem at the top of the seedling on the flood resistance of eggplant germplasm can be removed, and the true flood resistance of eggplant rootstock can be more accurately evaluated.

[0052] Compared with the prior art, the present invention causes greater damage to eggplant rootstocks when simulating waterlogging stress, making it easier to distinguish the waterlogging resistance of different materials. At the same time, the waterlogging resistance is judged based on the survival rate after restoration management, which greatly reduces the difficulty of judging different levels. The method for evaluating the waterlogging resistance of rootstock eggplants has the advantages of simple operation, good repeatability and strong reliability.

[0053] The above are only embodiments of the present invention. The invention is not limited to the field involved in this implementation case. The common knowledge such as the known specific structure and characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A method for evaluating waterlogging resistance of eggplant rootstock, characterized in that: It includes sowing and raising seedlings, cutting off the tops of the seedlings when they are in the 4-5 leaf stage, retaining the lower rhizomes and 2-3 true leaves; conducting flooding treatment, during which the water level is higher than the tops of the seedlings, and after the flooding treatment is completed, removing the seedlings and resuming growth, and evaluating the flood resistance of the eggplant rootstock based on the resumption of growth.

2. The method for evaluating waterlogging resistance of eggplant rootstock according to claim 1, wherein: The flooding treatment temperature is 20-30° C., and the flooding treatment time is 7-10 days.

3. The method for evaluating waterlogging resistance of eggplant rootstock according to claim 1, wherein: The waterlogging treatment includes a sensitive waterlogging control group, and the leaf shedding rate of the sensitive waterlogging control group is ≥90%, and the waterlogging treatment is completed.

4. The method for evaluating waterlogging resistance of eggplant rootstock according to claim 1, wherein: The sowing and seedling raising comprises selecting seeds with full grains, soaking them in 0.5 g / L gibberellic acid at a soaking temperature of 10-35° C. for 16-24 hours, drying them in the air, sowing them in plug trays, and carrying out normal field management until the seedlings reach the 4-5 leaf stage.

5. The method for evaluating waterlogging resistance of eggplant rootstock according to claim 1, characterized in that: After the sowing and seedling raising, the seedlings are screened to retain normal, healthy seedlings with similar growth status.

6. The method for evaluating waterlogging resistance of eggplant rootstock according to claim 1, characterized in that: In the flooding treatment, the water level is 10-15 cm higher than the top of the seedlings.

7. The method for evaluating waterlogging resistance of eggplant rootstock according to claim 1, characterized in that: The time for the recovery growth is 15-20 days.

8. The method for evaluating waterlogging resistance of eggplant rootstock according to claim 1, characterized in that: The method for evaluating the waterlogging resistance of eggplant rootstock according to the recovery growth situation is as follows: Calculate the survival rate of plants after waterlogging: the survival rate of plants after waterlogging = the number of plants that recovered / the total number of plants in the waterlogging treatment; Waterlogging tolerance was evaluated based on the survival rate of plants after waterlogging: strong: P ≥ 65%; Medium: 35%≤P<65%; Weak: P < 35%.

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