CN101315358B - Technical appraisement method for genetype moisture-proof ability of cowpea - Google Patents

Abstract

The invention discloses a technical identification method for the moisture-resistant ability of cowpea genotype, which is to measure the water content, chlorophyll content and injury rate of the leaves after flooding the cultivated cowpea seedlings, and use F=-1.48+2.15X ₇ + 0.17X ₈ -0.95X ₁₂ ; where: X ₇ , X ₈ , and X ₁₂ represent the α values of leaf water content, chlorophyll content, and injury rate respectively; α = (phenotype value of traits under flooding treatment/characters under natural conditions Phenotype value) x 100%. The phenotype values of traits under flooding treatment are the measured values of leaf water content, chlorophyll content, and damage rate detected after flooding treatment; the phenotype values of traits under natural conditions are the water content of leaves detected under natural conditions, The measured value of chlorophyll content and injury rate. This method overcomes the shortcomings of the traditional signing method, such as many indicators but not concentrated, poor comprehensiveness, inaccurate identification results, and inability to predict moisture resistance.

Description

Technical Identification Method of Humidity Resistance of Cowpea Genotypes

technical field

The invention relates to the degree of moisture tolerance of vegetable crops under moisture stress, in particular to an identification method for moisture tolerance of cowpea.

Background technique

Waterlogging is a general term for wet and flood. The former refers to the aerated environment caused when the soil moisture reaches saturation. Due to the lack of oxygen, the metabolism of the plant is changed and the normal growth and development of the plant is affected. The resulting hazard, the latter being the hazard caused by the submersion of the base or all of the crop by ground water. Compared with floods, wet waterlogging is a slow-varying water hazard, which is not easy to be discovered in time. In many parts of the world, such as China, Japan, India, Pakistan, Australia and many other countries, as well as in humid and semi-arid regions, the hazard of wetness and waterlogging seriously threatens the production of crops, affecting high and stable yields, and has become a serious problem of widespread concern.

Cowpea is a heat and drought tolerant annual crop. In southern my country and other regions, the rainfall in summer is relatively large. In the growing season of cowpea, the physiological water demand often far exceeds its physiological water demand, which can easily cause moisture damage and eventually lead to a decline in its yield and quality. Although the moisture tolerance characteristics of cowpea varieties have been described from the perspectives of morphology and physiology, such as Osunkoya et al. studied the impact of water stress on the growth of cowpea seedlings, Timsina et al. studied the plant water relationship and growth of cowpea varieties under flooding treatment, and the early maturity The interaction effect of sex and flooding degree. However, there is still a lack of research on the identification and screening of moisture tolerance of cowpea varieties, which affects the utilization of varieties. It is necessary to study the moisture tolerance and the genetic law of moisture tolerance of different genotypes. Most of the indicators in the traditional signing method need to measure the moisture damage index, plant height, fresh weight per plant, root-to-shoot ratio, number of nodules, root activity, leaf water content, chlorophyll content, carotenoid content, soluble protein content, and relative membrane permeability. There are 13 indicators including sex, injury rate and SOD activity; there are shortcomings such as non-concentration, poor comprehensiveness, inaccurate identification effect, and inability to predict moisture resistance.

Contents of the invention

The purpose of the present invention is to provide a kind of method easy and simple to operate, the technical identification method of the moisture-resistant ability of cowpea genotype with wide adaptability, to solve the above-mentioned problems.

The technical scheme of the present invention is: the technical identification method of cowpea genotype moisture-resistant ability, it is after the cowpea seedling that cultivates is flooded treatment, measures leaf water content, chlorophyll content, injury rate, utilizes F=-1.48+2.15X ₇ +0.17X ₈ -0.95X ₁₂ ; where: X ₇ , X ₈ , and X ₁₂ represent the α values of leaf water content, chlorophyll content, and injury rate respectively; α=(character phenotype value under flooding treatment/under natural conditions Trait phenotype value) × 100%. The phenotype values of traits under flooding treatment are the measured values of leaf water content, chlorophyll content, and damage rate detected after flooding treatment; the phenotype values of traits under natural conditions are the water content of leaves detected under natural conditions, The measured value of chlorophyll content and injury rate.

This method overcomes the shortcomings of the traditional signing method with many indicators but not concentrated, poor comprehensiveness, inaccurate identification effect, and inability to predict moisture resistance; this method is systematic and comprehensive; the method is easy to operate and widely adaptable, and can be used for other It can be used as a reference for the identification of plant moisture tolerance; it can distinguish the moisture tolerance of unknown cowpea genotypes; the accuracy of predicting the moisture tolerance of cowpea genotypes is high.

Detailed ways

1. The specific steps of the above-mentioned seedling cultivation are as follows: select disease-free and plump seeds, sterilize the surface with 70% alcohol for 2 minutes, rinse thoroughly with deionized water, put them on wet filter paper, and place them in a constant temperature incubator (28°C ± 1°C) Germinated in 2 days. The seeds (100 seeds of each kind) of germinated 12 cowpea varieties were sown in seedling pots, and every pot was filled with soil with equal weight and fertility. After emergence, the management should be the same to ensure its normal growth.

2. The specific steps of wet damage treatment and index determination are: after the above-mentioned unearthed seedlings grow for 2 weeks, select the seedlings with consistent growth to carry out flooding treatment (the water surface is about 1 cm higher than the soil surface), the control group is normal watering, and the experiment uses Completely random design, 3 repetitions, 8 plants in each repetition, after 15 days of treatment, the wet damage index, plant height, fresh weight per plant, root-shoot ratio, number of nodules, root activity, leaf water content, chlorophyll content, class There are 13 indicators including carotene content, soluble protein content, relative membrane permeability, injury rate and SOD activity.

3. Establish an optimal regression equation, and determine the specific steps of the genotype comprehensive evaluation value (F): first find out the α value of each repetition, and the formula is: α=(character phenotype value/natural condition under flooding treatment Phenotype value) × 100%, and then the average value was taken. The data transformation follows the method of membership function in fuzzy mathematics, and calculates the membership function value F of each index of each variety. Finally, take the average value, which is the comprehensive evaluation value of moisture resistance.

The measurement index is positively correlated with moisture resistance: F _ij ＝(X _ij -X _min )/(X _max -X _min )

The measurement index is negatively correlated with the moisture resistance: F _ij ＝1-(X _ij -X _min )/(X _max -X _min )

F _ij is the subordination value of the jth trait of the i-th material, X _ij is the ratio of stress to non-stress of the j-th trait of the i-th material, and X _max and X _min are the maximum and minimum ratios of the trait, respectively.

The specific steps for predicting the moisture resistance of cowpea using the regression equation are as follows: take the comprehensive evaluation value of moisture resistance (F) as the dependent variable, and screen out the independent variables that have a significant effect on the F value through stepwise regression, and establish the optimal regression equation F=-1.48 +2.15X ₇ +0.17X ₈ -0.95X ₁₂ . In the formula: X ₇ , X ₈ , and X ₁₂ respectively represent the α values of leaf water content, chlorophyll content, and damage rate; α=(phenotype value of traits under flooding treatment/phenotype value of traits under natural conditions)×100%. The phenotype values of traits under flooding treatment are the measured values of leaf water content, chlorophyll content, and damage rate detected after flooding treatment; the phenotype values of traits under natural conditions are the water content of leaves detected under natural conditions, The measured value of chlorophyll content and injury rate. After testing, the relationship between the equations is extremely significant. According to the stepwise regression, among the 13 individual indicators, the above three indicators have the greatest impact on the humidity and salt tolerance, so these indicators can be measured selectively in the identification, which further simplifies the identification work at the seedling stage. Among them, if F≥0.60 or above, the variety has high moisture resistance; if 0.50<F<0.60, it means that the variety has moderate moisture resistance; if D≤0.5, the variety has poor moisture resistance. After the correlation analysis of the comprehensive evaluation value and the predicted value of the equation of 12 cowpea varieties, the correlation coefficient between the two was R=0.91, which reached a very significant level. It shows that the regression method can be used to predict the moisture tolerance of long cowpea varieties.

Take Thai cowpea as an example:

According to the cultivation conditions introduced in the previous technical plan, the seedlings were cultivated and treated with wet damage, and the leaf water content, chlorophyll content, and damage rate were measured respectively, and the corresponding α values were calculated. The results were: 0.97, 0.77, and 0.14, respectively. . Then substitute into the formula F=-1.48+2.15X ₇ +0.17X ₈ -0.95X ₁₂ (X ₇ , X ₈ , and X ₁₂ respectively represent the α value of leaf water content, chlorophyll content, and damage rate), and calculate its F value It is 0.60, and from the meaning of the above-mentioned F value, it can be known that this variety belongs to a variety with strong moisture resistance. For the new cowpea germplasm, through the determination of the three indicators controlled under the same conditions, the F value can be obtained to judge the level of its moisture resistance.

Claims (1)

1. the technical appraisement method of a genetype moisture-proof ability of cowpea, it is after the cowpea seedling of cultivating is carried out submerging treatment, to measure leaf water content, chlorophyll content, injury rate, utilizes F=-1.48+2.15X ₇+ 0.17X ₈-0.95X ₁₂In the formula: X ₇, X ₈, X ₁₂Represent the α value of leaf water content, chlorophyll content, injury rate respectively; α=(under the submerging treatment under proterties phenotypic number/natural conditions proterties phenotypic number) * 100%; The cowpea seedling step of said cultivation is: select disease-free, full seed, after the alcohol surface sterilization 2min deionized water with 70% fully washes, be put on the moistening filter paper, in 28 ℃ ± 1 ℃ constant incubator, sprouted 2 days; The planting seed of the cowpea variety after sprouting is cultivated in seedling-growing container; Said submerging treatment: after 2 weeks, select the consistent seedling of growth to carry out submerging treatment the growth of seedling that is unearthed, the water surface is higher than the about 1cm of soil table; Control group is for normally watering.