Identification Of Salt Tolerance Phenotype Of Soybean Mutants And Population Genetic Analysis Of Salt Tolerance Gene Mapping

Soybeans are important food crops and oil crops in China.Soy products based on soybeans occupy a large proportion of the Chinese market.At the same time,soybeans are rich in protein and are one of the important sources of animal feed.However,in recent years,China's soybean industry has developed slowly,with a high import ratio,and the contradiction between supply and demand has become more prominent.Due to climate change and unreasonable farming methods by humans,the area of salinized land is further increasing,and soil salinity will seriously threaten the growth and development of soybean.Significance.Soil salinity will seriously threaten the growth and development of soybeans.Increasing soybean yield is important.Soybean mutant library cloning of salt-tolerant genes is an important part of functional genomic research of soybean,and provides salt-tolerant genes for in-depth study of functional genomics of soybean.In this study,in cooperation with researcher Feng Xianzhong of the Institute of Geography,Chinese Academy of Sciences,EMS mutagenesis was performed on soybean variety Jiyu47 to establish a soybean mutant bank.The mutant library was screened for salt tolerance,and soybean mutants with stable phenotypes were screened out,and candidate regions for salt tolerance genes were initially determined.In this project,a salt-tolerant?salt-sensitive?mutant and Jiyu47 were used as research objects to construct an F₂ population.Genetic analysis revealed that the phenotypic separation ratio was 3:1.This mutation is a recessive mutation.This mutation is a recessive mutation,an extreme pool is constructed,and the BSA segregated population grouping analysis method is used for re-sequencing analysis,and the following research results are obtained:1.Three salt-tolerant mutants SK4714-3M,SK4714-4M,and SK4713M,two moderately salt-tolerant mutations SK4575M,SK4613M,and one salt-sensitive mutant SK4867M were identified.It provides excellent germplasm resources for salt-tolerant soybean cultivation.2.The salt tolerance physiological indicators MDA and chlorophyll of Jiyu 47 and mutants at the seedling stage were tested under salt stress.The results showed that the MDA content of salt-tolerant mutants was significantly reduced,and the MDA content of salt-sensitive mutants was significantly increased;Chlorophyll content showed different decreasing trends under salt stress.The chlorophyll content of salt-tolerant mutants was significantly higher than Jiyu 47,and the salt-sensitive mutants were significantly lower than Ji yu 47.3.The mutant was used as the female parent,and Jiyu 47 was used as the male parent to configure six cross combinations to obtain F₁ generation hybrids.F₁ self-crossed to obtain the F₂ population.Genetic analysis revealed that the SK4714-3M,SK4714-4M,and SK4867M mutant F₂ populations had a 3:1 segregation ratio between phenotype.Therefore,the mutant type was identified as a single gene controlling recessive homozygous mutant.Thirty mutant individuals were randomly selected to extract equal amounts of DNA from pools,and analyzed by BSA sequencing to determine candidate regions for salt tolerance genes.4.Seed copy of Jiyu 47 and 6 soybean mutants.The important agronomic traits such as plant height,grain weight,leaf color,seed coat color,umbilical color,flower color and maturity of Jiyu 47 and 6 mutants were measured and observed.Except for the 100-grain weight,there were no significant differences in other agronomic traits.Studies have shown that mutant SK4613M has no significant difference in 100-seed weight compared with Jiyu 47,and mutants SK4575M,SK4714-3M,SK4714-4M,SK4713M,and SK4867M have a significantly reduced 100-seed weight compared with Jiyu 47.