QTL Mapping Of Soybean Protein Content, Oil Content And Fatty Acid Contents

Protein,oil and fatty acid are the main quality traits of soybean,and it is of great significance to improve their varieties.Molecular marker-assisted breeding combines genotype and phenotype,having the characteristics of accuracy,orientation,short cycle,and low cost,has promoted the development and application of polymerization breeding.In this study,Zhonghuang 13?reincarnation parent?× Dongshan 69?donor parent?,Zhonghuang 13?reincarnation parent?× Zhonghuang 20?donor parent?high-generation backcross introduction line group were used as the material,near infrared Analyze and gas chromatography were used to analyze the content of main components of protein,oil and five fatty acids in high-generation backcross populations,and polymorphic SSR primers combined with complete interval mapping were used to construct genetic linkage maps and locate QTL of protein,oil,and fatty acid to provide the basis for molecular breeding of soybean,the main research results were as follows:1.Phenotype analysis of quality traits and agronomic traits in high-generation backcross groupsParents Zhonghuang 13 and Dongshan 69,Zhonghuang 20 had differences in quality traits and main agronomic traits such as protein,oil and 5 fatty acid component contents.Among them,differences in protein content,oil content,100-grain weight,plant height were larger.High-generation backcross groups of Zhonghuang 13 × Dongshan 69 and Zhonghuang 13 × Zhonghuang 20 of BC2F7 and BC2F8 had a wide range of genetic variations and different degrees of super-parental separation in 7 quality traits and 6 agronomic traits.The content distribution of the 7 quality traits were nearly normal,and the groups were suitable for QTL mapping of quality traits.The main quality traits and agronomic traits of the two high-generation backcross groups differed significantly between families and years,indicating that the quality traits and agronomic traits were quantitative traits that were jointly affected by genes and the environment;protein,oil,and five fatty acid components vary between years The significant differences were basically the same.The significant differences were: polyunsaturated fatty acids> monounsaturated fatty acids> protein> oil.There were stable correlation between the quality and agronomic traits of the high-generation backcross groups of BC2F7 and BC2F8.Protein was significantly negatively correlated with oil and palmitic acid.Oil was significantly positively correlated with linoleic acid and oleic acid,oil was significantly negatively correlated with stearic acid;Palmitic acid was significantly positively correlated with stearic acid,and palmitic acid was significantly negatively correlated with oleic acid.Stearic acid was significantly negatively correlated with oleic acid and linoleic acid.Oleic acid was significantly negatively correlated with linoleic acid and linolenic acid.The 100-grain weight was significantly positively correlated with protein and oleic acid,and significantly negatively correlated with oil,palmitic acid and linoleic acid,providing a basis for indirect selection.2.Protein content,oil content and fatty acid content QTLQTL mapping of the main quality traits of 4 groups before and after Zhonghuang 13 × Dongshan 69 and Zhonghuang 13 × Zhonghuang 20 were expanded,and a total of 130 QTLs related to quality traits were located;Groups of Zhonghuang 13 × Dongshan 69 and Zhonghuang 13 × Zhonghuang 20 and the expanded groups were mapped to 22,21,34,and 53 QTLs related to quality traits,among them,those related to protein,oil,stearic acid,palmitic acid,linoleic acid,oleic acid,and linolenic acid The QTLs were 17,17,27,22,16,23,and 8,respectively.In different years and different groups,17 pairs of QTLs for quality traits were repeatedly located,of which 8 pairs of QTLs for quality traits were newly located.Satt651^Satt045 is the relative main effect QTL related to palmitic acid content detected in two years,the highest phenotype contribution rate is 9.70%,which is the relative main effect QTL of palmitic acid;Sat₀76^Satt305,Satt433^Sat₂38 were the relative main effect QTL related to oleic acid content detected in two years,among them,Sat₀76^Satt305 and Satt433^Sat₂38 had the highest phenotypic contribution rate of 24.13% and 18.05% respectively;Satt323^Sat₂58 had been repeatedly located in different years and are related to oleic acid content,and their phenotypic contribution rate was 7.56%,which was a slight oleic acid Effective QTL.Satt228^Satt525,Sat₃18^Satt478,Satt543^Satt672 were detected in different groups and were related to protein,oleic acid,and linoleic acid content respectively,and the phenotype contribution rates were up to 10.75%,11.39%,18.05%,all of which were quality traits Relative main effect QTL;Satt 155^Satt 211 were detected in different populations,which were related to protein and oil content and have a phenotypic contribution rate of more than 12.00%,indicating that protein and fat are related to each other in anabolic metabolism.The QTLs for quality traits that were repeatedly located are stable and have a high phenotype contribution rate,which provides a new reference for molecular marker-assisted breeding of soybean quality traits.