Germplasm Selection And Gene Mapping Of Terminal Inflorescence Length In Soybean

Inflorescence length is one of the plant-type traits of soybean,and it is also an important yield trait,affecting many aspects of soybean production such as yield,yield stability,and cultivation measures.Among the germplasm resources,there are abundant genetic variations in the terminal inflorescences of soybean.In this study,112 soybean determinate varieties were used to analyze phenotypic diversity and correlations between terminal inflorescence length(TIL),and pod number of terminal inflorescences(PNI),effective pod number of terminal inflorescences(EPNI),the ratio of effective pod number and pod number of terminal inflorescences(REPI),seeds number of terminal inflorescences(SNI),grain weight of terminal inflorescences(GWI),hundred-grain weight of terminal inflorescences(HGWI),plant height(PH),seeds number per plant(SNPP)in soybean.At the same time,one BC1F2 segregating populations derived from GR8836 and W1112 was used to map the major gene of soybean inflorescence length by bulked segregation alaysis(BSA)method.The results of the present study are listed as follows:In the 112 tested soybean varieties of determinate soybeans,there were abundant genetic variations in TIL ranging from 1.25 to 11.86 cm.Among them,there were two varieties namedTongdali and Jiyu80 that were beyond 10 cm length in TIL trait.There were 36 materials that were from 3 to 10 cm and 74 varieties that were from 0 to 3 cm in TIL trait respectively.The results of correlation analysis showed that there were significant positive correlation between TIL and PNI,EPNI,SNI,GWI,HGWI,and SNPP.There was not significant correlation between TIL and PH.In additon,the ratio of the number of effective pods in the terminal inflorescence and pod number is 98%.It shows that the terminal inflorescence is beneficial to the formation of grain.In the BC1F2 segregating population,the frequency distribution of TIL trait was skewed,indicating that there were major gene effect on TIL in researched popultaion.Genetic mapping results indicated that TIL gene was lacated on 41,880,000-46,450,000 region of 19 chromosome,which included 64 non-synonymous mutations.The research results will be beneficial for genetic improvement in plant type traits in soybean.