Site - Specific QTLs For Soybean Growth And Screening Of Soybean Germplasm Resources

Growing period is an important ecological trait in soybean which has a significant impact on the yield, quality and adaptability. Soybean growing period is a quantitative trait controlled by multiple genes with major or minor role. Annual wild soybean is wild type that can cross the cultivated varieties and is an excellent resource to broaden the genetic base of soybean. In this study, a F2 population was developed from the cross Hedou14× ZYD02810, where Hedou14 was a cultivar and ZYD02810 was an annual wild soybean. Using selective genotyping method, QTL analysis was carried out on growing period in this F2 population. The results showed that a QTL on growing period was mapped to chromosome6(LG C2) and linked with SSR marker Satt100(113.96cM) and Satt307(121.27cM). This QTL were collocated with known E1 locus and many other maturity related QTLs. In order to determine whether the E1 gene was the causal locus for this QTL, E1 genes were cloned and sequenced in parent line and two F2 early maturity descendant(14DW1F2027, 14DW1F2090). The sequencing results showed the E1 gene in 14DW1F2 027 was from ZYD02810 and the E1 gene in 14DW1F2090 was from Hedou14. The results in this section would be helpful for further research such as marker assisted selection and gene cloning.Seed longevity is an important index for assessing the soybean seed quality.Resistance of soybean seed storage performance is affected by many factors. Among which genetic factor possessed an important role, germplasms with good seed longevity underlie the genetic improvement for seed longevity in soybean. 38 germplasms with good longevity were screened out from 87 germplasms according to the germination rates of stored soybean seeds, including 24 landraces, 11 internal cultivars and 3 abroad lines. The results showed that the seed longevity was negative related with the seed size and positive related with the pigment content. The relationship between seed longevity and total dissolved solid was negative but not significant.In this study, the seed vigor of 21 soybean germplasms were tested with germination characteristics after being artificially aged and naturally aged respectively. A positive correlation was identified by correlation analysis between the germination characteristics of artificially aged seed and those of naturally aged seed, which indicating that the artificially aging was a good alternative way to assess the seed longevity compared with naturally ageing for most of germplasms. Additionally, the germination characteristics of artificially aged germplasms was positively related with oil content, and negatively related with protein content. These elite germplasms with good seed longevity could be directly used in breeding progress and researches to dissolve the genetic basis for seed longevity.