[Phylogenetic analysis of interspecies in genus Glycine through SSR markers].

The genetic diversity among 11 species of genus Glycine (altogether 37 accessions) was evaluated through SSR analysis. The number of alleles in different loci ranges from 6 to 29, averaging 15.9 per locus; alleles of subgenus soja account for 71.5% of those in subgenus Glycine, and the fingerprinting among subgenus Glycine is more divergent than that of subgenus soja. Principal factor analysis shows that the first and the second principal factor can classify genus Glycine into two groups which represent subgenus Glycine and subgenus soja. The results of UPGMA indicate that G. mas, G. soja and G. gracilis in subgenus soja are different species.

[Soybean germplasm diversity and genetic variance detected by microsatellite markers].

Microsatellite or Simple Sequence Repeats (SSR) marker is a new type of molecular marker developed recently, which can be used in genotype identification, pedigree analysis, and estimation of genetic distance. Using 5 pairs of SSR primer, 21 polymorphic fragments were obtained in 15 soybean germplasm. The number of alleles at each SSR locus is from 3 to 6, and the range of gene diversity is 0.439-0.668. In addition, analysis of genetic distance was also performed in this study. Pedigree analysis showed that mutation occurred for individuals in the F8 population of RIL after multigeneration meiosis, which was caused because of the changes in the number of repeat unit, to a limited extent.

[Construction and analysis of soybean genetic map].

Molecular linkage maps provide a powerful tool for the analysis of plant genome structure and function including the detection of quantitative trait loci (QTL). The molecular linkage map of soybean was constructed using an 88-individual RIL population derived from a cross between cultivated Changnong 4 and semi-wild Xinmin 6. The map contains 22 linkage groups and 240 markers, including 100 RFLP, 33 SSR, 62 RAPD, 42 AFLP, 1 SCAR and 2 morphological markers. It covers approximately 3,713.5 cM of soybean genome. Analysis of 72 RFLP markers showed that 16 of them revealed two or more independent loci and it suggested that there is an extensive homologous region in soybean genome. This map compared very well with the other published soybean maps.