Abstract: Reducing the content of phytic acid (PA, myo\|inositol 1, 2, 3, 4, 5, 6 hexakisphosphate) is important for improvement of the nutritional quality of soybean. By radiation, one novel soybean ［(Glycine max L. (Merr.)］ mutant with low PA content, Gm-lpa-ZC-2, was isolated and characterized. Classic genetic study has shown that the lpa mutation was determined by a single recessive gene and was mapped on linkage group B2. Following preliminary mapping of Gm-lpa-ZC-2, in this study, we constructed large genetic populations, developed some new position-specific microsatellite markers by using soybean whole genome sequence and bioinformatics tools, and fine mapped the mutant gene based on soybean genomics and methods of traditional mapping. The results showed that the genetic distance between mutant gene Gm-lpa-ZC-2 and SSR marker Satt168 and Satt416 was much larger than the prediction in our previous study, which should be 18.2 cM. Based on these results, 9 pairs of position-specific microsatellite marker which had polymorphism between the two parental lines Zhexiandou 4 and Gm-lpa-ZC-2 were developed in a 4 900-8 200 kb region between target gene and satt168 in LG B2 . The lpa mutation gene was fine mapped on LG B2, closely linked with microsatellite loci psm lpa-224, psm lpa-225 and psm lpa-226, at genetic distances of 0.8cM．

Key words: soybean ［Glycine max L. Merr.］, low phytate, mutant, fine mapping