The control of earliness has an agronomic importance since it reduces growing and harvesting time. Earliness is controlled by multiple genes in multiple pathways and influenced by the environment. In Arabidopsis thaliana, many earliness related genes were identified. Among them, Arabidopsis Frigida (FRI) gene confers late flowering phenotype, which is reversed to earliness by vernalization. Blast search using FRI against soybean EST database at TIGR identified Isoflavone reductase-like gene (TC217830). Fifty seven SNPs were identified in a total of 4,242 bp lengths in genomic region of Isoflavone reductase-like from 62 soybean genotypes (31 early maturity group and 31 late maturity group). From the obtained sequences, we identified 6 haplotypes of Isoflavone reductase-like gene. Among them, three haplotypes showed a significant association with maturity, suggesting that Isoflavone reductase-like gene is tightly linked to flowering time or actual gene it-self. Thus, to delimit a putative genomic region for maturity and flowering time, SSR markers near Isoflavone reductase-like gene were designed and analyzed for their genetic diversity, assuming that highly selected regions might posses lower genetic diversity. Through these experiments, the region related to maturity and flowering was delimited to nearby ac_satc_4 in scaffold 16.

Isoflavone is synthesized in several different organs such as root, leaf and developing and germinating seed. Isoflavone content reflects overall history of physiological event given to a plant during certain period of time. Amount of isoflavone in a orga