Genetic Control and Geo-Climate Adaptation of Pod Dehiscence Provide Novel Insights into Soybean Domestication.

Loss of pod dehiscence was a key step in soybean [ (L.) Merr.] domestication. Genome-wide association analysis for soybean shattering identified loci harboring , and Pairwise epistatic interactions were observed, and the dehiscent overcomes resistance conferred by or locus. Further candidate gene association analysis identified a nonsense mutation in associated with pod dehiscence. Geographic analysis showed that in Northeast China (NEC), indehiscence at both were required in cultivated soybean, while indehiscent alone is capable of preventing shattering in Huang-Huai-Hai (HHH) valleys. Indehiscent allele was only identified in wild soybean ( L.) accession from HHH valleys suggesting that it may have originated in this region. No specific indehiscence was required in Southern China. Geo-climatic investigation revealed strong correlation between relative humidity and frequency of indehiscent across China. This study demonstrates that epistatic interaction between and fulfills a pivotal role in determining the level of resistance against pod dehiscence, and humidity shapes the distribution of indehiscent alleles. Our results give further evidence to the hypothesis that HHH valleys was at least one of the origin centers of cultivated soybean.