Evolutionary Variation of Accumulative Day Length and Accumulative Active Temperature Required for Growth Periods in Global Soybeans

Soybean (Glycine max (L.) Merr.) is a typical short-day and thermophilic crop. This study aimed to reveal the required accumulative day length (ADL) active temperature (AAT) for DSF (days of sowing flowering) DFM flowering maturity) in global soybeans. A sample consisted 354 varieties from 27 countries five geographic regions, which were tested Nanjing, China two spring-sowing summer-sowing seasons. The ADL AAT calculated climatological data provided by Public Service Nanjing Meteorological Bureau. results showed that average soybeans 41.0 d 83.3 d, ADLDSF 606.6 d·h AATDSF 1185.9 d·°C, ADLDFM 1126.7 AATDFM 2145.1 respectively, all with wide variation among/within MG(maturity-group)-set subpopulations. From multiple regression on AAT, ADL, ADL×AAT contributed 38.5%, 44.79% 17.10% 86.98%, 11.42% 0.54% variation, their relative importance varied among MG subpopulations matched only partially genomic marker clusters, indicating genetic sources each subpopulation exchange happened