Genetic basis and adaptation trajectory of soybean from its temperate origin to tropics

<p>Soybean (<i>Glycine max</i>) serves as a major source of protein and edible oils worldwide. The genetic and genomic bases of the adaptation of soybean to tropical regions remain largely unclear. Here, we identify the novel locus <i>Time of Flowering 16</i> (<i>Tof16</i>), which confers delay flowering and improve yield at low latitudes and determines that it harbors the soybean homolog of <i>LATE ELONGATED HYPOCOTYL</i> (<i>LHY</i>). <i>Tof16</i> and the previously identified <i>J</i> locus genetically additively but independently control yield under short-day conditions. More than 80% accessions in low latitude harbor the mutations of <i>tof16</i> and <i>j</i>, which suggests that loss of functions of <i>Tof16</i> and <i>J</i> are the major genetic basis of soybean adaptation into tropics. We suggest that maturity and yield traits can be quantitatively improved by modulating the genetic complexity of various alleles of the <i>LHY</i> homologs, <i>J</i> and <i>E1</i>. Our findings uncover the adaptation trajectory of soybean from its temperate origin to the tropics.</p>