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

How soybean, a temperate origin crop, adapted to a tropical environment remains unclear. Here, the authors report Tof16, an ortholog of LHY, and the previously identified J locus, control soybean yield under short-day condition and loss of function of these two genes contributes to the adaptation to tropics. Soybean (Glycine max) 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 Time of Flowering 16 (Tof16), which confers delay flowering and improve yield at low latitudes and determines that it harbors the soybean homolog of LATE ELONGATED HYPOCOTYL (LHY). Tof16 and the previously identified J locus genetically additively but independently control yield under short-day conditions. More than 80% accessions in low latitude harbor the mutations of tof16 and j, which suggests that loss of functions of Tof16 and J 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 LHY homologs, J and E1. Our findings uncover the adaptation trajectory of soybean from its temperate origin to the tropics.

Automated summary

This study reports on the genes Tof16 and the J locus that control soybean yield under short-day conditions, and the loss of their function contributes to soybean's adaptation to tropical regions. Modulating the genetic complexity of LHY homolog alleles can quantitatively improve soybean's maturity and yield traits.