Multi-environmental population phenotyping suggests the higher risk of wheatRht-B1bandRht-D1bcultivars in global warming scenarios

ABSTRACT After six decades practice, the semi-dwarf alleles Rht-B1b and Rht-D1b (also called Rht-1 and Rht-2 ) had been applied into around 70% current wheat cultivars, laid the foundation for the worldwide wheat production supply, then the agronomic traits controlled by the two alleles still keep unclear except dwarfing wheat. Here 13 agronomic traits were investigated in 400 wheat accessions with seven environments, uncovered the genetic effects of Rht-B1b and Rht-D1b on wheat structure and yield traits in different genetic backgrounds and environments, and the distinct genetic effects between Rht-B1b and Rht-D1b , suggesting that the introduction of green revolution alleles profoundly shaped the agronomy traits of modern wheat cultivars. The late-sowing assays and regression analysis based on the phenotypic and their meteorological data showed the accessions containing Rht-B1b and Rht-D1b are more sensitive to the temperature increase, and the Rht-D1b may lost additional 8% yield compared the cultivars without the green revolution alleles if the average temperature increases 1 °C. These results suggest the application of green revolution are facing more challenges to maintain the futural wheat production supply in global warming scenarios.