Elucidation of the relationship between yield and heading date using CRISPR/Cas9 system-induced mutation in the flowering pathway across a large latitudinal gradient.

The naturally occurring genetic variation in the universal flowering (or heading date in crops) pathway has produced major advancements in crop domestication and expansion, and the various combinations of heading date genes have facilitated the plants to heading at suitable times in different ecological zones. However, gene combinations that can maximize crop yields may not exist in natural populations. Here, we planted a series of heading date mutants that harbored different heading mutant gene combinations generated by CRISPR/Cas9 gene editing technology, along with a collection of commercial varieties, across a large latitude gradient to evaluate the major effects of heading date genes and preferable gene combinations for each area. The relationship between yield and heading date was investigated. According to the pattern obtained from gene editing mutants, we concluded that the growth period of commercial varieties could be adjusted to achieve maximum yield performance in some areas. By combining the long vegetative growth allele and weak photoperiod sensitivity allele, we pinpointed an optimal balance between growth period and yield production, resulting in new partially determinate heading date to maximum yields and improved adaptability. We propose that harnessing mutations in the florigen pathway to customize the balance between vegetative and reproductive growth offers a broad toolkit for boosting crop productivity. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-021-01213-4.