Allelic variations of the Wx locus in cultivated rice and their use in the development of hybrid rice in China.

To make better use of global germplasm resources for improving the eating quality of hybrid rice, using the resequencing data from the 3,000 rice genomes project (3K RGP), the allelic variations of the rice Wx locus were analysed. With the exception of five rare alleles discovered for the first time in our study, most of these alleles were known alleles of Wx. Furthermore, a set of Kompetitive allele-specific PCR (KASP) markers based on these Wx alleles have been developed, and thirty-six main parents of hybrid rice from 1976 to 2018 were selected for Wx genotyping. The results showed that only three Wx alleles existed in the main parents of hybrids, and the allelic combination of the hybrids changed from Wx^a/Wx^b and Wx^lv/Wx^b to Wx^b/Wx^b with the development of hybrid rice. Wx^b is widely used in the male parents of hybrid rice. Wx^a and Wx^lv were used in the female parents of early hybrid rice, and they were gradually replaced by Wx^b. In the future, more favourable Wx alleles from cultivated rice should be identified, introduced, and effectively used to improve hybrid rice quality. [ABSTRACT FROM AUTHOR]