Breeding of indica glutinous cytoplasmic male sterile line wx209a via crispr/cas9 mediated genomic editing

Abstract

Glutinous cytoplasmic male sterile (CMS) line is necessary to select hybrid glutinous rice combination with high yield and quality. To develop glutinous CMS with low amylose content, in this study, we firstly knocked out the granule-bound starch synthase OsWaxy in 209B using CRISPR/Cas9 mediated genome editing technology and successfully obtained a glutinous maintainer line WX209B. Comparing with maintainer line 209B, WX209B showed decreased amylose contents and similar agronomic characters. And then, through one generation of hybridization and two generations of backcrossing with WX209B as the male parent and 209A as the female parent, the glutinous CMS line WX209A was successfully achieved. Our study provides a strategy to efficiently breed for the glutinous cytoplasmic male sterile line by combining CRISPR/Cas9-mediated gene editing technology with conventional backcross breeding method in a short period, which prepares the ground for further breeding of hybrid glutinous rice variety.