AUTHOR=Guo Jie , Li Yun , Xiong Liang , Yan Tingxian , Zou Jinsong , Dai Ziju , Tang Guang , Sun Kangli , Luan Xin , Yang Weifeng , Tan Quanya , Zhu Haitao , Zeng Ruizhen , Wang Shaokui , Zhang Guiquan 

TITLE=Development of Wide-Compatible Indica Lines by Pyramiding Multiple Neutral Alleles of Indica–Japonica Hybrid Sterility Loci

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.890568

DOI=10.3389/fpls.2022.890568

ISSN=1664-462X

ABSTRACT=<p>Since the development of <italic>indica</italic> hybrid rice in the 1970s, great success has been achieved in hybrid rice production in China and around the world. The utilization of inter-subspecific <italic>indica–japonica</italic> hybrid rice has always been considered due to its stronger heterosis characteristics. However, <italic>indica</italic>–<italic>japonica</italic> hybrids face a serious problem of sterility, which hinders the exploitation of their heterosis. In the past decades, the genetic basis of <italic>indica</italic>–<italic>japonica</italic> hybrid sterility has been well studied. It was found that in sterile <italic>indica</italic>–<italic>japonica</italic> hybrids, female sterility was mainly controlled by the <italic>S5</italic> locus and male sterility by the <italic>Sa</italic>, <italic>Sb</italic>, <italic>Sc</italic>, <italic>Sd</italic>, and <italic>Se</italic> loci. In this study, we developed wide-compatible <italic>indica</italic> lines (WCILs) by pyramiding multiple neutral (n) alleles of the hybrid sterility loci. First, we identified <italic>S<sup>n</sup></italic> alleles of the loci in single-segment substitution lines (SSSLs) in the genetic background of <italic>indica</italic> Huajingxian 74 (HJX74). Then, the <italic>S<sup>n</sup></italic> alleles of <italic>S5</italic>, <italic>Sb</italic>, <italic>Sc</italic>, <italic>Sd</italic>, and <italic>Se</italic> loci in SSSLs were pyramided in the HJX74 genetic background. The WCILs carrying <italic>S<sup>n</sup></italic> alleles at the <italic>S5</italic>, <italic>Sb</italic>, <italic>Sc</italic>, <italic>Sd</italic>, and <italic>Se</italic> loci showed wide compatibility with <italic>indica</italic> and <italic>japonica</italic> rice varieties. Therefore, the WCILs will be used to develop inter-subspecific <italic>indica–japonica</italic> hybrid rice with normal fertility.</p>