Marker-assisted Selection Of Restorers And Ecological Adaptation Of Japonica Hybrid Rice On CMS-YS

Rice heterosis utilization is an important technological measure for food security in China.Japonica hybrid rice based on cytoplasmic male sterility of Yinshui type (CMS-YS) is made byjaponica restorer lines with CMS-YS lines. The study on japonica hybrid rice of CMS-YS will enrichthe theory and also promote the development of japonica hybrid rice.This study analyzed indica-japonica index based on Cheng’s Index and indica-japonica property incytoplasm with mtDNA specific primer of CMS lines, maintainers, and restorers of JHR-YS based onmolecular techniques combined with experimental method in field, analyzed pollen abortivecharacteristics of CMS-YS lines. Also studied marker-assisted selection of the restorers used forJHR-YS based on molecular mapping of restoring genes in CMS-YS system, and ecologicaladaptability of JHR-YS by growing it in different ecological regions. The main results are followings.(1) CMS-YS japonica lines was typical abortive type, same as CMS-YS indica lines.(2) Revealed that CMS-YS lines and most of the restorer lines have the indica cytoplasm byanalyzing but YS-type japonica maintainer lines and a few restorer lines have the japonica cytoplasm.(3) CMS-YS lines, maintainers and part of restorer lines are japonica or partial japonica, only afew restorer lines are partial indica.(4) The flowering date of japonica CMS-YS lines was2.5days late than that of their maintainers,and flowering peak time was also1.2hours late. It was considered that the differences was resulted fromfrom YS cytoplasm, and breeding new maintainers is necessary to make it early, as a basis for highyielding seed production of japonica hybrid rice based on CMS-YS lines.(5) It is the first time to demonstrate that fertility restoration of japonica CMS-YS lines wascontrolled by two major genes and other minor genes, heritability h2mg(%) of the two major genes andthe minor genes was89.52%, was8.78%, respectively. Pollen fertility variation was98.3%controlledby major and minor genes, the rest1.7%is decided by the environment.(6) The two major genes, Rf-y1(t) and Rf-y10(t), were linked to RM10353with3.0cM and RM6100with1.2cM distance on chromosome1and chromosome10, respectively.(7) Rstorers R16、R382、R384、R386for CMS-YS japonica hybrid rice have been developed withMarker-assisted Selection.(8) Hybrid japonica rice combination between CMS-YS line, Liao65A, and restorer, R382that hadhigh general combination ability, had better fertility stability. Hybrid japonica rice combination betweenCMS-YS line Liao10A and R384that had high specific combination ability, had better ecologicaladaptability.