Molecular Breeding Of Rice Wide-compatibility BT-CMS Restorer Line(oryza Sativa L.)

There is a huge heterosis among indica-japonica subspecies,and it has become one of the main breeding goals to use the"three-line"package to achieve the heterosis among indica and japonica subspecies.The replacement of hybrid rice combinations is inseparable from the improvement of restorer lines.Because the restoring force and rice quality of restorer are important criteria for measuring restorer.Therefore,it is possible to aggregate the corresponding non-allelic nuclear restoration genes in the BT-CMS wide-compatibility restorer line according to the multi-gene recovery model to improve its restoring force to CMS lines.Through molecular breeding,high-quality restorer lines can be bred to assemble high-quality sub-species hybrid rice.In this study,9311 and the BT-CMS high-quality restorer line M152-06 were used to improve the restoring force and quality of BT-CMS wide-compatibility restorer lines（P152-07,TG2-5 and TG2-6）.Finally,BT-CMS indica restorer lines which with excellent quality and strong restoring force were bred,the main results as follows:（1）Pyramiding breeding of high-quality wide-compatibility restoration lines.Utilizing the medium amylose material M152-06 and the modified wide-compatibility restorer line P152-07 to improve restorer lines’quality.In the late season of 2017 got 8homozygous plants which contain Hd-1-2/Os MADS50/Sc/gs3/Wx-17T/S5/fgr/Pi-24 genes.They were investigated for three consecutive seasons,examined for the agronomic traits,quality traits,and restoring force.1)The amylose content of test cross F₁is in the range of 17.95-20.2%,which is significantly reduced by about 4%compared with the control,and the quality is improved;2)The pollen fertility of test cross F₁and the spikelet fertility in the late seasons were both improved compared to the control group.3)The restorer line carrying the premature gene Os MADS50 matured 6-9 days earlier than the control material which carrying the non-functional Osmads50 gene,and its test cross F₁also matured 6 days earlier than the combination.4)The restorer line carrying the gene gs3has a significantly increased grain size of 0.78-1.02mm compared to the combination which carrying the non-functional GS3 gene.The text cross F₁also becomes longer than its combination,but it doesn’t reach a significant level.（2）Cultivatie high restoring force restorer line,which carrying the Rf6 gene.We got one homozygous restorer line,which obtained high-yield/（Rlw-3,high-yield）/Sc/gs3/（20G-Alk和S5）/Gwt-7/Rf6/Rf1a genes.This restorer line was examined for its restoring force.The fertility of pollen F₁was in the range of 57.33%-63.76%,and the late season spikelet fertility is between 74.88%to 89.11%.Compared with its combination,the pollen fertility of F₁was increased by about 27%,and the spikelet fertility was increased by about 24%.（3）Cultivate high-quality and high restoring force restoration lines,which carrying the Rf6 gene.Using 9311,wide-compatibility restorer P152-07 and high-quality restorer M152-06 to improve the restoring force and quality of wide-compatibility restorer TG2-6.Finally obtained three restorer lines which carrying Hd-1-2/Os MADS50/Sc/gs3/Wx-17T/S5/fgr/Pi-24//High Yield/Rlw-3,High Yield/Rf6 gens.These restoration lines were investigated for agronomic traits,quality traits,and restoring force.1)Test F₁pollen fertility is between 59.44%to 70.92%,and the fertility of spikelet was in the range of76.83%-93.44%.Compared to the control group,its restoring force is significantly improved.2)The amylose content of test F₁was in the range of 15.19-16.69%,which was significantly lower than that of the control and reached the standard of medium amylose content.In this study,through molecular design breeding use 9311,a wide-compatibility restorer line M152-06,three wide-compatibility restorer lines（P152-07,TG2-5,TG2-6）and other intermediate materials,to improve the restorer lines’restoring force and quality.Finally obtain high-quality wide-compatibility BT-CMS restorer lines with strong restoring force,which can improve the fertility and quality of interspecific hybrid rice.