Studies On The Traits Related To Propagation And Hybrid Seed Production Of New Cytoplasmic Male Sterility And Photoperiod(Temperature) Sensitive Genetic Male Sterile Lines

Selection and development of cytoplasmic male sterile(CMS) line is an important part in the hybrid rice breeding program. The CMS line with better flowering traits, agronomic characters, and higher general combining ability (GCA) could be used as female parent to developed hybrid rice with high grain yield, good quality of rice and high yield of hybrid seed production. The development of African rice cytoplasmic male sterility (AF-CMS) lines creates a new cytoplasmic sterility type, enriches the cytoplasmic genetic diversity, and avoids the potential risk due to the long-term use of single cytoplasmic. It is very important to use an ideal photoperiod (temperature) sensitive genetic male sterility (PTGMS)line with high yield potentiality and low-risk characteristic, in seed production for developing super hybrid rice with high yield and quality.In this work, five AF-CMS lines, four common rice CMS lines, five new PTGMS lines, and GZ63S as control lines were used as female lines. Investigation was performed ontheir fertility, flowering traits and agronomic traits to assess their use value. A total of30hybrids derived from3isonucleus-alloplasmic sterile lines and10regular restorer lines were obtained. Nine agronomic traits of these30F1hybrid, such as filled grain number per panicle, panicle yield, panicle number per plant, spikelet number per panicle,1000-grain weight, grain filling percentage, panicle length, plant height and days to flowering, were recorded to evaluate the genetic influence of new cytoplasm to hybrid rice, and supply references for breeding programs and application of new cytoplasmic hybrid rice. The results of these studies were summarized as follows:1. Sterile pollen percentage of the four new CMS lines was more than99.5%, bagged seed setting rate was100%, indicating that those four AF-CMS lines were pure and stable, and could be used in hybrid rice breeding.2. Comparison of the4AF-CMS linesand4common rice CMS lines showed thatstigma exsertion rate of AF-Jin23A and AF-Zhong9A was higher than that of WA-Jin23A and ID-Zhong9A, respectively. And the panicle insertion rate of AF-Jin23A and AF-Zhong9A was less than that of WA-Jin23A and ID-Zhong9A, respectively. Mid-day flowering rate and palea lemna opening degree of AF-Jin23A and AF-IR58025A was higher than that of WA-Jin23A and ID-IR58025A, respectively. These results suggests that it is more suitable to use AF-CMS lines as promising linefor hybrid breeding program than using common rice CMS lines with the same nucleus genes.3. Variance analysis of9traits showed that the new Africa rice cytoplasmic produced higher per spikelets numberper panicle and panicle number per plant than the other two kind of cytoplasm, Africa rice cytoplasm and Indonesia paddy, and the other two cytoplasmic were similar; Maternal effect showed significant effect on seed setting rate, grain number in ear, panicle and have significant effect on yield. Three female parent of the main characters of the general combining ability is one of the best in the new9A and9six of traits for positive, not in the9A and9in A fairly. Together new rice cytoplasmic optimal in Africa.4. Studies about characteristics of5new G(T)CMS lines revealed the fertility alteration of M1S as the most significant, which is followed by M164S. The total stigma exsertion rate of4G(T)CMS lines were higher than GZ63S(CK) except for M1S. The filled grain rate of4G(T)CMS lines were lower than that of GZ63S(CK) except for M5S-1.Daily flowering of all5sterile lines was similar. Mid-day flowering rate and palea lemna opening degree of MIS and M164S were higher than that of the control line. Comprehensively,3new PTGMS, M4S with the most outstanding agronomic traits performance followed by M1S and M164S, could be the promising sterile lines in hybrid breeding.