Abstract:

【Objective】 This study aimed at detecting the genetic effects and heterosis level of yield-related traits of CMS-FA sterile lines and restorers as well as the breeding potential of CMS-FA hybrid rice parents. 【Method】 By incomplete diallel cross design, using five CMS-FA sterile lines as female parents and five corresponding restorers as male parents, twenty-five crosses were made. The parents and F1 generations were planted to obtain the data of yield-related traits. By using the additive-dominant model and MINQUE(1) method, the genetic variance, heritability, parent additional effects and combination dominant effects, and heterosis of ten yield-related traits were analyzed. 【Result】 Yield-related traits of CMA-FA hybrid rice were controlled by both additive and dominant effects, among which panicle number per plant, total grain number per panicle, filled grains per panicle, seed-set percent, 1000-grain-weight, flag-leaf length and growth duration and so on were mainly controlled by additive effects. The dominant effects prevailed in the traits of yield per plant, plant height, and panicle length and so on. As for narrow heritabilities, the dominant effects of 1000-grain-weight were the highest, the growth duration was the next, and the yield per plant was the lowest. Sterile line Jinnong 2A and restorers Jinhui 3 and Jinhui 5 had the best additive effects. The four combinations with the strongest dominant effects were Jinnong 2A×Jinhui 5, Jinnong 2A×Jinhui 2, Jinnong 4A×Jinhui 5 and Jinnong 5A×Jinhui 5. Three yield-related trais yield per plant, plant height and panicle length had stronger population mean heterosis of 7.351%-16.330% and population over-parent heterosis of 4.233%-10.507% in F1 with the highest heterosis reaching 10.307-49.462%. 【Conclusion】 Jinnong 2A was the best one of all the sterile lines tested, Jinhui 3 and Jinhui 1 were the best ones of restorers tested, and Jinhui 5 was a good parent for the development of high-yielding hybrid rice combination with short growth duration.

Key words: hybrid rice, new cytoplasmic resource(CMS-FA), heterosis, genetic effects, yield-related traits