Genetic Analysis Of Grain Quality Characters In Japonica Hybrid Rice (Oryza Sativa L.)

1. The performance and inheritance of 7 quality characters were studied using F2 rice grain derived from 8×8 diallel crossing made by 8 parents of different ecological type japonica rice. As shown by the results:(1)Difference in each character of 8 parents were not obvious, but in F2 generation, transgressive phenomena were found in all characters studied, indicating that the genes controlling these characters among parents were scattered. (2) The inheritance of grain width(GW), weight of grain (WG), chalkiness score (CS), gelatinization temperature (GT) and gel consistency(GC) were suit to additive-dominant model, and dominant effect was major effect in the 5 characters. The inheritance of grain length (GL) and amylose content (AC) were not suit to additive-dominant model, existing epistatic effects. (3) Dominant genes for GW and WG made the character value decreasing, and dominant genes for CS, GT and GC made the character value increasing . (4) Yueguang contained more recessive genes in ASV-GT than other varieties. Zhendao 88 had more dominant genes in GW and WG than other varieties. Xiushui 04 had more dominant genes in GL and GC and more recessive genes in CS than other varieties.2. The performance and combining ability of 7 agronomic characters and 9 quality characters in 11 male sterile lines of BT type and 7 japonica restorer lines bred in different decate in japonica rice were studied by using F1 plants and F2 rice grains derived from Augmented NCn crossing. The results shown: (1) Among the 77 F1, over better parent heterotic combinations were 55% for spikelets per panicle, 40%for filled grains perpanicle and 43% for 1000-grain weight.The frequency of heterotic combination was highest in spikelets per panicle . (2)For panicle characters, GCA of Liuyanl89A, LH422, 7R189 were excellent, and SCA of Cai A/Liuyan 189R, 731A/LH422, 731A/7R189 were excellent. (3) Rice grain quality of 9 male sterile lines bred inrecent years were good. Quality of F2 rice grain of crosses made by Liuyan 189R, Liuqianxin R, LH422, 7R189 were better than those of the crosses made by C bao, Ke C57 , 77302-1. (4) For milling quality , 4016A, 3726A, C bao and 7R189 had good GCA. For appearance quality , Zhongguo91A, QingkongA , YueguangA and Liuyanl89Rhad good GCA. For cooking and eating quality, 731A, 7R189 and LH422 had goodGCA. Overall evaluation, CaiA, Liuyanl89A, 7R189 and LH422 had better value for rice grain quality improvement than the other A and R lines. SCA of 3726A/Liuyanl89A, Liuyanl89A/7R189, Liuyanl89A/LH422, and CaiA/7R189 were excellent.