Studies on the combining ability of quality characters in early hybrid rice

By crossing 8 hybrid rice sterile lines with 12 early hybrid rice restorer lines(cultivars) through incomplete diallel cross(NC Ⅱ)desig n,96 combinations of early hybrid rice were obtained.Their combining ability reflected by 12 quality characters in their combinations and their parents were analysed.The results showed that there were very significant hereditary differences in quality characters of early hybrid rice.Significant differences existed in general combining ability(GCA) among 12 quality characters between parents,except in grain length,length/width,gelatinization temperature and protein content.The correlations between parents GCA in quality characters and their phenotypic values in early hybrid rice are all positive,except in brown rice recovery,milled rice recovery and head rice recovery.The correlations between the sum of GCA in quality characters of two parents and their F1 phenotypic values in early hybrid rice are all positive,The differences of special combining ability(SCA) variance in 12 quality characters are all significant,except in chalky rice percentage and gel consistency.The SCA differences of grain length and length/width and protein content are smaller,while the SCA differences in chalky rice percentage and gel consistency are largert,he SCA differences of other quality characters of early hybrid rices are placed in the middle.The correlations between SCA of quality characters in early hybrid rice and their heterosis are significantly positive.According to analysis of parents combining ability,Zhu 1 S and T98A are the first best hybrid rice sterile lines of good quality at present,Zaohui 1 hao and Zao 500 are the second best early hybrid rice restorer lines of good quality.