| Thirty early hybrid rice combinations were obtained from six male sterile lines and five restore lines in the study. Twelve quality characters of ?2 seed from FI plants and both parent seeds were analysized. The relations between the performance of quality characters of these combinations and the yields, and as well the parents were studied, including the genetic effects on grain quality character of these combinations. The main research results are as fellows:1. The brown rice rate(BRR) and length/width ratio(L/W) of the most combinations can meet Class I of National Standard on Fine Qualified Rice.The percentage to meet the National Standard are 96.7% and 93.3% respectively. However, the amylose content (AC) and gel consistency (GC) of half combinations only meet Class II of National Standard on Fine Qualified Rice. Few combination can meet Class II of National Standard on Fine Qualified Rice in chalky score(CS), chalkiness(CN), head rice percentage (HRP).2.Each quality characters performance of the combinations was the middle of both parents. But the grain length(GL), L/W and chalkiness area(CA) of these combinations tended to higher than those of their parents. HRP, grain width(GW), gelatinization temperature(GT), and GC of these combinations tended to lower than those of their parents. GW, CS, AC and GT of these combinations have significant positive relation to sterile lines. BRR, HRP, GW and CS of these combinations have significant positive relations to restore lines. Their GL, GW and CS have significant positive relation to mid-parent values.3.There existed the positive or negative competitive advantage among quality characters of these combinations, In all these combinations which crossed by various sterile lines (CK: XiangzaoxianSl), the standing of advantage are: T98A>Xiangl25S >Jin23A>ZaoS>810S>V20A. The performance of competitive advantage of various sterile lines in each character was not significant(CK: Xiangliangyou68), and the performance of few character in the most combination was good, but performanceof comprehensive quality was not good. Among all parents, the performances of R974 and Xiangl25S were best, R402, D34, D68, V20, Jin23A, T98Aand ZaoS were good, and 81 OS and XiangzaoxianS 1 were not good. ?4.Twelve quality characters of these combinations were affected by the additive and nonadditive effects of genes. Of them, BRR, milled rice percentage(MRP), CS, CN, GL and AC were affected by special combining ability(SCA) of parents, but HRR, GL, GW, L/W and CA were affected by general combining ability(GCA) of parents. The sterile lines have bigger effect on the other characters except BRR, MRP andGL.5.The heritability in broad sense (H2 B ) of each quality character of these combinations was high. But the heritability in narrow sense (H2N ) was low. The sequence of H2N in 12 quality characters from high to low was : L/W>GL>CN> GW>HRP>GT>AC>CS >CA>BRR>GL>MRP.6.There was close relation among the quality characters of these combinations, significant positive relation were found between BRR and MRR, HRR and GT, GL and L/W, and L/W was also positively correlated with CS , CA and GC, In addition, CS, GW and CA was significant positively correlated to AC; So the CA with GW, CS, AC and SC was. Whereas , there are negative relations between HRP and CS. GW, CS, CA, GT and CN was also significant negatively correlated to L/W.7. In these combinations , there were some correlations between yield characters and single quality character. Significant positive correlations were observed , such as the total grain per panicle with BRR, MRP; HRP with length per panicle, seed setting percentage, plumped number of grain per panicle; 1000-grain weigh with GL, GW, CS; and AC with plumped number of grain per panicle, seed setting percentage, theoretical yield. But 1000-grain weigh was significantly negative correlate to HRP, significant correlation was not found between yield character and comprehensive quality character. |
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