两系杂交粳稻配合力测定及通径分析

用5个粳型光敏核不育系和5个恢复系配制24个组合(缺失一个组合),单行种植,重复3,,按NCⅡ设计,估算配合力和有关方差,并按逐步剔除法作通径分析.结果表明,对单株产量贡献大的性状依次为每穗实粒数、单株有效穗、千粒重和结实率.就一般配合力而言,_(7001)S、_(6085)S、轮回422的单株谷重,每穗实粒数的一般配合力效应最高,所配组合的产量及实粒数也高.M_(105)S、皖恢9号的有效穗一般配合力及特殊配合力方差均高,所配组合易获多穗._(5088)S、M_(105)S、4859所配组合的千粒重高.就特殊配合力来说,单株产量特殊配合力效应最高的组合为5047×皖恢9号,其次是M_(105)S×培C_(115),结实率的特殊配合效应最高的为_(6085)S×轮回422和_(7001)S×皖恢9号.从组合产量优势看,有22个组合超过鄂宜105,5个组合超过当优C堡,其中2个是_(7001)S配组,3个是轮回422配组的组合.

COMBINING ABILITY ESTIMATION AND PATH ANALYSIS IN TWO-LINE HYBRID RICE——(Oryza sativa L.ssp.sinica)

The combining ability estimation of 5 characters and stepwise pathanalysis in two-line hybrid rice (O. sativa L. ssp. sinica, or japonica)were studied in a 5×5 (4×5 or 5×4) diallel system. The stepwise pathanalysis indicated that the sequence of characters contribution to the gr-ain yield per plant were filled spikelet number per panicle>panicle nu-mber per plant>1000-grain weight>setting rate. Of all the charactersgeneral combining ability(GCA), the grain yield per plant and filledspikelet number per panicle of 7001S, 6085S and Lun Hui422 GCA con-tributions are the largest. The panicle number per plant of M105S andWan Hui 9. GCA and variance of specifc combining ability (SCA) eff-ects accounts for much. The F_1 hybrid 1000-grain weight of 5088S, M105Sand 4859(new japonica R line)combinations is heavy. Of all the charactersSCA, the F_1 hybrid grain yield per plant of 5047S×Wan Hui 9 com-bination SCA contribution is the biggest, and M105S×Pei C115 combi-nation SCA is bigger. The F_1 hybrid setting rate of 6085S×Lun Hui422and 7001S×Wan Hui 9 combinations SCA are Larger. Among them,the yields of 22 combinations were over higher than the first conven-tional check variety(E Yi 105, local japonica variety), the yields of 5combinations were over the second check combination (Dong You C.Bao, japonica hybrid rice of three-line).