COMBINING ABILITY ESTIMATION AND PATH ANALYSIS IN TWO-LINE HYBRID RICE——(Oryza sativa L.ssp.sinica)
Yuan Qin;Wang Shouhai;Luo Yanchang, (Rice Institute, Anhui Academy of Agricultural Sciences) Cheng Rong, (Dept.of Agronomy, Anhui Agricultural College)
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 paniclepanicle nu-mber per plant1000-grain weightsetting 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).