增广NC Ⅱ设计及其在群体遗传分析中的应用

Augmented NC Ⅱ Design and its Application to Genetic Analysis in Populations

采用10个小麦品种作为亲本,进行5×5NCⅡ交配设计,为得到增广NCⅡ设计,将25个F_1组合及其相应的父、母本各5个种植于田间,将所得数据进行方差分析,并对基因型和基因型×重复两个变异来源进行详细分剖,结果发现亲本间变异大于F_1组合间变异,误差项的进一步分剖表明:亲本×重复的变异要比组合×重复的变异小得多。雌亲间配合效应的变异要比雄亲间的变异大。从遗传分析角度来说,理想的NCⅡ设计,应在提供数值相近的方差成分估值σ_f^2和σ_m^2的同时,能够提供原因成分V_A和亲属协方差COV_(ⅡS)的适宜估值。同时进行了V_r-W_r分析,结果表明加性-显性模式不合适。

Ten wheat varieties was adopted as parents and a 5×5 NCⅡ mating design wasmade. To get an augmented NCⅡ design, the 25 F_1 crosses and their corresponding maleand female parents were assigned to a randomized complete block field experiment. In ananalysis of augmented NCⅡ design the detailed subdivisions were accomplished for eachsource of genotypes and genotype × replicate variations. The results show that the varia-tion among parents is larger than that among F_1 crosses. Further partitioning of error termshows that the vatiation for parent × replicate is much smaller than that for cross × repli-cate. Variation of combing effects among female parents is larger than that among maleparents. But for the purpose of genetic analysis, the desirable NCⅡ design should offersome reasonable estimates for the causal components V_A and COV_(HS), and the estimates ofvariance components σ_f^2 and α_m^2 should be comparable.According to the results of V_r-W_r covariance analysis, additive-dominace model is re-jected, and epistasis can not be ignored. Subdivision of error variation is discussed.