不完全双列杂交样本容量的研究

A STUDY ON THE SAMPLE SIZE OF INCOMPLETE DIALLEL CROSS

将35个玉米自交系配制成20×15的不完全双列杂交,并作为总体。采用随机区组设计,三次重复。调查了抽丝期、株高和单株产量等性状。对总体和各容量的样本,都分析了一般配合力、特殊配合力、遗传方差分量和遗传力及它们的抽样方差和变异系数。结果表明:不完全双列杂交的最小适宜容量一组(遗传差异小的一组亲本)为8～12,另一组(遗传差异大的一组亲本)为6～9;样本容量对抽丝期和株高等遗传力高的性状的影响小于对单株产量等遗传力低的性状的影响;样本容量对一般配合力的影响小于对特殊配合力的影响。

Twenty maize (Zea mays L.) inbred lines and other fifteen lines were crossed according to the incomplete diallel cross design, which was defined as population. Randomized block design with three replications was used. The data were recorded on days to silking, plant height and kernel weight per plant. Sample incomplete diallel crosses with pxq size (p=4, 8, 12, 16, 20; q=3, 6, 9, 12, 15; when p=20, q≠15) were sampled from the population. By analysing the general combining ability (GCA), specific combining ability (SCA), components of variance and heritability of the samples and the population, it was concluded that the minimum suitable sample size of a incomplete diallel cross was p=8～12, q=6～9; sample size affected characters with higher heritability, such as days to silking and plant height, less than those with lower lheritability, such as kernel weight per plant; sample size 1fferted GCA less than SCA.