大豆高蛋白育种的亲本选配和后代选择的研究——Ⅰ大豆杂交F_2、F_3、F_4代蛋白质含量的遗传变异特点

用蛋白质含量不同的九个亲本配成六个组合,对其F_2、F_3、F_4代蛋白质含量的遗传基因作用方式和遗传参数等进行了系统的研究。试验结果表明,除C_2外,其它五个组合的蛋白质含量遗传主要是基因的加性效应,可用中亲值预测杂交后代蛋白质含量的平均表现。组合C_2除基因的加性效应外,还存在显性效应。多数组合蛋白质含量的遗传力一般中等偏高且随着世代的升高而增加。不同组合F_2、F_3、F_4代蛋白质含量变异系数和遗传进度较大,以及高蛋白超亲个体的普遍存在,均表明了早期世代选择高蛋白个体的必要性和可能性。

STUDIES ON SELECTION OF PARENTS AND EARLY GENERATIONS OF HIGH-PROTEIN BREEDING IN SOYBEAN I. CHARACTERISTICS OF GENETIC VARIABILITY OF PROTEIN CONTENT IN F_2, F_3, F_4 OF SIX SOYBEAN CROSSES

Our objectives were to investigate specific segregating feature of protein content of soybean hybrid so that selecting of nice high protein parents can be provided. Experiments were conducted through the early successive segregating generations of the six soybean crosses on Xiang Fang Experimental Farm at Harbin for three years. Generation means analysis indicated that gene action for seed protein content in all crosses but C2 was primarily additive, but instances of epistatic effect in C 4 and C 5 were noted. The mid-parent value of protein content could be used to predict the mean of segregating generations in these crosses. There .exist additive effect and epistatic ef- fect for high protein in C2. In general, the heritability of protein content in most populations ranged from 0.6 to 0.8, and increased as the generation in advance. Abnormal low heritability of protien content in some generations might be due to the influence by unusual environment. Early generation selection for high seed protein content would be desirable because of more plants with protein content equalling or exceeding that of better parent in most populations. Larger coefficients of genetic variability and genetic advance of protein content were found in F2, F3, F4 generations of six crosses.