提高陆地棉杂交后代产量性状选择效果的研究

Studies on the Enhancing Effect of Selection for Yield Traits in Segregating Population of Upland Cotton

以泗棉2号×CAU′CS-2-81为材料,系统地分析了选择单位、选择强度和群体规模与选择效果的关系,比较了系谱法与混合法的选择效果。结果表明:(1)选择效果随选择单位增大而提高;(2)选择强度与群体规模互作显著,欲提高选择效果,应扩大群体规模,降低选择强度;(3)优良基因型的丢失机率,系谱法高于混合法。因此,以产量为目标的育种方案中,应重新认识与评价混合法的作用。讨论了“平行选择法”的构想。

The relationship of selection effect with selection unit,intensity and population size was investigated in Upland cotton ,and selection efficiency of pedigree and mass selection was compared with material of cross between varieties Simian 2 (female) and CAU'CS-2-81 (male) during 1984 ?1989. The results showed that: (1) The selection effect increased with increase of selection units; (2) To enhance efficiency of selection for yield traits,the population size should be extended and the selection intensity reduced because of the significant interaction between selection intensity and population size; (3) The probability of losing elite genotypes in pedigree was larger than in mass selection. So the function of mass selection in Upland cotton breeding programs should be reevaluated. A modified selection procedure named the 'Parallel Selection Method' was discussed.