大豆高世代品系再选择方法的探讨

A STUDY ON RE-SELECTION OF ADVANCED GENERATION SOYBEANS STRAINS

对两个大豆高世代品系进行再选择。研究了几个主要性状的遗传变异和选择潜力 ,探讨了性状再选择的可能性。分析了两个品系中 8个性状和 3个产量性状的综合遗传变异度。在一定选择压下同时进行多性状选择的遗传进展进行估计 ,应用多元正态分布函数的近似计算 ,估计了多性状综合选择时所需基础群体的规模。为作物育种中多性状遗传进度研究及群体规模估计提出了新的设想。结果表明 ,南农 88-4 8在 60 0 -1 0 0 0株供选群体中 ,保持每荚粒数水平不变下 ,可使每株荚数和百粒重获得2 .5% -5%左右的相对遗传进度 ;苏豆 89-2在 1 2 0 0 -2 50 0左右的供选群体下 ,在保持产量的同时 ,可使成熟期、病斑率、虫蚀率获得 2 .5% -5%、2 .5% -5%、7.5%-1

Re-selection was made in two advanced generation soybean strains. Genetic variation and genetic gains of several principal characters of two strains were estimated, then the possibility of re-selection was discussed.The multivariate variability was also estimated for 8 agronomic traits and 3 yield-component traits, the multivariate relative genetic gains of 3 traits for simultaneous seleciton were analyzed. Population size needed in multiple character selection for different demands was evaluated by using approximate calcualtion of multiple normal distribution. A new idea served for study on genetic gains of multiple character and estimation of basic population size was represented in the paper. The results showed that 2.5%-5% relative genetic gains of number of pods per plant and 100-grain weight of the Nannong 88-48 strain can be got with number of grains per pod keeping at the original level from pure line selection of 600-1000 plants and about 2.5-5%,2.5%-5%,7.5%-15% relative genetic gains of days to maturity,incidence of infected seed,incidence of insect-bit seed of Sudou 89-2 strain can be obtained when its yield remains at the original level through pure line selection from 1200-2500 plants.