小麦高世代品系中再选择的方法探讨

 两个小麦高世代品系中进行再选择。单株选择，随机区组设计，分系比较。采用方差分析法估计了该二群体中几个主要性状的遗传变异度和遗传进度，从而探讨了再选择的方法和效果。应用多元正态分布的近似计算，估测了多个性状综合选择时，所需的基础群体规模，为作物育种中的多性状遗传进度研究和群体规模估计提出了新的设想。 通过本文对两个小麦高世代品系的具体分析计算得出，南农82-4品系的产量三因素可在有700-1500株供选基础群体下，通过纯系选择，在保持原有单株穗数水平上，每穗粒数和千粒重获得2.5%-5%左右的相对遗传进度。南农2101品系在有2000-3000株左右的供选基础群体下，通过纯系选择，在保持该品系原有产量水平上，使赤霉病抗性、开花期和穗上发芽率获2.5%-5%、2.5%-5%和7.5%-15%的相对遗传进度。

A STUDY ON RE-SELECTION METHOD FOR ADVANCED STRAIN OF WHEAT

Re-selection was made in two advanced generation wheat strains. Genetic variation and genetic gains of several principal characters of the two strains were estimated, then the re-selection methods and effects were disecused. The number of plants (basic population size) needed in multiple character selection for different demands were estimated by using approximate calculation of multiple normal distribution. A new idea served for study on genetic gains of multiple characters and estimation of basic population size was represented in this study, Through analysis and probability calculation on the two strains, we have got the results that about 2.5%-5% relative genetic gains of grains per spike and 1000-grain weight of Nannong 82-4 strain can be got with ears per plant keeping at the original level from pure line selection of 700-1500 planta, and about 2.5% -5%, 2.5%-5% and 7.5%-15% relative genetic gains of scab injury degree, anthesis and pre-harvest sprouting rate of Nannong 2101 strain can be obtained when its yield charecter remains at the original level from pure line selection of 2000-3000 plants.