玉米群体改良与自交系和杂交种选育相结合的方法研究

本文论述了作者新设计的一种育种方法。其要点为:借用Ketata改进了的TTC法,检验群体性状有无上位性;在目标性状无上位性时,按不完全双列杂交分析方法估算参试亲本的配合力效应,配合力方差和遗传力;根据统计分析所提供的信息,选择高配合力的自交系和杂交组合,制定适宜的群体改良方案。利用这种新方法进行研究的结果表明: 1.Suwan—1群体的13个性状中,只有部份性状存在显著的上位性,多数性状均不显著。且所有性状的一般配合力方差均大于特殊配合力方差。 2.S_(21),S_(29)、S_(30)、S_(37)是入选的自交系,连续自交选择4代之后。测定其配合力表现亦高。 3.合二xS_(21)、合二xS_(37)、合二xS_(40)、331x、S_(57),(合二x331)×S_(29)是入选的高产组合。其中合二xS_(37)参加了品种比较试验,比中单2号(ck)增产10.2％,现累计推广面积达3万余亩。初步证明作者设计的方法是有效的。

A STUDY ON THE NEW METHOD OF COMBINING POPULATION IMPROVEMNT WITH SELECTING INBRED LINES AND HYBRIDS IN MAIZE

This report discribes a new breeding method. The main points are as follows: 1) The epistases of traits in population are tested with TTC method improved by Ketata. 2) If there is no epistases in objective characters, the effects and variances of combining abilities, and the heritabilities of parents are calculated with incomplete diallel design. 3) Selection can be made of the inbred lines and hybridized combinations with higher combining abilities, and an appropriate programme of population improvement, designed according to the informations provided by statistic analysis above. By this new method the following results are obtained. Firstly, The epistases of only some of the 13 traits in Suwan—1 population are significant, and the variances of G. C. A. of all the characters are higher than that of S, C. A. Secondly, among the inbred lines Su—21, Su—29, Su—30 and Su—37 are selected. After inbreeding 4 generations accompanied by continuous selection, their combining abilities are also higher. And thirdly, among the high yielding crossbred combinations are He—2×Su—21, He—2×Su—40, (He—2×331)×Su—29, He—2×Su—37. He—2×Su—37, the last of which yields 10.2 per cent higher than Zhong Dan No. 2 (CK), and it has been spread in 2,000 hec. (30,000 mu), This shows that the new breeding method is effective.