改良S1选择法对12个玉米群体改良效果的比较分析

为了对玉米群体进行合理有效的改良利用，通过改良S1选择法对12个玉米群体改良一轮后进行效果比较分析。结果表明，穗行数、行粒数和百粒重是构成产量的三因素，遗传增益最大的群体为蒙群2，其它依次为蒙群4、蒙群1等7个群体，蒙群3及3个国外引进群体遗传增益为负值；玉米群体在穗部、植株性状以及遗传变异中均存在一定的变化。试验研究得出，蒙群2、蒙群4、中综7号、蒙 C群、蒙 A群产量遗传增益均较大，并在其他农艺性状中改良效果显著，可直接选择优株自交进行选系，而其余7个群体遗传增益小，改良利用潜力不大。

Comparative Analysis of lmproving Effects of 12 Maize Populations with lmproved S1 Selection Method

ln this study, 12 maize populations were improved with the improved S1 selection method, aiming to increase the improvement efficiency of maize popula-tions. The results showed that number of rows per spike, number of grains per row and 100-grain weight were the three important component traits of maize yield. The highest genetic increment was found in Mengqun 2, fol owed by Mengqun 4, Mengqun 1 and other 7 maize populations. Negative genetic increment was shown in Mengqun 3 and 3 introduced foreign maize populations. Some changes were shown in spikes, plant traits and genetic diversity of maize populations. Based on our results, we concluded that Mengqun 2, Mengqun 4, Zhongzong 7, Mengqun C and Mengqun A could be directly used for the line breeding by selfing for their higher genetic increment of yield and better improvement effects of other agricultural traits. Compared with these 5 populations, the improvement potential of other maize populations was limited for their lower genetic increment.