两种密度系谱法选择玉米自交系的一般配合力分析

Selection of maize inbred lines with pedigree under two densities-based on the general combination ability analysis

【目的】探究高密度选育玉米自交系的效果。【材料】将3个二环系的S1代玉米育种材料等分为2份,在97500和60000株/hm2两个密度下连续自交选择两代,各二环系的S3代与测验种杂交形成3组试验材料,采用NCⅡ遗传设计分析两种密度下的选择效果。【结果】3个育种材料S3代单株粒重一般配合力(GCA)的最大值分别为29.4236,18.1563和14.7467,均出现在高密度选系内;高、低两种密度选系的GCA总合平均分别为43.4906和-43.4938;高密度选系GCA>5的自交系共17个,占所有被测系的50%,低密度选系GCA>5的自交系有8个,占所有被测系的23.5%。试验的16个S1中,有10个S1高密度选系的GCA相对较大,而GCA相对较大的S1低密度选系仅有2个,4个S1在高密度选择中其S2代被淘汰。在低密度选择的S3,经测配其GCA均较低。【结论】高密度创造的逆境环境条件简单易行,能准确、有效、经济地选育出一般配合力较高的玉米自交系。

[Objective] The effects of breeding maize inbred lines in high density stress were studied; [Mathod] Three bi-cycle lines of S1 maize breeding material were divided into two parts,with 97 500 and 60 000 plant/hm^-2 density two consecutive two generations of self-selection, Line of the bi-cycle S3 generation hybrid varieties with the test group formed three test materials,NC Ⅱ genetic analysis was used to design two choices for the density effect. [Result] The maximun values of three breeding material S3 generation GCA were 29. 423 6,18. 156 3,14. 746 7, both in high density in the electoral system. Two low-density selections of GCA combined average of 43. 490 6, -43. 493 8. Line GCA under high density above five accounted for 17 measured 50% all over,Line GCA under low-density above five accounted for eight 23.5% all over. Among 16 test lines,there were 10 lines with relatively large GCA value under high-density than that under low-density. Only two S1 lines were relatively large GCA value selected under low-density. Four S1 lines under high-density by choice were eliminated in S2 generation. The S3 lines being selected under the low-density were founded with relatively low GCA value by testing. [Conclusion] The results suggested that breeding the GCA lines was the very convenient,reliable acceptable method in high density stress.