选用8个自交系为测验种,采用不完全双列杂交设计,对5个玉米人工合成群体新选的15个自交系的配合力、杂种优势以及主要性状遗传参数进行了分析。结果表明,单株产量GCA表现突出,且构成产量因子性状GCA表现也较好的新选自交系有GP2-1,GP5-2和GP5-5;SCA值高、杂种优势强的组合是48-2×GP3-3和ES40×GP1-2;在穗长、秃尖长、穗粗等12个性状中,亲本的基因加性效应对F1性状形成起主导作用,而穗重和单株产量的遗传变异主要来自于基因非加性效应。因此,对于高产组合的选配,至少要选择1个GCA高的材料作亲本,并在此基础上兼顾SCA的选择,而利用群体自交选系则应根据性状遗传特性决定其选择时期和选择强度。
The primary objective of this study was to estimate combining ability and its genetic parameters of a set of 15 newly inbred lines. The materials included 8 testers, which used commonly in southwest regions, 15 newly inbreds obtained from 5 synthetic corn populations named GP1, GP2, GP3, GP4, GPS, and 120 ( 15 × 8) combinations which were crossed with 15 new maize inbred lines and the 8 testers by NC Ⅱ mating design. The combining ability of 15 inbred lines from five groups was analyzed based on the date for the experiment. The genetic parameters were done basing on combining ability. The results showed that GP2-1, GPS-2 and GPS-5 with the better comprehensive characters Coulb be directly used in maize breeding program. The SCA of 48-2 × GP3-3, ES40 × GP1-2 was high in most traits, they brought out strong heterosis. GCA variance was bigger than SCA variance in ear length, sterile length, ear diameter etc twelve characters, yet SCA variance of ear weight and plant weight was bigger than GCA variance. So, these characters were selected would be based on their heribility. For example, ear length, sterile length, ear diameter etc can be selected in early stage, ear weight and plant weight ought to be selected in lately stage. We should pay attention to GCA, SCA when cross elite hybrid combinations.