以西南生态区9个骨干自交系为材料，建立西南春玉米基础群体MCO-0，用测交法和后代鉴定法对其进行改良，对其不同世代的群体产量及产量性状、穗部性状、株型性状增益分析。结果表明，以MCO-0为基础群体，经过两轮的改良，MCO-2群体主要目标性状单株产量、穗行数等均有所增益，穗长、轴粗等为负增益。MCO-2经过一轮改良后的MCO-3群体株高、穗位高等有所增益，穗长、穗粗等为负增益。以MCO-1相比，MCO-3主要目标性状单株产量、秃尖长、ASI均有所增益，其余性状有的轮次有所增益，有的轮次为负增益。

The nine inbred lines were used as materials to establish the basic population MCO-0 of southwest spring maize, which was improved by cross test and progeny identification. The population yield and yield traits, ear traits and plant type traits of different generations were analyzed. The results showed that MCO-0 was used as the basic population, and after a round of improvement, the main target characters of MCO-2 population including yield per plant, rows per ear, grains per row, anthesis-silking interval(ASI), etc. were all improved, while ear length, axis diameter, growth period, etc. were negative gains. After a round of improvement of MCO-2, the plant height, ear height, ASI, etc. were increased, while the ear length, ear diameter, number of grains per row, etc. were negative gains. After a round of improvement of MCO-2, the plant height, ear height, ASI, etc. were increased, while the length of ear, the thickness of ear, the number of grains per row, and the number of rows per ear were decreased. Compare with MCO-1, the main target traits of MCO-3 yield per plant, bald head length and ASI were all increased, and some of the other traits were increased or decreased in some rounds.

S513.035.1

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