12个玉米群体产量相关性状的密度效应分析

以蒙群1、蒙群2、蒙群3、蒙群4、蒙A群、蒙B群、蒙C群共7个自有群体和中综5号、中综7号2个国内合成的群体以及3个加拿大引进群体C群1、C群2、C群3为供试材料研究产量相关性状的密度效应。试验设计采用二因素裂区试验设计，密度为主区，2个处理，分别为75 000、150 000株/hm²；玉米群体为副区，共12个处理。通过增密效应分析得出，在秃尖长、穗行数、行粒数、穗长、穗粗、百粒重产量性状中，行粒数和穗长适宜作为耐密的选择指标，蒙群2、蒙群4、蒙A群、蒙B群4个群体的耐密性优于其他8个群体；在抗性性状中，倒伏率和空秆率是衡量耐密性的重要指标，蒙A群、蒙群1、蒙群4、C群1、中综7号群体的耐密性优于其余7个群体。综合产量与抗性指标，蒙A群、蒙群4适宜增密种植，蒙群1、蒙B群、蒙C群、中综7号群体可适当增密，C群2、C群3、蒙群3、蒙群2、C群1、中综5号群体不适于增密。

Density Effect of Yield-Related Traits in 12 Maize Populations

Twelve maize populations, including 7 self-breeding maize populations, Meng Pop.1 to Meng Pop.4, Meng A Pop., Meng B Pop., Meng C Pop.; two internal maize populations, CSyn5 and CSyn7; and 3 Canada populations, C Pop.1 to C Pop.3, were used as test maize populations in this study. Two-factor split-plot design was employed. Density was the main plot and maize population was the subplot. There were two treatments for density, they were 75 000 plant/ha, and 150 000 plant/ha. There were 12 treatments for the maize population. The results in the maize densification effect analysis showed that number of grains per spike and spike length were the most efficient indexes for selecting dense-tolerant variety among the six yield-related traits, spike diameter, 100-seed weight, spike length, number of rows per spike, and number of grains per spike, the length of the bald. The dense-tolerant of Meng Pop.2 and 4, Meng A and Meng B Pop. were higher than the other 8 maize populations. Lodging percentage and bare plant rate were two most important indexes of resistance traits for evaluating the dense-tolerant of maize population. The dense-tolerant of Meng A Pop., Meng Pop.1 and 4, C Pop. 1 and CSyn7 were better than the other 7 maize populations. The results in integrating yield and tolerant trait analysis showed that the planting density of Meng A Pop. and Meng Pop.4 were suitable to be densified; Meng Pop.1, Meng B Pop., Meng C Pop. and CSyn7 were able to be densified, but C Pop.1, C Pop.2, C Pop.3, Meng Pop.2, Meng Pop.3 and CSyn5 were not suitable to be densified.