密度压力下玉米杂交种农艺性状与产量相关性研究

对近40年25个玉米杂交种的农艺性状与产量关系进行了研究。采用逐步回归、通径分析和偏向关等方法分析了不同密度下其农艺性状与产量的关系。结果表明:各个密度下的农艺性状对产量的影响不同。在低密度下,千粒重>病株率>行粒数>穗行数>穗位高>空秆率;在中密度下,千粒重>株高>行粒数>空秆率>倒伏率>穗行数>出籽率;在高密度下,千粒重>空秆率>穗位高>行粒数>倒伏率>穗行数>出籽率。在华北地区玉米杂交种选育中,主攻方向是选育千粒重高、耐密、抗倒伏的品种。在保持株高、穗位高、生育期等性状在现有水平的基础上,应重点强调在高密度压力下对倒伏株率和空秆率的选择,优先考虑千粒重的增加,其次是行粒数的增加。

Study on Relativity Between Yields and Agronomic Traits of Major Maize Hybrids Under Different Density

The analysis, which was based on the split-spot experimental design with varieties as main plot as well as density as sub-plot, and focused on both direct and indirect effects of agronomic traits upon yield, was conducted in Beijing ecological region in 2005. The results showed that the contribution to yield for different traits had become quite different in order, and consequently the breeding goal for modern maize hybrids in north China was to breed excellent hybrids which should process many merits including high resistance to lodging, tolerance to high density planting. The conclusion was that while plant height, ear height and maturity duration were maintained at the nowadays level, more emphasis should be laid upon selection for lodging rate and no ear plant rate primarily under the high density stress. In addition, the increase for 1 000 kernel weight should be under the breeding goal for yield improvement firstly, and then the increase for rows per ear.