1970-2000年代玉米单交种的遗传产量增益分析方法的比较

以田间试验为基础, 对直接种植法的不同方法进行分析, 以期找到适合我国的评估方法, 为遗传产量增益的研究提供理论支持。以1970s–2000s期间大面积推广的杂交种为材料, 分别于2005–2006年(试验1)以及2007–2008年(试验2)在新疆农业科学院和北京顺义试验基地进行。每个试验设置3种密度。依据1970年代单交种在3.0万株 hm^-2密度下的产量与2000年代的单交种在6.0万株 hm^-2密度下的年均单位面积的产量差异, 计算得到1970s–2000s期间我国玉米遗传产量年增益速率为94.7 kg hm^-2。在7.5万株 hm^-2密度下, 2000年代单交种较1970年代单交种的产量增值是遗传因素作用的结果。1970年代单交种在1.5万株hm^-2密度下的产量与2000年代单交种在7.5万株 hm^-2密度下的产量差值是育种与栽培共同作用的结果。由二者的比值得到育种对总产量增益的贡献率为52.9%。Duvick的直接种植法适用于我国评估遗传产量增益速率, Tollnaar的试验设置方法适用于评估我国玉米遗传贡献率。

Comparison of Analysis Method of Genetic Yield Gain for the Single-Cross Hybrids Released During 1970s-2000s

The different methods belonging to planting direct were analyzed in order to find out appropriate one to evaluate genetic yield gain based on our experiment. Maize hybrids, spanning four decades (from 1970s–2000s), and representing the main maize areas in China and the most popular hybrids of their time were tested during 2005–2006 and 2007–2008 in Beijing and Xinjiang. Trials were conducted under three plant densities. The difference between the yield of the 1970s hybrids with 30 000 plants ha^-1 and the yield of the 2000s hybrids was divided by 40 years, providing an estimated genetic yield gain per year of 94.7 kg ha^-1. The difference between the yield of the 2000s hybrids and the yield of the 1970s hybrids with 75 000 plants ha^-1 resulted from genetics. The difference between the yield of the 1970s hybrids with 15 000 plants ha^-1 and the yield of the 2000s hybrids with 75 000 plants ha^-1 was due to breeding and management. The ratio showed the contribution of breeding to total yield gain was 52.9%. Direct planting method proposed by Duvick was applicable to evaluate the genetic yield gain. The experiment design conducted by Tollnaar was applicable to evaluate the contribution of genetics to total yield gain.