高产油菜品种稳产性形成机制

Formation mechanism of yield stability in high-yielding rapeseed varieties

作物生产中,稳产与高产同等重要。本试验以高产但稳产性存在差异的品种“湘杂油518”和“大地199”为材料,分别在武汉和兰州进行播期、施氮量、种植密度的单因素田间试验,测定农艺及生理指标、各处理籽粒产量,计算其变异系数,探究主要农艺性状与稳产性的关联度,为油菜大面积丰产及良种选育提供理论依据。结果表明,(1)播期、氮肥及密度显著影响油菜产量;相同试点,两品种的最高产量差异不显著,但其在各处理间的稳产性差异明显;本试验中,大地199在不同播期、氮肥处理下产量变异系数均低于湘杂油518,稳产性较强。(2)与湘杂油518相比,大地199各关键生育期的叶面积指数(leaf area index,LAI)、光能利用效率(light energy utilization efficiency,LUE)、地上部干物质累积量和花期根系形态等指标均较优,且变异系数小,是其高产且稳产性强的基础。(3)灰色关联度分析发现,各处理条件下,油菜籽粒产量与群体角果数、花期地上部干重和平均根直径等指标关联度较大;且产量变异系数与群体角果数、花期地上部干重和平均根直径变异系数极显著正相关。综上,优化油菜群体角果数、花期地上部干重和平均根直径等指标,可为油菜品种选育及大面积丰产提供理论支撑。

In crop production,yield stability is as important as high yield.To explore the relationship between main agronomic traits and yield stability and to provide a theoretical basis for large-scale high yield and improved variety breeding of rapeseed,a single factor field experiments of sowing date,nitrogen rate,and planting density were carried out in Wuhan and Lanzhou.The high yielding varieties[Xiangzayou 518(XZY 518)and Dadi 199(DD 199)]with different yield stability were used as the materials,the agronomic,physiological indices and the yield of each treatment were measured,and the variation coefficient of each index was calculated.The results showed that:(1)Sowing date,nitrogen rate,and plant density significantly affected the rapeseed yield.There was no significant difference in the maximum yield between two varieties,however there was a significant difference in the yield stability among these treatments.The yield variation coefficients of DD 199 were lower than that of XZY 518 with the strong stability.(2)Compared with XZY518,the indices of leaf area index(LAI),light energy utilization efficiency(LUE),aboveground dry matter accumulation,and root morphology at flowering stage of DD 199 were better,while the variation coefficient of were smaller,which was the basis of high and stable yield.(3)Grey correlation analysis showed that under each treatment,the yield of rapeseed was significantly positive correlated with the population pod number,aboveground dry weight,and average root diameter at flowering stage.In addition,the variation coefficient of population pod number,aboveground dry weight,and average root diameter at flowering stage were significantly positively correlated with the variation coefficient of yield.In conclusion,optimizing the indices such as population pod number,aboveground dry weight,and average root diameter at flowering stage can provide a theoretical support for breeding of rapeseed variety and achieving high yield at large-scale.