冬小麦不同灌浆时期穗和叶茎鞘对粒重的贡献

为了揭示冬小麦穗和叶茎鞘在不同灌浆时期对粒重的贡献,于2011-2012年度,在大田条件下,选用河南省大面积推广的6个冬小麦品种,进行穗遮光和去叶+茎鞘遮光处理,研究了冬小麦不同灌浆时期的干物质积累转运量和粒重,分析了穗和叶茎鞘对粒重的贡献率。结果表明,穗遮光和去叶+茎鞘遮光显著影响冬小麦茎鞘干物质转运量、转运率以及其对穗粒重的贡献率。穗和叶茎鞘对冬小麦粒重的贡献率总体表现为灌浆前期低、中后期高;在灌浆中期穗对粒重的贡献优于叶茎鞘,而在灌浆前期和后期呈相反规律,且其影响效应因品种而异;整个灌浆期穗对单粒重和穗粒重的平均贡献率分别为30.31%和34.64%,叶茎鞘分别为32.87%和35.95%。穗对粒重贡献的关键时期为灌浆中期,筛选和培育灌浆中期穗对粒重贡献率高的品种有利于提高冬小麦粒重。

Contribution of Spike and Leaf,Stem and Sheath to Grain Weight during Different Grain Filling Periods of Winter Wheat

To explore the methods of increasing grain weight and yield potential,six winter wheat cultivars were selected to reveal the contribution of winter wheat spike and leaf,stem and sheath to grain weight during grain filling period. A field experiment of spike shaded and defoliation,stem and sheath shaded was conducted in 2011-2012 to investigate dry matter accumulation,translocation and grain weight,and the contribution rate of spike and leaf,stem and sheath to grain weight of winter wheat.Results showed that both the spike shaded and defoliation,stem and sheath shaded can significantly affect dry matter accumulation,translocation,and its contribution rate to grain weight per spike. The lower contribution rate of spike and leaf,stem and sheath to grain weight was found during the early filling period,while higher contribution rate was found during the middle-late filling period. During the middle filling period,the contribution of spike to grain weight was superior to that of leaf,stem and sheath,and opposite tendency was obtained during the early and late grain filling stages,but the effects among different cultivars were different. Across the whole filling period,the average contribution rate of spike to single grain weight and grain weight per spike was 30.31% and 34.64%,respectively and that of leaf,stem and sheath was 32.87% and 35.95%,respectively.In conclusion,the middle grain filling period is the critical contribution stage of spike to grain weight,and breeding cultivars with high contribution at this stage is prone to increase the grain weight of winter wheat.