剪叶对不同穗型小麦品种干物质积累及籽粒产量的影响

 【目的】为了探讨高产条件下不同穗型小麦品种叶片对产量的贡献。【方法】选用两种穗型小麦品种为试验材料，研究了抽穗期剪叶对剩余叶片净光合速率、地上干物质积累、茎节重、籽粒结实与粒重的影响。【结果】抽穗期剪叶均导致两种穗型品种的干物质积累量下降和籽粒产量降低，以多穗型品种豫麦49受影响较大；剪叶提高了剩余叶片净光合速率，以多穗型品种豫麦49增幅较大；剪叶提高了茎秆内贮存物质的转移率，以大穗型品种宿2001转移率增幅较大，表现为茎节干重明显减轻。剪叶后，剩余叶片净光合速率和茎秆内贮存物质转移率的提高，均不足以弥补剪叶造成的损失，最终表现为结实粒数减少，粒重降低；随被剪叶片数增加、叶位升高，结实粒数和粒重降低更多。【结论】不同穗型小麦品种叶片对籽粒产量的贡献存在差异，多穗型品种大于大穗型品种，因此，在小麦抽穗后，多穗型品种叶片对增加籽粒产量起着重要作用。

Effects of Leaf Removal on Dry Matter Accumulation and Grain Yield in Different Spike-type Wheat Varieties

Objective] This paper aimed to determine the contribution of leaves in different spike-type wheat varieties to grain yield in high-yield conditions. Method] Two spike-type wheat varieties were selected as experimental materials, effects of leaf removal at heading stage on the net photosynthetic rate of remnant leaves, dry matter accumulation above ground, nodal weight per unit and setting kernels and grain weight in different spike-type wheat varieties were studied. Result] The results showed that dry matter accumulation and grain yield of two spike-type varieties decreased because of leaf removal at heading stage, multi-spike variety-YM49 was influenced more than that of large-spike variety S2001.Though the net photosynthetic rate of remnant leaves raised owing to leaf removal and the net photosynthetic rate of remnant leaves in multi-spike variety-YM49 increased more evidently. Leaf removal increased the transfer rate of substance saved in stem, the nodal dry weight in large-spike variety-S2001 lightened significantly after leaf removal. But none could compensate the loss caused by leaf removal, final results were that both setting kernels and grain weight decreased. With the increment of leaves removed and the rise of leaf- position, setting kernels and grain weight decreased evidently. Conclusion] The contribution of leaves in two spike-type wheat varieties to grain yield is different, multi-spike variety is more than large-spike variety, Thus leaves in multi-spike variety play important role for increasing grain yield after heading.