关键词: 小麦, 穗型, 剪叶, 光合速率, 干物质积累, 籽粒产量

Abstract: In order to ascertain the contribution of leaves in different spike-type wheat varieties to grain yield in high-yield condition, two spike-type wheat varieties were selected as experimental materials, effects of leaf removal at heading date on the photosynthetic rate of remnant leaves, node dry weight and setting kernels and grain weight in different spike-type wheat varieties were studied. The results showed that the photosynthetic rate of remnant leaves raised owing to leaf removal and the photosynthetic rate of remnant leaves in multi-spike cultivar-YM49 increased more evidently. The node dry weight in large-spike cultivar-S2001 lightened significantly after leaf removal. But all of these could not 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. Effects of leaf removal at heading stage on yield components of YM49 were more than that of S2001. Therefore it is more important for realizing high yield in multiple spike-type wheat variety to safeguard canopy leaves by taking effective measures.

Key words: Wheat, Spike-type, Leaf removal, Photosynthetic rate, Grain yield