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作 者 ：王磊,王鹏程,张彤,张恒月,丁圣彦*

期 刊 ：生态学报 2009年 29卷 6期 页码：3328~3334

关键词：大豆；干旱；结荚期；光合；产量；

Keywords:soybean, drought, pod-setting stage, photosynthesis, yield,

摘 要 ：以大豆为研究对象，研究结荚期土壤水分的短期变动对大豆叶片光合生理生态以及最后产量形成的影响。研究发现，与叶片的水分状况相比，大豆的叶片气孔对土壤水分的匮缺更加敏感，在实验的第2天，处理组叶片气孔导度降为对照的24.9%（P＜0.01），但是叶片水势和对照相差不显著（P＞0.05）；随着土壤干旱的进行，处理组叶片的净光合速率、蒸腾速率等都显著下降，但ФPSⅡ只有在第3天才出现显著的下降。复水后第3天，净光合速率比对照高24.3%（P＜0.01），表现出了明显的旱后超补偿效应；研究发现，结荚期即使短期的土壤水分干旱，也会对大豆后期的生物量的分配产生较大的影响，使处理组的豆干重降低13.9%（P＜0.01），根茎比增加35.3%（P＜0.05），收获指数减少17.4%（P＜0.05）。

Abstract:Global climate change is likely to drive up regional drought frequencies, aggravating China′s water shortage problem. Therefore, it is imperative to strengthen researches on crops adapting to the soil drought and agricultural water use efficiency. Soybean is an important source of high-quality protein and edible oil with relatively high water requirement. With an underdeveloped root system, it is the most drought-sensitive bean species. The number of pods per soybean plant is determined during the early stage of pod development. This stage is characterized by active cell division in the young ovules and is marked by rapid pod expansion. Drought stress occurring at this stage significantly increases the rate of pod abortion thus decreasing final seed yield. Therefore, this research focused on the effect of short-term soil water shortage during the pod-setting stage on leaf photosynthetic physioecology and final yield of the soybean, to provide a theoretical basis for water-saving cultivation and high-efficiently water using of soybean. It showed that leaf stomata appeared to be more sensitive to soil water content than leaf water content. On the second day of the experiment, leaf gs of the treatment group decreased to 24.9% of that of the CK (P＜0.01), but there was no statistically significant difference in leaf water potential (P＞005). Along with the water withholding, both leaf net photosynthetic rate and transpiration rate of the treatment group declined significantly during the drought, but ФPSⅡ only dropped on the third day of the experiment. On the third day after rewatering, net photosynthetic rate of the treatment group was 24.3% higher than that of the CK, showing a marked ultra-compensation effect after drought stress. Average seed dry weight, root/shoot ratio and harvest index of the treatment group were respectively 13.9% lower (P＜0.01), 35.3% higher (P＜0.05), and 17.4% lower (P＜0.05) than those of the CK. These results suggest that even a short-term drought during the pod-setting stage could influence later biomass distribution markedly.

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