限量补灌对旱地高产田小麦光合和产量的影响

在多年创高产旱地条件下，研究了不同补灌处理对旱地高产田小麦光合特性和产量的影响。结果表明：增加补灌次数和补灌量，小麦旗叶叶绿素含量、光合速率、气孔导度、蒸腾速率升高，胞间CO2浓度降低，光合功能持续期延长，产量和产量构成因素增加，以补灌3水（越冬＋拔节＋灌浆）处理W4效果最佳，但产量和2水（拔节＋灌浆）处理W3没有显著差异。随着补灌次数和补灌量继续增加，W5、W6改善旗叶光合衰退的效果主要表现在后期，对产量提高的贡献并不大，相对与2水、3水处理，开始产生负效应，产量和产量构成因素千粒重、穗粒数反而下降。综合考虑产量和水分利用效率等因素，在本旱地高产试验田．拔节期、灌浆期2水补灌120mm的W3处理是最经济高效的补灌方案。

Effect of Limited Supplementary Irrigation on Photosynthesis and Yield of Wheat in High-yield Dryland

Effect of different supplementary irrigation treatments on photosynthesis and yield of wheat in high-yield dryland was studied with field experiment. The results indicated that with the increase of supplementary irrigation times and quota, the chlorophyll content, photosynthetic rate, stomatal conductance, tran- spiration rate and photosynthetic active duration of flag leaf increased while intercellular CO2 concentration decreased, and the yield and yield factors increased also. W4 which was irrigated three times at wintering, jointing and filling stages was the best. And there was no significant difference compared with W3 which was irrigated two times at jointing and filling stages on yield. With irrigation times and quota further increasing, negative effect of W5 and W6 produced. The role of over-irrigation improving photosynthesis decline of flag leaf was mainly at the latter stage and had no role for yield increase. The yield, 1000-grain weight and grain per spike decreased on the contrary. Considering the yield and water use efficiency, W3 of irrigating 120mm was economical and high efficiency in this field.