小麦花后淹水胁迫对根区土温及籽粒灌浆的影响

为了探讨淹水对花后冬小麦根区土温及籽粒灌浆的影响，在淮北平原涝渍易发地河南商丘市，对处于花后灌浆阶段的冬小麦进行淹水试验。结果表明，淹水使小麦百粒重降低，花后灌浆阶段淹水1 d、3 d和5 d使乳熟期的小麦百粒重比非淹水处理分别降低6.93%、10.35%和10.31%；淹水使小麦灌浆速率受到抑制，淹水5 d、3 d、1 d和CK的平均单粒灌浆速率分别为1.36、1.39、1.52和1.61 mg·d^-1，淹水超过5 d使小麦的乳熟时间推后。淹水使10~40 cm土层间温差变小，淹水时间越长，10~40 cm土温降低越多，淹水结束后土温回升也越快。花后淹水使小麦干物质量及籽粒产量降低，淹水5 d以上使小麦地上、地下部分干物质量显著降低。因此，小麦花后灌浆阶段淹水会影响根区环境和地上部干物质的形成，并最终影响籽粒灌浆及产量。

Root Zone Soil Temperature and Grain Filling Progress of Winter Wheat under Water Flooding at Grain Filling Stage

In order to investigate the effects of water flooding on root zone soil environment and grain filling of winter wheat at grain filling period, a field experiment with water flooding treatments for 1 day (F1), 3 days (F3), and 5 days (F5) applied at grain filling stage was carried out in Shangqiu, one of the water flooding-prone zones in Huaibei Plain. Results showed that the 100-grain weight of winter wheat at mild-rape stage was decreased by water flooding applied at grain filling stage. The 100-grain weight of F5, F3 and F1 flooding teatments at harvest was lower than that of CK by 6.93%, 10.35%, and 10.31%, respectively. The grain filling rate of wheat was restrained by water flooding. Mean grain filling rate of wheat in F5, F3, F1 and CK was 1.36,1.39,1.52,1.61 mg·d^-1, respectively. The milk-rape period was delayed for 5 days by water flooding. Difference in soil temperature between 10 cm and 40 cm soil layer was decreased by water flooding. The longer water flooding, the more decrease in soil temperature of the 10~40 cm soil layer. During the water logging period, diurnal soil temperature in 10 cm soil layer was higher than that in CK. Dry matter and grain yield of winter wheat was decreased by water flooding applied at grain filling stage. Biomass of root and shoot of winter wheat was decreased significantly by water flooding for 5 days. Therefore, water flooding applied at grain filling stage had effects on the root zone environment and above-ground biomass formation, then grain filling and grain yield.