关键词: 扁穗牛鞭草, 扁穗牛鞭草, 外源钙离子, 低温胁迫, 保护酶活性
中图分类号：Q945.78

Abstract: The paper aims to analyze the characteristics of air, water and soil temperature during the whole growth period of late rice and the measures to avoid cold-dew wind disaster, environmental temperatures were recorded using a cropland microclimatic and real observation system. The results indicated that: the accumulated water temperature was the highest during the vegetative stage and the accumulated soil temperature was the highest during the reproductive stage. The differences among daily mean air, water and soil temperature were quite big during the vegetative stage. They were close and synchronously declined after the booting stage. The water temperature at noon was positively correlated with sunshine hours and negatively correlated with leaf area index (LAI). Water temperature was higher for 14 hours, which was longer than that of early rice. Water could be used to adjust low temperature. When cold-dew wind occurred, air temperature dropped rapidly and the minimum appeared at 6:00. The daily mean air temperature was 2℃ lower than daily mean water temperature, the minimum air temperature was 5.3℃ lower than the minimum water temperatures. All day long the water temperature was stable, deep-water irrigation could smooth the morning and night temperature drop, this might enhance the mean air temperature for 1.5℃. Drainage and drying field in sunny days, water and soil temperature were upward significantly after 11:00. Cold- dew wind after the heading caused the shriveled grain increase. After deep-water irrigation, drainage and drying field in sunny days could reduce the rate of shriveled grain and the rate of unfilled grains, and improve thousand kernel weight significantly.