不同程度干旱胁迫及复水对春玉米(丹玉39)茎流动态的影响

Effects of different drought stresses and re-watering on sap flow dynamic of spring maize Danyu 39

利用大型移动防雨棚开展了玉米干旱胁迫及复水试验,通过分析玉米植株茎流速率变化规律,揭示了不同程度干旱胁迫及复水对玉米植株茎流速率的影响及其对环境因子的响应规律。结果表明:1不同发育期干旱胁迫及对照试验的玉米植株茎流速率在晴天均呈单峰曲线,在阴天或多云天呈现不规则的上下波动状态;干旱胁迫导致玉米茎流速率显著下降并且峰值提前;复水后的茎流速率与对照间的差异缩小,但仍低于对照且峰值提前;2比较拔节—吐丝期茎流速率平均值为:对照>重度干旱胁迫>中度干旱胁迫,吐丝—乳熟期和乳熟—成熟期均为:对照>中度干旱胁迫>重度干旱胁迫。3茎流速率与净辐射、气温呈现显著正相关,与相对湿度呈现显著负相关;重度干旱胁迫后,土壤水分的亏缺影响了玉米植株茎流速率,减弱了相对湿度对其茎流速率的影响。

A field experiment of water stress and rewatering for maize was carried out using the large moving water-proof shed. The effects of different water stresses and rewatering on the sap flow rate of maize and its response to environmental factors were revealed by analyzing the variations of sap flow rates. The results showed that the daily dynamic of maize sap flow under different water conditions exhibited a single peak curve in sunny days,and displayed multiple peak curves in cloudy days. The sap flow rates were significantly decreased by drought and the peak value appeared early with drought. Sap flow after rewatering showed minor difference from the control,but the values were lower than those of the control and the peak value appeared earlier than the control. In addition,the average sap flow rate at jointing to silking stage was highest in the control,followed by under severe stress and then under moderate stress; At silking to milk and milk to mature stages,it was the highest in the control,followed by under moderate stress and then under severe stress. Also,the plant sap flow of maize showed good response to environmental factors such as net radiation,air temperature and relative humidity. The stress of soil moisture affected the sap flow rate,and reduced the effect of relative humidity on the sap flow rate.