冬小麦水分生理特性对水分胁迫的响应

采用盆栽试验对不同土壤水分条件下冬小麦水分生理生态特性进行了初步研究。结果表明,随干旱胁迫的加剧,不同生长时期冬小麦叶片相对含水率和叶水势均呈减小趋势,叶片水分饱和亏均呈增大趋势。且不同土壤水分条件下冬小麦叶片相对含水率和饱和亏与土壤持水量关系密切。严重干旱处理下冬小麦叶片相对含水率和叶水势始终维持在较低水平,而轻度干旱和正常水分处理尤其是正常水分处理维持在较高水平。冬小麦日蒸腾平均值的大小顺序为正常水分处理(3.375 mmol·cm~(-2)·s~(-1))>轻度干旱处理(3.107 mmol·cm~(-2)·s~(-1))>中度干旱处理(2.332 mmol·cm~(-2)·s~(-1))>严重干旱处理(2.018 mmol·cm~(-2)·s~(-1))。各处理冬小麦蒸腾出现较大差异的时间在12:00和14:00。不同土壤水分条件下除严重干旱外冬小麦蒸腾速率均与光合有效辐射强度显著相关,各处理均与大气相对湿度和叶片温度显著相关,与土壤水分密切相关。土壤水分对冬小麦的生物量和产量具有显著影响,正常水分处理生物量和产量最高,高于其他3个处理,严重干旱处理最低。

Response of Physiological Characteristics of Winter Wheat to Water Stress

The physiological characteristics of winter wheat under different soil water conditions were stud- ied using pot culture experiment.The results showed that leaf RWC and leaf water potential decreased with soil water decreasing,and leaf WSD increased with soil water decreasing in different growth stages.The leaf RWC, WSD of winter wheat was significantly correlated to soil water content under different soil water conditions.The leaf RWC and water potential of medium soil drought treatment and serious soil drought treatment kept lower, but that of normal soil water treatment and light soil drought treatment were higher.The average whole day transpiration under different soil water conditions was in such order as:normal soil water treatment (3.375mmol·cm~(-2)·s~(-1))>light soil drought treatment(3.107 mmol·cm~(-2)·s~(-1))>middle soil drought treatment (2.332 mmol·cm~(-2)·s~(-1))>serious soil drought treatment(2.018 mmol·cm~(-2)·s~(-1)).The remarkable difference of transpiration appeared at 12:00 and 14:00 under different soil water conditions.Significant correlation was found between transpiration and light intensity,RH,leaf temperature and soil water content.All these resulted in diversity of biomass under different soil water conditions.The biomass of normal soil water treatment was highest and the serious soil drought treatment the lowest.