断根对冬小麦光合特性及耐旱性的影响

目的]采用叶绿素荧光分析技术探讨断根对冬小麦光合特性的影响,并对不同断根程度冬小麦的耐旱性进行比较。方法]在对水分敏感的冬小麦花期开展试验。断根处理分小断根(A1)与大断根(A2)两种。小断根为单面刀在距小麦主茎一侧2 cm处垂直切下,深度为10 cm。大断根为单面刀在距小麦主茎两侧2 cm处垂直切下,深度为10 cm。于花期(2013年4月19日)给予各处理冬小麦一次性充分供水(土壤含水量占田间持水量的80%),此后不再供水任其水分胁迫自然加重并避免降水影响,测定供水后1、4、7、10、13 d各处理冬小麦旗叶叶绿素荧光参数。结果]冬小麦叶绿素荧光对水分胁迫非常敏感,其参数的变化与水分胁迫的加剧密切相关。通过叶绿素荧光数据对比,在胁迫加剧的过程中断根处理小麦比对照小麦具有更强的耐旱能力,而双侧断根处理较单侧断根具有更强的耐旱力。结论]该研究可为旱地节水农业的持续发展提供理论及实践依据。

Effects of Root-cutting on Photosynthetic Characteristics of Winter Wheat and Its Drought Tolerance

Objective] The aim was to discuss the effects of root-cutting on photosynthetic characteristics of winter wheat by chlorophyll fluorescence analysis,and compare their drought tolerance.Method] The test was conducted on in winter wheat flowering period in which it was sensitive to water.The root-cutting treatments were unilateral root-cutting （A1） and bilateral root-cutting（A2）.A1 treatment was that singleside knife was used to cut vertically from 2 cm of on one side of the main stem,and the depth was 10 cm; A2 treatment was that that singleside knife was used to cut vertically from 2 cm of both sides of the main stem,and the depth was 10 cm.At the flowering stage（April 19,2013）,the winter wheat of all treatments were fully irrigated all at once（the soil water content was 80％ of field capacity）,after that,there were no irrigation and avoid to the effects of rainfall,and then the chlorophyll fluorescence parameters of flag leaf of winter wheat of all treatments were determined after irrigating 1,4,7,10 and 13 days.Result] The chlorophyll fluorescence of winter wheat was very sensitive to water stress,its parameters change was closely related to the increasing of water stress.By chlorophyll fluorescence data comparison,the dought tolerance of root-cutting treatments was stronger than that of the control during the process of increasing water stress,while bilateral root-cutting treatment had stronger drought tolerance to water stress than that of unilateral root-cutting treatment.Conclusion] The study provides a theoretical and practical basis for sustainable development of water saving agriculture in dry land.