干旱胁迫下黑穗画眉草的生理响应

目的]探讨云南昆明周边黑穗画眉草(Eragrostis nigra)的抗旱生理特性。方法]以采自云南3个不同地方的黑穗画眉草为试验材料(编号为H_1、H_2、H_3),采用不同浓度的聚乙二醇(PEG 6000)模拟干旱胁迫,研究在不同胁迫情况下抗氧化酶、叶绿素含量、可溶性总糖含量及光合参数的变化。结果]H_1、H_2、H_3的过氧化物酶(POD)活性、抗坏血酸过氧化物酶(APX)活性、过氧化氢酶(CAT)活性、可溶性总糖含量和丙二醛含量均与胁迫强度和处理时间呈正相关,叶绿素含量与胁迫强度和处理时间呈负相关。3个材料的净光合速率(Pn)、蒸腾速率(Tr)、胞间CO_2浓度(Ci)和H_1的气孔导度(Gs)均与处理时间和胁迫强度呈负相关。H_2和H_3干旱胁迫时Gs随处理时间的延长先增加后减小,轻度胁迫时有最大值。结论]3种黑穗画眉草均有一定的抗干旱胁迫能力,H_1抗旱能力高于其他2种,更能适应干旱缺水的环境。

Physiological Response of Eragrostis nigra Under Drought Stress

Objective] To discuss the physiological characteristics of drought resistance around Yunnan Province. Method] With Eragrostis nigra in three different areas (H1, H2, H3) of Yunnan Province as the test materials, drought stress was simulated by different concentrations of PEG 6000.Changes of antioxidase, chlorophyll content, total soluble sugar content and photosynthetic parameter were researched under the stress. Result] POD, APX and CAT activities, total soluble sugar content and MDA content of H1 , H2 , H3 had positive correlation with stress strength and treatment time.Chlorophyll content had negative correlation with stress strength and treatment time.The net photosynthesis (Pn), transpiration rate (Tr), stomatal conductance (Gs) and intercellular CO2 concentration (Ci) of three E.nigra had negative correlation with treatment time and stress strength.Under drought stress of H2 and H3 , Gs firstly enhanced and then reduced as the treatment time pro-longed, and achieved the maximum value at light stress.Conclusion] Three E.nigra have some drought stress capability, drought resistance of H1 is higher than those of the other two, which can adapt to the arid environment easier.