水分亏缺下紫花苜蓿和高粱根系水力学导度与水分利用效率的关系  

The root system hydraulic conductivity and water use efficiency of alfalfa and sorghum under water deficit

作　　者：李文娆[1,2] 李小利[3] 张岁岐[2] 山仑[1,2] 

机构地区：[1]河南大学生命科学学院生态科学与技术研究所,开封475004 [2]西北农林科技大学中国科学院教育部水土保持与生态环境研究中心黄土高原土壤侵蚀与旱地农业国家重点实验室,杨凌712100 [3]河南工业大学化学化工学院,郑州450001

出　　处：《生态学报》2011年第5期1323-1333,共11页Acta Ecologica Sinica

基　　金：国家重点基础研究发展计划(973计划)项目(2009CB118604);国家自然科学基金(30971714);河南省自然科学基金研究项目(092300410095);省部共建河南大学科研课题(SBGJ090405)

摘　　要：利用聚乙二醇(PEG-6000)模拟水分亏缺条件(胁迫水势-0.2MPa,胁迫48h),研究了变水条件下紫花苜蓿(品种:阿尔冈金和陇东)和高粱(品种:抗四)根系水力学导度(Lpr)、根系活力、根叶相对含水量、水分利用效率等参数的动态变化,以期进一步明确植物水分吸收及散失过程调控的生理生态学基础。结果表明:水分亏缺限制了紫花苜蓿和高粱根系吸水,表现在Lpr的下降和根系活力的降低;继而调控了其地上部反应,引起气孔导度、光合速率、叶片相对含水量和蒸腾速率等的下降,但限制性的提高了其水分利用效率,尤其在胁迫初期。恢复到正常供水条件后,Lpr、根系活性、气孔导度等水分利用参数逐渐部分或完全恢复到了胁迫前水平,但恢复程度存在种间和品种间差异,并且根系吸水能力的恢复对于是植株地上部生长状态的恢复至关重要,尤其是水分恢复初期。紫花苜蓿根系中检测到水通道蛋白(AQPs)的存在,水分亏缺对紫花苜蓿Lpr的影响认为主要是通过影响AQPs的活性实现的。比较紫花苜蓿和高粱水分吸收与利用状况在变水条件下的动态变化,认为紫花苜蓿幼苗对干旱逆境的适应能力相对弱于高粱,品种间陇东适应能力更强。How to absorb more water and consume less water for plant has become increasingly more important because of water shortage.Root system is essential to uptake water from soil and stomata are important tissues to dismiss water for plant growth.However,one of great challenges in agricultural production is how to balance water absorption by roots and water use by shoots,especially under water deficit. In this paper we are focus on the regulating mechanism between roots water absorption and shoots water consumption,to clarify eco-physiological basis of drought resistance and understand the adaptive traits to drought stress.In drought-stressed plants,roots system hydraulic conductivity（Lpr）,roots vigor,relative water content of leave and roots,water use efficiency and some parameters dedicated water use characteristics,such as stomatal conductivity,net photosynthetic rate,intercellular CO2 concentration and transpiration rate,etc.of alfalfa（Medicago sativa L cultivars： Algonquin and Long-Dong） and sorghum（Sorghum bicolor L.cultivars： Kang-Si） were studied.Under variable water conditions of mimicked by PEG-6000,when tested plants undergo for 48 h stress（-0.2MPa water potential） and subsequent water recovery of 48 h,the experimental results indicated that roots water absorption（Lpr） affected vitally water use and photosynthesis of shoots,especially at primary of water deficit and water recovery.Water absorption of alfalfa and sorghum was inhibited firstly by water deficit companying with decrease of Lpr and root vigor and then,decline of stomatal conductivity.Net photosynthetic rate,relative water content of leave and transpiration rate etc.were induced.On the other hand,a limited increased in water use efficiency not in sorghum but in alfalfa are observed.It also shows that water deficit affect alfalfa stronger than that of sorghum.After rewatering from stress,Lpr,root vigor,other parameters related to water characteristics（stomatal conductivity,net photosynthetic rate,relative water content of

关 键 词：根系吸水 水分利用效率 紫花苜蓿 高粱 干旱适应性 

分 类 号：S541.9[农业科学—作物学]