【作者】 陈托兄；

【导师】 卢欣石；

【作者基本信息】 北京林业大学 ， 草业科学， 2009， 博士

【摘要】 以紫花苜蓿秋眠型标准品种（Maverick,Vernal,Pioneer5446,Legend,Archer,AB1700,Dona Aan,Pierce,CUF101）及中苜1号为材料,通过对NaCl处理下萌发期、苗期、营养期生理生化指标的测定,探讨了紫花苜蓿的耐盐机理以及耐盐能力的大小。主要结论主要如下:1.50 mM NaCl对紫花苜蓿种子萌发没有促进作用。在高浓度下,紫花苜蓿发芽势、发芽率、根长、苗高、发芽指数、活力指数随着盐浓度的增加而降低。紫花苜蓿种子恢复萌发率在50mM NaCl处理下均低于10%;但100 mM-200mM NaCl处理下均在150mM达到最大;在200mMNaCl处理下,恢复萌发率又有所降低。2.根据模糊数学隶属函数平均值（Δ）对萌发期紫花苜蓿耐盐性进行分类,结果如下:Dona Aan、Pierce、Pioneer5446和CUF101耐盐性强,Vernal、Maverick和Legend耐盐性弱,ABI700、中苜1号和Archer耐盐能力居中。以活力指数隶属度对萌发期紫花苜蓿耐盐性分类和综合分类基本吻合,因此活力指数可以作为评价耐盐性的指标。3.O₂^-产生速率与盐浓度呈极显著正相关,表明随着盐浓度的增加,对苗期紫花苜蓿的活性氧伤害程度加剧。依据模糊数学隶属法对苗期紫花苜蓿的盐胁迫下抗氧化能力进行分类:Dona Aan,Pierce,中苜1号具有较强的抗氧化能力;Archer,Pioneer5446,Maverick具有中度抗氧化能力,而CUF101,ABI700,Legend,Vernal的抗氧化能力较差。5.在较低浓度下营养期紫花苜蓿光合响应存在着预警阶段-恢复阶段-耗尽阶段。6.不同生育时期紫花苜蓿电导率随着盐处理浓度的增加而增加。以电导率函数对不同生育时期紫花苜蓿进行分类,其中Dona Aan、Pierce、Pioneer5446和CUF101耐盐性强,Vernal、Maverick和Legend耐盐性弱,ABI700、Archer和中苜1号耐盐性居中,以电导率分类的结果基本和种子萌发期的综合评价结果吻合,因此可以用电导率作为紫花苜蓿萌发期耐盐性鉴定的指标之一。不同生育时期的电导率隶属函数值排序基本相同,用电导率作为紫花苜蓿的耐盐性鉴定指标之一是可行的。更多还原

【Abstract】 Salt tolerance of the different fall dormancy alfalfa in geminating period has been studied by measuring the germination energy,the germination rate,the seedling early growth,the germination index,the activity index under NaCl stress.In order to elucidate mechanism of reactive oxygen species（ROS） regulation and the relevance to salt-tolerance in the different fall dormancy alfalfa,we used Maverick,Vernal,Pioneer5446,Legend,Archer,ABI700,Dona Aan,Pierce,CUF101,Zhongmu No.1 to investigate the effects of increasing NaCl on ROS,anti-oxidative enzymes, malondialdehyde（MDA） and membrane permeability（MP）in shoots and/or roots.In addition,we designed experiments to clarify the response of photosynthetic indexes（Pn,Gs and Ci） under NaCl stress.The conductivity of different growth stages has been determined,and MDA content in the leaves of seedling stage.1.Seed germination of the different fall dormancy alfalfa has not been promoted under 50 mM NaCl.the length of root,the germination index,the activity index and NaCl concentration declined with NaCl concentration increasing when NaCl concentration was greater than 50 mM.The percentage of recovery were lower than 10%under 50 mM NaCl.The percentages of recovery were maxmium when NaCl concentration was 150 mM NaCl.Under the treatments with 100 mM,150 mM and 200 mM NaCl.2.The salt tolerance abilities of alfalfa in geminating period were evaluated comprehensively by subordinate function value method.The results showed that Dona Aan,Pierce,Pioneer5446,CUF101 had the most salt tolerance,that Maverick,Vernal,Legend had the weakest salt tolerance,that ABI700,Zhongmu No.1,Archer had medium salt tolerance.Subordinate degree of alfalfa in the activity index indicated that Aan,Pierce,Pioneer5446,CUF101 had the most salt tolerance,that Maverick,Vernal,Legend had the weakest salt tolerance,that ABI700,Zhongmu No.1,Archer had medium salt tolerance.So the activity index can be taken as the indexes of salt tolerance for alfalfa during germination.3.The correlation between the O₂^- production rate and NaCl concentration was significantly positive during seedling stage.In shoots of the different fall dormancy alfalfa,the degree of ROS damage has increased with the increase of NaCl concentration.The antioxidant capacity of the different fall dormancy alfalfa in seedling stage was evaluated comprehensively by subordinate function value method.The results showed that Dona Aan,Pierce,Zhongmu No.1 had the best antioxidant capacity,that CUF101,ABI700,Legend,Vernal had the weakest antioxidant capacity, that Archer,Pioneer5446,Maverick had the medium antioxidant capacity.4.The photosynthetic response of the different fall dormancy alfalfa consisted of alarm phase, phase of resistance or phase of restoration,phase of exhaustion under 50 and 100 mM NaCl.5.With the increase of NaCl concentration,the conductivity of the different fall dormancy alfalfa seed has increased during different growth stages.Subordinate degree of alfalfa in the conductivity during different growth stages indicated that Dona Aan,Pierce,Pioneer5446,CUF101 had the most salt tolerance,that Maverick,Vernal,Legend had the weakest salt tolerance,that ABI700,Zhongmu No.1,Archer had medium salt tolerance.So the conductivity can be taken as the indexes of salt tolerance for alfalfa during different growth stages.更多还原