摘要
以8个野生金荞麦(Fagopyrum dibotrys)种质为试材,在室内模拟35和45℃高温胁迫,测定了各种质气体交换和叶绿素荧光参数,探讨金荞麦对高温胁迫的光合适应机制,并在利用主成分分析和隶属函数法综合考虑各综合指标权重的基础上,评价种质间耐热性强弱。随着高温胁迫强度的增加,各金荞麦种质的净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、水分利用效率(WUE)、PSⅡ的潜在活性(Fv/Fo)、最大光化学效率(Fv/Fm)、实际光量子产量(Yield)和光化学猝灭系数(qP)等参数均逐渐降低;叶片非光化学荧光猝灭系数(NPQ)则先增加后降低(JQ4、JQ5和JQ7)或一直增加(JQ1、JQ2、JQ3、JQ6和JQ8)。利用主成分分析将9个单项指标转换为相互独立的两个综合指标(第一、二主成分),其权重分别为0.816和0.184。隶属函数法综合评价出8个金荞麦种质耐热性顺序分别为JQ6>JQ2>JQ3>JQ1>JQ8>JQ4>JQ5>JQ7。为抵御高温,耐热性强的金荞麦种质通过调节气孔导度,减小蒸腾速率,提高水分利用率,并将过剩的激发能以热的形式耗散掉,以保护光合机构。
To explore the adaptation mechanisms of Fagopyrum dibotrys to high temperature stress and to evaluate the differences of heat resistance of eight F.dibotrys germplasm resources,it was measured that the characteristics of gas exchange and chlorophyll fluorescence parameters in leaves of eight germplasm resources under the high temperature(35 ℃ and 45 ℃) stress.The results showed that: There were very obvious effects of heat stress on photosynthesis and chlorophyll fluorescence parameters; With the strength of the heat stress,it was significantly decreased that the net photosynthetic rate(Pn),stomatal conductance(Gs),transpiration rate(Tr),water use efficiency(WUE),PSⅡ potential activity(Fv/ Fo),PSⅡ maximum photochemical efficiency(Fv/ Fm),PSⅡ actual photochemical quantum yield(yield) and PSⅡ photochemical fluorescence quenching(qP) in all of germplasm resources; However,it was increased that the non-photochemical fluorescence quenching(NPQ) in leave of JQ4,JQ5,JQ7,but decreased as the strength of heat stress was increased,and steadily increased that the non-photochemical fluorescence quenching(NPQ) in leave of JQ1,JQ2,JQ3,JQ6,JQ8.The nine single indexes were changed into two comprehensive indexes by using the principal components analysis.The weight of two comprehensive indexes were 0.816 and 0.184,respectively.According to the results of subordinate function value analysis,the heat resistance capability was in the order of JQ6>JQ2>JQ3>JQ1>JQ8>JQ4>JQ5>JQ7 in eight F.dibotrys materials.Based on above,the better heat-tolerant F.dibotrys germplasm resourses could regulate the stomatal conductance,decrease the transpiration rate,increase the water use efficiency,and made excited energy dissipated as thermal dissipation to resist high temperature and protect the photosynthetic apparatus.
出处
《草业科学》
CAS
CSCD
北大核心
2015年第4期560-569,共10页
Pratacultural Science
基金
贵州省动植物育种专项[黔农育专字(2012)018]
贵州省科教青年英才培育工程项目[黔省专合字(2012)142号]
贵州省科技成果重点推广计划[黔科合成字(2013)5084]
国家自然科学基金项目(31260572)
关键词
金荞麦
高温胁迫
气体交换参数
叶绿素荧光参数
Fagopyrum dibotrys
high temperature stress
gas exchange parameters
chlorophyll fluorescence pa-rameters
