紫花苜蓿对牛角花齿蓟马为害的光合生理响应  

Photosynthetic physiological response of Medicago sativa to Odontothrips loti damage

作　　者：寇江涛[1,2] 师尚礼[1,2] 胡桂馨[1,2] 周万海[1,2] 

机构地区：[1]甘肃农业大学草业学院,兰州730070 [2]草业生态系统教育部重点实验室,甘肃省草业工程实验室,中-美草地畜牧业可持续研究中心,兰州730070

出　　处：《生态学报》2014年第20期5782-5792,共11页Acta Ecologica Sinica

基　　金：国家现代牧草产业技术体系建设专项(CARA-35);教育部高校博士学科点基金项目(20106202110003);国家自然科学基金项目(31260579)

摘　　要：为了探索紫花(Medicago sativa L.)苜蓿对优势种害虫——牛角花齿蓟马(Odontothrips loti Haliday)为害的光合生理响应机制,揭示苜蓿对牛角花齿蓟马为害的补偿机制,以抗蓟马苜蓿无性系R-1和感蓟马苜蓿无性系I-1为材料,测定不同虫口密度牛角花齿蓟马为害后R-1、I-1无性系气体交换参数、叶绿素荧光诱导动力学参数的变化。结果表明:随着牛角花齿蓟马虫口密度的增加,R-1无性系叶绿素含量先升高后降低,I-1无性系叶绿素含量降低,R-1、I-1无性系的净光合速率(Pn)和水分利用效率(WUE)降低,胞间CO2浓度(Ci)、气孔导度(Gs)和蒸腾速率(Tr)升高;在相同虫口密度下,R-1无性系的叶绿素含量、Pn、WUE均高于I-1无性系。随着虫口密度的增加,R-1、I-1无性系的初始荧光(F0)升高,PSⅡ实际光合效率(ФPSⅡ)、非光化学淬灭系数(NPQ)、光化学淬灭系数(q P)、PSⅡ潜在活性(Fv/F0)和PSⅡ原初光能转化效率(Fv/Fm)均降低;在相同虫口密度下,R-1无性系的F0低于I-1无性系,R-1无性系的ФPSⅡ、q P、Fv/F0和Fv/Fm均高于I-1无性系。从各个指标的变化幅度来看,随着虫口密度的增加,R-1无性系气体交换参数和绿素荧光动力学参数的增幅、降幅均小于I-1无性系。说明牛角花齿蓟马为害造成了紫花苜蓿PSⅡ反应中心受损,使得紫花苜蓿对光能的利用能力下降,光合效率降低。但在低虫口密度(1、3头/枝条)下,R-1无性系具有较高的光合效率,光合补偿效应显著大于I-1无性系,说明R-1无性系对牛角花齿蓟马为害具有较强的抗性。Plant photosynthetic capability usually changes after damage by a herbivorous pest. Photosynthetic compensation is the physiological response of the plant to pest damage with the level of compensation varying with the change in pest damage. This paper explores the photosynthetic response mechanism of alfalfa to the dominant insect-Odontothrips loti- and explains the compensatory mechanism of alfalfa to thrip damage. The thrip resistant clone,R-1 and susceptible clone,I-1were used to investigate the gas exchange and chlorophyll fluorescence parameter changes under different insect densities（ 0,1,3,5,and 7 per branch,respectively）,Photosynthesis equipment,GFS-3000（ Walz,Germany） and modulated chlorophyll fluorometer imaging-PAM（ Walz,Germany） were used. For the 7 per branch treatment,the results indicate that the chlorophyll content of R-1 initially increased and then decreased,while the chlorophyll content of I-1 decreased. ForR-1,the chlorophyll content was 11. 32% lower than CK（ 0 thrip per branch）,and for the 3,5,and 7 per branch treatments of I-1,the chlorophyll contents were 14.05%,22.02% and 26.27% lower than CK,respectively. For both R-1and I-1,the net photosynthetic rate（ Pn） and water use efficiency（ WUE） decreased,while the intracellular concentration of CO2（ Ci）,stomatal conductance（ Gs） and transpiration rate（ Tr） increased. For R-1,the Pnof 3,5,and 7 per branch treatments were 6.98%,19.03% and 20.11% lower than CK,and the WUE of all the treatments were 16.32%,23.95%,37.12% and 45.89% lower than CK. For I-1 treatments,the Pnof all the treatments were 5.38%,8.77%,22.47% and35. 66% lower than CK,and the WUE were 25. 23%,31. 05%,45. 78% and 61. 81% lower than CK,respectively. The chlorophyll content,WUE and Pnof R-1 were all greater than I-1 under the same insect density. As insect density increased,the initial fluorescence（ F0） increased,which for the R-1 clone resulted in F0 for 5 and 7 per branch treatments of 6.99% and 9.13% higher than CK,respectively. For the

关 键 词：紫花苜蓿 牛角花齿蓟马 虫口密度 光合生理 抗虫性 

分 类 号：S435.4[农业科学—农业昆虫与害虫防治]