Symbiotic interactions as drivers of trade-offs in plants: effects of fungal endophytes on tall fescue

查看全文 作　　者：Pedro [1,2]E.Gundel;Lucas [3]A.Garibaldi;Marjo [4]Helander;Kari [1]Saikkonen 机构地区：[1]Department of Plant Production,MTT Agrifood Research Finland,31600 Jokioinen,Finland;[2]IFEVA-CONICET-Faculty of Agronomy,Buenos Aires University(UBA),Buenos Aires,Argentina;[3]Sede Andina,Universidad Nacional de Río Negro(UNRN)and Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET),Mitre 630,8400 San Carlos de Bariloche,Río Negro,Argentina;[4]Section of Ecology,Department of Biology,University of Turku,Turku,Finland 出　　处：《Fungal Diversity》索引2013年第3期,共10页 摘　　要：Studying the controls on biomass allocation trade-offs in plants are important since they affect harvestable product yields and are critical to understanding symbiotic interactions.Epichloae fungal endophytes associate with cool-season grasses,growing systemically within the plant inter-cellular spaces and are transmitted through seeds.We explore the endophytes influence on the relationship between the plant reproductive and vegetative aboveground biomass(reproductive effort:RE)and on the trade-off between two components of the reproductive biomass,number and weight of panicles(RPN),using tall fescue as a model system.Naturally endophyte-colonized,manipulatively endophyte-free,and naturally endophyte-free plants from Northern European wild-populations together with the cultivar Kentucky-31 were grown under different environmental conditions(nutrients x water).The endophyte had an effect on the RPN(E+:6.19,ME-:4.68 and E-:4.40)which indicates how reproductive biomass is partitioned into number and mass of panicles,but not on RE(≈0.06).As expected,wild plants showed higher reproductive effort(≈0.06)compared to the cultivar KY-31(0.05),irrespective of endophyte presence.Endophyte-colonized plants had lighter panicles than endophyte-free plants,a pattern that was clear among low-yielding plants.Similarly,the tradeoff between RPN and RE was higher for endophytecolonized plants.This was again evident among plants with low RE indicating that colonized plants split the yield into either greater number of panicles and/or lighter panicles.The effect of vertically transmitted endophytes has earlier been studied as ratios(e.g.RE);however,our study shows that this approach may hide size-dependent endophyte effects on these relationships.Our study reveals that Neotyphodium endophyte affects trade-offs in tall fescue plants in a complex manner,and is influenced by a number of biological and abiotic factors. 关 键 词：ALLOMETRY Biomass partitioning NEOTYPHODIUM FESTUCA SYMBIOSIS Plant-endophyte interaction