摘要
虽然许多物种的遗传多样性和植物生产力之间的关系已经得到证实,但环境条件和生物群落是否会改变这种关系尚不清楚。针对这一问题,本文研究了基因型多样性、干旱和菌根对植物生产力和植物性状的交互作用。该研究建立在堪萨斯州曼哈顿南部的康扎草原生物研究站。本研究对焦点物种大须芒草(Andropogon gerardii)采用两种水平的基因型丰富度处理:单种栽培和3基因型混合栽培。在试验区的一半以上建立避雨棚进行抗旱处理,并在每个基因型丰富度和抗旱处理的选定盆栽中使用硫菌酯-甲基杀菌剂抑制丛枝菌根真菌的生长。结果表明,基因型丰富度和菌根对大须芒草的地上生物量无显著影响。干旱对大须芒草各基因型地上生物量、成花数和过早结实有不同的影响,而且生物量和功能性状在单独栽培和混合栽培处理中有显著差异。这些研究结果说明,干旱和基因型丰富度对不同基因型的植物有不同的结果。
While the relationship between genetic diversity and plant productivity has been established for many species,it is unclear whether environmental conditions and biotic associations alter the nature of the relationship.To address this,we investigated the interactive effects of genotypic diversity,drought and mycorrhizal association on plant productivity and plant traits.Our mesocosm study was set up at the Konza Prairie Biological Research Station,located in the south of Manhattan,Kansas.Andropogon gerardii,the focal species for our study,was planted in two levels of genotypic richness treatment:monoculture or three-genotype polyculture.A rainout shelter was constructed over half of the experimental area to impose a drought and Thiophanate-methyl fungicide was used to suppress arbuscular mycorrhizal fungi in selected pots within each genotypic richness and drought treatment.Genotypic richness and mycorrhizal association did not affect above-ground biomass of A.gerardii.Drought differentially affected the above-ground biomass,the number of flowers and bolts of A.gerardii genotypes,and the biomass and the functional traits also differed for monoculture versus polyculture.Our results suggest that drought and genotypic richness can have variable outcomes for different genotypes of a plant species.
基金
supported by the funding provided to Meghan Avolio by the United States Environmental Protection Agency.
