Effects of the ecological factors and their interactions on the phenotypic plasticity of Arabidopsis thaliana
生态因子及其交互作用对拟南芥(Arabidopsis thaliana)表型可塑性的影响

A pot experiment of orthogonal design was conducted to study the effects of four ecological factors, including salt, water, light, and defoliation, and their interactions on 18 phenotypic traits in two genotypes of Arabidopsis thaliana (i.e. genotypes col-0 and ws-0). Results showed that different ecological factors affected the different types of the phenotypic traits: soil water affected mainly the traits relating to modular number; salt affected such traits as biomass, number of siliques, and total number of maturing seeds that directly reflect the plant fitness; and light affected the traits relating to phenology, thus the development of individuals. The directions of phenotypic plasticity of A. thaliana to soil water were variable along the water gradient without an apparent trend. The collective effects of all the factors on phenotypic plasticity were not simply the additive effects of single factors: any two factors could show significant effects on specific traits in the absence of interactions, or any two factors with significant interactions on specific traits may display non-significant effects individually. In responses to the interactive effects of the studied ecological factors, nine phenotypic traits exhibited plasticity in the col-0 genotype, and only four in the ws-0. The inter-related phenotypic traits within the same genotypes displayed the similar patterns of plasticity. The number of rosette leaves at bolting (LN) and the average number of maturing seeds per silique (ANMS) were not affected by any of the ecological factors nor their interactiuons. The reason for lack of plasticity in those two quantitative phenotypic traits requires further investigation.