Classification of intra-specific variation in plant functional strategies reveals adaptation to climate.

Background And Aims: In plants, extensive intra-specific variation exists in the allocation of resources between vegetative growth and reproduction, reflecting different functional strategies. A simple method for the classification of intra-specific variation in these strategies would enable characterization of evolutionary and ecological processes.

Methods: C-S-R theory can be applied to classify functional strategies (competitive C; stress tolerant, S; ruderal, R) in different plant species. Using a diverse set of arabidopsis ( Arabidopsis thaliana ) accessions grown under common conditions, it was tested whether a simple approach designed for allocating C-S-R strategies at the species level can also be used to analyse intra-specific variation.

Key Results: Substantial intra-specific variation between arabidopsis accessions was found along the S-R axis. There was a positive correlation of temperature at the geographical origin with the dimension of S and a negative correlation with the dimension of R. Flowering time in a natural annual cycle and leaf dry matter content were identified as the main determinants of this adaptation, with plants originating from warmer climates having a higher leaf dry matter content and flowering earlier in a common garden.

Conclusions: It was shown that functional strategies reflect adaptation to climate, with consequences for important traits such as fecundity and total plant dry weight. The approach could be used in genome-wide association studies to determine the genetic basis of functional strategies in wild species or crops.