Abstract: Mechanisms of kin selection have been studied to explain how siblings grow together, but the findings remain controversial. This can be ascribed to the use of single indicators without considering other factors. Three ecotypes of Arabidopsis were used to examine kin responses of siblings growing together. Plant traits of leaves, plant shape, reproductive activity, and roots were investigated. We found that Arabidopsis recognized their kin neighbors, showed selective responses to distinct plant traits among ecotypes, and modes of responses were dependent on neighbor's growing distance. If single traits were used to judge kin response performance, the results were chaotic. However, by developing and studying an integrated performance value based on multiple traits, we determined that Ler showed similar integrated performances at all planting distances, while the integrated performance of Col was ranked mainly as medium distancedistance> small distance> large distance, which suggested kin cooperation. However, in comparison to medium and small distances, at which performance was consistent with kin recognition, we found that at large distance, strangers of Ws performed better than kin plants, which suggested competition. Thus, we conclude that kin recognition could be affected by plant competition conditions that are the result of growing distance, and that the integrated performance of individuals was more suitable to evaluate kin interactions of plant species.

Key words: arabidopsis, competition, integrate performance, kin recognition, planting distance