Differential genetic influences on competitive effect and response in Arabidopsis thaliana

Abstract

Summary 1Competition plays an important role in structuring populations and communities, but our understanding of the genetic basis of competitive ability is poor. This is further complicated by the fact that plants can express both competitive effect (target plant influence upon neighbour growth) and competitive response (target plant growth as a function of a neighbour) abilities, with these ecological characteristics potentially being independent. 2 Using the model plant species Arabidopsis thaliana , we investigated patterns of intraspecific variation in competitive effect and response abilities and their relationships to other plant traits and resource supply rates. 3 Both competitive effect and response were measured for 11 genotypes, including the Columbia ecotype and 10 derived mutant genotypes. Plants were grown alone, with intragenotypic competition, and with intergenotypic competition in a replicated blocked design with high nutrient and low nutrient soil nutrient treatments. We quantified competitive effect and response on absolute and per-gram bases. 4 Competitive effect and response varied among genotypes, with the relative competitive abilities of genotypes consistent across fertilization treatments. Overall, high rates of fertilization increased competitive effect and competitive response abilities of all genotypes. Both competitive effect and response were correlated with neighbour biomass, though genotype-specific traits also influenced competitive response. 5 At the genotype level, there was no correlation between competitive effect and response in either fertilization treatment. Overall patterns in competitive response appeared consistent among inter-and intragenotypic competition treatments, indicating that a target genotype's response to competition was not driven by the genetic identity of the competitor. 6 These findings indicate that within A. thaliana , there is the potential for differential selection on competitive effect and response abilities, and that such selection may influence different sets of plant traits. The concept of a single competitive ability for a given plant is not supported by these data, and we suggest continued recognition of these dual competitive abilities is essential to understanding the potential role of competition in influencing intra-and interspecific processes.

Genetic lineages of the invasive Aegilops triuncialis differ in competitive response to neighboring grassland species

“…1, 2). This result supports those of previous work demonstrating genetic lineages respond differently to competition (Cahill et al 2005;Latta et al 2004;Muller and Bartelheimer 2013). We add to this body of work by showing that genetic lineages within the invaded range respond differently to competition.…”

The roles of demography and genetics in the early stages of colonization

“…Dispersal usually increases with population density as a result of competition [25 -27]. On the other hand, individual responses to intraspecific competition [28] and dispersal tendencies both [24,29] have strong genetic components. Dispersal tendencies can increase in populations with related individuals as a strategy to avoid kin competition [30] or inbreeding [31].…”

Functional genetics of intraspecific ecological interactions in Arabidopsis thaliana

“…[1,2]) and the development of traits involved in processes such as niche construction [3]. Many related ecological interactions, such as competition and facilitation, have been shown to have a genetic basis [4][5][6][7][8] as have other broader processes at the community level such as community composition [9,10]. Further steps toward understanding connections between evolutionary and ecological processes can elucidate how evolution affects individuals interacting both within and between species.…”