Comparative Analysis of Growth, Genome Size, Chromosome Numbers and Phylogeny of Arabidopsis thaliana and Three Cooccurring Species of the Brassicaceae from Uzbekistan

Abstract

Contrary to literature data Arabidopsis thaliana was rarely observed in Middle Asia during a collection trip in 2001. Instead, three other Brassicaceae species were frequently found at places where A. thaliana was expected. To reveal reasons for this frequency pattern, we studied chromosome numbers, genome sizes, phylogenetic relationships, developmental rates, and reproductive success of A. thaliana, Olimarabidopsis pumila, Arabis montbretiana , and Arabis auriculata from Uzbekistan in two temperature treatments. There are little but partially significant differences between phenotypes. All studied species have very small genomes. The 1Cx-values of different genotypes within the sampled species are correlated with altitude. Developmental rates are also correlated with 1Cx-values. In our growth experiments, Arabidopsis had high seed sterility at higher temperature, which might be one reason for the rarity of A. thaliana in Middle Asia.