Item

Abstract

Studies of natural variation at the genetic level have not only given us direct understanding of the molecular mechanisms underlying adaptive traits such as stress tolerance or flowering, but also of adaptive evolution. Recently, several studies using natural variants of Arabidopsis thaliana have investigated the genetic basis of hybrid incompatibility, a phenomenon in which offspring shows reduced fitness in comparison to its parents. Yet, we are only in the beginning to understand what role the different factors, molecular and environmental, play in shaping natural populations. We identified a case of hybrid necrosis in wild A. thaliana collected around Tuebingen, Germany and investigated both, its genetic basis and distribution at a population level. Based on segregation and phenotypic variation in F2, the Tuebingen hybrid necrosis seems to be caused by a single locus and showed linkage to chr 4. We are currently testing the candidate genes and the prevalence of this phenotype among individuals in the parental population. Moreover, we follow a case of F2 hybrid chlorosis, which was found in a cross between Lov-5 (Lovvik, Sweden) and Sha (Shahdara, Tadjikistan) and is caused by two recessively interacting genes, located in chr 1 and 5. Further, we plan to investigate how environmental factors, both abiotic and biotic, could influence the hybrid phenotypes and the population dynamics.