In this study, we aimed to systematically assess the frequency at which potentially deleterious phenotypes appear in natural populations of the outcrossing model plant Arabidopsis arenosa, and to establish their underlying genetics. For this purpose, we collected seeds from wild A. arenosa populations and screened over 2,500 plants for unusual phenotypes in the greenhouse. We repeatedly found plants with obvious phenotypic defects, such as small stature and necrotic or chlorotic leaves, among first-generation progeny of wild A. arenosa plants. Such abnormal plants were present in about 10% of maternal sibships, with multiple plants with similar phenotypes in each of these sibships, pointing to a genetic basis of the observed defects. A combination of transcriptome profiling, linkage mapping and genome-wide runs of homozygosity patterns using a newly assembled reference genome indicated a range of underlying genetic architectures associated with phenotypic abnormalities. This included evidence for homozygosity of certain genomic regions, consistent with alleles that are identical by descent being responsible for these defects. Our observations suggest that deleterious alleles with different genetic architectures are segregating at appreciable frequencies in wild A. arenosa populations.

• Klíčová slova
• Arabidopsis arenosa, abnormal phenotypes, reference genome, runs of homozygosity, wild populations,
• MeSH
• Arabidopsis * genetika   MeSH
• fenotyp MeSH
• mapování chromozomů MeSH
• semena rostlinná MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Whole-genome duplication is a common mutation in eukaryotes with far-reaching phenotypic effects, the resulting morphological and fitness consequences and how they affect the survival of polyploid lineages are intensively studied. Another important factor may also determine the probability of establishment and success of polyploid lineages: inbreeding depression. Inbreeding depression is expected to play an important role in the establishment of neopolyploid lineages, their capacity to colonize new environments, and in the simultaneous evolution of ploidy and other life-history traits such as self-fertilization. Both theoretically and empirically, there is no consensus on the consequences of polyploidy on inbreeding depression. In this meta-analysis, we investigated the effect of polyploidy on the evolution of inbreeding depression, by performing a meta-analysis within angiosperm species. The main results of our study are that the consequences of polyploidy on inbreeding depression are complex and depend on the time since polyploidization. We found that young polyploid lineages have a much lower amount of inbreeding depression than their diploid relatives and their established counterparts. Natural polyploid lineages are intermediate and have a higher amount of inbreeding depression than synthetic neopolyploids, and a smaller amount than diploids, suggesting that the negative effect of polyploidy on inbreeding depression decreases with time since polyploidization.

• Klíčová slova
• fitness, genome doubling, inbreeding depression, polyploid establishment, polyploidy,
• MeSH
• diploidie MeSH
• inbrední deprese * MeSH
• inbreeding MeSH
• Magnoliopsida * genetika   MeSH
• polyploidie MeSH
• Publikační typ
• časopisecké články MeSH
• metaanalýza MeSH
• práce podpořená grantem MeSH