Abstract (eng)
The Prospero autumnale complex is chromosomally very diverse encompassing several diploid cytotypes with varying basic chromosome numbers (x = 5, 6, and 7) and genome sizes as well as and many auto- and allopolyploids, thus making it an ideal system to analyze the evolution of genomes and the role of chromosomal change in species diversification. Analysis of the repeat profiles of two diploid cytotypes, B6B6 (x = 6) and B7B7 (x = 7), and their Group I allotetraploids (2n = 25-28) revealed similar and high proportions of repetitive DNA in all genomes (c. 75%). The most abundant repetitive DNA type in all three genomes was the retrotransposon superfamily Ty1-copia (c. 40%). DNA transposons and tandem repeats made up a small portion of the genomes. Analysis allowed for identification of satellite DNA PaB6 and four novel satellite DNAs, all of which made up only a small proportion of the genomes. The mapping of satDNA PaB6 and two novel satDNAs, Pa138 and Pa147, in Prospero autumnale diploid genomes as well as diploid homoploid hybrid and Group I-IV allotetraploids of different genomic origin revealed many polymorphisms. The localization of satDNA PaB6 was consistent with previous analysis. It was only detected in chromosomes inherited from the B6B6 and Group I parents. In contrast, the other two satDNAs had unique loci distribution patterns and were polymorphic. The evolution of the Prospero autumnale complex is not accompanied by morphological or karyotypic changes, but by changes in the repeatome, specifically satDNAs, most dynamic components of their genomes.