| Abstrakt: |
Studies on the interplay between morphological diversity and genomic duplication are crucial, since novel traits may have profound evolutionary and ecological consequences. Within the Lythraceae, Cuphea stands out as the most karyotypically diverse genus, exhibiting a broad distribution across contrasting ecosystems in the Neotropics such as wetlands, forests, savannas, and prairies, ranging from coastal regions to the central continent, and from sea level to mountainous areas, with a remarkable array of morphological variation in vegetative and reproductive structures. To elucidate the potential relationships between karyotypic diversity and morphological variability in Cuphea, we compiled a morphological database, chromosome numbers and a molecular phylogenetic tree to infer the phylogenetic signal of morphological traits and karyotype evolution in this genus. Our findings confirm the pivotal role of polyploidy in the extensive karyotypic diversification observed in Cuphea. Ancestral state reconstruction revealed that the ancestral chromosomal number for the genus is x = 11 and there is a high incidence of polyploidy in the genus, with at least 11 events of whole-genome duplication, in addition to 20 events of dysploidy (10 ascending and 10 descending). We found evidence to support a positive correlation between chromosome numbers and overall size of selected morphological traits with polyploid species showing longer floral tubes. Our investigations also revealed a potential association between polyploidy and the adaptive radiation of Cuphea during its distribution expansion to the North America. These results reinforce the importance of whole-genome duplication events in producing trait diversity and, consequently, speciation. [ABSTRACT FROM AUTHOR] |
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