A single species, different repeatomes? Genomic plasticity in Passiflora foetida L. complex and comparative insights across the subgenus Passiflora

The genus Passiflora L. comprises approximately 650 species, and exhibits high diversity in the Neotropics, especially the subgenus Passiflora. Several species of this subgenus have an abundant repetitive fraction, consistent with their increased genome sizes. However, the repetitive DNA fraction of Passiflora foetida (n = 10), sister to the other species of the subgenus (n = 9) and the species with the smallest genome, has not yet been described in detail. In addition, this species comprises a complex of morphological varieties with a wide geographical distribution. The aim of this study was to characterize its repeatome variability in comparison to other species in section Dysosmia and other sections in the same subgenus, and to investigate whether it may reflect the high variability reported for this species complex. The results showed that P. foetida has a proportion of repetitive DNA fraction in part consistent with its small genome size, but with marked intraspecific variation. The LTR Ty1/copia retrotransposons were the most abundant, as in the other species of the subgenus, but Ty3/gypsy represented a much smaller fraction compared to the others. The variation observed within P. foetida was greater than that detected among Dysosmia species. Satellite DNAs were partly unique and partly similar to species from different subgenera, supporting its phylogenetic position. In addition, one Dysosmia-specific satellite showed a proximal chromosomal location, making it the first candidate of a centromeric repeat for the genus, despite its variation in abundance among chromosomes.