Background The cytogenomic study of repetitive regions is fundamental for the understanding of morphofunctional mechanisms and genome evolution. Passiflora edulis a species of relevant agronomic value, this work had its genome sequenced by next generation sequencing and bioinformatics analysis performed by RepeatExplorer pipeline. The clusters allowed the identification and characterization of repetitive elements (predominant contributors to most plant genomes). The aim of this study was to identify, characterize and map the repetitive DNA of P. edulis , providing important cytogenomic markers, especially sequences associated with the centromere. Results Three clusters of satellite DNAs (69, 118 and 207) and seven clusters of Long Terminal Repeat (LTR) retrotransposons of the superfamilies Ty1/Copy and Ty3/Gypsy and families Angela, Athila, Chromovirus and Maximus-Sire (6, 11, 36, 43, 86, 94 and 135) were characterized and analyzed. The chromosome mapping of satellite DNAs showed two hybridization sites co-located in the 5S rDNA region (PeSat_1), subterminal hybridizations (PeSat_3) and hybridization in four sites, co-located in the 45S rDNA region (PeSat_2). Most of the retroelements hybridizations showed signals scattered in the chromosomes, diverging in abundance, and only the cluster 6 presented pericentromeric regions marking. No satellite DNAs and retroelement associated with centromere was observed. Conclusion P. edulis has a highly repetitive genome, with the predominance of Ty3/Gypsy LTR retrotransposon. The satellite DNAs and LTR retrotransposon characterized are promising markers for investigation of the evolutionary patterns and genetic distinction of species and hybrids of Passiflora .

ABSTRACT. We analyzed the genetic diversity of populations of two sympatric species of Lymania (Bromeliaceae), both endemic to the Atlantic rainforest of southern Bahia (Brazil). Lymania azurea has a restricted occurrence, while Lymania smithii has a wider distribution. Our aim was to provide genetic data to contribute to the design of more efficient conservation strategies for these bromeliads, possibly justifying inclusion in the official Brazilian list of Endangered Species. Up to now, L. azurea has been classified by the Brazilian Ministry of the Environment as "data deficient". We sampled four populations of L. azurea throughout its distribution area in southern Bahia and two populations of L. smithii in the same region. Genotyping was performed with 48 random amplified polymorphic DNA markers. Based on the Jaccard genetic similarity index, L. smithii has greater diversity than L. azurea. An analysis of molecular variation showed greater genetic variance within than between populations for both species. L. azurea was found to have 20% inbreeding, probably due to population fragmentation, with L. smithii showing only 10%. When we analyzed pairs of populations of L. azurea within a conservation unit, we found low population structure (Ф ST = 0.098), apparently due to a large degree of gene flow between them. In disturbed areas, we found a higher Ф ST (0.372). We found low genetic variability for L. azurea, probably as a consequence of habitat fragmentation, supporting the need for its inclusion in the Brazilian list of endangered flora.

No abstract

No abstract