Molecular genetic diversity and differentiation of populations of ‘somnus’ passion fruit trees (Passiflora setacea DC): Implications for conservation and pre-breeding

• The genetic variability and population structure of twelve Passiflora setacea populations were investigated.
• Using ISSR and RGA there was a high level of genetic diversity in Passiflora setacea.
• An analysis of molecular variance showed that most genetic variation occurred within populations.
• Obtained data assist to the protection and sustainable utilization of P. setacea.

The ‘somnus’ passion fruit tree (Passiflora setacea) is native to the ‘Cerrado’ and ‘Caatinga’ biomes in Brazil and possesses agrobiological and commercial traits of interest. Studies examining the nature of genetic variability in natural populations are important for the utilization of these traits in conservation and breeding programs. In this study, we analyzed 12 populations of P. setacea from different locations distributed in three agro-ecological zones within the Bahia state of Brazil. Eleven ISSR primers and four pairs of RGA primers were used to assay 109 and 49 unique and reproducible loci, of which 108 (99%) and 49 (100%) were polymorphic. Although the level of genetic diversity in ‘somnus’ passion fruit trees was greater than that observed for other species of the same genus, preferential collection of certain populations, such as those located in the cities of Vitória da Conquista and Licinio de Almeida, is important when considering the fact that ‘somnus’ passion fruit trees occur in areas that are highly disturbed. This disturbance is primarily due to the deployment of pasture, predatory extraction and accelerated urban expansion. An analysis of molecular variance revealed a balance between the estimated genetic variation within and among populations. These data may be useful for developing strategies for preservation of this species in the Cerrado.