Characterization and analysis of the genetic variability of sweet passion fruit (Passiflora ligularis juss.) in colombia using microsatellite markers

Abstract

Sweet passion fruit is the second economically important species of the genus Passiflora and Colombia is the largest producer in the world with 53,000 t/year. There are however, few studies on intraspecific diversity within the species that establish genetic relationships between individuals. The objective of this research was to explore the genetic variability of cultivated sweet passion fruit in Colombia using microsatellite markers. Ten microsatellite markers were evaluated in 41 accessions (82 individuals) from the main producing departments in the country. A total of five microsatellites were amplified with 66 alleles identified and an average of 12.2, including 7 unique and 13 rare. Diversity indexes showed a polymorphic information content of 0.74 (PIC), and an observed (Ho) and expected (He) heterozygosity average of 0.98 and 0.96 under Hardy-Weinberg equilibrium conditions. The average genetic distance within and among populations was 0.65 and 0.80, being Boyacá, Valle del Cauca and Putumayo the most distant (> 0.87). Classification Trees (nj) and Multiple Correspondence Factorial Analysis (MCA) revealed little geographical structuring of accessions and individuals dispersal of a common origin. The lack of structure and high intraspecific variability could be explained by the phenomenon of allogamy present in the species and seed exchange among farmers. In conclusion, these results suggest a complementary agromorphological assessment in order to establish the total genetic variability and implement a breeding program through assisted selection of superior genotypes in search of more productive and resistant cultivars to phytosanitary problems that affect crops.