Diversity of avocado (Persea americana Mill.) cultivars from Antioquia (Northeast Colombia) and comparison with a worldwide germplasm collection

Abstract

: In this study, the genetic diversity of 90 avocado (Persea americana Mill) cultivars from Antioquia (Colombia) was comparedto 67 germplasm collection accessions using 14 microsatellites. An average of 4.32 ± 2.0 alleles per locus was found, as observed inprevious studies. The expected and observed heterozygosity ranges were 0.384–0.724 and 0.393–0.686, respectively. The Antioquianavocados were genetically structured according to an analysis of molecular variance test (fixation index (FST) = 0.054, P < 0.00001). Anunweighted pair group method with arithmetic mean (UPGMA) dendrogram with FST paired data produced 2 clusters: one composed byAntioquian avocados and the other by the germplasm collection. Another UPGMA dendrogram with individual Nei–Li distances andadditional STRUCTURE analysis separated the Antioquian avocados into 3 clusters (K = 3). Combining samples from the Colombianand germplasm collections produced K = 2. Genetic differentiations between the Antioquian and worldwide avocado germplasmcollection could be due to crosses within the Antioquian avocados having been enhanced by insect pollinators, whereas avocadosstored in the germplasm collection were constituted by cultivars with known genetic origins. Findings from this study demonstratedthat criollo avocado genetics are unique in Antioquia, since the species has been naturally crossed in the field and its closest accessionis from Guatemala. Nevertheless, it is important to continue genotyping this species in other locations in Colombia from Sylvester andcultivar populations of this crop to determine its origin