Ploidy level and genomic composition of Musa spp. accessions at the USDA-ARS Tropical Agriculture Research Station

Abstract

Plant germplasm collections serve as repositories for important genes. However, insufficient and inaccurate characterization of the genetic diversity in a collection can slow or can prevent full utilization of genetic resources. Bananas and plantains (Musa spp., Colla) are some of the most important food crops in the world. Germplasm characterization efforts in Musa have focused mostly on agronomic and morphological traits although with the advent of molecular markers genotypic characterization efforts are increasing. Genomic composition in Musa is based on a plant's ploidy level and on whether it is of a hybrid origin. Genomic compositions of Musa spp. have been associated with disease and insect resistance, production and flavor characteristics. The Musa spp. collection of the USDA-ARS Tropical Agriculture Research Station consists of 135 accessions, many of which are of unknown genomic composition. In an effort to better characterize the collection, RAPD and PCR-RFLP markers, as well as flow cytometry, were employed to determine genomic composition and ploidy level. Plant accessions maintained in the collection belong to several Musa species and their hybrids with different ploidy levels. In addition, several differences in ploidy as well as genomic composition were identified when comparing findings in this study to those reported in the literature.