Submitted to: Journal of Agriculture of the University of Puerto Rico
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 28, 2008
Publication Date: July 9, 2009
Citation: Irish, B.M., Crespo, A., Goenaga, R.J., Ayala Silva, T., Niedz, R.P. 2009. Ploidy level and genomic composition of the USDA-ARS Tropical Agriculture Research Station Musa sp. Germplasm Collection. Journal of Agriculture of the University of Puerto Rico, 93(1-2):1-22. Interpretive Summary: Plant genetic resources are being lost at alarming rates due to a number of factors including, urbanization and climate change. As part of the National Plant Germplasm System (NPGS) the USDA ARS Tropical Agriculture Research Station is doing its part to protect these resources. A banana and plantain collection is currently maintained on site and is being characterized for economic, agronomic and molecular traits of importance. Initial efforts focused on the molecular characterization of the collection to determine taxonomic relationships. All current accessions have been classified into specific taxonomic groups and propagation mistakes corrected. In addition the summarized data has provided some useful information regarding the genetic diversity maintained in the collection.
Technical Abstract: Plant germplasm collections serve as repositories for important genes. However, insufficient and inaccurate characterization of the genetic diversity in a collection slows and can prevent full utilization of these collections to maximum potential. Bananas and plantains (Musa sp., 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 with little effort on molecular markers. Genomic composition in Musa is based on a plant’s ploidy level and whether it is of a hybrid origin. The different Musa sp. genomic compositions have been associated with disease and insect resistance, production and flavor characteristics. The USDA-ARS TARS Musa sp. collection consists of 140 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. In an effort to better characterize the collection, RAPD and PCR-RFLP markers as well as flow cytometry were employed to determine genomic composition. Plant accessions maintained in the collection belong to a wide array of genotypes including accessions which are diploid, triploid and tetraploid, and belong to the Musa acuminata species, as well as diploid, triploid, and tetraploid Musa hybrids.