Location: Tropical Crops and Germplasm ResearchTitle: Musa spp. germplasm management: microsatellite fingerprinting of USDA-ARS National Plant Germplasm System (NPGS) collection Author
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/29/2014
Publication Date: 9/10/2014
Citation: Irish, B.M., Cuevas, H.E., Simpson, S.A., Scheffler, B.E., Sardos, J., Ploetz, R., Goenaga, R.J. 2014. Musa spp. germplasm management: microsatellite fingerprinting of USDA-ARS National Plant Germplasm System (NPGS) collection. Crop Science. 54:2140-2151. Interpretive Summary: Plant germplasm collections provide important sources of genetic diversity and agricultural traits for plant breeders and farmers. Effective and efficient conservation involves the systematic cataloging and evaluating of plants within these collections. Molecular marker tools were used to assess genetic relationships and to identify underrepresented and redundant germplasm among plants within the Musa spp. (banana) collection. Results from the molecular analyses of the plants accessions in the collection showed high genetic diversity with much of the cultivated banana germplasm well represented. The markers were limited in their resolution and were unable to distinguish among morphologically distinct accessions within particular cultivated banana subgroups. However, the markers were extremely useful in identifying propagation mistakes, especially in germplasm maintained in tissue culture where phenotypic differences are difficult to observe. Molecular markers used in this study proved to be an excellent tool to better manage the Musa spp. genetic resources and to complement evaluations of germplasm in the field.
Technical Abstract: The USDA-ARS Tropical Agriculture Research Station (TARS) is responsible for conserving germplasm of a number of important agricultural crop species. A banana (Musa spp.) collection has been established at TARS that is comprised of diploid, triploid and tetraploid accessions of cultivated, ornamental, wild and synthetic hybrid accessions. To estimate genetic diversity, identify gaps, determine integrity, and generate clonal reference multi-locus DNA profiles for a total of 175 accessions in the collection, a set of 22 microsatellite markers developed by Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD) and proposed by the Global Musa Genomics Consortium (GMGC) were screened with an additional 15 reference DNA samples. Twenty-one out of the 22 microsatellite markers amplified well and generated a total of 302 alleles with an average number of 14.4 alleles per locus. In general, profiles were reproducible and consistent for the 21 loci, for the internal reference samples and clonal plants in the field and tissue culture. The average number of alleles and gene diversity estimates demonstrated substantial genetic diversity in the collection. Principal Coordinate and cluster analyses grouped accessions in the collection according to their ploidy level and genomic compositions. Markers that were used in the study distinguished accessions to the subgroup level and identified mislabeled accessions; notably in the tissue culture collection where phenotypic differences are difficult to observe. The accessions and fingerprint profiles for the TARS collection are available through the USDA, National Plant Germplasm System (NPGS), Germplasm Resource Information Network (GRIN-Global) database http://www.ars-grin.gov/.