Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: 1/4/2005
Publication Date: 1/4/2005
Citation: Frelichowski, J., Ulloa, M., Percival, A., Stewart, J., Cantrell, R. 2005. Germplasm evaluation of cotton accessions from the U.S. cotton germplasm collection, USDA-ARS (Gossypium hirsutum L. Landraces of Mexico). National Cotton Council Beltwide Cotton Conference. p. 1020-1024.
Technical Abstract: Future improvement of cotton relies on introgression of genetic variability from wild cotton resources. Characterizing, understanding and adding to cotton germplasm collections is important for future cotton improvement. A set of 434 Gossypium hirsutum L. landraces of Mexico from the U.S. Cotton Germplasm Collection was planted at Shafter, CA for phenotypic and genetic characterization of variability. Commonly used phenotypic characters were scored for each accession and tissue was bulked of each accession for DNA extraction. PCR based microsatellite markers from public sources and developed at Shafter are being used to describe genetic variation in the same accessions. A subset of accessions will be scored on individual plants for phenotypic and molecular marker variation to compare between and within accession variation. The combination of the two approaches will provide a better description of the variation in the collection, provide a template for future data collection and description of cotton germplasm, and may discover relationships between the markers and the phenotypic traits (i.e. linkage to genes). Preliminary results showed that significant variation still exists in the collection from the data collection. Diversity between and within accessions was the highest for accessions collected within the states of Guerrero, Yucatan, Oaxaca, Veracruz and Chiapas. The use of molecular markers is expected to reveal more variation not evident in the physical traits, and will become a valuable tool in the maintenance and utility of the diversity of the germplasm collection.