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ARS Home » Southeast Area » Griffin, Georgia » Plant Genetic Resources Conservation Unit » Research » Publications at this Location » Publication #137750

Title: Identifying and selecting for genetic diversity in Papua New Guinea sweetpotato Ipomoea batatas (L.) Lam. germplasm collected as botanical seed

item Jarret, Robert - Bob

Submitted to: Genetic Resources and Crop Evolution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/1/2002
Publication Date: 12/1/2002
Citation: Fajardo, D.S., Labonte, D.R., Jarret, R.L. 2002. Identifying and selecting for genetic diversity in Papua New Guinea sweetpotato Ipomoea batatas (L.) Lam. germplasm collected as botanical seed. Genetic Resources and Crop Evolution. 49:463-470.

Interpretive Summary: Sweetpotato germplasm is typically collected outside the US as vine cuttings or storage roots. In order to introduce these plant materials into the US, they must first be processed through Plant Quarantine in order to ensure that they are not infected with pathogens or infested with insect pests. This manuscript describes efforts to collect sweetpotato germplasm as botanical seed as a means to facilitate more rapid introduction of germplasm into the US as botanical seed is not subject to quarantine restrictions. Results indicated that genetic diversity in populations of plants derived from sweetpotato seed collected in Papua New Guinea could be captured in a relatively small number of plants as identified by analysis of DNA. These results indicate that collection of sweetpotato germplasm as botanical seed may be an acceptable alternative to its collection as vegetative cuttings or roots in some instances, and that analysis of DNA can be used to select for diversity within plants derived from seed.

Technical Abstract: Genetic analysis was conducted on 141 "Ipomoea batatas" L. (Lam.) Genotypes derived from botanical seed originally collected from 26 sites in 4 provinces in Papua New Guinea. Relatedness among accessions was estimated by analysis of the AFLP data using the Dice coefficient of similarity and UPGMA. The molecular analysis revealed relatively limited genetic diversity within and between sites. Genotypes collected in a given region often displayed molecular marker variability similar to that observed over the entire area sampled. A subset of 15 genotypes derived from seed collected from New Ireland Island differed from genotypes collected in PNG. Analysis of AFLP data indicated a moderate level of diversity across all plant materials analyzed. Three methods of selection were evaluated for their efficacy in capturing the molecular marker diversity within the plant materials in the form of a subset. A marker assisted selection-based subset of 12 genotypes captured 92% of the molecular marker diversity.