|Krause, Charles - Chuck|
Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/11/2007
Publication Date: 8/1/2007
Citation: Palumbo, R., Hong, Q., Craig, R., Locke, J.C., Krause, C.R., Tay, D., Wang, G. 2007. Target Region Amplification Polymorphism (TRAP) as a Tool for Detecting Genetic Variation in the Genus Pelargonium. HortScience. 42(5):1118-1123. Interpretive Summary: The Ornamental Plant Germplasm Center (OPGC) in Columbus, OH, designated preservation of geranium germplasm a high priority. Diverse kinds of heirloom bedding plants are to be saved for future breeding possibilities. The OPGC geranium collection includes plants from 2 primary lines. This research was performed to determine if a new method of plant fingerprinting, called TRAP (Target Region Amplification Polymorphism) would be appropriate for geranium identification. Improved sample preparation resulted to clean up tissue so that chemical impurities wouldn’t impede accurate detection. Current DNA extraction techniques were then optimized and the TRAP procedure separated 46 accessions. DNA starting materials (primers) were generated with sufficient fragments to use in the separation of 46 different primer combinations. Molecular characterization of 46 selections was achieved to yield another tool for successful varietal discrimination for future geranium breeding.
Technical Abstract: Pelargonium is one of the priority genera collected by the Ornamental Plant Germplasm Center (OPGC). In order to protect future breeders from a loss of genetic diversity, OPGC collects heirloom cultivars, breeding lines and wild species. The current Pelargonium collection at OPGC consists primarily of cultivars originating from P. xhortorum and P. xdomesticum. Our goal was to determine the feasibility of TRAP (Target Region Amplification Polymorphism) for the analysis of this large collection, so that in the future the most diverse genotypes may be retained. In order to achieve this goal we first modified existing DNA extraction techniques to account for the high levels of phenolic compounds present in some Pelargonium species, and second optimized the TRAP procedure using the DNA isolated from 46 accessions. Preliminary analysis indicated that TRAP can efficiently detect genetic variations in the genus Pelargonium. For most of the initial 46 accessions tested, one or two primer combinations generated enough fragments to discriminate each of the accessions, and similar clades were produced by cluster analysis of the polymorphic fragments amplified by different primer combinations. These results demonstrate that TRAP is an effective method for molecular characterization of ornamental collections.