|McCreight, James - Jim|
Submitted to: Genetic Resources and Crop Evolution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/2/1996
Publication Date: N/A
Interpretive Summary: Genes are located on chromosomes. Genes consist of short segments of DNA arranged in a linear fashion on chromosomes. The location of these genes on chromosomes is important to the Plant Geneticist and breeder because such a knowledge allows him to genetically manipulate plants for their improvement. Genetic markers can help locate economically important genes on chromosomes. There are a number of markers which can help reveal the genetic composition of plants. In this paper, two genetic marker types are tested to determine which one would be more effective for cucumber improvement. Data indicate that one marker type (RAPD) is more effective than the other type (isozyme). This research will help geneticists and plant breeders interested in plant improvement, especially cucumbers and melons. It will allow them to better use the genetic material which they have for more rapid cultivar development.
Technical Abstract: Principal component analyses of variation at isozyme and random amplified polymorphic DNA (RAPD) loci in eight cucumber and seven melon cultivars, breeding lines, and plant introductions were used to determine the utility of these markers for assessing genetic variation among and within populations of each species. Although dendrograms derived from cluster analyses using species variation at marker loci were dissimilar, these disparities were consistent with differences in the pedigrees and/or other information (e.g., morphological) known about each accession and species. Empirical estimations of variances associated with each marker type in the accessions of cucumber and melon examined indicate that, per band, lower coefficients of variation can be attained in the estimation of genetic difference when using RAPDs compared to isozymes. The disparity between the marker analyses made may be related to the amount of genome coverage characteristic of a particular marker system in a species and its efficiency in sampling variation in a population.