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United States Department of Agriculture

Agricultural Research Service

Title: Comparison of Four Molecular Markers in Measuring Relationships among Accession of the Wild Potato Relatives Solanum Subgenus Potatoe Sect. Etuberosum

item Spooner, David
item Nienhuis James, - UNIVERSITY OF WISCONSIN
item Douches David S, - MICHIGAN STATE UNIV
item Contretas Andrea, - VALDIVIA CHILE

Submitted to: Journal of Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 30, 1995
Publication Date: N/A

Interpretive Summary: Wild species relatives of crop plants have tremendous potential to be used in breeding programs to improve the world's food supply. Because of this, various programs, such as the USDA, support programs of the collection, storage, and distribution of wild crop relatives to breeders to encourage the use of these wild species for crop improvement. These collections of wild species (housed in facilities called genebanks) often number in the thousands, and we often know little about them. One way to understand the characteristics of these collections is to study their genetic attributes, a class of very effective techniques called molecular tests. There are many types of molecular tests available to study these collections, but little is known about how one type of test corresponds to another; that is if the different tests say the same thing. This study compares four molecular tests (technically referred to as chloroplast DNA, isozymes, single to low-copy nuclear DNA, and random amplified polymorphic DNA's) to show their use in a group of wild potato species of use for potato improvement.

Technical Abstract: We evaluated chloroplast DNA (cpDNA), isozymes, single to low- copy nuclear DNA, (RFLP's), and random amplified polymorphic DNA's (RAPD's) in terms of concordance and efficiency for systematic relationships of 15 accessions each of Solanum etuberosum and S. palustre, and four accessions of S. fernandezianum. These self-compatible, diploid (2n = 24), and morphologically very similar taxa constitute all species in Solanum sect. Etuberosum, a group of non-tuber-bearing species closely related to Solanum sect. Petota (the potato and its wild relatives). Genetic distance and multidimentional scaling results show general concordance of isozymes, RFLP's and RAPD's between all three taxa; cpDNA shows S. etuberosum and S. palustre to be more similar to each other than to S. fernandezianum. Interspecific sampling variance shows a gradation of resolution from allozyme (low) to RAPD to RFLP (high); while intraspecific comparisons graded from RFLP's (low) to RAPD's (high; lack of sufficient allozyme variability within species precluded comparisons for allozymes). Experimental error was low in RFLP's and RAPD's. These results leave unresolved the progenitor-derivative relationships within sect. Etuberosum.

Last Modified: 4/22/2015
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