ARTICLES
Authors: T. G.. Isleib , C. C. Holbrook , D. W. Gorbet
The genetic base of peanut (Arachis hypogaea L.) in the U.S.A. has at times been extremely narrow, particularly in specific production areas where a single cultivar may be grown in near-monoculture. Because peanut is not a native North American species, all U.S. cultivars necessarily trace their ancestry to plant introductions (PIs), but most of the genetic base of current cultivars rests on selections from farmer-stock peanuts of obscure origin. The objectives of this study were to (a) summarize and document the use of introduced genetic resources in cultivar development and (b) estimate the resulting economic impact. Different PIs were used as parents in early breeding programs. B.B. Higgins used Gambian line Basse as a parent of the GA 207 cross that gave rise to selections used in Georgia, Florida, and North Carolina as the basis for further improvement. PI 121067 was one of seven parents used by W.C. Gregory to initiate the program in North Carolina. A different set of PIs including PI 121070, PI 161317, PI 168661, and A. monticola Krapov. & Rigoni were used in the Texas and Oklahoma programs. Recycling of lines as parents and exchange of germplasm among breeding programs proliferated these PIs in the pedigrees of cultivars released since 1960. Over the past 20 yr, there have been concerted efforts to incorporate additional germplasm into U.S. breeding populations, usually with the purpose of improving resistance to diseases or pests, but also with the objective of broadening the genetic base. These efforts have had a significant economic impact on U.S. peanut farmers, the largest from the development of cultivars with resistance to Sclerotinia blight (Sclerotinia minor Jagger), root-knot nematodes (Meloidogyne spp.), and tomato spotted wilt virus. Use of these resistant cultivars has an economic impact of more than $200 million annually for U.S. peanut producers. In the runner and virginia market types, the average PI ancestry of all cultivars was 17.9%. There are several examples of successful cultivars with up to 25% ancestry from a single PI, including Georgia Green and NC-V11. In the spanish market type, most successful cultivars have derived 50 or more of their ancestry from PIs. Several recent or impending releases incorporate PI germplasm but have not yet been proven in the U.S. seed market.
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Keywords: Arachis hypogaea L., coancestry, Disease resistance, Genetic Vulnerability, genetic resources.
How to Cite: Isleib, T. , Holbrook, C. & Gorbet, D. (2001) “Use of Plant Introductions in Peanut Cultivar Development”, Peanut Science. 28(2). doi: https://doi.org/10.3146/i0095-3679-28-2-11