Abstract

Pedigreed natural crossing to produce marker-idenpngied hybrids for specific uses has been exploited in USDA-ARS/Georgia cooperative peanut (Arachis hypogaea L.) germplasm enhancement projects since the discovery in 1959 of suitable genetic markers. The principal advantages of natural hybridization using dominant alternative alleles to idenpngy the outcrosses are that (1) the production of F₁ hybrid plants is not dependent upon conventional manual emasculation, (2) the identification and harvest of plants exhibiting the markers can be performed by semiskilled workers, and (3) the procedure is more economical than the standard crossing method.

We utilized pedigreed natural crosses to screen an extensive sample of white-testa peanut phenotypes from the world gene pool for the five-loci recessive genotype, r₁ r₁ f₁ f₁ f₂ f₂ d₁ d₁ d₂ d₂. Four accessions, ‘Spanwhite”, P. I. 299468, P. I. 408730, and P. I. 306228, were found to be recessive at all five of the loci which condition testa color. F₂ populations from marker-identified natural crosses of each of these lines to a tester genotype which was homozygously dominant at four of the testa-color loci fit the ratio of 225 tan:31 white expected from the cross of these genotypes.

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Keywords: Arachis hypogaea L, Duplicate alleles, Flavonoid, Genetic marker, Genetic ratio 225:31, Groundnut, outcrossing, peanut flour, qualitative inheritance, seedcoat color

How to Cite:

Hammons, R. & Branch, W., (1982) “Pedigreed Natural Crossing to Identify Peanut Testa Genotypes”, Peanut Science 9(2), p.90-93. doi: https://doi.org/10.3146/

Author Notes

¹Cooperative investigations of Agricultural Research Service, USDA and the University of Georgia Agricultural Experiment Stations, Coastal Plain Station, Tifton, GA 31793.