Fatty Acid Genotypes of Five Virginia-Type Peanut Cultivars

Reduction of linoleic acid in the fatty acid profile of Virginia-type peanut (Arachis hypogaea L.) cultivars is desirable because it would improve the stability and shelf-life of in-shell and other peanut products. A low-linoleate/high-oleate trait controlled by two recessive genes, ol 1 and ol 2 , has been identified in Univ. of Florida breeding line F435. Most runner-type cultivars and breeding lines genotyped to date were found to differ from F435 by only one ol allele. Genotypes differing from F435 at two ol loci were Virginia types. The number of genes controlling inheritance of the trait has major implications with respect to the numbers of backcross and F 2 test progeny required in an efficient backcross breeding program. To determine the number of genes differentiating F435 from large-seeded Virginia-type cultivars, F435 was crossed as a male with five common Virginia-type cultivars. F 4 :5 progenies were assayed for fatty acid content by gas chromatography. Progenies were classified as having high or low oleate levels and chi square analysis was applied to the data. Segregation ratios of populations derived from crosses with 'NC 7', 'NC 9', 'NC 10C', and 'VA-C 92R' were consistent with a monogenic model and inconsistent with the digenic model. These cultivars have genotype Ol 1 Ol 1 ol 2 ol 2 or ol 1 ol 1 Ol 2 Ol 2 . Progeny of 'NC-V 11' / F435 followed a ratio consistent with the digenic model and inconsistent with the monogenic model, indicating that NC-V 11 has genotype Ol 1 Ol 1 Ol 2 Ol 2 . Oleate levels were elevated by 220 to 280 g kg -1 , linoleate levels decreased by 190 to 270 g kg -1 , and palmitate levels decreased by 30 to 40 g k -1 in high-oleate subpopulations. Other fatty acids exhibited changes that were statistically significant but probably too small in magnitude to significantly alter processing quality or stability of oil.