Inheritance of Oil Production and Quality Factors in Peant (Arachis hypogaea L.)

Peanut (Arachis hypogaea L.) has the potential to become a major source of biodiesel but for market viability, peanut oil yields must increase and specific quality requirements must be met. Oil yield in peanut is influenced by many components, including oil concentration, seed mass, and mean oil produced per seed. All of these traits can be improved through selection as long as there is sufficient genetic variation. Thus, elucidating the genetics of oil concentration, seed mass, and mean oil produced per seed in peanut is essential to advancing the development of genotypes with high oil yields. Additive genetic effects were predominant for oil concentration in two generation means analyses involving a proprietary high oil breeding line and additive genetic variance was highly significant in a complete four-parent diallel analysis. Genetic variance for weight of 50 sound mature kernels (50 SMK) and mean oil produced per SMK (OPS) was additive the diallel analysis. Narrow-sense heritability estimates were high for oil concentration in both the diallel and generation means analyses. Narrow-sense heritability was also high for 50 SMK, but was low for OPS. The low OPS heritability estimate was caused by the negative correlation between oil concentration and seed mass. Consequently, oil concentration and seed mass can be improved through early-generation selection, but large segregating populations from high oil crosses will be needed to identify progeny with elevated oil concentrations that maintain acceptable seed sizes.

Increasing the ratio of oleic to linoleic acid (O/L) in peanut oil and reducing the long chain saturated fatty acid concentration (which includes arachidic, behenic, and lignoceric acids) produces high quality, stable methyl esters for biodiesel. Therefore, elucidating the inheritance of these factors and their relationships in peanut populations segregating for high oil is critical. The results from generation means analysis confirm that the high-oleic trait is under simple genetic control and can be manipulated through selection. Oil concentration was negatively correlated with oleic acid concentration in the F2 generations of both crosses and positively correlated with arachidic acid in most of the segregating generations that were evaluated. Therefore, developing a peanut genotype high in oil and oleic acid concentration that has reduced long chain saturates will require the evaluation of large numbers of segregating progeny.