Inheritance of Fatty Acid Content in Peanut Oil1

Abstract

The stability or shelf-life of peanut (Armhis hypogaea L.) oil is related to the fatty acid content of the oil, with the major factor being the ratio of oleic (C18:l) to linoleic (C18:2) acid (OK ratio).To obtain information needed for development of cultivars with improved oil quality, eight parents representing a range in oleic and linoleic content were crossed in diallel. Individual F, seeds (F, embryos) from the greenhouse and F, bulk seed from the 56 crosses grown in the field were analyzed to determine levels of the eight major fatty acids. General combining ability (GCA) was consistently more important than specific combining ability (SCA) in both generations, suggesting that additive effects are important in the inheritance of fatty acid composition. Maternal effects were significant in the F, but dissipated in the F,; thus the differences in the environment provided by the maternal parent was more critical to oil composition than heritable extranuclear factors. Reciprocal effects were significant in both generations suggesting an interaction between nuclear and extranuclear factors. Correlations between GCA effects and self means for O/L ratio were nonsignificant. Since no significant correlations were found between percent oil and any of the fatty acids or related variables, selection for improved fatty acid composition should not affect the oil content of seed. Of The stability, or shelf-life, of peanut (Armhis hypogaea L.) oil is measured by the number of days before the onset of oxidative rancidity, a process which is generally induced in either the whole peanut or peanut oil by exposure to heat and air (5,17,22). Oxygen reacts with the double bonds of unsaturated fatty acids to form products that have undesirable flavor and odor. Linoleic acid (C18:2) is more susceptible to this process than the monounsaturate, oleic acid (C18:l) or other saturated fatty acids (5,15). Eight major fatty acids account for 98% of the total fatty acids in peanut oil (19,25), but of these oleic and linoleic together make up 75-80% of the total (13,21), ranging from 36-80% and from 2-43%, respectively (5,16,21). There is a negative correlation between the percentage of oleic and linoleic acids (l0,21), since linoleic acid is produced from the conversion of oleic acid. Since the seed of most peanut cultivars are composed of approximately 50% oil (3,13,21), quality of a peanut product can be greatly affected by oil stability. The iodine value (Iod), which provides a measure of the degree of oil unsaturation, has been commonly used as a means of predicting shelf-life. The ratio of oleic to linoleic acid (O/L ratio) is also a measure of oil stability (23,24,26). Selection

Impact of climate change on oil fatty acid composition of peanut (Arachis hypogaea L.) in three market classes

“…Similar correlations have been reported in previous studies (Dwivedi et al, 1993;Hammond et al, 1997;Anderson et al, 1998). Mercel et al (1990) has also suggested that fatty acid composition should not affect the oil content of seed.…”

Antioxidant Properties of Extracts Obtained from Raw, Dry-roasted, and Oil-roasted US Peanuts of Commercial Importance

“…In the US, Runner, Virginia, Spanish, and Valencia markettype peanuts are commercially grown. The peanuts kernel contains ∼52% oil by weight [1], which is rich in monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA) [2]. The high-oleic peanut genotype, whose acreage in the US has been increasing consistently over the past five years, contains upwards of 80% oleic and 5% linoleic acids [3].…”

Genetic Analysis of Oil Content and Fatty Acid Composition in Safflower (Carthamus tinctorius L.)

“…Therefore, the additive-dominance genetic model was adequate for all the traits [22] and it was concluded that both kinds of gene effects were important for controlling the inheritance of all the traits studied [12]. Significant effects of GCA and SCA have also been reported for the inheritance of different fatty acids in oil castor [14], peanut [13], sunflower [23] and Brassica juncea L. [24]. The greater importance of SCA compared to GCA has been reported in peanut oil for oil quantity and quality [13].…”

“…Improving oil yield requires adequate information regarding the nature of general combining ability (GCA) and specific combining ability (SCA) of the parents available in a wide array of genetic material to be used in the hybridization programs. Information is also required about the nature of gene actions involved in the expression of quantitative and qualitative traits [13,14]. Diallel analysis provides a unique opportunity to test a number of lines in all possible combinations [12].…”