Genetic diversity studies on oil content and its fatty acid composition of groundnut

Abstract

Groundnut is an important oilseed crop of the world. The oil quality plays an important role in the nutritional composition and trade. In the present study, 50 groundnut genotypes were evaluated at ICRISAT, Hyderabad, during rainy season, 2023 using alpha lattice design in three replications. The analysis of variance showed significant difference among the genotypes for all the recorded traits. The variability, heritability and genetic advance as per cent of mean estimates were high for major fatty acids, oleic acid, linoleic acid and palmitic acid, indicating the predominance of additive gene action in governing the inheritance of these traits, for which simple selection may be sufficient in achieving potential genetic gain of oil quality. This high variability for palmitic acid, oleic acid and linoleic acid was also confirmed from PCA as they have high scores in PC1. Correlation analysis disclosed that, selecting for stearic acid reveals less contribution to genetic improvement of oil content in groundnut while, oleic acid, linoleic acid and palmitic acid may not affect the oil content in groundnut. The correlation among the fatty acids revealed that, oleic acid which has significant nutritional and market value showed significant negative correlation with all other fatty acids. Thus, to increase both nutritional quality and quantity of oil, selection of genotypes need to be carefully planned. These findings were also confirmed from PCA biplot. The highest oil content and stearic acid was recorded by ICGV 06420 and ICGV 99247, respectively. For palmitic acid, the highest value was present in GPBD 4 and for oleic and linoleic acid, it was in ICGV 181045 and Chico, respectively. Through PCA and genetic divergence analysis, 21 genotypes were identified with high O/L which serves as candidates for future studies in groundnut breeding aiming for increasing its nutritional quality and quantity of groundnut oil.