Variability for Oil Content and Fatty Acid Composition in Diverse Accessions of Niger (Guizotia abyssinica L.f. Cass)

Abstract

Niger is a minor oilseed crop primarily grown in Ethiopia and India. The oil content in niger seeds ranges from 32% to 47%. Niger oil has several nutritional and therapeutic benefits. Despite these benefits, the crop has been widely neglected by breeders due to its low productivity. Therefore, understanding the extent of genetic variability within the niger germplasm is a prerequisite for selecting superior genotypes and enhancing productivity. The present experiment was conducted at the ICAR-Indian Institute of Oilseeds Research, Hyderabad, Telangana, during the kharif seasons of 2022 and 2023. The study used an augmented randomized complete block design (ARCBD) with 111 accessions and four checks to assess variability in oil content and fatty acid composition. The analysis of variance showed significant differences among the accessions. Oil content ranged from 26.1% to 44.8%, with the highest oil content recorded in IC260240 (44.8%). Unsaturated fatty acids, such as linoleic and oleic acids, constituted the major portion of fatty acids among the accessions. The presence of a higher amount of unsaturated fatty acids indicates low susceptibility to autoxidation and confers a therapeutic advantage to niger oil. The accessions IC260250 and IC211053 exhibited high levels of linoleic and oleic acid content, respectively. Based on the Euclidean distance matrix method, the accessions were grouped into six hierarchical clusters. Cluster II had the highest number of accessions (34), followed by Cluster IV with nine accessions. The maximum genetic distance was observed between Clusters III and VI. Palmitic and stearic acids showed a significant positive correlation, whereas linolenic acid and oleic acid exhibited a significant negative correlation. No discernible variations were observed in the fatty acid composition among the accessions during the two seasons. The elite accessions identified from this study can be utilized as donors in the niger oil quality improvement program.