Evaluation of diversity of walnut promising genotypes in Kermanshah province according to oil properties and determine the correlation of these traits with some morphological and ecological characters

Walnut kernel due to the chemical composition of fatty acids can be nutritionally and economically very important and has positive effect on human health. In this study, which was carried out during 2014 growing season, Eighteen walnuts genotypes in terms of fruit and kernel characteristics which were higher than “Chandler”, were selected to evaluate their oil and fatty acids. The oil was measured with Soxhlet and its variation range was between 57. 32-75 percent dry weight in walnut kernel. The type and amount of fatty acids were analyzed by Gas Chromatography (GC). Results of this study showed that kernel oil contains more than 88 percent unsaturated fatty acids. Among the identified fatty acids in walnut oil, linoleic acid (39.38-57.77%) was the predominant fatty acid followed by oleic acid (20.67-41.29%), linolenic acid (7.84-12.89%), palmitic acid (6.7-9.33%) and stearic acid (1.47-4.67%). (Traits in this study showed no significant correlation between kernel weight and altitude with oil amount, but the negative correlation was observed between oleic acid and linoleic acid. Results of this study showed, walnut oil content and fatty acid composition were not affected by physical characteristics and climatic conditions.