Kernel Chemical Composition of the Walnut Genetic Resources Grown in the High Atlas Mountains of Morocco

More than half of the cultivated walnuts (Juglans regia L.) in Morocco are seedlings, resulting from seed propagation by farmers. Principal Component Analysis (PCA) was used to compare protein, oil content, fatty acid composition and tocopherol homologues in 14 selected clones from the High Atlas Mountains. The results showed a high genetic variability of these components among genotypes, confirming high genetic diversity of walnut in the Atlas Mountains. Thus, the application of a chemometric approach appears to be useful to evaluate genetic diversity in walnut. These genotypes are generally characterized by high values of oleic acid and medium values of gamma-tocopherol. Three genotypes with high quality oil were identified, characterized by high oleic acid content and low values of linolenic and linoleic acids. No evidence was found to suggest the existence of separate populations within the walnut genotypes from the High Atlas Mountains.