The preliminary results of quality assessment of walnut fruits formed in the botanical garden of Samara University using a microfocus X-ray method

Abstract

The growing interest in nuts as an undoubted essential component of a healthy diet, widespread in recent years, determines the expansion of nuts world cultivation areas, as well as the volume of seed production received. The reasons ensured the growing popularity of walnut as the oldest culture are not only the pleasant taste of the seeds (kernel), widely used in food directly and as a component of various products, but also their unique chemical composition, including richness in proteins, vitamins and oil, in which essential polyunsaturated fatty acids are widely presented. The walnut is introduced into territories outside its natural area even now due to efforts of specialists working in the fields of plant introduction and selection as well as amateur enthusiasts who try to grow this valuable crop in their gardens. The introduction of species of Juglans L. genus into the Botanical Garden of Samara University began in the 1930s. As we know one of the goals of making a dendrological collection on the territory of the Samara Region was the introduction of new plant species, including walnut, which has valuable wood and fruits with high nutritional and taste properties, into forest plantations and gardens. The collection of walnut trees was created from seed samples received from various geographical locations (Saratov, Volgograd, Stavropol, Crimea, Ukraine, Moldova, Kyrgyzstan, Uzbekistan, etc.). The large-scale study of walnuts in the Samara (from 1936 to 1992 - Kuibyshev) Region faced climatic difficulties, but was always revived. Currently, the walnut collection contains about 900 specimens of genotypes of various origins, which are natural hybrids on their own roots. As a result of the introduction study of walnuts, extensive material has been collected; it is related to their stress resistance, structural and functional features. The paper presents the results of a preliminary X-ray screening of walnut fruits of the 2021 harvest from the dendrological collection of the Botanical Garden of Samara University, performed for trees of different ages and genealogy related to ordinary and accelerated forms of fruiting. The prospects of this research method for assessing the quality of nuts are shown. The dense shell of the seed and the features of its internal structure are not an obstacle to revealing the degree of development of the nucleus. The results obtained open up the possibility of a non-damaging express assessment of the quality of nuts as a specific seed material for the purpose of selection and a detailed study of their structural features.