Assessment of influence of the method of vegetative propagation of varieties of <i>Vaccinium corymbosum</i> L. on the biochemical composition of the fruits

Abstract

The results of a comparative study of the main characteristics of the biochemical composition of fruits of the same age of generative plants of 5 introduced varieties of V. corymbosum of different ripening dates – early ripening Weymouth, mid-ripening Bluecrop and Concord, late ripening Elizabeth and Atlantic obtained by traditional (stem-cuttings) and microclonal vegetative methods are presented. A significant effect of the propagation method on the biochemical composition of the fruits, the degree of which was determined by the chemical nature of its components and the plant genotype, was established. In the fruits of cloned plants, depending on the genotype, ambiguous changes in the range of 5–40 %, relative to traditional plants, in the content of solids, free organic, ascorbic and hydroxycinnamic acids, soluble sugars and pectin substances, as well as the index of sugar acid index, were revealed. For most varieties, a common trend in the nature of differences between cloned and traditional plants in the accumulation of bioflavonoids was shown, consisting in the increase in the first case of their total number by 5–27 %, including 6–34 % of anthocyanin pigments. The greatest positive effect of the microclonal propagation method on the content of P-vitamins in fruits of late ripening varieties, especially Atlantik, was found, with a 3–6 times lesser degree of similar influence in Weymouth and Concord varieties, against the background of the prevailing negative effect in mid-ripening Bluecrop. With the relative stability of the ratio of the components of the P-vitamin complex of blueberry fruits to the tested propagation methods, significant shifts were revealed in the composition of their anthocyanin complex in cloned plants of early ripening and especially mid-ripening varieties towards a decrease in the proportion of anthocyanins proper and an increase in that of leukoanthocyanins, compared to traditional plants, reaching 1.5–1.6-fold value in Concord variety with the opposite direction of less pronounced shifts in late-ripening varieties.In cloned plants (with the exception of the Bluecrop variety), the integral level of the nutritional and vitamin value of the fruits was found to be 2.6–4.4 times higher than their traditional counterparts by a total of 14 indicators of the biochemical composition when the varieties were arranged in accordance with a decrease in the degree of data differences in the series: Atlantik > Elizabeth > Weymouth > Concord > Bluecrop, in which late ripe varieties of blueberries were characterized by the greatest advantages.