Influence of nutrient media on the physiological parameters of grape microclones

Successful rooting of grape microclones in uncontrolled environmental conditions (in vivo) depends on the level of resistance, which is formed at the stage of their passage and growth in vitro. An important role in this case is played by indicators of the water regime of the vegetative mass. The purpose of this study was to get acquainted with the results of determining the water-holding capacity, the intensity of transpiration of grape microclones in vitro and to establish the share of their influence on the adaptation potential in vivo. Biotechnological, laboratory, vegetation, and mathematical and statistical research methods were used in this study. The obtained results showed that to optimize the physiological processes in the tissues of the leaves and shoots of grape microclones, to increase their viability under in vivo conditions, it is advisable to cultivate them in vitro on structured nutrient media (MS + agroperlite, MS + vermiculite, MS + agroperlite + vermiculite) with the content of phytohormones IAA – 0.2 mg/l, and 6-BAP – 0.3 mg/l. Structured nutrient media contributed to an increase in water retention capacity and a decrease in the intensity of transpiration of tissues of leaves and shoots of microclones of both technical and rootstock varieties. During 60 minutes of research, from 0.006 g to 0.034 g of water evaporated from microclones of technical varieties, from 0.003 g to 0.053 g from microclones of rootstock varieties, respectively. Transpiration intensity (after 10 min) decreased by 1.7-1.8 times. On the control Murashige and Skoog nutrient medium, plants evaporated a larger amount of water during the corresponding period of time: from 0.006 g to 0.079 g (technical varieties) and from 0.008 g to 0.086 g (rootstock varieties); the intensity of transpiration was higher. After cultivation of grape microclones on structured nutrient media, they were characterized by a higher content of dry matter in the tissues of leaves and shoots (14.6-15.0%) and better survival rates in vivo (76.3-98.5%, at 58.5-65.2% in control). The reliability of the results obtained is confirmed by the results of multivariate analysis of variance. The obtained results expand the understanding of dynamic changes in the indicators of the water regime of the vegetative mass of grape microclones in vitro, their influence on plant survival under in vivo conditions