Phytohormones and Mineral Nutrient Changes in Young Plants of Grapevine Genotypes at Different Growth Stages

Climate change is considered a threat for viticulture by altering phenology, yield, and key physiological processes. The plant responses depend on the genotype characteristics and the microclimate of crop area. In this research, “Castellana Negra”, “Negramoll”, and “Tintilla” were cultivated for 102 days, and physiological variables were assessed under natural conditions. Results indicated similar trends in growth between “Negramoll” and “Tintilla”, while ”Castellana Negra” grew slowly and possessed fewer leaves compared to the other genotypes. Stomatal conductance was constant among the genotypes, excepting “Negramoll”, which demonstrated lower values at d 76 compared to “Castellana Negra” and “Tintilla”, coinciding with the elevated leaf temperature. Regarding the hormonal changes, “Castellana Negra” accumulated the highest concentration of salicylic acid (SA) compared to “Negramoll” and “Tintilla”, which showed similar content. Furthermore, an antagonistic change between SA and jasmonic acid (JA) was observed in all genotypes, as well as between abscisic acid (ABA) and JA at the beginning and end of the trial. The variations in micronutrients did not show a clear tendency between cultivars. Therefore, to thoroughly elucidate the role of phytohormones and other physiological factors in the growth and development of these genotypes under varying environmental conditions, long-term experiments could be conducted.