Influencia de la inoculación micorrícica sobre la composición fenólica y la capacidad antioxidante de la vitis vinífera l. Cv. Tempranillo bajo diferentes escenarios de cambio climático

Resumen

The foreseen climate change is going to affect the agricultural suitability, viticulture being one of those sectors more sensible to environmental constraints. Projected warming combined with severe droughts in the growing season is expected to have detrimental impacts on the grape berry ripening affecting the berry quality. Thus, the demonstrated intra-varietal diversity of cv. Tempranillo has led to the search of new clones able to cope with the projected scenarios. On the other hand, new strategies such as deficit irrigation of vineyards have emerged as a promising tool to withstand water stress in this new challenging scenario. Also, the promotion of the symbiotic association of grapevines with arbuscular mycorrhizal fungi (AMF) which are known to benefit host plants by improving nutrient uptake, growth and water status of grapevines and helping them to cope with abiotic stresses. However, less is known about their effect on the phenolic content and antioxidant properties under climate change scenarios as well as, the role that plant hormones, which interact to regulate the establishment and functioning of symbiotic associations with AMF, play under abovementioned conditions. Besides, the cultivation of grapevines produced a huge amount of pruning wastes which could be reused in the pharmaceutical and nutritional industries due to their elevated content in nutraceuticals and antioxidant metabolites. Again, the role of AMF on the primary and secondary metabolism of grapevine leaves under elevated temperature remains unclear. Taking all into account the general objective of this PhD thesis was to assess the intra-varietal diversity of grapevine cv. Tempranillo to respond to different climate change scenarios (elevated air temperature and deficit irrigation) and to analyze if the potential benefits of mycorrhizal symbiosis on plant metabolism could be maintained under the predicted environmental conditions. The study was carried out on fruit-bearing cuttings clones of cv. Tempranillo with different agronomic traits and origins (CL-260, CL-1048, CL-1089, CL-8, CL-280 and CL-843) inoculated (+M) or not (−M) with AMF and grown under controlled conditions. Plants were subjected to two temperature regimes (24/14°C and 28/18°C (day/night)) from fruit set to berry maturity and different irrigation regimes (early season deficit irrigation, ED; late season deficit irrigation, LD; and full irrigation, FI) throughout berry development. This dissertation provided evidence of the broad diversity within Tempranillo variety highlighting the importance of an appropriate clonal selection based on the plausible applications and/or the environmental or biotic modulator factors and demonstrates the importance of adopting measures to protect the indigenous cohorts of AMF in vineyards. Moreover, since each clone responded differently to each mycorrhizal inoculum and responses varied according to the environmental conditions, it may be profitable to identify the AMF inoculants most suitable for a given clone in a given environment.