Castanea sativa Mill. ante Phytophthora cinnamomiRands, estrés hídrico y otros factores del cambio global

Abstract

Castanea sativa Mill. (European chestnut) is a multipurpose tree species native to Europe which is important for the production of edible nuts and its ecological relevance. However, the species undergoes the impact of the ‘ink disease’ caused by the invasive pathogen Phytophthora cinnamomi (Pc) and the increasing drought stress posed by the current climate change. The responses and the physiological basis of resistance to Pc and tolerance to drought in C. sativa are not well understood yet, which is crucial to mitigate the impacts of Pc and climate change on the species and to aid in chestnut breeding programs. Knowledge gaps in C. sativa include the effect of extreme climate events on the tree non-structural carbohydrates (NSC) but also the role that plant hormones play in modulating resistance to Pc and tolerance to drought. Intergenerational maternal effects and grafting are responsible for changes in the phenotype of trees including modifications in the susceptibility to biotic and abiotic stress. However, it is unknown whether intergenerational maternal effects can affect susceptibility of C. sativa trees to drought stress and Pc and how the resistance to Pc and tolerance to drought is changed by grafting in C. sativa. Through a multidisciplinary approach, in the present thesis we aimed to fill in the above knowledge gaps by performing greenhouse experiments complemented with biochemical analysis at the laboratory. The results constitute novel insights into the responses of chestnuts to Pc, drought and waterlogging and open new possibilities for future research in the species.