Response of heritage and modern wheat varieties to altitude induced stresses by synthesis of volatile compounds. A multivariate statistical analysis

The genotype × altitude interactive effect on crops quality is a crucial topic for researchers who face the challenge of climate changes. In this study, three common and durum wheat, including two old varieties, were grown for three years in different organic farms sited at three altitudes in the Abruzzo region (Italy). Volatile organic compounds (VOCs), along with agronomic yield and protein content were analysed. Genotype × altitude interaction resulted always statistically significant and altitude of cultivation negatively affected yield and protein content. A multivariate statistical approach permitted to unravel the most important VOCs useful to predict the effect of altitude of cultivation on wheat species. Durum wheat synthetized a higher number of VOCs than common wheat as a response to altitude-induced stress. Elevation of cultivation determined also a strong variety-dependent adaptative response, with characteristic VOCs patterns for any specific wheat. Heritage wheat emitted a higher number of volatiles in response to altitude changes, with (E)-2-Nonenal being a putative marker of these varieties. These results reveal the complexity behind the plants system defence against abiotic and biotic stresses induced by altitude and could open new perspectives for the study of the dependence of wheat production and quality on the territory.