Carignan Grape Cultivar Salt Tolerance during the Germination Phase across the Mediterranean Basin

Abstract

Carignan is a black grape cultivar widely planted throughout the western Mediterranean Basin. The grape faces significant viticultural hazards such as soil salinization, which affects about 6% of the world’s total land area. The search for salt tolerance genotypes to be introduced in crossbreeding programs and obtaining new cultivars is a key factor. The seed germination and salt tolerance of Carignan were studied from different coastal vineyards across the Mediterranean Basin, and as well as whether the distance from the sea affected germination and salt tolerance. Carignan seeds, independently of the temperature and distance from the sea, germinated more than 50% under 125 mM NaCl concentrations. Seed recovery was elevated, including the capacity of gemination after high salt exposure (500 mM NaCl). The results on germination behavior related to the distance from the sea showed that all tested vineyards, except for the one farthest from the sea, had similar germination responses. The optimum germination condition to select salt-tolerant accessions is alternating temperatures 25/10 °C and 125 mM NaCl. Thanks to the ability of the Carignan to germinate in a saline substrate and their capacity for recovery, it could be useful to crossbreeding programs, for integrating as rootstock selection or for the improvement of cultivars through sexual reproduction.