GWAS and linkage mapping for the identification of loci involved in salt tolerance in rice

Soil salinity is one of the environmental constraints affecting crops. Among cereals, rice (Oryza sativa L.) is one of the most salt-sensitive ones although cultivars can differ in their response to salt stress. The identification of European elite rice varieties tolerant to salt stress and, first of all, the dissection in them of salt stress tolerance mechanisms are of high interest for European rice breeding. Salinity tolerance in rice is a very complex trait, having different components that change as a function of the plant developmental stages or of the intensity of the imposed stress. A panel of 281 temperate japonica rice varieties and a population of 208 F7 RILs obtained by crossing two cultivars (Baldo and Vialone Nano) with opposite salt tolerance/sensitiveness behaviour have been subjected to GBS and phenotyping in mid-salt stress condition. GWAS approach on the first panel highlighted interesting genome-phenotype correlations that are under deeper investigations in order to identify putative tolerance-related traits. Phenotyping of the accessions and RILs resulted in the identification of promising cultivars/lines that is under physiological and electrophysiological characterisation. Preliminary results from these activities are reported.