Investigation on the reaction of sunflower recombinant inbred lines to NaCl stress at seedling stage

In order to investigate the reaction of sunflower recombinant inbred lines to salt stress in seedling stage, a factorial experiment based on randomized complete block design was implemented in controlled condition. The first factor consisted of 77 recombinant inbred lines (generation F9) and the second factor was salinity stress with NaCl (salinity levels 0 and 6 dS m-1) and traits including shoot length, root length, shoot fresh weight, root fresh weight, shoot dry weight and root dry weight were measured. Results of analysis of variance revealed that all studied traits influenced by genotype, salinity and genotype×salinity interaction. 33 lines out of 77 lines (43%) in salinity level of 6 dS m-1 could not germinate and 44 lines out of 77 lines (57%) could maintain their viability. Mean values of all of studied traits were decreased in salinity level of 6 dS m-1 compared to normal conditions. Clustering of genotypes was performed using the studied traits in each condition by squared Euclidean distance criteria and Ward algorithm. Studied lines were grouped in three classes. In normal conditions, 17, 18 and 42 lines were located in cluster one, two and three, respectively, while, in salinity conditions, 26, 8, and 9 lines were classified in above mentioned groups. Maximum distance was observed between cluster 1 and cluster 2. Results of cluster analysis were in coincidence with those obtained by principle component analysis and discriminant function analysis. Line C86 was possessed maximum values of studied traits and hence, present as salinity tolerant line.