Phenotypic Correlation between Yield Components and Responsive Genes under Salinity Stress for Tomato Lines

Water salinity greatly affects growth and production of agricultural crops. Thus, yield enhancement under salinity conditions is a major goal of plant breeders. Six advanced tomato lines along with their original populations and two salinity tolerant lines were used to evaluate their response to salt stress using five water salinity levels of NaCl (0.5 control treatment, 2.4, 4.8, 7.2, and 9.6 dS·m^-1 ). The Phenotypic correlation coefficients (r) were calculated for all possible pairs of the studied traits, over all the five salinity levels and the fourteen genotypes at the two seasons The results showed significant and desirable positive correlation between total yield and nine traits; plant height (0.83**), stem diameter (0.76**), leaf area (0.67**), average fruit weight (0.84**), average fruit number (0.95**), Ca⁺⁺ content (0.45*), K⁺ content (0.80*), fruit flesh thickness (0.88**) and WUE (0.99**). Significant negative correlations were detected between total yield trait and both Na⁺ content (–0.53*) and total soluble solids (–0.82). These results indicated the importance of these traits in yield improvement and in selection program. Based on the performance of the tomato genotypes at different salinity levels, four genotypes were selected to represent salt susceptible, moderately salt tolerant, salt tolerant, and reference salt tolerant. The Phenotypic correlation coefficients values between the total yield trait and 50 genes for the selected tomato genotypes under high salinity level were determined. The results showed significant and desirable positive correlation between total yield trait and eight of the fifty genes; JAZ8, LesAffx.30832.1.S1 (0.97*), Polcalcin jun (Les.5056.1.S1_x_) (0.99**), Polcalcin jun (Les.5056.1.S1_a_) (0.98*), ER5 (Les.3766.1.S1_) (0.96*).