Screening of recombinant inbred lines for salinity tolerance in bread wheat (Triticum aestivum L.)
Screening and increasing of salinity tolerance of crops is an important aim of many plant breeders. Screening a large number of plants for salinity tolerance is not easy, therefore this investigation was performed to evaluate and screen 186 F8 recombinant inbred lines (RILs) derived from a cross between Superhead#2 (Super Seri) and Roshan wheat varieties for salinity tolerance. All the individuals were evaluated under two treatments including control (10 mM NaCl) and salt stress (150 mM NaCl). Different traits relating to salt tolerance, including dry matter of shoot and root, sodium and potassium concentration, chlorophyll content and relative water content (RWC) were measured. Significant differences were observed among wheat RILs for all the measured traits. Seedling growth was reduced by salinity in all RILs and we observed a significant negative correlation between shoot dry matter and sodium concentration (r = -0.52**), whereas significant positive correlations between shoot dry matter and K+/Na+ ratio (r = 0.36**), chlorophyll content (r = 0.20**) and RWC (r = 0.39**) were detected. Based on our results, sodium concentration of leaf, K+/Na+ ratio, chlorophyll content and RWC are good indexes for screening bread wheat genotypes for salinity tolerance.
Key words: Screening, salinity tolerance, recombinant inbred lines, wheat.