ارزيابي واكنش ژنوتيپ هاي گندم نان به تنش شوري در مرحله جوانه زني

Evaluation of Bread Wheat Genotypes Under Salt Stress at Germination Stage

Germination of seed is an effective factor in the establishment of final plant population. Optimal plant population per unit area could be achived when seeds germinate adequately. Tolerance to salinity during germination and early seedling stage is an important factor for establishment and survival of plants in saline soils or in areas that are irrigated with saline water. To identify salt tolerant genotypes of bread wheat at germination stage, 38 genotypes (32 advanced lines, 3 landraces and ,3 commerical cultivars)were evaluated in different salt concentrations of 0(control), 50, 100, 150, 200 and 250 mM NaCl with 7 mM CaCl2, using factorial expriment based on CRD with three replications. Seeds were treated and incubated for seven days in 25 °C. Results showed that salinity reduced the rate of germination, length of root and shoot, dry weight of root and shoot about 18%, 49%, 70%, 77%, 56% and 68%, respectivly. However, concentration of sodium was increased in both root and shoot, by 13.1 and 10.6 times, and concentration of potassium in both root and shoot by 3.6 and 1.13 times as compared with the control treatment, respectively. Tolerant genotypes had greater length of shoot, root and shoot dry weigth as compared with those of sensitive genotypes. However, sodium transported to shoot was not substantial. When salinity increased, sensitive genotypes had greater concentration of potassium in both root and shoot, as compared with that of tolerant genotypes.