Effects of Salinity and Drought Stresses Due to NaCl and Poly Ethylene Glycol on Germination Characteristics and Seedling Growth of Wild Mustard (Sinapis arvensis

This experiment was conducted to study the effect of salinity and drought stress on germination and growth characteristics of wild mustard seedlings collected from irrigated wheat fields on the base of a complete randomized design in Iranian Plant Protection Research Institute. Different levels of salinity and drought stress included of 0 (control), -2, -4, -6, -8 and -10 bar were created by NaCl and poly-ethylene-glycol (PEG), respectively. Measured criteria included of final germination percentage, germination speed, seedling length, plumule length, radicle length and seedling vigor index. According to the results, mentioned stresses had negative significant effect on germination rate and percentage, length of plumule, radicle and seedling and seedling vigor index. More significant effect in drought stress than salinity stress showed higher resistance of wild mustard in salinity stress rather than drought stress. Both salinity and drought stress affected length of plumule more than length of radical. It means that length of plumule is more sensitive to mentioned stresses. According to fitted model, X50 (the potential caused to 50% reduction of final germination and germination rate of wild mustard) related to salinity stress (7.33 and 5.03, respectively) was significantly higher than X50 related to drought stress (4.47 and 2.90, respectively).