the effects of salinity and methyl jasmonate on some morphological traits of chamomile (matricaria chamomilla)

abstract salinity stress is among the major barriers to plant production in many parts of the world, especially in arid and semi-arid areas. jasmonates are one of the newest plant growth regulators that reduce the damages caused by environmental stresses. in this study, the effects of salinity and methyl jasmonate on some morphological traits of chamomile including root and shoot lengths, fresh weights and dry weights were evaluated. seeds were planted in green house in pots as a completely randomized design with three pots as replications for each treatment. plants were treated with 100 and 200 mm concentrations of salt at the four-leaf phase for six days alternately. methyl jasmonate was sprayed on plants at concentrations of 0.01-0.1 µm/l along with salinity treatments which was continued for 6 hours. salinity and methyl jasmonate reduced stem length. salinity reduced dry and fresh weights in proportion to control group. but methyl jasmonate improved the effects of salinity. growth study of root and shoot in seedlings showed salinity effects and reduction in weights. increased dry and fresh weights of treated plants in proportion to control group showed the protective effect of methyl jasmonate.