Maryam Chavoushi - Department of Biology, Shahid Bahonar University of Kerman, Kerman, Iran Department of Horticulture, Shahid Bahonar University of Kerman, Kerman, Iran
Khosrow Manoochehri Kalantari - Department of Biology, Shahid Bahonar University of Kerman, Kerman, Iran Department of Horticulture, Shahid Bahonar University of Kerman, Kerman, Iran
Mohamad Javad Arvin - Department of Biology, Shahid Bahonar University of Kerman, Kerman, Iran Department of Horticulture, Shahid Bahonar University of Kerman, Kerman, Iran

Salinity stress is one of the main limiting factors for optimum agricultural productivity of safflower, Carthamus tinctorius L., in arid and semi-arid regions. It could leads to significant changes in plant biochemical, physiological, and growth traits. Salinity induced endogenous rise in jasmonic acid and its methyl esters (MeJA) has been reported. In the present study, effects of salinity stress (6 and 12 ds m-1) and the exogenous application of MeJA (0.1 and 0.5 mM) on the leaf number, shoot fresh weight, shoot length, chlorophyll a/b, soluble sugar, proline, and malondialdehyde (MDA) contents were investigated in two safflower varieties (Isfahan and IL111). Salinity stress negatively affected the growth of both varieties. Lipid peroxidation was not observed in Isfahan variety, but it significantly increased in the salinity resistant safflower, IL111. Soluble sugar and proline as the important osmoprotectants and free radical scavengers were elevated by salinity stress. Exogenous application of MeJA to the salinity stress-imposed plants slightly improved the growth due to inductions in the rate of photosynthesis; however, MeJA application impaired the growth of non-stressed plants because of induction of stomatal closure and as a result reduced photosynthesis. 

Carthamus tinctorius, Growth, Methyl jasmonate, Salinity stress, Physiology