محمد مدرسی

Heat stress is main factor affecting the rate of plant which causes the growth rate somewhat increase and then after that decrease. Given the role of mediator of heat stress by plant hormones; in this research effect of salicylic acid and jasmonic acid on morphological and biochemical characters of German Chamomile (Matricaria Chamomilla L. CV Bona) under natural heat stress conditions, was studied. This experiment was carried out as completely randomized block design with 3 replications. Treatment of experiment in clouding four level salicylic acid (0, 12.5, 25, 50 mg.L-1) and four level jasmonic acid (0, 1, 1.5, 2 mg.L-1) was applied. Planting date was set in a way that more growth stages and flowering period faced with heat stress. The morphological triate included plant height, capitol diameter, flower wet weight, flower dry weight and biochemical traite included essential oil and essential chamazulene was studied. The analysis of variance showed that interaction of the hormone salicylic acid and jasmonic acid on flower wet weight and essential chamazulene was significant. Also the analysis of variance showed that effect of hormone jasmonic acid on essential chamazulene had significant effect. The interaction of both hormones on essential chamazulen had significant effect. We observed the best essential chamazulen in jasmonic acid 2 mg.L-1 treatment under heat stress.