Introduction: Water deficit stress is one of the most important abiotic stresses that seriously led to decreased plants production. Thus, several strategies have been proposed to alleviate the tense of cellular damage caused by stress and to improve tolerance water deficit. The aim of this research is to investigate the effect of prolin foliar application on quantitative and qualitative yield of chamomile in water deficit conditions.
Materials and Methods: The research was conducted in a factorial based on randomized complete blocks design with two factors of water deficit (0, 25, 50 and 75 percent depletion of FC levels) and prolin foliar application (0, 50 and 100 mg/L) with three replications at University of Guilan in 2012. Endogenous prolin content, activity of catalase, ascorbat proxidase and proxidase enzymes, as well as chlorophyll a, chlorophyll b, chlorophyll a+b, chlorophyll a/b, carotenoid contents were measures.
Results: Results showed that water deficit, affected on chlorophyll a content, endogenous prolin content, activity of catalase, ascorbat proxidase and proxidase enzymes, significantly. Chlorophyll a, chlorophyll a+b, chlorophyll a/b, activity of catalase and proxidase enzymes were affected by water deficit × prolin content interaction, significantly. The mean comparison of interaction effect of water deficit and prolin indicated that non-stress and 100 mg/L had the highest chlorophyll a, chlorophyll a+b, chlorophyll a/b chl content. The highest peroxidase enzyme content was obtained at 75% field capacity drought stress with 100 mg/L prolin.
Conclusion: Results showed increasing water deficit intensity increased activity of catalase, ascorbat proxidase and proxidase enzymes and prolin; while it decreased chlorophyll content of leaves. It also, increased endogenous prolin content which considered as a defense reaction to water deficit stress. Overall, it could be concluded according to increased antioxidant activity and endogenous prolin content that exogenous foliar application of prolin can relatively reduce the adverse effects of water deficit stress.
Keywords: Antioxidant enzymes, Water deficit, Quantitative and Qualitative yield, Prolin, Chamomile