Fungistatic activity of chitosan salicylate as an inducer of wheat resistance to dark brown spot
Keywords:chitosan, salicylic acid, fungistatic activity, causative agent, spot blotch of wheat, Cochliobolus sativus
A comparative evaluation of fungistatic activity of Chitosan salicylic acid and Chitosan salicylate is studied in respect to dark brown spot of wheat C. sativus. The connection between the concentration of chitosans and the degree of inhibition of mycelial growth in the fungus has been revealed. Samples of Chitosan and its derivative with SA in concentration of 0.01–0.05 % do not practically affect the growth of the pathogen mycelium C. sativus during the 10th day of cultivation in vitro. Increase in the concentration of polymers to 0.1–0.2 % leads to an increase in their fungisatiс activity, and the linear growth of the mycelial fungus of C. sativus is suppressed by 47.7–74.3 %. At concentration of 0.1–0.2 %, Chitosan and its derivatives are usually used as inducers of disease resistance. Chitosan and Chitosan salicylate at a concentration of 0.5 % have completely suppressed the growth of C. sativus. It has been established that ascomycete S. sativus has the ability to metabolize SA at low concentrations (0.25–1 mM), and high concentrations of SC (10 mM) are effective inhibitors of linear growth pathogen. In general, our studies showed that chitosan salicylate at a concentration of 0.1 % has a slight fungistatic activity, but it can contribute to the overall effectiveness of Chitosan salicylate as an inducer of resistance in protecting wheat from dark brown spot.