Herbal
Leyli Honarmand; Nadali Babaeian Jelodar; Nadali Bagheri; Ali Dehestani; Valiollah Babaezad
Abstract
Introduction: Early blight is one of the most significant tomato diseases and fungicide application is the most common measure used to control its damage. Exploitation of generally regarded as safe (GRAS) and defense inducers have been focused on as alternative strategies to avoid environmental impacts ...
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Introduction: Early blight is one of the most significant tomato diseases and fungicide application is the most common measure used to control its damage. Exploitation of generally regarded as safe (GRAS) and defense inducers have been focused on as alternative strategies to avoid environmental impacts of fungicides. Defense inducers enhance plant defense system against stresses through inducing specific changes in plant physiological characteristics. In the present study the effect of potassium sorbate (KS) on physiological, biochemical and defense response of Alternaria solani-infected tomato plants was investigated. Methods This research was conducted as split plot-factorial with three factors, presence or absence of a pathogen, the use of either KS or distilled water (control) for foliar spraying, and three time courses for sampling (24, 72, and 168 hours). Results: The results showed that the fresh and dry weights in inoculated plants were lower than that of non-inoculated plants. The pathogen caused damage to the plant cell membrane and significantly reduced photosynthetic pigments. Additionally, the amount of MDA and chla in inoculated plants was significantly decreased compared to non-inoculated plants. The activity of POD and CAT enzymes significantly increased in plants treated with KS compared to the control. Chitinase enzyme in plants treated with KS showed a significant increase in the inoculated plants 168 hours, which can be a sign of immune system stimulation. The results revealed that the KS inducer was effective on the weight and growth of plants and reduced biotic stress damages through increased activity of antioxidant and defense enzyme
