Plant defense activation and down-regulation root rot and wilt in chickpea diseases by some abiotic substances

Abstract

Rhizoctonia solani in addition to Fusarium oxysporum f. sp. ciceris have been recorded the most closely related fungi to root rotted as well as wilted chickpea plants assembled from various locations in Ismailia Governorate, Egypt. In the pathogenicity tests, all isolates were capable of infecting chickpea plants cv. Giza 2 and caused signs of root rot in addition to wilt diseases to variable degrees. The isolate of Rhizoctonia solani number 4 with accession No. (OR074128) and F. oxysporum isolate number 3 with accession No. (OR074126 ) were the more virulent ones. In the present study, abiotic substances viz hydroquinone, salicylic acid, benzoic acid, and chitosan were evaluated compared with Topsin M-70® fungicide for controlling these diseases under in vitro in addition to in vivo conditions. The application of abiotic substances demonstrated fungicidal action was inhibited the mycelia outgrowth of the two examined fungi by varying degrees. Chitosan was the greatest efficacy accompanied by hydroquinone and salicylic acid. In the pots and field experiments, all treatments significantly decreased root rot in addition to wilt diseases incidence consequently raised the number of survival plants. The highest protection from the infection of both the tested pathogenic fungi occurred under chitosan treatment followed by hydroquinone and salicylic acid. showed the best increase over the control, hydroquinone came next followed by salicylic acid. In physiological aspects, the activities of defense-related enzymes, exactly (peroxidase “PO”, polyphenol oxidase “PPO”, total phenol content “TPC”) and photosynthetic pigments enhanced in all abiotic substances applications as contrasted with untreated inoculated plants in addition to untreated uninoculated plants.