Biochemical changes in periwinkle (Catharanthus roseus) leaves infected with Alternaria alternata

Abstract

Periwinkle (Catharanthus roseus L.), an important medicinal and ornamental plants growing worldwide. Periwinkle plant is attacked by Alternaria alternata (Fr.) Kessiler causing leaf blight disease. The disease was prevalent in all the periwinkle growing areas of Muzaffarnagar district, surveyed during 2018-19. Infection of periwinkle leaves with Alternaria alternata caused alternation in biochemical composition of leaves. Infected leaf as a result of 75% disease intensity exhibited significant reduction in total chlorophyll 1.42 mg/g, total sugar content 0.85mg/g, amino acid 0.62 mg/g and total alkaloids 1.87mg/g as compare to healthy leaves. The phenomenon was reversed in case of phenol content of leaf. Phenol content in healthy leave 1.25 mg was increased to 3.15 mg/g as a result of 75% disease intensity (table 1).