Chlorotic Leaf Spot Disease of Arka Calotropis gigantea Molecular Characterization of the Causal agent and Effect on Phytochemical constituents

Abstract

newline ABSTRACT newlineThe present work entitled, Chlorotic Leaf Spot Disease of Arka (Calotropis newlinegigantea): Molecular Characterization of the Causal Agent and Effect on newlinePhytochemical Constituents is focused on the effect of disease on active newlinephytochemical constituents in leaves of Calotropis gigantea and the molecular newlinecharacterization of the causal agent. Based on the nature of symptoms i.e. systemic newlinebrilliant chlorotic to yellow spots on the leaves of C. gigantea may be the infection due to newlinevirus. Phytochemical constituents viz. antioxidant activity, quinones, flavonoids, total newlinephenols, ascorbic acid, PPO activity have higher values in infected leaves whereas total newlinechlorophyll and carotenoids had lower values in infected leaves. In case of PPO activity it newlinewas found maximum at same time interval for both of the samples. However, PPO newlineactivity was found higher in infected sample and lower in healthy sample. Molecular newlinecharacterization studies revealed the presence of virus particles on the basis of results newlineobtained from Virus Like Particle (VLP) purification and electron microscopy. Some newlineicosahedral, enveloped entities of approximately 50-60 nm were observed which proved newlinethe presence of virus. The sequencing results showed similarity to insect infected virus newlineNucleopolyhedrosis (OpMNV) and Paramecium bursaria chlorella virus (PBCV) from newlineocean virome studies which were bacterial in origin. Irrespective of different strategies newlineperformed for cloning, ligation and PCR the sequencing results were similar. However, newlinethese viruses have not been reported in plants. Thus results are indicative of presence of a newlinenovel virus or new DNA which needs to be further investigated.