Phytoplasmas: Emerging Plant Pathogens in India Rao Govind P.* Division of Plant Pathlogy, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India *Corresponding Author gprao_gor@rediffmail.com
Online published on 30 November, 2019. Abstract Phytoplasma (Class Mollicutes) are wall-less prokaryotes with pleiomorphic or filamentous shape of50-800 nm and inhabit phloem sieve elements in infected plants and phloem-sucking leafhopper species. Plants infected with phytoplasmas exhibit symptoms suggesting a profound disturbance in the normalbalance of growth regulators. Because the phytoplasma is unculturable and the titre of phytoplasma is very low in phloem cells, the identification of these mollicutes is very tricky and unreliable in early days of infection. The history of phytoplasma associated diseases is more than 100 years old in India, but only in late 1990’s the authentic identification of phytoplasmas based on molecular assays could be made possible which helped in reliable taxonomic classification of phytoplasma associated diseases with different plants. The list of diseases caused by phytoplasmas in India continues to grow. Many newly emerging diseases with diverse geographic distribution, have been identified in recent years as being associated with phytoplasmas. Phytoplasmas have been found associated with more than 100 plant species in India including vegetables, spices, medicinal plants, ornamentals, cash crops, palm species, fruit trees and weed species. The increasing trends of reporting new phytoplasma diseases on economic agriculture crops during last decade in India indicate the importance of this emerging groups of mollicutes in India. Sesame phyllody, brinjal little leaf, sugarcane grassy shoot, sandal spike, coconut root wilt, arecanut yellow leaf and ornamental diseases are the major diseases caused by phytoplasmas in India causing severe economic losses. In this manuscript, the historical background, present scenario and future roadmaps of phytoplasma diseases in India are discussed. Top Keywords Mollicutes, Indian scenario, phytoplasma, emerging pathogens. Top |