Citrus industry: Phytoplasma-associated diseases and related challenges for Asia, America and Africa

Abstract Citrus production has been widely affected by pathogens which causes economic losses to the growers resulting in severe social effects in many of the areas where the economy is based on agriculture. In the past decade citrus-associated phytoplasmas have originated widespread epidemics in some citrus-growing regions of the world. They are associated to either specific symptoms such as witches' broom or non-specific symptoms like leaf yellowing, leaf mottling and lopsided fruit. So far about 21 citrus cultivars have been reported to be infected by phytoplasmas enclosed in 11 ribosomal groups; among these 16SrI (aster yellows) and 16SrII (peanut witches’ broom) are the most widespread. Here symptomatology, economic importance, transmission and strategies used for disease management are reported together with the molecular classification of the detected phytoplasma strains in Asian, American and African continents.