Survey, diagnosis and identification of resistant source of leaf curl virus infecting papaya (Carica papaya L.) in India

Abstract

A survey conducted, at the orchards of papaya at different locations in India, revealed that the incidence of leaf curl disease ranged from 13.00-32.00 per cent and 12.00-28.00 per cent during 2006-07 and 2007-08 respectively. Maximum incidence of leaf curl (27.50%), during 2006-07, was recorded in District Etawah. Whereas, maximum leaf curl disease incidence (23.50%), during 2007-08, was recorded in Lucknow district. Symptoms of papaya leaf curl disease appeared in the form of severe distortion of leaves associated with curling and rolling of leaves, leathery leaf, vein zigzag and reduction in the size of petioles, internodes, and main shoot. As for as varietal response was concerned, maximum leaf curl incidence (80.00 and 86.67%) was observed in cultivar Co-4 followed by MF-1 (80.00 and 83.33%). While minimum leaf curl incidence (23.33 and 20.00 percent) was observed on Harichaap cultivar during 2006-07 and 2007-08, respectively. Variety Harichaap was found resistant against leaf curl disease during both the years. Six cultivars (varieties) viz., CO-2, CO-3, CO-6, Coorghoneydew, Pusa Delicious and Pusa Dwarf were rated as moderately resistant.

Identification of Novel Begomoviruses Associated with Leaf Curl Disease of Papaya (Carica papaya L.) in India

“…Symptoms recorded at different locations were almost identical, with notable characteristic symptomatic expression seen on leaves with severe leaf curl. A literature survey also showed that similar type of symptoms, such as downward leaf curling, vein thickening and clearing, rubbery, fragile, distorted petioles curling, deformation and yellowing of young leaves, were well documented on papaya [10,15,25,52].…”