New Record of Ceratocystis fimbriata Causing Wilt of Pomegranate in India.

Abstract

Wilt of pomegranate (Punica granatum L.) was first noticed in two areas of the Bijapur district (16°49'N; 75°43'E) of India in 1990. Around 1993, rapid spread of this disease was observed in the entire Bijapur district. The cause was not identified until 1995. Initial symptoms were yellowing and wilting of leaves on one to several branches leading to death of affected plants in a few weeks. Cross sections of diseased plants revealed brown discoloration in the outer xylem from roots to the main trunk. A survey of 44 locations from 1995 to 1998 showed an approximate loss of Rs. 30 lakhs (ca. US$69,770) and 7.5% (3,474 of 47,096 plants wilted) of the crop. At 13 locations, plants also were severely infested with shot hole borer (Xyleborus spp.). In 1996, the fungus, a Ceratocystis sp., was isolated from discolored stem, root, and branch tissues on wilted plants collected from various locations, e.g., A. Sangapur, Bagalkot, Bijapur, Bilagi, Kanamadi, Tajpur, and Tikota. The fungus isolated from Bagalkot was confirmed by the International Mycological Institute (UK) as C. fimbriata Ellis & Halst. (Specimen No. W 5496, PBUR) in 1997; the strain of this fungus, i.e., Latin American group, was identified in 1998 by T. C. Harrington (Iowa State University). Morphological characteristics of mycelium, conidia, conidiophore, chlamydospores, perithecia, and ascospores were similar to those described previously (1). Pathogenicity of this fungus was confirmed by inoculating wounded roots. This is the first report of C. fimbriata causing wilt on pomegranate. Reference: (1) Anonymous. C.M.I. Descriptions of Pathogenic Fungi and Bacteria. No. 141. CAB, Surrey, England.