Maize Chlorotic Dwarf and Related Viruses

Abstract

Maize chlorotic dwarf virus (MCDV), which has a polyhedral particle about 30 nm in diameter, was designated as the type member of the Maize Chlorotic Dwarf Virus group in 1981 by the International Committee on Taxonomy of Viruses (Matthews, 1982). The rice tungro spherical virus (RTSV) has similar characteristics and is listed as a probable member. RTSV is one of two morphologically distinct particles involved in rice tungro and related diseases of rice in the Far East. The second is that of the rice tungro bacilliform virus (RTBV), which is 35 nm in diameter and 150’350 nm long (Hibino et al., 1978; Saito, 1977; Saito et al., 1981). In many rice tungro studies the contribution of RTSV cannot be separated from that of RTBV. Therefore, this discussion will focus on MCDV and the disease it causes, maize chlorotic dwarf (MCD), but will include information on rice tungro and related diseases if the spherical particle was clearly identified. Diseases considered to be related to the rice tungro disease found in the Philippines are: rice waika in Japan, leaf yellowing in India, penyakit habang and mentek in Indonesia, penyakit merah in Malaysia, and yellow-orange leaf in Thailand (Ling and Tiongco, 1979). Several reviews summarize information on this group of diseases (Ling, 1972; Ling and Tiongco, 1979; Shikata, 1979).