First Report of Banana Streak Virus Infecting Banana Cultivars (Musa spp.) in Taiwan.

Banana (Musa sapientam L.) is an economically important crop for both export and local consumption in Taiwan. Recently, leaf symptoms characteristic of banana streak disease (1) were found on banana cv. Mysore (AAB group) introduced from Australia in the germ plasm collection of the Taiwan Banana Research Institute. The citrus mealybug (Planococus citri) has been shown to transmit banana streak virus (BSV) but not banana bunchy top virus or cucumber mosaic virus (CMV) (2). When mealybugs were fed on leaves of diseased Mysore banana and transferred to healthy banana cv. Cavendish seedlings in a growth chamber, the latter developed fine chlorotic streaks characteristic of symptoms caused by BSV within 1 to 3 months. Some chlorotic streaks became necrotic. BSV was detected in diseased but not healthy leaves of Mysore and Cavendish bananas by polymerase chain reaction (PCR) with primer pairs of BSV provided by J. E. Thomas of Queensland Department of Primary Industries. Subsequently, fine chlorotic streaks were observed in leaves of Cavendish banana in several fields in southern Taiwan. Some of these diseased plants developed severe leaf necrosis, causing heart rot of spindle leaves characteristic of symptoms caused by CMV. Presence of BSV in these plants was verified by PCR assay. However, CMV was also detected by double antibody sandwich-enzyme-linked immunosorbent assay with a monoclonal antibody to CMV, indicating that these plants were simultaneously infected by both viruses. This is the first report of BSV infecting Musa spp. in Taiwan. References: (1) B. E. L. Lockhart. Phytopathology 76:995, 1986. (2) B. E. L. Lockhart. 1995 Food & Fertilizer Technol. Center (ASPAC) Tech. Bull. 143. 11 pp.