The transmission of banana bunchy-top virus in micropropagated banana
Abstract. Plants were established in vitro from banana bunchy-top virus (BBTV) infected plants.Explants containing either vegetative shoot apices or terminal floral apices were used to initiate cultuer. Plants multiplied in culture were indistinguishable from non-infected(con-trol)plants and lacked characteristic symptoms of BBTV infection.After 16 months in culture plants were established in the glasshouse and after 1 month in pots some plants started to show symptoms of the disease. After a further 5 months,73%of the plants showed characteristic symptoms of the disease while 27% were symptomless and similar in appearance to control plants.These plants have been grown to maturity in the field without showing recognizable symptoms. This study demonstrates that BBTV can be transmitted in an apparently symptom-less condition in culture and has important consequences for the dissemination of banana germplasm within Australia and internally.