David Hunter

Investigations into the seed and mealybug transmission of Taro bacilliform virus

Investigations were conducted into the transmission of Taro bacilliform badnavirus (TaBV) by seed and mealybugs. Seed transmission was investigated by artificially pollinating TaBV-infected taro. Seeds derived from four successfully pollinated plants tested positive for TaBV by PCR. Twenty seeds derived from each pollinated plant were also germinated; 2/80 seedlings showed TaBV-like symptoms and tested positive for TaBV by PCR. Pollen samples taken from TaBV-infected plants also tested positive for the virus. Mealybug transmission was investigated by exposing 51 healthy taro plants to Pseudococcus solomonensis that had been reared on TaBV-infected taro plants. Typical virus symptoms developed on 17 plants between 24 and 36 days after feeding; all these plants, in addition to 13 symptomless plants, tested positive for TaBV by PCR. This is the first report of TaBV transmission by P. solomonensis and the first report of P. solomonensis in Samoa.

Diseases of crops in the Maldives.

The Maldives represents a typical atoll environment. For many years, the isolation of the islands has ensured that plant disease incidence was minimal. However, a recent increase in agricultural activities and tourist resort development has led to a substantial rise in the import of plant material which has not been checked by an adequate quarantine facility. Consequently, plant disease incidence in the country is increasing. Surveys have identified the major plant diseases affecting agricultural crops in the Maldives and the implementation of a quarantine service to minimise further introduction of plant disease is recommended.