There are several research stations in the Republic of Fiji which are maintaining a field gene bank of several crops including banana. You can contact these stations for your trail materials.
Few of them are
1. Naduruloulou Research Station (kava, duruka, tree crops, fruits, spices, indigenous and exotic fruits and trees, vegetative propagation)
2. Dobuilevu Research Station (root crops, fruits, ginger)
3. Legalega Research Station (pulses, fruits, indigenous and exotic fruits, breadfruit, noni, vegetative propagation)
4. Seaqaqa Research Station (fruits , root crops, ginger, indigenous ad exotic fruits and trees).
5. Sigatoka Research Station (vegetables, tropical fruits, cereals, wild vegetables and fruits, banana, breadfruit)
For more details