Phytoplasma disease surveys in Tonga, New Caledonia and Vanuatu

Abstract

Phytoplasma disease surveys of Tonga, Vanuatu and the French Pacific territory of New Caledonia were conducted. Samples were collected from plants showing phytoplasma disease-like symptoms and phytoplasmas were detected by nested polymerase chain reaction, followed by restriction fragment length polymorphism analysis and DNA sequencing. In New Caledonia, phytoplasmas were associated with diseases of pineapple (Ananas comosus), onion (Allium cepa), garlic (Allium sativum), tomato (Lycopersicon esculentum) and strawberry (Fragaria sp.). In Tonga, they were associated with diseases of Indian mulberry (also known as noni; Morinda citrifolia), sweet potato (Ipomoea batatas) and a weed Cyanthileum cinereum (Syn. Vernonia cinerea). In Vanuatu, they were associated with sweet potato and sand-binder (Ipomoea pes-caprae ssp. brasiliensis). DNA sequence comparisons revealed that there were phytoplasmas with a high similarity (most >95% similar) to members of the ‘Candidatus Phytoplasma australiense’ or ‘Candidatus Phytoplasma solani’ (16SrXII) group, the ‘Candidatus Phytoplasma aurantifolia’ (16SrII) group and the Mexican periwinkle virescence (16SrXIII) group.