Symptoms of leaf yellowing, chlorosis, shortening of internodes and slight stunting were recently observed in cassava fields in Kawanda, Uganda. Interestingly, some plants of four other species growing nearby, i.e. sticky mallow (Malvaviscus arboreus), croton (Codiaeum variegatum), Chinese hibiscus (Hibiscus rosa-sinensis) and passion fruit (Passiflora edulis), showed little leaf, chlorosis, and leaf yellowing and deformation. Molecular studies showed that the 16S rRNA sequences of phytoplasmas detected in cassava (EU315317) and M. arboreus (EU315318) showed 98% of identity with that of the cactus witches' broom phytoplasma (AJ293216), whilst sequences from C. variegatum (EU315315), H. rosa-sinensis (EU315314), and P. edulis (EU315319) exhibited 99% of identity with that of Catharantus roseus phytoplasma (EU096500). The phylogeny results suggest that two distinct sub-types have been identified in (i) cassava and M. arboreus and in (ii) C. variegatum, H. rosa-sinensis and P. edulis, in plants growing geographically close to each other. This is the first record of phytoplasma group 16SrII, 'Candidatus Phytoplasma aurantifolia', in Uganda.
Arocha, Y.; Echodu, R.; Talengera, D.; Muhangi, J.; Rockefeller, E.; Asher, O.; Nakacwa, R.; Serugga, R.; Gumisiriza, G.; Tripathi, J.; Kabuye, D.; Otipa, M.; Vutseme, K.; Lukanda, M.; Boa, E. Occurrence of &#8216;Candidatus Phytoplasma aurantifolia&#8217; (16SrII group) in cassava and four other species in Uganda. Plant Pathology (2008) 58 (2) 390-390. [DOI: 10.1111/j.1365-3059.2008.01963.x]