Posts Tagged ‘coconut (Cocos nucifera L.’


International Journal of Systematic and Evolutionary Biology


‘Candidatus Phytoplasma palmicola’, associated with a lethal yellowing-type disease of coconut (Cocos nucifera L.) in Mozambique

Nigel A. Harrison1, Robert E. Davis2, Carlos Oropeza3, Ericka E. Helmick1, María Narváez3, Simon Eden-Green4, Michel Dollet5 and Matthew Dickinson6
+ Author Affiliations

1University of Florida, Fort Lauderdale Research and Education Center, 3205 College Avenue, Davie, FL 33314, USA
2Molecular Plant Pathology Laboratory, USDA–Agricultural Research Service, Beltsville, MD 20705, USA
3Centro de Investigación Científica de Yucatán (CICY), CP 97200 Mérida, Yucatan, Mexico
4EG Consulting, Larkfield, Kent, UK
5CIRAD, Etiologie – dépérissement, UPR 29, Campus international de Baillarguet, 34398 Montpellier cedex 5, France
6School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
Nigel A. Harrison naha@ufl.edu


In this study, the taxonomic position and group classification of the phytoplasma associated with a lethal yellowing-type disease (LYD) of coconut (Cocos nucifera L.) in Mozambique were addressed. Pairwise similarity values based on alignment of nearly full-length 16S rRNA gene sequences (1530 bp) revealed that the Mozambique coconut phytoplasma (LYDM) shared 100 % identity with a comparable sequence derived from a phytoplasma strain (LDN) responsible for Awka wilt disease of coconut in Nigeria, and shared 99.0–99.6 % identity with 16S rRNA gene sequences from strains associated with Cape St Paul wilt (CSPW) disease of coconut in Ghana and Côte d’Ivoire. Similarity scores further determined that the 16S rRNA gene of the LYDM phytoplasma shared <97.5 % sequence identity with all previously described members of ‘Candidatus Phytoplasma’. The presence of unique regions in the 16S rRNA gene sequence distinguished the LYDM phytoplasma from all currently described members of ‘Candidatus Phytoplasma’, justifying its recognition as the reference strain of a novel taxon, ‘Candidatus Phytoplasma palmicola’. Virtual RFLP profiles of the F2n/R2 portion (1251 bp) of the 16S rRNA gene and pattern similarity coefficients delineated coconut LYDM phytoplasma strains from Mozambique as novel members of established group 16SrXXII, subgroup A (16SrXXII-A). Similarity coefficients of 0.97 were obtained for comparisons between subgroup 16SrXXII-A strains and CSPW phytoplasmas from Ghana and Côte d’Ivoire. On this basis, the CSPW phytoplasma strains were designated members of a novel subgroup, 16SrXXII-B.

The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA gene sequences determined in this study are EU549768, KF364359, KF387570, KF419286, KF751387 and KF751388.

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