title: Molecular phylogeny of Rigidoporus microporus isolates associated with white rot disease of rubber trees (Hevea brasiliensis).
abstract: Rigidoporus microporus (Polyporales, Basidiomycota) syn. Rigidoporus lignosus is the most destructive root pathogen of rubber plantations distributed in tropical and sub-tropical regions. Our primary objective was to characterize Nigerian isolates from rubber tree and compare them with other West African, Southeast Asian and American isolates. To characterize the 20 isolates from Nigeria, we used sequence data of the nuclear ribosomal DNA ITS and LSU, β-tubulin and translation elongation factor 1-α (tef1) gene sequences. Altogether, 40 isolates of R. microporus were included in the analyses. Isolates from Africa, Asia and South/Central America formed three distinctive clades corresponding to at least three species. No phylogeographic pattern was detected among R. microporus collected from West and Central African rubber plantations suggesting continuous gene flow among these populations. Our molecular phylogenetic analysis suggests the presence of two distinctive species associated with the white rot disease. Phylogenetic analyses placed R. microporus in the Hymenochaetales in the vicinity of Oxyporus. This is the first study to characterize R. microporus isolates from Nigeria through molecular phylogenetic techniques, and also the first to compare isolates from rubber plantations in Africa and Asia.
authors.affiliation: Department of Forest Sciences, University of Helsinki, P.O. Box 27, 00014 Helsinki, Finland. Electronic address: abbot.oghenekaro@helsinki.fi.
authors.forename: Abbot O
authors.initials: AO
authors.lastname: Oghenekaro
authors.affiliation: Botanical Museum, Finnish Museum of Natural History, University of Helsinki, P.O. Box 7, Finland; Biology Department, Clark University, 950 Main Street, Worcester, MA 01610, USA.
authors.forename: Otto
authors.initials: O
authors.lastname: Miettinen
authors.affiliation: Plant Protection Division, Rubber Research Institute of Nigeria, P. M. B. 1049, Benin City, Nigeria.
authors.forename: Victor I
authors.initials: VI
authors.lastname: Omorusi
authors.affiliation: Plant Protection Division, Rubber Research Institute of Nigeria, P. M. B. 1049, Benin City, Nigeria.
authors.forename: Grace A
authors.initials: GA
authors.lastname: Evueh
authors.affiliation: Mycology and Pathology Laboratory, Forest Research Institute, Malaysia, 52109 Kepong, Malaysia.
authors.forename: Mohd A
authors.initials: MA
authors.lastname: Farid
authors.affiliation: Biology Department, Clark University, 950 Main Street, Worcester, MA 01610, USA.
authors.forename: Romina
authors.initials: R
authors.lastname: Gazis
authors.affiliation: Department of Forest Sciences, University of Helsinki, P.O. Box 27, 00014 Helsinki, Finland.
authors.forename: Fred O
authors.initials: FO
authors.lastname: Asiegbu
mesh_terms: D028482:Hevea / Q000382:microbiology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology*; D020072:Polyporales / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*
keywords: Host shift; ITS; LSU; Natural rubber; tef1; β-tubulin