title: Taxonomic revision and phylogenetic analyses of rubber powdery mildew fungi.
abstract: Powdery mildew is a fungal disease that infects a wide range of plants, including rubber trees, which results in a reduction of latex yields of up to 45%. The causal agent of powdery mildew of rubber was first described as Oidium heveae, but later morpho-molecular research suggested that in the past, O. heveae has been confused with Erysiphe quercicola. However, it is still under debate whether the causal agent should be classified as a species of the genus Erysiphe emend. or Golovinomyces and Podosphaera, respectively. Therefore, the aim of this study was to undertake the morpho-molecular characterization of powdery mildew species associated with rubber trees, thus resolving these taxonomic issues. Morphological observation under light and scanning electron microscopes (SEM) clearly identified two morphotypes of the rubber powdery mildew. With the support of morphological and phylogenetic data, one of the two morphotypes was identified as the asexual morph of E. quercicola, while the second morphotype is still insufficiently known and according to the morphological results obtained we assume that it might belong to the genus Golovinomyces. More collections and additional molecular data are required for final conclusions regarding the exact taxonomic position of the second morphotype of rubber powdery mildew and its relation to the name O. heveae. The haplotype analysis identified eight haplotype groups of E. quercicola indicating the high genetic diversity of the species.
authors.affiliation: World Agroforestry Centre, East and Central Asia, Kunming, 132 Lanhei Rd, Heilongtan, Kunming, Yunnan, China; Center of Excellence in Fungal Research, School of Science, Mae Fah Luang University, Chiang Rai, 57100, Thailand; Center for Mountain Ecosystem Studies, Kunming Institute of Botany, Chinese Academy of Science, Kunming 650201, Yunnan China; Rubber Research Institute of Sri Lanka, Dartonfield, Agalawatta, Sri Lanka.
authors.forename: K K
authors.initials: KK
authors.lastname: Liyanage
authors.affiliation: World Agroforestry Centre, East and Central Asia, Kunming, 132 Lanhei Rd, Heilongtan, Kunming, Yunnan, China; Center for Mountain Ecosystem Studies, Kunming Institute of Botany, Chinese Academy of Science, Kunming 650201, Yunnan China.
authors.forename: Sehroon
authors.initials: S
authors.lastname: Khan
authors.affiliation: Center of Excellence in Fungal Research, School of Science, Mae Fah Luang University, Chiang Rai, 57100, Thailand.
authors.forename: Siraprapa
authors.initials: S
authors.lastname: Brooks
authors.affiliation: World Agroforestry Centre, East and Central Asia, Kunming, 132 Lanhei Rd, Heilongtan, Kunming, Yunnan, China; Center for Mountain Ecosystem Studies, Kunming Institute of Botany, Chinese Academy of Science, Kunming 650201, Yunnan China.
authors.forename: Peter E
authors.initials: PE
authors.lastname: Mortimer
authors.affiliation: World Agroforestry Centre, East and Central Asia, Kunming, 132 Lanhei Rd, Heilongtan, Kunming, Yunnan, China; Center for Mountain Ecosystem Studies, Kunming Institute of Botany, Chinese Academy of Science, Kunming 650201, Yunnan China.
authors.forename: Samantha C
authors.initials: SC
authors.lastname: Karunarathna
authors.affiliation: World Agroforestry Centre, East and Central Asia, Kunming, 132 Lanhei Rd, Heilongtan, Kunming, Yunnan, China; Center for Mountain Ecosystem Studies, Kunming Institute of Botany, Chinese Academy of Science, Kunming 650201, Yunnan China. Electronic address: j.c.xu@cgiar.org.
authors.forename: Jianchu
authors.initials: J
authors.lastname: Xu
authors.affiliation: World Agroforestry Centre, East and Central Asia, Kunming, 132 Lanhei Rd, Heilongtan, Kunming, Yunnan, China; Center of Excellence in Fungal Research, School of Science, Mae Fah Luang University, Chiang Rai, 57100, Thailand. Electronic address: kdhyde3@gmail.com.
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Hyde
mesh_terms: D002681:China; D004271:DNA, Fungal / Q000032:analysis / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D014644:Genetic Variation; D006239:Haplotypes; D028482:Hevea / Q000382:microbiology*; D025301:Hyphae / Q000166:cytology; D008855:Microscopy, Electron, Scanning; D016533:Mycological Typing Techniques; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology*; D004718:Saccharomycetales / Q000145:classification* / Q000235:genetics / Q000502:physiology* / Q000648:ultrastructure; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D013172:Spores, Fungal / Q000166:cytology / Q000502:physiology / Q000648:ultrastructure
chemical_list: D004271:DNA, Fungal; D004275:DNA, Ribosomal
keywords: Erysiphe quercicola; Golovinomyces; Haplotypes; Hevea brasiliensis; Morphology; Podosphaera