IMA Fungus 7(2): 265-273, doi: 10.5598/imafungus.2016.07.02.06

New Raffaelea species (Ophiostomatales) from the USA and Taiwan associated with ambrosia beetles and plant hosts

Jiri Hulcr, Z. Wilhelm De Beer^‡, Yin-Tse Huang^§, Craig Bateman^§, Alina S. Campbell^|, Tyler J. Dreaden^§, You Li^§, Randy C. Ploetz^|, Adam Black^¶, Hou-Feng Li^#, Chi-Yu Chen^¤, Michael J. Wingfield^«, Jiri Hulcr^§

‡ University of Pretoria, Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), Pretoria, South Africa§ University of Florida, School of Forest Resources and Conservation, Institute of Food and Agricultural Sciences, Gainesville| University of Florida, Tropical Research and Education Center, Homestead¶ Peckerwood Garden Conservation Foundation, Hempstead# National Chung Hsing University, Department of Entomology, Taichung, Taiwan¤ National Chung Hsing University, Department of Plant Pathology, Taichung, Taiwan« University of Pretoria, Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), Pretoria, South Africa

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Citation: Hulcr J, Wilhelm De Beer Z, Huang Y-T, Bateman C, Campbell AS, Dreaden TJ, Li Y, Ploetz RC, Black A, Li H-F, Chen C-Y, Wingfield MJ, Hulcr J (2016) New Raffaelea species (Ophiostomatales) from the USA and Taiwan associated with ambrosia beetles and plant hosts. IMA Fungus 7(2): 265-273. https://doi.org/10.5598/imafungus.2016.07.02.06

Abstract

Raffaelea (Ophiostomatales) is a genus of more than 20 ophiostomatoid fungi commonly occurring in symbioses with wood-boring ambrosia beetles. We examined ambrosia beetles and plant hosts in the USA and Taiwan for the presence of these mycosymbionts and found 22 isolates representing known and undescribed lineages in Raffaelea. From 28S rDNA and β-tubulin sequences, we generated a molecular phylogeny of Ophiostomatales and observed morphological features of seven cultures representing undescribed lineages in Raffaelea s. lat. From these analyses, we describe five new species in Raffaelea s. lat.: R. aguacate, R. campbellii, R. crossotarsa, R. cyclorhipidia, and R. xyleborina spp. nov. Our analyses also identified two plantpathogenic species of Raffaelea associated with previously undocumented beetle hosts: (1) R. quercivora, the causative agent of Japanese oak wilt, from Cyclorhipidion ohnoi and Crossotarsus emancipatus in Taiwan, and (2) R. lauricola, the pathogen responsible for laurel wilt, from Ambrosiodmus lecontei in Florida. The results of this study show that Raffaelea and associated ophiostomatoid fungi have been poorly sampled and that future investigations on ambrosia beetle mycosymbionts should reveal a substantially increased diversity.

Keywords

entomogenous fungi, insect-fungus interactions, Japanese oak wilt, laurel wilt, molecular phylogenetics, mycosymbioses