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 plant-pathogenic 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.
Highlights
Raffaelea (Arx & Hennebert 1965) is a genus of primarily asexual fungi including more than 20 species in Ophiostomatales (Harrington et al 2010, de Beer et al 2013, Musvuugwa et al 2015)
All isolates we examined resided in Raffaelea s. str., the R. lauricola complex, or the R. sulphurea complex in the phylogenetic analyses of the 28S ribosomal DNA (rDNA) and βT data matrices (Fig. 1)
The R. lauricola complex was sister to the Raffaelea s. str. clade with 81 % Maximum likelihood (ML) bootstrap and 100 % Bayesian posterior probabilities (BPP) support, and the well-supported R. sulphurea clade resolved within Leptographium s. lat
Summary
Raffaelea (Arx & Hennebert 1965) is a genus of primarily asexual fungi including more than 20 species in Ophiostomatales (Harrington et al 2010, de Beer et al 2013, Musvuugwa et al 2015) These fungi commonly occur in symbioses with wood-boring ambrosia beetles (Coleoptera: Curculionidae: Scolytinae and Platypodinae). Musvuugwa et al (2015) described a Raffaelea species, R. vaginata, with an observed sexual morph, similar to those of O. seticolle and O. deltoideosporum The latter authors emended the circumscription of the genus to include both asexual and sexual morphs, and transferred the two Ophiostoma species to Raffaelea as R. seticollis and R. deltiodeospora, consistent
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
