@article{gonzalez_rodriguez-carres_boekhout_stalpers_kuramae_nakatani_vilgalys_cubeta_2016, title={Phylogenetic relationships of Rhizoctonia fungi within the Cantharellales}, volume={120}, ISSN={["1878-6162"]}, DOI={10.1016/j.funbio.2016.01.012}, abstractNote={Phylogenetic relationships of Rhizoctonia fungi within the order Cantharellales were studied using sequence data from portions of the ribosomal DNA cluster regions ITS-LSU, rpb2, tef1, and atp6 for 50 taxa, and public sequence data from the rpb2 locus for 165 taxa. Data sets were analysed individually and combined using Maximum Parsimony, Maximum Likelihood, and Bayesian Phylogenetic Inference methods. All analyses supported the monophyly of the family Ceratobasidiaceae, which comprises the genera Ceratobasidium and Thanatephorus. Multi-locus analysis revealed 10 well-supported monophyletic groups that were consistent with previous separation into anastomosis groups based on hyphal fusion criteria. This analysis coupled with analyses of a larger sample of 165 rpb2 sequences of fungi in the Cantharellales supported a sister relationship between the Botryobasidiaceae and Ceratobasidiaceae and a sister relationship of the Tulasnellaceae with the rest of the Cantharellales. The inclusion of additional sequence data did not clarify incongruences observed in previous studies of Rhizoctonia fungi in the Cantharellales based on analyses of a single or multiple genes. The diversity of ecological and morphological characters associated with these fungi requires further investigation on character evolution for re-evaluating homologous and homoplasious characters.}, number={4}, journal={FUNGAL BIOLOGY}, author={Gonzalez, Dolores and Rodriguez-Carres, Marianela and Boekhout, Teun and Stalpers, Joost and Kuramae, Eiko E. and Nakatani, Andreia K. and Vilgalys, Rytas and Cubeta, Marc A.}, year={2016}, month={Apr}, pages={603–619} } @misc{samuels_ismaiel_rosmana_junaid_guest_mcmahon_keane_purwantara_lambert_rodriguez-carres_et al._2012, title={Vascular Streak Dieback of cacao in Southeast Asia and Melanesia: in planta detection of the pathogen and a new taxonomy}, volume={116}, ISSN={["1878-6162"]}, DOI={10.1016/j.funbio.2011.07.009}, abstractNote={Vascular Streak Dieback (VSD) disease of cacao (Theobroma cacao) in Southeast Asia and Melanesia is caused by a basidiomycete (Ceratobasidiales) fungus Oncobasidium theobromae (syn. =Thanatephorus theobromae). The most characteristic symptoms of the disease are green-spotted leaf chlorosis or, commonly since about 2004, necrotic blotches, followed by senescence of leaves beginning on the second or third flush behind the shoot apex, and blackening of infected xylem in the vascular traces at the leaf scars resulting from the abscission of infected leaves. Eventually the shoot apex is killed and infected branches die. In susceptible cacao the fungus may grow through the xylem down into the main stem and kill a mature cacao tree. Infections in the stem of young plants prior to the formation of the first 3-4 lateral branches usually kill the plant. Basidiospores released from corticioid basidiomata developed on leaf scars or along cracks in the main vein of infected leaves infect young leaves. The pathogen commonly infects cacao but there are rare reports from avocado. As both crops are introduced to the region, the pathogen is suspected to occur asymptomatically in native vegetation. The pathogen is readily isolated but cultures cannot be maintained. In this study, DNA was extracted from pure cultures of O. theobromae obtained from infected cacao plants sampled from Indonesia. The internal transcribed spacer region (ITS), consisting of ITS1, 5.8S ribosomal RNA and ITS2, and a portion of nuclear large subunit (LSU) were sequenced. Phylogenetic analysis of ITS sequences placed O. theobromae sister to Ceratobasidium anastomosis groups AG-A, AG-Bo, and AG-K with high posterior probability. Therefore the new combination Ceratobasidium theobromae is proposed. A PCR-based protocol was developed to detect and identify C. theobromae in plant tissue of cacao enabling early detection of the pathogen in plants. A second species of Ceratobasidium, Ceratobasidium ramicola, identified through ITS sequence analysis, was isolated from VSD-affected cacao plants in Java, and is widespread in diseased cacao collected from Indonesia.}, number={1}, journal={FUNGAL BIOLOGY}, author={Samuels, Gary J. and Ismaiel, Adnan and Rosmana, Ade and Junaid, Muhammad and Guest, David and Mcmahon, Peter and Keane, Philip and Purwantara, Agus and Lambert, Smilja and Rodriguez-Carres, Marianela and et al.}, year={2012}, month={Jan}, pages={11–23} } @article{yin_kone_rodriguez-carres_cubeta_burpee_fonsah_csinos_ji_2011, title={First Report of Root Rot Caused by Binucleate Rhizoctonia Anastomosis Group F on Musa spp}, volume={95}, ISSN={["1943-7692"]}, DOI={10.1094/pdis-08-10-0602}, abstractNote={ A research program was initiated at the University of Georgia in 2003 to identify banana cultivars suitable for production in the coastal and southern areas of the state. During a root disease survey conducted in October 2007 on bananas (Musa spp.) grown at the University of Georgia Bamboo Farm and Coastal Gardens in Savannah, GA, root lesions and root rot were observed on banana cvs. Gold Finger, Kandarian, and Manzano. Root lesions were dark brown to black and irregular in shape, with partial or entire roots affected. Lateral roots and outer layers of cord roots (roots arising from interior layers of the corm) of infected plants were blackened and rotted. Diseased root samples were collected from three plants of each cultivar, surface sterilized with 0.6% sodium hypochlorite, and placed on tannic acid benomyl agar (TABA). Pure cultures of the fungus consistently associated with diseased tissue were obtained by subculturing hyphal tips on TABA. Mycelia of the fungus on potato dextrose agar (PDA) were light to deep brown and the hyphae tended to branch at right angles. A septum was present in each hyphal branch near the point of origin and a slight constriction at the branch was observed. The hyphae of two isolates were stained with 0.6% phenosafranin and 3% KOH and binucleate hyphal cells were observed. On the basis of these morphological features, the isolates appeared to be binucleate Rhizoctonia anamorphs (teleomorph Ceratobasidium Rogers). For molecular identification, the internal transcribed spacer (ITS) regions and the 5.8S gene from rDNA of the isolates were cloned and sequenced (GenBank Accession No. HQ168370). The ITS regions (775 bp) were 100% identical between the two isolates and 99% identical to Ceratobasidium sp. AG-F strain SIR-1 isolated from sweet potato in Japan (GenBank Accession No. AF354085). The anastomosis group of the isolates was confirmed by pairing with strain SIR-1 on PDA. On the basis of morphological and molecular characteristics and the anastomosis assay, the two isolates were identified as a Ceratobasidium sp. AG-F (1–3). Pathogenicity assays were conducted by inoculating banana plants (cv. Golden pillow, synonym = Manzano) grown in pots under greenhouse conditions (25 to 27°C). Twenty wheat seeds infested with each isolate were placed uniformly around each plant at a depth of 10 cm in the soil. The plants were incubated in the greenhouse and the roots were examined 2 months after inoculation. Brown-to-black lesions and root rot, identical to symptoms associated with field banana roots, were observed on all inoculated plants but not on the noninoculated control plants. The fungus was reisolated from affected root samples and the identity was confirmed by morphological and molecular characteristics and the anastomosis assay. To our knowledge, this is the first report of banana root rot caused by binucleate Rhizoctonia anastomosis group F. With the increased interest in producing bananas for food and ornamental purposes, the occurrence of Ceratobasidium root rot on bananas needs to be considered when designing disease management programs and searching for suitable cultivars for banana production. }, number={4}, journal={PLANT DISEASE}, author={Yin, J. and Kone, D. and Rodriguez-Carres, M. and Cubeta, M. A. and Burpee, L. L. and Fonsah, E. G. and Csinos, A. S. and Ji, P.}, year={2011}, month={Apr}, pages={490–490} } @article{copes_rodriguez-carres_toda_rinehart_cubeta_2011, title={Seasonal Prevalence of Species of Binucleate Rhizoctonia Fungi in Growing Medium, Leaf Litter, and Stems of Container-Grown Azalea}, volume={95}, ISSN={["0191-2917"]}, DOI={10.1094/pdis-11-10-0796}, abstractNote={ Rhizoctonia web blight is an annual problem on container-grown azalea (Rhododendron spp.) in the southern and eastern United States but little is documented about the distribution or persistence of Rhizoctonia spp. in container-grown azalea. Sixty web-blight-damaged azalea plants (‘Gumpo White’) were collected in August 2005 and 2006 and arranged in a completely randomized design on an outdoor irrigation pad. A nylon mesh bag containing 30 necrotic leaves collected from web-blight-damaged ‘Gumpo White’ azalea plants were placed on the surface of the medium under the plant canopy in each container to simulate leaf litter. Ten plants were destructively sampled into eight zones by dividing stems into three zones (lengths of 0 to 2, 4 to 6, and 9 to 15 cm above the medium surface), bagged leaves into one leaf litter zone, and the medium into four zones (three horizontal layers: 1 to 3, 3 to 7, and 7 to 10 cm below the medium surface, with the middle layer further divided by removing the central 7.5-cm-diameter core) in December, February, and May. Only the three stem zones were sampled from 10 plants in early and late June and late July. Of 8,940 total isolations, 3,655 fungi with morphological characteristics of a Rhizoctonia sp. were recovered. Percent recovery differed from the eight zones (P < 0.0001) but did not differ between years (P = 0.3950) and sampling times (P = 0.1896). Frequency of recovery of Rhizoctonia spp. was highest from the lower stem and the leaf litter, and decreased with distance from the leaf litter. Recovery from stems over the six sample times was analyzed separately. Percent recovery differed between stem zones (P < 0.0001), sample times (P = 0.0478), and experiment years (P < 0.0001). In both years, mean recovery of Rhizoctonia spp. was higher from the lower stem and decreased with distance to the upper stem layer. From a subsample of 145 isolates, 95.1% were identified as binucleate Rhizoctonia (BNR) anastomosis groups (AGs)-A, -G, -K, -R, -S, and -U (-P), and 2.8 and 2.1% were Rhizoctonia solani AG-2 and an uncultured Laetisaria sp., respectively. Based on frequency analysis, recovery of BNR AGs differed by plant zone (P < 0.0001) but not over sample times (P = 0.4831). The six AGs of BNR are the predominant Rhizoctonia fungi occupying the habitat niches in container-grown azalea, with little change in population frequency and composition from fall to summer; thus, BNR pathogenic and nonpathogenic to azalea have established a mixed Rhizoctonia community on container-grown azalea. }, number={6}, journal={PLANT DISEASE}, author={Copes, Warren E. and Rodriguez-Carres, Marianela and Toda, Takeshi and Rinehart, Tim A. and Cubeta, Marc A.}, year={2011}, month={Jun}, pages={705–711} }