SHORT COMMUNICATION Rhizoctonia solani AG 1-IB and AG 4 HG-I causing leaf blight and root rot in plants from the Lamiaceae family in Brazil Maruzanete P. de Melo 1 & Cléia S. Cabral 2 & Ailton Reis 3 & Kedma S. Matos 4 & Pâmela P. Martins 1 & José E. A. Beserra Júnior 1 & Kátia L. Nechet 5 & Bernardo A. Halfeld-Vieira 5 Received: 24 May 2017 /Accepted: 30 August 2017 # Sociedade Brasileira de Fitopatologia 2017 Abstract Rhizoctonia solani is a fungal complex represented by 14 anastomosis groups. Each group has distinct character- istics that are reflected in the management and control strate- gies for diseases caused by this fungus. In three distinct geo- graphical regions, plants of the Lamiaceae family from vege- table and medicinal herb gardens were observed, with Mentha piperina, Mentha spicata and Origanum manjerona present- ing symptoms of leaf blight and Ocimum basilicum, Ocimum vulgare and Rosmarinus officinalis presenting root rot symp- toms. Mycelia, hymenia, basidiospores and microsclerotia were found on the stems and leaves of Mentha piperina and Mentha spicata. These are typical morphological markers of the genus Rhizoctonia. The ITS region was amplified for nine isolates and subsequently sequenced. In the phylogenetic analysis, the isolates were identified as Rhizoctonia solani belonging to AG 1-IB and AG 4 HG-I anastomosis groups. All isolates inoculated in their respective hosts caused disease symptoms resembling those typically observed in the field. This is the first report of R. solani AG 1-IB in M. spicata, M. piperina and Origanum majorana and of R. solani AG 4 HG-I in O. vulgare, R. officinalis and O. basilicum in Brazil. Keywords Basidiomycetes . Root rot . Medicinal plants . Leaf blight . Anastomosis group Plant species from the Lamiaceae family are distributed worldwide. In Brazil, there are about 28 genera and 350 spe- cies from this plant family, comprising many of medicinal interest and used as condiments, such as mint (Mentha spp.), rosemary (Rosmarinus officinalis L.), oregano (Origanum vulgare L.), lavender (Lavandula angustifolia Mill.), basil (Ocimum basilicum L.), sage (Salvia officinalis L) and thyme (Thymus vulgaris L.). These plants are widely used in cooking and as medicine due to their production of active compounds (Lorenzi and Matos 2002). The use of medicinal plants and their sub-products is increasing in many parts of the world, including Brazil (Perecin 2001). The development of mono- cultures due to the interest in the cultivation of medicinal plants to increase their production can create favorable condi- tions for the occurrence of diseases (Martins et al. 2000). The fungus Rhizoctonia solani J. G. Kuhn (teleomorph: Thanatephorus cucumeris) is a soil-borne plant pathogen. It produces microsclerotia, structures that allow it to survive in soil for several years under adverse conditions. R. solani causes disease in many hosts at different growth stages, lead- ing to a variety of symptoms in plants, such as damping-off, root rot, fruit rot, leaf spot and blight. In some pathosystems, the presence of leaf spots is observed due to infections by basidiospores on the leaf surface (Sneh et al. 1991). The Rhizoctonia solani complex is an economically impor- tant group of pathogens. They cause disease in many plants growing in different geographical regions of the world. The current classification of the R. solani complex is based on compatible hyphae interactions, which forms anastomosis groups (AGs). To date, 14 anastomosis R. solani groups are known, namely AG 1 to AG 13 and AG B1 (Carling et al. Section Editor: Flávio H. V. Medeiros * Bernardo A. Halfeld-Vieira bernardo.halfeld@embrapa.br 1 Centro de Ciências Agrárias, Departamento de Fitotecnia, Iningá, Universidade Federal do Piauí, Teresina, PI 64049-550, Brazil 2 Departamento de Fitopatologia, Universidade de Brasília, Brasília, DF 70910-900, Brazil 3 Embrapa Hortaliças, CP 218, Brasília, DF 70250-970, Brazil 4 Centro de Ciências Agrárias, Universidade Federal de Roraima-UFRR, Boa Vista, RR 69310-000, Brazil 5 Embrapa Meio Ambiente, CP 69, Jaguariúna, SP 13820-000, Brazil Trop. plant pathol. DOI 10.1007/s40858-017-0181-1