A multiproxy approach to evaluate biocidal treatments on biodeteriorated majolica glazed tiles.

The Fishing House located on the grounds of the Marquis of Pombal Palace, Oeiras, Portugal, was built in the 18th century. During this epoch, Portuguese gardens, such as the one surrounding the Fishing House, were commonly ornamented with glazed wall tile claddings. Currently, some of these outdoor tile panels are covered with dark colored biofilms, contributing to undesirable aesthetic changes and eventually inducing chemical and physical damage to the tile surfaces. Phylogenetic analyses revealed that the investigated biofilms are mainly composed of green algae, cyanobacteria and dematiaceous fungi. With the aim of mitigating biodeterioration, four different biocides (TiO2 nanoparticles, Biotin® T, Preventol® RI 80 and Albilex Biostat® ) were applied in situ to the glazed wall tiles. Their efficacy was monitored by visual examination, epifluorescence microscopy and DNA-based analysis. Significant changes in the microbial community composition were observed 4 months after treatment with Preventol® RI 80 and Biotin® T. Although the original community was inactivated after these treatments, an early stage of re-colonization was detected 6 months after the biocide application. TiO2 nanoparticles showed promising results due to their self-cleaning effect, causing the detachment of the biofilm from the tile surface, which remained clean 6 and even 24 months after biocide application. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

Fungal Planet description sheets: 128-153.

Novel species of microfungi described in the present study include the following from Australia: Catenulostroma corymbiae from Corymbia, Devriesia stirlingiae from Stirlingia, Penidiella carpentariae from Carpentaria, Phaeococcomyces eucalypti from Eucalyptus, Phialophora livistonae from Livistona, Phyllosticta aristolochiicola from Aristolochia, Clitopilus austroprunulus on sclerophyll forest litter of Eucalyptus regnans and Toxicocladosporium posoqueriae from Posoqueria. Several species are also described from South Africa, namely: Ceramothyrium podocarpi from Podocarpus, Cercospora chrysanthemoides from Chrysanthemoides, Devriesia shakazului from Aloe, Penidiella drakensbergensis from Protea, Strelitziana cliviae from Clivia and Zasmidium syzygii from Syzygium. Other species include Bipolaris microstegii from Microstegium and Synchaetomella acerina from Acer (USA), Brunneiapiospora austropalmicola from Rhopalostylis (New Zealand), Calonectria pentaseptata from Eucalyptus and Macadamia (Vietnam), Ceramothyrium melastoma from Melastoma (Indonesia), Collembolispora aristata from stream foam (Czech Republic), Devriesia imbrexigena from glazed decorative tiles (Portugal), Microcyclospora rhoicola from Rhus (Canada), Seiridium phylicae from Phylica (Tristan de Cunha, Inaccessible Island), Passalora lobeliae-fistulosis from Lobelia (Brazil) and Zymoseptoria verkleyi from Poa (The Netherlands). Valsalnicola represents a new ascomycete genus from Alnus (Austria) and Parapenidiella a new hyphomycete genus from Eucalyptus (Australia). Morphological and culture characteristics along with ITS DNA barcodes are also provided.

Avocado Dieback Caused by Neofusicoccum parvum in the Andalucia Region, Spain.

From 2002 to 2006, adult avocado trees, Persea americana Miller cv. Hass, located in the subtropical-fruit-producing area of Andalucia (southern Spain) developed symptoms of dieback characterized by death of twigs and branches in the tree canopy. Sections of surface-disinfested, necrotic branch tissues were plated on Difco potato dextrose agar (PDA) (Sparks, NV) and a Neofusicoccum-like fungus was isolated. On PDA, the isolates had white, appressed mycelium that turned dull gray as the colony aged, although conidia were not formed. Abundant pycnidia and conidia developed when isolates were cultured on 2% water agar with sterilized pine needles as substratum at 25°C under near-UV light for 2 weeks. Conidia were hyaline, unicellular, ellipsoid with an obtuse apex and subtruncate base, averaged 16.2 µm long by 5.8 µm wide and ranged from 12.0 to 20.0 by 4.0 to 8.0 µm, and becoming brown with one or two septa with age. Sequenced rDNA fragments (ITS1, 5.8S rDNA, and ITS2, amplified with ITS1 and ITS4 primers) of two avocado isolates were 100% homologous with Neofusicoccum parvum (Pennycook & Samuels) Crous, Slippers, & A.J.L. Phillips (1) (GenBank Accession Nos. AM410965 and AM410966). Morphological and molecular results confirmed this species as N. parvum, reported as the anamorph of Botryosphaeria parva (1). A pathogenicity test was conducted using two isolates on sets of five 2-year-old avocado plants produced from seeds of cv. Topa-Topa growing in 5-liter pots with soil. Unwounded and wounded plants were used for inoculations. Plants were wounded 2 to 3 cm below the apical tip with a lance (4 mm long and 1 mm deep). For inoculation, 4-mm 2-week-old PDA culture plugs were placed in contact with wounded tissues and covered with Parafilm. Five noninoculated plants treated similarly served as controls. Plants were maintained in the greenhouse with a temperature range of 18 to 26°C, and 1 month later, brown stem lesions, as much as 5 cm, originating from the inoculation site followed by dieback of branches were observed. Reisolations from necrotic branches were successful, and both isolates with identical morphology to those used for inoculations were recovered. Pathogenicity tests of seedlings using the same methods also caused stem lesions on unwounded plants and the pathogen was reisolated. To our knowledge, this is the first report of N. parvum causing dieback of avocado trees in Spain. Previously, B. parva has been reported causing stem-end rot of avocado fruit in New Zealand (2). In Spain, since diseased orchards are increasing rapidly, this pathogen could be efficiently distributed by pruning activities (tools and vegetal debris) as observed with other diseases (3). The presence of N. parvum in this subtropical area presents a serious disease problem not only to avocado but also to mango (Mangifera indica L.), which is another susceptible host (4). References: (1) P. W. Crous et al. Stud. Mycol. 55:235, 2006. (2) W. F. T. Hartill et al. N. Z. J. Crop Hortic. Sci. 30:249. 2002. (3) A. J. L. Phillips. Phytopathol. Mediterr. 41:3, 2002. (4) B. Slippers et al. Mycologia 97:99, 2005.