Until now, only Lasiodiplodia theobromae has been reported in association with gummosis and dieback of cashew plants and other tropical fruit plants in northeastern Brazil. This study aims to identify and characterize species of Lasiodiplodia associated with gummosis and dieback on tropical fruit plants grown in Cear a, Para ıba, Pernambuco, Piau ı and Rio Grande do Norte States in northeastern Brazil with a description of two new species: Lasiodiplodia caatinguensis sp. nov. and Lasiodiplodia pontae sp. nov. Fungal identification was accomplished using a combination of morphophysiological and pathogenic characteristics, together with phylogenetic analyses based on partial translation elongation factor 1-a sequence (TEF1-a), internal transcribed spacer (ITS) and b-tubulin (b-tub). Six species of Lasiodiplodia were identified as being associated with several tropical fruit species: Lasiodiplodia brasiliense (Manilkara zapota, Mangifera indica and Spondias purpurea), L. caatinguensis sp. nov. (Anacardium occidentale, Citrus sinensis, S. purpurea and S. lutea), L. euphorbicola (Annona muricata and Cocos nucifera), L. pontae sp. nov. (A. occidentale and S. purpurea), L. pseudotheobromae (A. occidentale, S. purpurea and Tamarindus indica) and L. theobromae (A. occidentale, S. purpurea and Talisia esculenta). This is the first study to use molecular data of Lasiodiplodia taken from the stems and branches of Annona spp., A. occidentale, M. zapota, T. indica, T. esculenta and Spondias spp. After L. caatinguensis sp. nov., the species L. pseudotheobromae and L. theobromae were the second most frequent species. All identified species were able to cause necrotic lesions at different levels of severity when inoculated on mango fruits and young plants of Annona spp., cashew and Spondias spp.

RESUMOPalavras-chave adicionais: Cajueiro, graviola, Spondias, inoculação.Lasiodiplod ia theob roma e is a cosmopolitan, polyphagou s a nd opportunistic fungus with reduced pathogenic specialization, which is capable of infecting plant species in tropical and temperate regions, causing varied symptoms. This study aimed to characterize L. theobromae isola tes associated with tropical fruit plants in Northea stern Brazil, considering their cultural, morphological and pathogenic characteristics. The evaluated aspects were mycelial growth, colony coloration, conidium dimension and pa thogenicity of the isolates for seedlings of yellow Lima, J.S.; Moreira, R.C.; Cardoso, J.E.; Martins, M.V.V.; Viana, F.M.P. Cultural, morphological and pathogenic characterization of Lasiodiplodia theobromae associated with tropical fruit plants. Summa Phytopathologica, v.39, n.2, p.81-88, 2013. mombin (Spondias mombin L.), cashew (Anacardium occidentale L.), soursop (Annona muricata L.), and Brazil plum (Spondias tuberosa Arruda). Data of morphological and cultural characterization revealed diversity in the pathogen population. High pathogenic variability was also detected, although no pathogenic specificity was found for cashew. Brazil plum showed higher relative resistance to the fungus. The data also demonstrated interaction between morphocultural characteristics and aggressiveness of L. theobromae isolates. Additional keywords: Cashew, soursop, Spondias, inoculation. La sio d ip lo d ia th ABSTRACTLasiod iplodia theobromae (Pat.) Griffon e Maubl. (syn. Botryodiplodia theobromae Pat.) é um fungo cosmopolita, polífago e oportunista, portanto, com reduzida especialização patogênica, infectando espécies de plantas em regiões tropicais e temperadas, causando os mais variados sintomas (22). É geralmente associado a processos patogênicos em plantas estressadas e submetidas a processos naturais ou provocados por insetos, pássaros, primatas nativos e pelo próprio homem, através de práticas culturais (21,29).Lasiodiplodia theobromae tem sido demonstrado capaz de colonizar tecidos de plantas sem exibir sintomas de infecção, característica típica de comportamento endofítico (5,17,18). Uma das hipóteses é que esse fungo tenha evoluído da condição de endofitismo clássico para o parasitismo, em consequência de pressões ambientais, especialmente nas regiões semi-áridas, onde as condições climáticas, notadamente o estresse hídrico, favorecem a infecção (27). Corroborando esta idéia, verifica-se a crescente expansão das doenças causadas por L. theobromae em frutíferas tropicais, proporcionando inestimáveis perdas, tanto no sistema produtivo como em pós-colheita, representando uma ameaça à fruticultura no Nordeste (8, 11). A lista de hospedeiros e a severidade de ataque desse fitopatógeno também se têm verificado (12).O controle das doenças causadas por L. theobromae torna-se bastante difícil, face às características ecológicas intrínsecas do fungo e a grande variedade de hospedeiros (2, 3, 4,15,17,20). O manejo

In this study, we reported thirty-nine endophytic fungi identified as Colletotrichum spp. associated with Brazilian pepper tree or aroeira (Schinus terebinthifolius Raddi. Anacardiaceae) in Paraná state, Brazil. These endophytes were identified by morphological and molecular methods, using PCR taxon-specific with CaInt/ITS4, CgInt/ITS4, and Col1/ITS4 primers, which amplify specific bands in C. acutatum, C. gloeosporioides lato sensu, and Colletotrichum boninensis, respectively, and by DNA sequence analysis of the nrDNA internal transcribed spacer region (ITS1, 5.8S, ITS2). We also assayed the presence of dsRNA particles in Colletotrichum spp. isolates. Combining both morphological characters and molecular data, we identified the species C. gloeosporioides, C. boninense, and C. simmondsii. However, we found a high genetic variability intraspecific in C. gloeosporioides which suggests the existence of several other species. Bands of double-stranded RNA (dsRNA) were detected in three of thirty-nine isolates. Identity of these bands was confirmed by RNAse, DNAse, and S1 nuclease treatments for the isolates LGMF633, LGMF726, and LGMF729. This is the first study reporting these particles of dsRNA in C. gloeosporioides.

We combine Density Functional Theory and Molecular Dynamics to study graphene–BN monolayers ranging from 2 nm to 100 nm. We find that the mechanical properties are independent of scale when we increase graphene and the BN domain proportionately.

The Botryosphaeriaceae family is one of the most important groups of plant pathogenic fungi associated with tropical woody species such as Anacardium occidentale (cashew) and Mangifera indica (mango), which are fruiting species with broad distributions and high economic importance in north-eastern Brazil. This study was designed to characterize species of this family associated with cashew, mango and Psidium guajava (guava) that cause dieback and stem and branch cankers. Characterization comprised phylogenetic, morphological, physiological and pathogenic features. The phylogenetic study combined sequences of the internal transcribed spacer (ITS) of the rDNA and partial elongation factor 1-α (EF1-α) regions of DNA. Measurements of fungal conidia and colony growth on different culture media and at different temperatures were conducted. Pathogenicity tests were also performed through inoculation of different host species. By combining the sequences of the referenced genes, it was possible to identify the following Botryosphaeriaceae species: Neofusicoccum kwambonambiense, Neoscytalidium hyalinum and Pseudofusicoccum stromaticum as the first report in cashew, Neoscytalidium hyalinum in mango and Neofusicoccum brasiliense as the first report in guava. Examination of N. brasiliense revealed conidia, providing the first morphological description of the species. Neofusicoccum kwambonambiense did not sporulate, but the other isolates produced conidia with dimensions comparable to those described in the literature. All isolates were virulent to mango fruits and young cashew and “caja-umbu” plants, causing necrotic lesions and gum exudation by the hosts. The isolates of Neofusicoccum were the most aggressive in the inoculated hosts.