Population structure of Monosporascus cannonballus isolates from melons produced in Northeastern Brazil based on mycelial compatibility groups

[EN] The population structure of Monosporascus cannonballus, which causes vine decline in melons, was assessed based on the determination of mycelial compatibility groups (MCGs) in a collection of 58 isolates obtained from seven melon fields in three municipalities of Northeastern Brazil. For comparison, an additional 11 isolates of M. cannonballus from Spain were included in the analysis. MCGs were determined through comparisons of paired isolates growing on PDA culture media in the dark at 30ºC in various combinations. The Brazilian isolates were assigned into four MCGs: MCG-1 (n = 35 isolates), MCG-2 (n = 20), MCG-3 (n = 2), and MGC-4 (n = 1). MCG-1 and MCG-2 included isolates from all surveyed areas. The Spanish isolates were assigned into six different MCGs, and none of them were compatible with the Brazilian isolates. The genetic structure was determined using the frequencies of MCGs and genotypic diversity indices. The maximum genotypic diversity was 6.9 and 54.5% for the Brazilian and Spanish populations, respectively. The low level of genetic diversity in the M. cannonballus population from Northeastern Brazil suggests that breeding melons for disease resistance may be a promising strategy for the region.This research was partially funded by CAPES (Project 203/2009 - International Cooperation CAPES-Brazil/DGU-Spain). We are thankful CNPq for the research fellowships granted to C. S. Bezerra, M. P. S. Camara, R. Sales Junior and S.J. Michereff. We thank Prof. Eduardo S. G. Mizubuti, Universidade Federal de Vicosa, Vicosa, Minas Gerais State, Brazil, for useful advice on data analyses.De Souza Bezerra, C.; Câmara Correia, K.; Saraiva Câmara, MP.; Sales Júnior, R.; Armengol Fortí, J.; Michereff, SJ. (2013). Population structure of Monosporascus cannonballus isolates from melons produced in Northeastern Brazil based on mycelial compatibility groups. Acta Scientiarum. Agronomy. 35(2):161-167. https://doi.org/10.4025/actasciagron.v35i2.15182S16116735

Associação de Rhizoctonia solani Grupo de Anastomose 4 (AG-4 HGI e HGIII) à espécies de plantas invasoras de área de cultivo de batata

Os grupos 3 e 4 de anastomose (AG-3 e AG-4) do fungo Rhizoctonia solani são importantes grupos associados à batata no mundo. No Brasil, o AG-3 é relatado afetando principalmente batata e fumo. Já o AG-4 causa perdas consideráveis em culturas de importância econômica, como a soja, o feijão e o amendoim, podendo ocorrer também em hortaliças como o espinafre, o pimentão, o brócolis, o tomate, a batata e frutíferas como o melão. Recentemente foi constatada, em Brasília-DF, a associação de R. solani a plantas invasoras em áreas de cultivo de batata. Entretanto, não há informação a respeito da etiologia do patógeno bem como do papel de espécies invasoras como outras hospedeiras no ciclo do patógeno. Objetivou-se com esse estudo caracterizar isolados de R. solani obtidos de batata e de outras três espécies de plantas invasoras associadas a áreas de cultivo da cultura: juá-de-capote [Nicandra physaloides (L.) Pers., Solanaceae], beldroega (Portulaca oleracea L., Portulacaceae), e caruru (Amaranthus deflexus L., Amaranthaceae). Foi confirmada a hipótese de que os isolados obtidos de R. solani de beldroega, caruru e juá-de-capote pertencem ao grupo 4 de anastomose e são patogênicos à batata, exceto o isolado de beldroega. Estes isolados apresentaram patogenicidade cruzada às três espécies e também patogênicos à maria-pretinha (Solanum americanum Mill.), uma outra espécie de Solanaceae invasora. A classificação dos isolados no grupo AG-4 HGI ou no grupo AG-4 HGIII (isolado de caruru) foi confirmada através de características culturais e moleculares (seqüenciamento da região ITS-5.8S do rDNA). Os resultados deste trabalho trazem implicações importantes para o manejo das podridões radiculares de Rhizoctonia em batata.The anastomosis groups 3 and 4 (AG-3 and AG-4) of the fungus Rhizoctonia solani are important groups associated with potatoes worldwide. In Brazil, the AG-3 is reported affecting mainly potatoes and tobacco. The AG-4 cause considerable losses in crops of economic importance, such as soybean, beans and peanuts and may also occur in vegetables such as spinach, pepper, broccoli, tomatoes, potatoes and fruit such as melons. The association of R. solani with invasive plants was recently established in potato production areas from Brasília, DF. However, there is no information about the etiology of the pathogen as well as the role of invasive species as alternative hosts in the life cycle of the pathogen. The objective of this study was to characterize isolates of R. solani obtained from potatoes and three other invasive plant species associated with areas of potato production: Shoo-fly plant [Nicandra physaloides (L.) Pers., Solanaceae], pigweed (Portulaca oleracea L., Portulacaceae), and low-amaranth (Amaranthus deflexus L., Amaranthaceae). It was confirmed the hypothesis that the R. solani isolates obtained from pigweed, low-amaranth and Shoo-fly plant belong to the anastomosis group 4 and, except for the isolate from pigweed, are pathogenic to potatoes. These isolates were cross pathogencic to all the three weed species tested and also to American nightshade (Solanum americanum Mill.), another Solanaceae invasive of potato fields. The placement of the isolates in the group AG-4 HGI or in the group AG-4 HGIII (isolate from caruru) was confirmed by cultural and molecular characteristics (sequencing of the ITS-5.8S region of rDNA). The results of this study provide important implications for the management of the Rhizoctonia root rot in potatoes.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Characterization of fungal species associated with cladode brown spot on Nopalea cochenillifera in Brazil

Cladode brown spot (CBS) is an important disease of Nopalea cochenillifera in the semiarid region of Northeastern Brazil. It has been reported in several countries, but its etiology is controversial, attributed to a complex of pathogens. Fifty fungal isolates were obtained and identified based on morphology and phylogeny, through analysis of the ribosomal DNA internal transcribed spacers (ITS), translation elongation factor 1-alpha (TEF1-alpha), β-tubulin (TUB-2), second largest subunit of RNA polymerase (RPB2), glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and the mating type locus MAT1?2 (ApMAT) partial gene sequences. Seven fungal general and twenty species were identified ? Alternaria sp., A. longipes and A. tenuissima; Colletotrichum fructicola and C. siamense; Fusarium lunatum, F. incarnatum, and F. verticillioides; Lasiodiplodia euphorbicola, L. iraniensis, L. pseutheobromae, L. theobromae and Lasiodiplodia sp.; Neofusicoccum batangarum; Neopestalotiopsis australis, N. protearum and Neopestalotiopsis sp.; and Nigrospora sphaerica, N. hainanensis and Nigrospora sp. Four of these species had already been reported on Cactaceae of the genus Opuntia, but only N. batangarum, C. fructicola and C. siamense have been reported to date on the genus Nopalea. All isolates were pathogenic to detached cladodes of N. cochenillifera ?Miúda?. Differences in aggressiveness were observed among the species, with L. iraniensis and F. lunatum characterized as the most aggressive species, whilst F. verticillioides as the least aggressive. This study provide important information on the fungi associated with cladode brown spot and improve the strategies for the management of disease on N. cochenillifera.Fil: Conforto, Erica Cinthia. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias; ArgentinaFil: Bernardi Lima, Nelson. Unidad de Fitopatologia y Modernizacion Agricola; Argentina. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigaciones Agropecuarias. Unidad de Fitopatologia y Modelizacion Agricola. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Unidad de Fitopatologia y Modelizacion Agricola.; ArgentinaFil: Silva, Fabio Junior Araújo. Universidad Federal Rural Pernambuco; BrasilFil: Câmara, Marcos Paz Saraiva. Universidad Federal Rural Pernambuco; BrasilFil: Maharachchikumbura, Sajeewa. Universidad Federal Rural Pernambuco; BrasilFil: Michereff, Sami Jorge. Universidad Federal Rural Pernambuco; Brasi

DIVERSIDADE GENOTÍPICA E PATOGÊNICA DE Colletotrichum musae NO ESTADO DE PERNAMBUCO

Sessenta isolados de oriundos de Colletotrichumcampos de produção de banana dos Municípios de Vicência, São VicenteFérrer e Machados, no Estado de Pernambuco, foram avaliados quanto a características morfológicas,moleculares, culturais, de virulência e de diversidade genética. Os isolados foram identificados como C. musae, tendo a maioria conídios retos, oblongos, com ápices arredondados. A taxa de crescimento micelial variou de1,36 a 1,91 cm/dia. Foram encontrados três grupos de coloração para as colônias: branca, creme e salmão,enquanto a presença de setores variou de 0 a 8 por isolado e, na maioria dos isolados (73,3%), houve a presença de microescleródios. A diferença em virulência foi significativa para a área abaixo da curva de progresso da doença, indicando variabilidade entre os isolados. O dendrograma gerado pela análise UPGMA dos marcadores ISSR–PCR revelou a formação de três grupos pelo coeficiente de similaridade de Dice, os quais correspondem, na sua maioria, às três áreas amostradas

Chitosan produced from Mucorales fungi using agroindustrial by-products and its efficacy to inhibit Colletotrichum species

This study evaluated corn steep liquor (CSL) and papaya peel juice (PPJ) in mixture as substrates for thecultivation (96 h, 28◦C, pH 5.6, 150 rpm) of Mucorales fungi for chitosan production, and determinedthe growth-inhibitory effect of the fungal chitosan (FuCS) obtained under optimized conditions againstphytopathogenic Colletotrichum species. All Mucorales fungi tested were capable of growing in CSL-PPJmedium, showing FuCS production in the range of 5.02 (Fennelomyces heterothalicus SIS 28) − 15.63 mg/g(Cunninghamella elegans SIS 41). Highest FuCS production (37.25 mg/g) was achieved when C. eleganswas cultivated in medium containing 9.43% CSL and 42.5% PPJ. FuCS obtained under these conditionsshowed a deacetylation degree of 86%, viscosity of 120 cP and molecular weight of 4.08 × 104g/mol.FuCS at 5000, 7500 and 10,000 ppm inhibited the growth of all Colletotrichum species tested. FuCS alsoinduced alterations in the morphology of C. fructicola hyphae. CSL-PPJ mixtures are suitable substratesfor the cultivation of Mucorales fungi for FuCS production. Chitosan from C. elegans cultivated in CSL-PPJmedium is effective in inhibiting phytopathogenic Colletotrichum species.info:eu-repo/semantics/publishedVersio

Draft genome assembly of Colletotrichum musae, the pathogen of banana fruit

Colletotrichum musae is an important cosmopolitan pathogenic fungus that causes anthracnose in banana fruit. The entire genome of C. musae isolate GM20 (CMM 4420), originally isolated from infected banana fruit from Alagoas State, Brazil, was sequenced and annotated. The pathogen genomic DNA was sequenced on HiSeq Illumina platform. The C. musae GM20 genome has 50,635,197 bp with G + C content of 53.74% and in its present assembly has 2763 scaffolds, harboring 13,451 putative genes with an average length of 1626 bp. Gene prediction and annotation was performed by Funannotate pipeline, using a pattern for gene identification based on BUSCO

Fusarium: more than a node or a foot-shaped basal cell

Recent publications have argued that there are potentially serious consequences for researchers in recognising distinct genera in the terminal fusarioid clade of the family Nectriaceae. Thus, an alternate hypothesis, namely a very broad concept of the genus Fusarium was proposed. In doing so, however, a significant body of data that supports distinct genera in Nectriaceae based on morphology, biology, and phylogeny is disregarded. A DNA phylogeny based on 19 orthologous protein-coding genes was presented to support a very broad concept of Fusarium at the F1 node in Nectriaceae. Here, we demonstrate that re-analyses of this dataset show that all 19 genes support the F3 node that represents Fusarium sensu stricto as defined by F. sambucinum (sexual morph synonym Gibberella pulicaris). The backbone of the phylogeny is resolved by the concatenated alignment, but only six of the 19 genes fully support the F1 node, representing the broad circumscription of Fusarium. Furthermore, a re-analysis of the concatenated dataset revealed alternate topologies in different phylogenetic algorithms, highlighting the deep divergence and unresolved placement of various Nectriaceae lineages proposed as members of Fusarium. Species of Fusarium s. str. are characterised by Gibberella sexual morphs, asexual morphs with thin- or thick-walled macroconidia that have variously shaped apical and basal cells, and trichothecene mycotoxin production, which separates them from other fusarioid genera. Here we show that the Wollenweber concept of Fusarium presently accounts for 20 segregate genera with clear-cut synapomorphic traits, and that fusarioid macroconidia represent a character that has been gained or lost multiple times throughout Nectriaceae. Thus, the very broad circumscription of Fusarium is blurry and without apparent synapomorphies, and does not include all genera with fusarium-like macroconidia, which are spread throughout Nectriaceae (e.g., Cosmosporella, Macroconia, Microcera). In this study four new genera are introduced, along with 18 new species and 16 new combinations. These names convey information about relationships, morphology, and ecological preference that would otherwise be lost in a broader definition of Fusarium. To assist users to correctly identify fusarioid genera and species, we introduce a new online identification database, Fusarioid-ID, accessible at www.fusarium.org. The database comprises partial sequences from multiple genes commonly used to identify fusarioid taxa (act1, CaM, his3, rpb1, rpb2, tef1, tub2, ITS, and LSU). In this paper, we also present a nomenclator of names that have been introduced in Fusarium up to January 2021 as well as their current status, types, and diagnostic DNA barcode data. In this study, researchers from 46 countries, representing taxonomists, plant pathologists, medical mycologists, quarantine officials, regulatory agencies, and students, strongly support the application and use of a more precisely delimited Fusarium (= Gibberella) concept to accommodate taxa from the robust monophyletic node F3 on the basis of a well-defined and unique combination of morphological and biochemical features. This F3 node includes, among others, species of the F. fujikuroi, F. incarnatum-equiseti, F. oxysporum, and F. sambucinum species complexes, but not species of Bisifusarium [F. dimerum species complex (SC)], Cyanonectria (F. buxicola SC), Geejayessia (F. staphyleae SC), Neocosmospora (F. solani SC) or Rectifusarium (F. ventricosum SC). The present study represents the first step to generating a new online monograph of Fusarium and allied fusarioid generaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones en Productos Naturales (CIPRONA