Although the genus Pseudocercospora has a worldwide distribution, it is especially diverse in tropical and subtropical countries. Species of this genus are associated with a wide range of plant species, including several economically relevant hosts. Preliminary studies of cercosporoid fungi from Brazil allocated most taxa to Cercospora, but with the progressive refinement of the taxonomy of cercosporoid fungi, many species were relocated to or described in Pseudocercospora. Initially, species identification relied mostly on morphological features, and thus no cultures were preserved for later phylogenetic comparisons. In this study, a total of 27 Pseudocercospora spp. were collected, cultured, and subjected to a multigene analysis. Four genomic regions (LSU, ITS, tef1 and actA) were amplified and sequenced. A multigene Bayesian analysis was performed on the combined ITS, actA and tef1 sequence alignment. Our results based on DNA phylogeny, integrated with ecology, morphology and cultural characteristics revealed a rich diversity of Pseudocercospora species in Brazil. Twelve taxa were newly described, namely P. aeschynomenicola, P. diplusodonii, P. emmotunicola, P. manihotii, P. perae, P. planaltinensis, P. pothomorphes, P. sennae-multijugae, P. solani-pseudocapsicicola, P. vassobiae, P. wulffiae and P. xylopiae. Additionally, eight epitype specimens were designated, three species newly reported, and several new host records linked to known Pseudocercospora spp.

Comprehensive comparative phylogenetic analyses were performed on 17 Gamboa serogroup viruses (GAMSVs) from distinct geographic regions in the Americas and other representative members of the genus (Peribunyaviridae), based on small (S), medium (M), and large (L) open reading frame full-length and partial sequences. Genome characterization showed that the GAMSVs divide into four clades or genotypes. The GAMSVs have a genetic organization similar to other orthobunyaviruses, except that they have a larger NSm protein than other orthobunyaviruses. A serosurvey for Gamboa virus antibodies was performed in plasma from birds, other wild animals, and humans living around the Tucuruí hydroelectric dam in Pará state, northern Brazil, a known focus of GAMSV activity. Newborn chicks () were experimentally infected with a GAMSV, and the pathogenesis is described. Histopathological changes were primarily in the lungs and liver. Also, a review of the ecology of the GAMSVs in the Americas is included. In sum, this study presents the genomic and evolutionary characterization of the Gamboa group and the potential model of pathogenesis, which would be helpful for diagnostic purposes, epidemiology, and immunopathogenesis studies.

The dayflower species Commelina benghalensis and C. diffusa are among the main weeds in coffee crops. The purpose of this study was to evaluate the efficacy of herbicides/herbicide mixtures in controlling dayflower species and to evaluate the possible intoxication of coffee cultures, as well as the effect of mixture interactions. Two experiments were conducted, the first one in a 12 x 2 factorial arrangement with 12 herbicides/mixtures (glyphosate, glyphosate + metsulfuron-methyl, glyphosate + flumioxazin, glyphosate + 2.4-D, glyphosate + oxyfluorfen, glyphosate + carfentrazone-ethyl, metsulfuron-methyl, flumioxazin, 2.4-D, oxyfluorfen and carfentrazone-ethyl) and two dayflower species (C. benghalensis and C. diffusa) and the second one, in a 6 x 2 + 1 factorial arrangement, with six herbicides/mixtures (glyphosate, glyphosate + metsulfuron-methyl, glyphosate + flumioxazin, glyphosate + 2.4-D, glyphosate + oxyfluorfen and glyphosate + carfentrazone-ethyl) and two application forms on coffee plants (reaching 1/3 of the coffee canopy and with a protected canopy), plus a control treatment without herbicides. There was tolerance variation within the dayflower species to the tested herbicides. Commelina benghalensis was controlled by glyphosate, 2.4-D, glyphosate + 2.4-D and glyphosate + metsulfuron-methyl, while C. diffusa was controlled by 2.4-D and glyphosate mixtures by + metsulfuron-methyl, glyphosate + oxyfluorfen and glyphosate + flumioxazin. The mixture glyphosate + 2.4-D is effective in controlling dayflower, but it caused intoxication and growth reduction of the coffee. There was antagonism in the mixture glyphosate + carfentrazone-ethyl in controlling both species, as well as for glyphosate + oxyfluorfen and glyphosate + flumioxazin for C. benghalensis.

Knowledge on weed biology and ecology is fundamental to provide suitable control practices in weed management systems. The objective of this research was to understand the effect of light and temperature on germination of Chamaesyce hirta, as well as to evaluate the effect of depth of seed placement in the soil in the emergence of the plant. Two experiments were conducted. In the first one, in the laboratory, the seeds were placed to germinate in plastic boxes and kept in a B.O.D. germination chamber, under constant temperatures of 20, 25, 30 and 35 ºC, either in the dark or under continuous light. Daily germination assessments were performed. The percentage of germinated seeds in the 10-day period and the germination speed index (GSI) were calculated. In the second trial, carried out in greenhouse conditions, 100 seeds were planted, under six levels of seeding depth (0, 1, 2, 3, 4 and 5 cm) and three soil cover conditions: no straw, under black oats (Avena strigosa) straw and under corn (Zea mays) straw. Daily plant emergence was counted along 30 days and total emergence and GSI were calculated. Germination of C. hirta seeds occurs both in the presence and absence of light. For the highest temperature, both increased germination and GSI were reported in the presence of light. The highest levels of emergence were obtained with the absence of plant cover and under corn straw at 0 cm depth. The presence of black oat straw on the soil reduced the emergence of C. hirta.

Luffa cylindrica (Cucurbitaceae) is an Asian vine widely known as the source of loofah (4). In Brazil (local name bucha), it is cultivated by small scale producers as a cash crop. In January 2012, samples of fruits were collected in three areas in the municipality of Cipotânea, state of Minas Gerais (Brazil) bearing rot symptoms. These had large necrotic areas with a grayish epidermis and slightly sunken tissue. Internally, the fibrous parts were necrosed, darkened, and unmarketable. Isolations by surface sterilization of necrotic tissue with 10% bleach and plating onto potato dextrose agar yielded colonies with consistent morphology. A representative culture was deposited in the culture collection of the Universidade Federal de Viçosa (UFV) as COAD1119. Inoculations of seven healthy-appearing L. cylindrica fruits were performed with culture disks obtained from 4-day-old cultures grown on PDA, which were placed onto two points on the epidermis of each of seven fruits. Each point was either intact or previously injured with a sterile needle. Controls consisted of two fruits treated equally but with tap water agar disks in place of fungal inoculum. Fruits were then placed on trays with water-soaked cotton and the trays were wrapped in plastic bags and left over a bench at room temperature for 2 days. The plastic bags were then removed. After 5 days, necrosis was evident and fungal fruit bodies appeared at points with injury. No symptoms appeared on controls. Isolation from diseased tissue yielded colonies identical to those of the inoculated fungus. A dried sample was deposited in the local herbarium at UFV (VIC 32053). Slides were mounted in lactophenol and observed. The fungus had subepidermal perithecia, globose to subglobose, from 75.5 to 134 μm diam.; asci bitunicate, cylindrical, 8-spored; pseudoparaphyses filiform; ascospores fusoid to ellipsoidal, from 26 to 45 μm long and 8 to 11.5 μm wide, one septate, and hyaline. This morphology is consistent with Stagonosporopsis cucurbitacearum (syn. Didymella bryoniae) (3), a broad spectrum pathogen of cucurbits. Genomic DNA was extracted from the isolate growing in pure culture and ITS and LSU sequences were generated and deposited in GenBank under the accession numbers KC582022 and KC582021, respectively. Sequences were compared in BLASTn with other entries in GenBank, and the closest match for each region were S. cucurbitacearum strain CAP14C and D. bryoniae strain CBS 133.96 (JQ936326 and GU456335) with 100% of nucleotide homology for ITS and 100% of nucleotide homology for LSU. Cercospora citrullina and C. cucurbitae have been reported in Brazil on L. cylindrica and mistakenly indicated as synonyms of D. bryoniae (2). To our knowledge, this is the first valid report of S. cucurbitacearum causing fruit rot of loofah in Brazil and the first time pathogenicity to this host has been demonstrated. Losses due to the disease on the crop were reported to be high by growers and management to be difficult since there are no fungicides registered for this crop in Brazil. References: (1) M. M. Aveskamp et al. Stud. Mycol 65:1, 2010. (2) M. A. S. Mendes and A. F. Urben. Fungos em Plantas no Brasil. Brasília, Brazil: EMBRAPA-SPI. Retrieved from http://pragawall.cenargen.embrapa.br/aiqweb/michtml/micbanco01a.asp , 2012. (3) E. Puithalingam and P. Holliday. CMI Descriptions of Pathogenic Fungi and Bacteria 332:1, 1972. (4) J. W. Purseglove. Tropical Crops – Dicotyledons. Longman Group, London, 1968.