RESUMO
Yield losses induced by a complex of begomoviruses are observed across all major tomato-producing areas in Brazil. Tomato severe rugose virus (ToSRV) is the most widespread begomovirus in the country. Conversely, tomato common mosaic virus (ToCmMV) displays a more restricted geographical distribution to areas associated with the Atlantic Rain Forest (ARF) biome, encompassing the States of Espírito Santo-ES, Minas Gerais-MG, and Rio de Janeiro-RJ. Here, we characterized 277 tomato-infecting isolates collected in fields located within the ARF biome from 2006 to 2018. ToSRV displayed the highest prevalence (n = 157), followed by ToCmMV (n = 95) and tomato interveinal chlorosis virus (n = 14). Four other begomoviruses were also detected, but with very low incidences. ToCmMV was the predominant begomovirus in the ARF biome up to 2014-2015 with very low ToSRV incidence. Subsequently, ToSRV became the most prevalent species in ES and RJ, but ToCmMV was still predominating in the "Zona da Mata" meso-region in MG. Due to the remarkable endemic distribution of ToCmMV, we carried out phylogeographical studies of this virus using information from all 28 available isolates with complete DNA-A sequences. The closest common ancestor of ToCmMV was more likely originated around Coimbra-MG area ≈ 25 years before the formal report of this viral species. So far, all surveys indicated tomatoes as the only natural hosts of ToCmMV with outbreaks occurring mainly (but not exclusively) in highland areas. ToSRV shows a more widespread incidence across both highland and lowland areas of the ARF biome.
Assuntos
Begomovirus , Doenças das Plantas/virologia , Solanum lycopersicum/virologia , Begomovirus/classificação , Begomovirus/genética , Begomovirus/isolamento & purificação , Biodiversidade , Brasil , DNA Viral , Filogeografia , Floresta ÚmidaRESUMO
Colocasia esculenta, taro (T), is a major staple food crop in the tropics, including Brazil. Rumohra adiantiformis, leatherhead fern (LF), is broadly cultivated for its ornamental fronds that are used as a component of flower arrangements. Soft root rot of T and LF, and accompanying rapid plant wilt and death, was observed in plantations in Espírito Santo (Brazil), at Venda Nova do Imigrante, in April 2014 (LF) and July 2015 (T). Great losses were observed. Firstly, a few individual scattered plants showed symptoms of disease in the plantations, then aggregates of plants and, after a few seasons, the majority of the plants in the field died before harvest, leading to the abandonment of the activity by farmers. A white mycelial matt was observed on the crown and roots ofying T and LF plants. Infected corms become necrotic and dark brown mycelial strands were observed internally in tissues. Diseased organs were carefully washed and surface sterilized in 10% sodium hypochlorite. Samples of tissue were removed from the boundary of necrotic tissues and placed on potato dextrose-agar (PDA) plates and incubated at 23±2 C in the dark. Homogeneous mycelial colonies were isolated from both T and LF and, upon observation of microscope mounts under an Olympus BX 53 light microscope, pear-shaped hyphal swellings at the septae (Castro et al. 2013) were observed. . A representative isolate from each host was deposited in the local culture collection as COAD 2911 (LF isolate) and COAD 2912 (T isolate). Additionally, DNA was extracted from each culture using the Wizard Genomic DNA Purification Kit (Promega) and the internal transcriptional spacer region was PCR amplified using the primers ITS5 and ITS1 (White et al. 1990). The amplicons were sequenced by MACROGEN (http://www.macrogen.com). Consensus sequences were deposited in GenBank: MW561595 (LF), MW561596 (T). Consensus regions were compared against other sequences available in Genbank. A BLASTn analysis resulted in LF and T sequences respectively 99% (526/531bp) and 98% (412/420 bp) identity with that of Dematophora bunodes (MN984619). Additionally, a phylogenetic analysis of a selected sequence alignment was performed on the CIPRES webportal (Miller et al., 2010) using MrBayes v.3.1.1 (Ronquist & Huelsenbeck, 2003). A phylogenetic tree was generated showing that the placement of LF and T isolates is in D. bunodes (Wittstein et al. 2020). Pathogenicity tests were performed for LF and T isolates against their original hosts. For inoculum, bags of twice-autoclaved parboiled rice were seeded separately with each isolate, which were allowed to colonize the rice for two weeks. Four healthy young LF and T plants were utilized. Two extra healthy plants grown in the same conditions, but not inoculated, served as controls. Thirty g of Dematophora-colonized rice was placed in direct contact with stems or roots of each LF or T plant. Plants were maintained in a dew chamber for 48 h after inoculation and then transferred to a greenhouse bench. All inoculated plants developed wilt and root rot and died after 15-20 days. Controls remained healthy. White mycelial colonies were formed over tissues of diseased LF and T and upon observation under the microscope, typical pear-shaped swellings were observed in slides prepared from newly obtained pure cultures from LF and T. Dematophora bunodes (formerly Rosellinia bunnodes) has a worldwide distribution and is well known as a polyphagous plant pathogen (Farr and Rossman, 2020) but has never been reported as a pathogen either of LF or T before in Brazil and worldwide. Its report on LF and T further expands an already large host-range and resolves the etiology of the disease on LF and T.
RESUMO
Severe yield losses induced by a complex of whitefly-transmitted Begomovirus species (family Geminiviridae) have been reported in tomatoes in Brazil (Reis et al. 2020). Nine isolates were obtained from tomato plants exhibiting begomovirus-like symptoms (viz. apical and interveinal chlorosis, yellow spots, and stunting) during independent field surveys: one isolate in Sumaré, São Paulo-SP State (isolate SP-066) in 2001, two in Serra Negra, Minas Gerais-MG (MG-012 and MG-016) in 2002, five in Caxias do Sul, Rio Grande do Sul-RS (RS-039, RS-045, RS-046, RS-047 and RS-058) in 2011 and one in Domingos Martins, Espírito Santo-ES (ES-148) in 2016. Disease incidence across all sampled fields ranged from 30% (in Domingos Martins-ES) to 90% in Sumaré-SP. Total DNA extraction was done by a modified CTAB method (Boiteux et al., 1999). Begomovirus infection was confirmed in all isolates by selective amplification of viral DNA-A segments using the primer pairs 'PAL1v1978 / PAR1c496' (Rojas et al., 1993) and 'BegomoAFor1' / 'BegomoARev1' (Ha et al., 2006), which produce two large and non-overlapping segments (≈1120 bp and ≈1205 bp, respectively). These PCR amplicons were initially characterized via direct Sanger dideoxy sequencing at CNPH. BLASTn analysis of the partial DNA-A genomes of these nine isolates indicated identity levels of 95-97% to three euphorbia yellow mosaic virus (EuYMV) reference isolates (= KY559532, JF756674, and KY559583) found infecting the weed Euphorbia heterophylla L. The entire DNA-A (2,609 nts = MN746971) and DNA-B (2,579 nts = MN746970) components of the MG-016 isolate were obtained via high-performance sequencing using Illumina HiSeq 2500 system (Macrogen Inc., South Korea). Sequences were assembled with the CLC Genomics Workbench program 10. Contigs were validated by BLASTx and BLASTn and compared to the ssDNA virus database at NCBI (www.ncbi.nlm.nih.gov). The fully-characterized MG-016 isolate displayed identity levels ranging from 97 to 99% to the EuYMV reference isolates as well as similar genomic features such as the conserved TATA box, nonanucleotide, and iterons (that were in agreement with a cognate nature of the DNA-A and DNA-B components). A partial sequence of the DNA-B genome was also obtained for the MG-012 isolate (MT7831942). The isolates MG-012 and MG-016 were found in mixed infections with tomato severe rugose virus (ToSRV) and tomato golden vein virus (TGVV), respectively. In addition, the complete DNA-A genomes of ES-148 (MN746972) and SP-066 (MN782438) were also obtained via a combination of primer walking and Sanger dideoxy sequencing, displaying 96-98% identity to EuYMV isolates. To our knowledge, this is the first report of multiple and independent events of natural infection of tomatoes by EuYMV isolates. Our results confirm the natural host status of tomatoes to EuYMV isolates as indicated in previous infectivity assays using biolistic inoculation (Barreto et al., 2013). The weed E. heterophylla is widely disseminated and very often present within tomato fields due to its higher levels of tolerance to the major herbicide (metribuzin) employed in this crop. Therefore, this weed may act as a persistent reservoir of tomato-infecting EuYMV isolates, which may allow the selection of viral populations potentially more adapted to this vegetable crop.
RESUMO
Symptoms of fruit phyllody and slow growth, which are suggestive of phytoplasma infection, were observed in strawberry plants cultivated in commercial fields. In order to provide evidence of association of phytoplasma with affected plants, assays for detecting and identifying were performed through computer-simulated restriction fragment length polymorphism (RFLP) and phylogenetic analysis. Total DNA was extracted from symptomatic and asymptomatic samples and used as template in nested PCR primed by the primers P1/Tint followed by R16F2n/16R2. Amplified DNA fragments of 1.2 kb from the 16S rRNA gene revealed the presence of phytoplasma in all symptomatic samples. Molecular detection was confirmed by electron transmission microscopy, which evidenced pleomorphic bodies in the phloem vessels. Nucleotide sequence representative of the strawberry phytoplasma shared 97.2 to 99â% similarity with phytoplasmas currently classified as members of the distinct subgroups within the 16SrXIII group. Similarity coefficient (F) values ranged from 0.70 to 0.92, indicating that strawberry phytoplasma delineates a new strain in addition to 'Candidatus Phytoplasma hispanicum'-related strains. The evolutionary tree displayed that this strain emerges as a new branch in relation to those previously described. The novel strain, designated SFP (strawberry fruit phyllody) phytoplasma represents the new 16SrXIII-J subgroup and its sequence, denominated SFP-Br02, was deposited in the GenBank database (EU719108). These findings contribute for the knowledge of the genetic diversity existing among members of the group 16SrXIII and establishes strawberry as an additional host of representatives of this group in Brazil.
Assuntos
Fragaria/microbiologia , Filogenia , Phytoplasma/classificação , Doenças das Plantas/microbiologia , Polimorfismo de Fragmento de Restrição , Técnicas de Tipagem Bacteriana , Brasil , Primers do DNA , DNA Bacteriano/genética , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/genética , Análise de Sequência de DNARESUMO
The world population growth has raised concerns about food security. Agricultural systems are asked to satisfy a growing demand for food with increasingly limited resources, and simultaneously still must reduce the impacts on the environment. This scenario encourages the search for safe and sustainable production strategies. Reducing losses in the production process can be one of the main ways to guarantee food safety. In fruticulture, it is estimated that more than 50% of the production can be lost between harvest and the final consumer due to postharvest diseases caused by phytopathogenic fungi. The fungi of the genus Colletotrichum are opportunistic and are associated with several diseases, being the anthracnose the most relevant in terms of the quality and yield losses in fruit species around worldwide. To control these diseases, the use of synthetic fungicides has been the main instrument utilized, however, because of their phytotoxicity to human health, the environment, and strong selection pressure imposed by continuous applications, the fungicides have caused resistance in the pathogen populations. So reducing the excessive application of these products is indispensable for human health and for sustainable Agriculture. Towards this purpose, research has been carried out to identify the phytopathological potentiality of essential oils (EOs) extracted from plants. Therefore, this review aims to contribute to the formation of knowledge bases, about the discoveries, recent advances, and the use of EOs as a strategy to alternatively control fungal disease caused by Colletotrichum spp. in postharvest fruits. Here, we provide valuable information exploring the application potential of essential oils as commercially useful biorational pesticides for food preservation, contributing to sustainable production and global food security.
Assuntos
Colletotrichum , Fungicidas Industriais , Óleos Voláteis , Conservação de Alimentos , Frutas , Fungicidas Industriais/farmacologia , Humanos , Óleos Voláteis/farmacologiaRESUMO
OBJECTIVE: To investigate the association of movement patterns evaluated by the Dynamic Movement Assessment (DMA) with the occurrence of musculoskeletal injuries in navy cadets. DESIGN: Cohort study. SETTING: Participants were filmed performing the six functional tests of the DMA (deep squat, step up, single-leg squat, hop, plank and side-plank tests). PARTICIPANTS: 240 navy cadets. MAIN OUTCOME MEASUREMENTS: Depending on the number of certain movement patterns on the Dynamic Movement Assessment (DMA), participants were classified as high, moderate, medium or low risk of developing injuries. Predictive associations between injuries and risk classification were examined using logistic regression analysis. RESULTS: Considering sex, previous injuries and the type of secondary school as covariates, participants who were classified as high risk were not more likely to develop injuries. Non-military high school was an independent risk factor for any injuries (OR = 3.14, 95% CI [1.43,6.91]; OR = 4.57, 95% CI [1.92,10.83]), overuse injuries (OR = 2.58, 95% CI [1.05,6.30]; OR = 2.55, 95% CI [1.06, 6.14]) and acute injuries (OR = 4.88, 95% CI [1.19,19.99]), respectively. Previous musculoskeletal symptoms also increased the chance of AI (OR = 4.45, 95% CI [1.15,17.18]; OR = 5.91, 95% CI [1.13,30.88]). CONCLUSIONS: Movement patterns evaluated by DMA are not associated with an increased risk of injuries. However, attendance of a non-military high school and previous musculoskeletal symptoms are associated with musculoskeletal injuries.
Assuntos
Traumatismos em Atletas , Transtornos Traumáticos Cumulativos , Militares , Estudos de Coortes , Humanos , Movimento , Fatores de Risco , Instituições AcadêmicasRESUMO
Abstract Aims: To investigate the inter-and intra-rater agreement of the Dynamic Movement Assessment (DMA™) risk classification. Method: In this study, after the anthropometric measurements were made, 17 female soccer athletes were filmed performing the six DMA™ tests (full squat, step-up, single-leg squat, jump test, test plank, and side plank). Both, major and secondary deviations, were observed during the tests. Two experienced health professionals performed video analysis using Kinovea 8.15.0 (inter-rater agreement). To assess the intra-rater agreement, the same video analysis was performed two months later. Participants were rated from 0 to 21 points and at low, medium, moderate, and high risk of developing musculoskeletal injuries. To assess the reliability of the assessment of movement patterns of DMA, the intraclass correlation coefficient (ICC) was performed with a 2-way random-effects model with an absolute agreement (inter-rater) and a 2-way mixed-effects model and consistency (intra-rater). Weighted Kappa Agreement Analysis (kw) was performed with linear weights to assess the level of agreement related to the risk classification of DMA (high, moderate, medium, or minimum). The Analysis was performed with StatsDirect v.3 and SPSS (23.0). Results: Comparing the number of points between the inter-and intra-rater, the ICC was 0.91 (95% CI = 0.74-0.97) and 0.84 (95% CI = 0.59-0.94), respectively, with kw = 0.46 (P = 0.02) intra -rater and kw = 0.46 (P = 0.006) inter-rater (Table 9). Conclusion: DMA has excellent inter-and intra-rater reliability to evaluate movement patterns and classify the risk of musculoskeletal injuries.
Assuntos
Humanos , Feminino , Traumatismos em Atletas , Futebol/lesões , Antropometria/instrumentação , Reprodutibilidade dos TestesRESUMO
During a field survey in 1994, five cucumber (Cucumis sativus) cv. Hokushin plants showing symptom of yellowing, mottling, and vein banding on the leaves were collected from a commercial field of the Federal District. By electron microscopy, quasi-spherical particles with double membrane, typical tospovirus-like particles were found in the infected leaf material. All samples strongly reacted with antibody of zucchini lethal chlorosis tospovirus (ZLCV), but not with antibodies of other to-spoviruses reported in Brazil (1): tomato spotted wilt virus (TSWV), tomato chlorotic spot virus (TCSV), groundnut ringspot virus (GRSV), chrysanthemum stem necrosis virus (CSNV), or iris yellow spot virusonion isolate (IYSV-BR). The virus was identified as ZLCV, which was first isolated in 1994 from zucchini (Cucurbita pepo) in São Paulo State, Brazil. Tomato (Lycopersicon esculentum) plants showing stem necrosis and necrotic spots and rings on the leaves were collected in Viçosa, Minas Gerais State. By electron microscopy, molecular studies, and enzyme-linked immunosorbent assay with antibodies of the six tospoviruses occurring in Brazil, the virus was identified as CSNV. This virus was first reported in 1995 on a Chrysanthemum sp. in São Paulo State and recently reported in the Netherlands from Dendranthema indicum. This is the first report of the natural occurrence of ZLCV and CSNV on cucumber and tomato, respectively. Reference: (1) A. C. de Ávila et al. 1998. Pages 32-34 in: Int. Symp. on Tospoviruses and Thrips in Floral and Vegetable Crops, 4th.
RESUMO
Developing strawberry cultivars that can be grown on a large scale, it is necessary to gather desirable characteristics such as: tolerance to Tetranychus urticae, high fruit yield and wide adaptability to several cropping managements. Therefore, our objective was to study the genetic diversity among 13 strawberry cultivars under different managements and to recommend promising crosses to obtain segreganting populations with high fruit yield and T. urticae tolerance. Trial was performed under field conditions at the Centro Regional de Desenvolvimento Rural Centro Serrano of the Instituto Capixaba for Technical Assistance and Rural Extension (Incaper), Domingos Martins-ES. We evaluated strawberry cultivars Albion, Aleluia, Aromas, Camarosa, Camino Real, Campinas, Diamante, Dover, Festival, Seascape, Toyonoka, Tudla, and Ventana, cultivated in three cropping managements: open field, low tunnel and high tunnel. Experimental design was randomized complete blocks with three replications. Variables evaluated were: number of two-spotted spider mite/cm2 on the leaf (NTSSM), total number of fruits (TNF), number of commercial fruits (NCF) and fruit yield (YIE, t/ha). We applied the generalized Mahalanobis distance and Tocher's optimization method to study the genetic diversity among cultivars in each management, and the relative contribution of traits to genetic diversity was evaluated according to the criterion described by Singh (1981). For the low tunnel and high tunnel environments, the crosses Aleluia x Camarosa, Aleluia x Aromas and Aleluia x Festival are the most promising to generate segregating populations with a higher possibility to appearance transgressive individuals, while for the open field cultivation system, we recommend the cross among Aleluia x Toynoka. The variables that most contributed for genetic dissimilarity were total number of fruits, fruit yield and number of commercial fruits for the environments open field, low tunnel and high tunnel, respectively.
´Para desenvolver cultivares de morango que podem ser cultivados em larga escala é necessário reunir características desejáveis como: tolerância ao Tetranychus urticae, alta produtividade de frutos e ampla adaptabilidade a diversos sistemas de cultivo. Portanto, o objetivo do trabalho foi estuda a diversidade genética entre 13 cultivares de morango sob diferentes manejos e recomendar cruzamentos promissores para obtenção de populações segregantes com alta produtividade de frutos e tolerantes ao T. urticae. O experimento foi conduzido sob condições de campo no Centro Regional de Desenvolvimento Rural Centro Serrano do Instituto Capixaba de Assistência Técnica e Extenção Rural (Incaper), Domingos Martins-ES, no mês de outubro (primavera). Foram avaliadas as cultivares Albion, Aleluia, Aromas, Camarosa, Camino Real, Campinas, Diamante, Dover, Festival, Seascape, Toyonoka, Tudla e Ventana, cultivadas em três sistemas de cultivo: campo aberto, túnel baixo e túnel alto. O delineamento experimental utilizado foi blocos casualizados com três repetições. As variáveis avaliadas foram: número de ácaro/cm² na folha (NTSSM), número total de frutos (TNF), número de frutos comerciais (NCF) e produtividade de frutos (YIE, t/ha). Foram empregadas a distância generalizada de Mahalanobis e o método de otimização de Tocher para o estudo da diversidade genética entre os cultivares em cada manejo, e a contribuição relativa dos caracteres para a diversidade genética foi avaliada segundo o critério de Singh (1981). Para os manejos túnel baixo e túnel alto, os cruzamentos entre os cultivares Aleluia x Camarosa, Aleluia x Aromas e Aleluia x Festival são os mais promissores para gerar populações segregantes com alta possibilidade de aparecimento de indivíduos transgressivos, enquanto que para o campo aberto recomenda-se o cruzamento entre os cultivares Aleluia x Toynoka. As variáveis que mais contribuíram para a dissimilaridade genética foram o número total de frutos, produtividade e número de frutos comerciais para os ambientes campo aberto, túnel baixo e túnel alto, respectivamente.