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Planta medicinal é qualquer planta que produza princípios ativos que possam ser utilizados com finalidade terapêutica. Essas plantas podem ser atacadas por pragas e doenças que comprometem suas propriedades curativas e a produção. Nesse sentido, o objetivo do presente trabalho foi avaliar a reação de boldo (Plectranthus barbatus), menta (Mentha spicata), penicilina (Alternanthera brasiliana), hortelã-pimenta (Mentha piperita) e citronela (Cymbopogon nardus) a Meloidogyne javanica. O experimento foi conduzido em casa de vegetação no campo experimental do Instituto Taquaritinguense de Ensino Superior (ITES), Taquaritinga, SP, a partir de mudas transplantadas para vasos de 5 L contendo substrato esterilizado. Realizou-se a inoculação nas mudas após 20 dias do transplante com 640 ovos + juvenis de segundo estádio (J2) por planta. Decorridos 90 dias após a inoculação, as raízes foram processadas para extração dos ovos e determinação do fator de reprodução (FR) do nematoide. Todas as plantas medicinais avaliadas foram resistentes (FR < 1) a M. javanica, podendo ser utilizadas em rotação de culturas em áreas com ocorrência desse nematoide. Medicinal plant is any plant that produces active principles that can be used for therapeutic purposes. These plants can be attacked by pests and diseases that compromise healing properties and production. In this sense, the aim of the present work was to evaluate the reaction of boldo (Plectranthus barbatus), mint (Mentha spicata), penicillin (Alternanthera brasiliana), peppermint (Mentha piperita), and citronella (Cymbopogon nardus) to Meloidogyne javanica. The experiment was carried out in a greenhouse in the experimental field of Instituto Taquaritinguense de Ensino Superior (ITES), municipality of Taquaritinga, São Paulo state, Brazil, using seedlings transplanted into 5 L pots containing sterilized substrate. The seedlings were inoculated 20 days after transplanting with 640 eggs + second stage juveniles (J2) per plant. After 90 days after inoculation, the roots were processed to extract the eggs, and determine the nematode reproduction factor (RF). All medicinal plants evaluated were resistant (RF < 1) to M. javanica, and can be used in crop rotation in areas with occurrence of this nematode. Made available in DSpace on 2022-09-15T17:06:26Z (GMT). No. of bitstreams: 1 27361.pdf: 213035 bytes, checksum: ae0e75ab8d8d2b0d0175dbf60ddd389d (MD5) Previous issue date: 2022

Climate change can cause significant shifts in the occurrence and severity of agricultural diseases, altering the distribution of phytosanitary problems with severe economic, social, and environmental consequences. Despite their importance, these new geographic and temporal distributions of plant diseases still demand scrutiny. In the present study, we prospect the geographic distribution of sugarcane brown rust (Puccinia melanocephala) considering average temperature and relative humidity in the main producing region of the state of São Paulo. The geographic database was structured using GIS with projections of future climate change provided by IPCC. Mathematical logic equations were defined and applied to data of average temperature and relative humidity, resulting in monthly maps of climate favorability for the occurrence of the disease. Prospective maps for three future periods (2011-2040, 2041-2070, and 2071-2100) and two greenhouse gas emission scenarios were compared to the reference period (1961-1990). The analysis considered months from December to May. Our study shows a tendency of decrease in the favorability for the disease in a longer term (2071-2100), more noticeable in the scenario A2 than in B1. These results suggest; however, that this disease demands attention in the management of the producing region for future climate scenarios. Made available in DSpace on 2022-07-11T12:21:07Z (GMT). No. of bitstreams: 1 Prospecting-brown-rust-of-sugarcane-in-Sao-Paulo-2022.pdf: 1163510 bytes, checksum: 5e08a1030e2fce46e6d3620b2535d7f2 (MD5) Previous issue date: 2022

A cenoura é uma hortaliça do grupo das raízes tuberosas, cultivada em larga escala em vários estados brasileiros. Dentre os problemas fitossanitários associados à cultura destacam-se os nematoides galhadores do gênero Meloidogyne, cujas infestações podem acarretar em até 100% de perda da produção. A busca por alternativas ao controle químico tem se intensificado nos últimos anos, com o advento de bionematicidas, especialmente os formulados à base de fungos nematófagos. Assim, o objetivo desse estudo foi comparar a eficiência da aplicação dos fungos Paecilomyces lilacinus e Pochonia chlamydosporia em comparação ao uso do controle químico, em plantio de cenoura sob infestação de nematoide-das-galhas. O estudo foi conduzido no Instituto Taquaritinguense de Ensino Superior (ITES), Taquaritinga, SP, em condições de campo, utilizando a cenoura híbrida var. ?Sirkana?. O delineamento experimental foi em blocos ao acaso (DBC) com cinco repetições e seis tratamentos: 1. P. lilacinus; 2. P. chlamydosporia; 3. P. lilacinus + P. chlamydosporia; 4. Adicarbe; 5. Cadusafós e 6. Testemunha (sem aplicação). As doses dos respectivos tratamentos constaram de 0,67 L/m2 de canteiro com substrato colonizado pelos fungos nematófagos, 30 kg/ha de p.c. de Aldicarbe e 25 kg/ha de p.c. de Cadusafós. Pelos resultados obtidos, os fungos nematófagos P. lilacinus e P. chlamydosporia podem ser recomendados no controle de nematoides-das-galhas em cultivo de cenoura, como alternativa ao controle químico. The carrot is a vegetable of the tuberous roots group, cultivated on a large scale in several Brazilian states. Among the phytosanitary problems associated with the crop, galling nematodes of the genus Meloidogyne stand out, whose infestations can lead to up to 100% loss of production. The search for alternatives to chemical control has intensified in recent years with the advent of bionematicides, especially those formulated based on nematophagous fungi. Thus, the aim of this study was to compare the efficiency of the application of the fungi Paecilomyces lilacinus, and Pochonia chlamydosporia compared to the use of chemical control, in carrot planting under root-knot nematode infestation. The study was carried out at Instituto Taquaritinguense de Ensino Superior (ITES), municipality of Taquaritinga, São Paulo state, Brazil under field conditions, using the hybrid carrot var. 'Sirkana'. The experimental design was in complete randomized blocks with five replications and six treatments: 1. P. lilacinus; 2. P. chlamydosporia; 3. P. lilacinus + P. chlamydosporia; 4. Adicarb; 5. Cadusaphos and 6. Check Treatment (not applicable). The doses of the respective treatments consisted of 0.67 L/m2 of planting bed with substrate colonized by nematophagous fungi, 30 kg/ha of p.c. of Aldicarb, and 25 kg/ha of p.c. of Cadusaphos. Based on the results obtained, the nematophagous fungi P. lilacinus and P. chlamydosporia can be recommended for the control of root-knot nematodes in carrot cultivation, as an alternative to chemical control. Made available in DSpace on 2022-09-16T21:05:19Z (GMT). No. of bitstreams: 1 27363.pdf: 270821 bytes, checksum: 85e38379afcefb1c054c308c3377787b (MD5) Previous issue date: 2022

Made available in DSpace on 2022-04-28T19:41:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-07-01 Background. The necessity of a competent vector for transmission is a primary ecological factor driving the host range expansion of plant arthropod-borne viruses, with vectors playing an essential role in disease emergence. Cassava begomoviruses severely constrain cassava production in Africa. Curiously, begomoviruses have never been reported in cassava in South America, the center of origin for this crop. It has been hypothesized that the absence of a competent vector in cassava is the reason why begomoviruses have not emerged in South America. Methods. We performed a country-wide whitefly diversity study in cassava in Brazil. Adults and/or nymphs of whiteflies were collected from sixty-six cassava fields in the main agroecological zones of the country. A total of 1,385 individuals were genotyped based on mitochondrial cytochrome oxidase I sequences. Results. A high species richness was observed, with five previously described species and two putative new ones. The prevalent species were Tetraleurodes acaciae and Bemisia tuberculata, representing over 75% of the analyzed individuals. Although we detected, for the first time, the presence of Bemisia tabaci Middle East-Asia Minor 1 (BtMEAM1) colonizing cassava in Brazil, it was not prevalent. The species composition varied across regions, with fields in the Northeast region showing a higher diversity. These results expand our knowledge of whitefly diversity in cassava and support the hypothesis that begomovirus epidemics have not occurred in cassava in Brazil due to the absence of competent vector populations. However, they indicate an ongoing adaptation process of BtMEAM1 to cassava, increasing the likelihood of begomovirus emergence in this crop. Dep. de Fitopatologia/BIOAGRO Universidade Federal de Viçosa, MG Dep. de Proteção Vegetal Universidade Estadual Paulista, SP Faculdade de Engenharia Agronômica Universidade Federal do Pará, PA Instituto Federal do Sudeste de Minas Gerais, MG Dep. de Fitotecnia Universidade Federal do Piauí, PI Embrapa Amazônia Oriental, PA Dep. de Fitotecnia e Fitossanidade Universidade Federal do Paraná, PR Centro de Ciências Agroveterinárias Universidade do Estado de Santa Catarina, SC Centro Multidisciplinar do Campus de Barra Universidade Federal do Oeste da Bahia, BA Centro de Ciências Agrárias/Fitossanidade Universidade Federal de Alagoas, AL Embrapa Arroz e Feijão, GO Instituto Capixaba de Pesquisa e Extensão Rural, ES Faculdade de Engenharia Florestal Universidade Federal do Pará, PA Dep. de Proteção Vegetal Universidade Estadual Paulista, SP

Wheat blast, caused by the fungus Magnaporthe oryzae Triticum (MoT) pathotype, is one of the most important yield-reducing diseases of wheat, mainly in the tropical wheat-growing regions of South America. In this study, we assessed the effects of nitrogen (N) fertilization on wheat blast epidemics. Factorial experiments were carried out in Londrina (2015 and 2016) and Floresta (two sowings in 2017) with N rates (0, 40, 80 and 120 kg/ha for the first experiment, and 0, 60 and 120 kg/ha for the second) and wheat genotypes (three and six cultivars, for the first and second experiments, respectively) as factors. Wheat blast on spikes occurred only in two out of four experiments: 2015 in Londrina and first sowing of 2017 in Floresta. Nitrogen increased blast severity in the first crop of 2017 in Floresta, where blast severity on spikes ranged from 10 to 94% and yield ranged from 47 to 2823 kg/ha, depending on N rate and genotype. Nitrogen did not affect wheat blast (except for genotype S1) in the 2015 Londrina trial, where blast severity on spikes ranged from 16.9 to 36.8%. Differences in blast severity among genotypes were likely due to different crop heading periods. Our results suggest that N fertilization and sowing time should be considered in a management strategy for reducing the risk of wheat blast epidemics.

Resumo: A avaliação de genótipos de feijão guandu como antagônico, resistente ou tolerante ao nematoide das galhas (Meloidogyne enterolobii), pode elevar o potencial multiuso dessa leguminosa e verificar a reação de genótipos a esse fitopatógeno, considerado um dos mais agressivos do gênero, se faz necessário devido à sua ampla disseminação e escassez de controle no território nacional. Assim este trabalho teve por objetivo avaliar a reação de seis genótipos de feijão guandu (Cajanus cajan) ao patógeno M. enterolobii. A avaliação final das plantas ocorreu 80 dias após a inoculação dos fitopatógenos, na qual foram mensuradas variáveis de desenvolvimento das plantas: altura da planta, número de hastes, peso da matéria fresca da raiz e peso da matéria seca. Assim como também variáveis de desenvolvimento do nematoide M. enterolobii: número de galhas, índice de massas de ovos, fator de reprodução e redução do fator de reprodução. A hospedabilidade dos genótipos de feijão guandu foi avaliada por meio de cinco critérios classificatórios de distintos ajuizamentos. Para a produção de forragem, três genótipos foram moderadamente resistentes a M. enterolobii, FGSob/14-09, FGg59-95/14-37 e FG CAM/14-49. No entanto, os genótipos de feijão guandu não se enquadraram como plantas antagonistas, apresentando suscetibilidade ao fitopatógeno. [ Reaction of genotypes of pigeon pea (Cajanus cajan (L.) Millspaugh) to the root-knot nematode (Meloidogyne enterolobii). Abstract: The eEvaluation of genotypes of pigeon pea genotypes as antagonistic, resistant or tolerant to the root-knot nematodes (Meloidogyne enterolobii), may increase the multipurpose potential of this legume, and verifying the reaction of genotypes reaction to this phytopathogen, considered one of the most aggressive pathogens of the genus, isf necessary due to its wide dissemination and scarcity of control in the national territory. Thus, the objective aim of this studywork was to evaluate the reaction of six genotypes of pigeon pea (Cajanus cajan) to the pathogen M. enterolobii. The final evaluation of the plants occurred 80 days after the inoculation of plant phytopathogens, and the following in which plant development variables were measured: plant height, stem number of stems, weight of root fresh root matter weight and weight of dry matter weight. As well as dDevelopmental variables of the nematode M. enterolobii were also evaluated: gall number of galls, egg mass index, reproduction factor and reproduction factor reduction. The host suitability genotypes of pigeon pea genotypes wasere evaluated based ony means of five classification criteria from different trials. For fodder the production of fodder, three genotypes were moderately resistant to M. enterolobii, FG Sob/14-09, FGg59-95/14-37 and FGCAM/14-49. However, the genotypes of pigeon pea did not fit as antagonistic plants, presenting susceptibility to the phytopathogen. Made available in DSpace on 2019-01-24T00:30:31Z (GMT). No. of bitstreams: 1 CNPC2018Reacao.pdf: 256806 bytes, checksum: b2a69f4ba52d8af53ba28127eccb4afd (MD5) Previous issue date: 2019-01-23

Colour-thresholding digital imaging methods are generally accurate for measuring the percentage of foliar area affected by disease or pests (severity), but they perform poorly when scene illumination and background are not uniform. In this study, six convolutional neural network (CNN) architectures were trained for semantic segmentation in images of individual leaves exhibiting necrotic lesions and/or yellowing, caused by the insect pest coffee leaf miner (CLM), and two fungal diseases: soybean rust (SBR) and wheat tan spot (WTS). All images were manually annotated for three classes: leaf background (B), healthy leaf (H) and injured leaf (I). Precision, recall, and Intersection over Union (IoU) metrics in the test image set were the highest for B, followed by H and I classes, regardless of the architecture. When the pixel-level predictions were used to calculate percent severity, Feature Pyramid Network (FPN), Unet and DeepLabv3+ (Xception) performed the best among the architectures: concordance coefficients were greater than 0.95, 0.96 and 0.98 for CLM, SBR and WTS datasets, respectively, when confronting predictions with the annotated severity. The other three architectures tended to misclassify healthy pixels as injured, leading to overestimation of severity. Results highlight the value of a CNN-based automatic segmentation method to determine the severity on images of foliar diseases obtained under challenging conditions of brightness and background. The accuracy levels of the severity estimated by the FPN, Unet and DeepLabv3 + (Xception) were similar to those obtained by a standard commercial software, which requires adjustment of segmentation parameters and removal of the complex background of the images, tasks that slow down the process. Made available in DSpace on 2021-09-14T13:01:47Z (GMT). No. of bitstreams: 1 AP-Predictive-models-Forests-2021.pdf: 3767412 bytes, checksum: aeaec795a200faae684d5a3ea753e45e (MD5) Previous issue date: 2021

lbgBackground and Objective:l/bg Fungi of the genus ligTrichoderma l/ighave high versatility in the control of different plant diseases. Among the main mechanisms of action of these fungi against phytopathogenic fungi, the production of Volatile Organic Compounds (VOCs) is mentioned. These compounds are said to inhibit the mycelial growth of various fungal pathogens. The objective of this work was to evaluate the ligin vitrol/ig inhibition of the mycelial growth of ligSclerotinia sclerotiorum l/igby VOCs from six ligTrichoderma l/igstrains in different stages of development of the biocontrol agent. lbgMaterials and Methods:l/bg In this work, the ligin vitro l/igevaluation of the mycelial growth of the phytopathogen ligS. sclerotiorum l/igby VOCs from six ligTrichoderma l/igstrains was carried out: ligT. koningiopsis l/ig(CEN1386), ligT. asperelloides l/ig(CEN1397), ligT. longibrachiatum l/ig(CEN1399) ligT. lentiforme l/ig(CEN1416), ligTl/ig. ligperbedyil/ig (CEN1389) and ligT. azevedoil/ig (CEN1241). Observations were made at different stages of antagonist development: mycelial Growth Phase (GP), Sporulation Phase (SP) and paired with the Pathogen Phase (PP). Besides, the sporulation of the tested strains was quantified. lbgConclusion:l/bg In all experimental conditions, the VOCs produced by the CEN1241 strain showed a greater inhibitory effect, although the inhibition was less evident when the cultures of ligS. sclerotiorum l/igwere exposed in the GP phase of the antagonist. Greater sporulation was observed with ligT. lentiformel/ig (CEN1416), a fact not related to a better ability to inhibit ligS. sclerotioruml/ig, by VOCs.

Several species of predatory mites, naturally occurring in coconut plantations, play an important role in regulating populations of phytophagous mites that are key pests of this crop. Plant essential oils (EOs) are bioactive mixtures of compounds that hold potential for controlling phytophagous arthropods with minimal impacts on non-target organisms and the environment. This study aimed to characterize the chemical composition and assess the bioactivity of the EO extracted from the leaves of the ?Pera? sweet orange grafted on ?Rangpur lime? to a key pest of coconut plantations worldwide, namely the coconut mite Aceria guerreronis (Acari: Eriophyidae), and its compatibility with the naturally-occurring generalist predatory mite Typhlodromus ornatus (Acari: Phytoseiidae). Briefly, sabinene was the major component, followed by δ-3-carene and (E)-β-ocimene. The EO was toxic to A. guerreronis (LC50 = 4.28 mg/mL; LC80 = 10.39 mg/mL) but not to T. ornatus. The LC80 of the EO did not repel A. guerreronis and was toxic to the pest mite only in the first hours (

Despite the importance of viral strains/variants as agents of emerging diseases, genetic and evolutionary processes affecting their ecology are not fully understood. To get insight into this topic, we assessed the population and spatial dynamic parameters of citrus leprosis virus C (CiLV-C, genus Cilevirus, family Kitaviridae). CiLV-C is the etiological agent of citrus leprosis disease, a non-systemic infection considered the main viral disorder affecting citrus orchards in Brazil. Overall, we obtained 18 complete or near-complete viral genomes, 123 complete nucleotide sequences of the open reading frame (ORF) encoding the putative coat protein, and 204 partial nucleotide sequences of the ORF encoding the movement protein, from 430 infected Citrus spp. samples collected between 1932 and 2020. A thorough examination of the collected dataset suggested that the CiLV-C population consists of the major lineages CRD and SJP, unevenly distributed, plus a third one called ASU identified in this work, which is represented by a single isolate found in an herbarium sample collected in Asuncion, Paraguay, in 1937. Viruses from the three lineages share about 85% nucleotide sequence identity and show signs of inter-clade recombination events. Members of the lineage CRD were identified both in commercial and non-commercial citrus orchards. However, those of the lineages SJP were exclusively detected in samples collected in the citrus belt of São Paulo and Minas Gerais, the leading Brazilian citrus production region, after 2015. The most recent common ancestor of viruses of the three lineages dates back to, at least, ?1500 years ago. Since citrus plants were introduced in the Americas by the Portuguese around the 1520s, the Bayesian phylodynamic analysis suggested that the ancestors of the main CiLV-C lineages likely originated in contact with native vegetation of South America. The intensive expansion of CRD and SJP lineages in Brazil started probably linked to the beginning of the local citrus industry. The high prevalence of CiLV-C in the citrus belt of Brazil likely ensues from the intensive connectivity between orchards, which represents a potential risk toward pathogen saturation across the region. Made available in DSpace on 2021-11-17T02:10:55Z (GMT). No. of bitstreams: 1 fmicb-12-641252.pdf: 2022500 bytes, checksum: a6c8e0bda620f64c25a37cf380a427d3 (MD5) Previous issue date: 2021

The biotrophic fungus Hemileia vastatrix causes coffee leaf rust (CLR), one of the most devastating diseases in Coffea arabica . Coffee, like other plants, has developed effective mechanisms to recognize and respond to infections caused by pathogens. Plant resistance gene analogs (RGAs) have been identified in certain plants as candidates for resistance ( R ) genes or membrane receptors that activate the R genes. The RGAs identified in different plants possess conserved domains that play specific roles in the fight against pathogens. Despite the importance of RGAs, in coffee plants these genes and other molecular mechanisms of disease resistance are still unknown. This study aimed to sequence and characterize candidate genes from coffee plants with the potential for involvement in resistance to H. vastatrix . Sequencing was performed based on a library of bacterial artificial chromosomes (BAC) of the coffee clone ?Híbrido de Timor? (HdT) CIFC 832/2 and screened using a functional marker. Two RGAs, HdT_LRR_RLK1 and HdT_LRR_RLK2, containing the motif of leucine-rich repeat-like kinase (LRR-RLK) were identified. Based on the presence or absence of the HdT_LRR_RLK2 RGA in a number of differential coffee clones containing different combinations of the rust resistance gene, these RGAs did not correspond to any resistance gene already characterized (SH1-9). These genes were also analyzed using qPCR and demonstrated a major expression peak at 24 h after inoculation in both the compatible and incompatible interactions between coffee and H. vastatrix . These results are valuable information for breeding programs aimed at developing CLR-resistant cultivars, in addition to enabling a better understanding of the interactions between coffee and H. vastatrix. Made available in DSpace on 2022-01-26T14:00:41Z (GMT). No. of bitstreams: 1 receptor-like-kinase.pdf: 797260 bytes, checksum: 18841c8c3f9b08408ff2d898ecc48880 (MD5) Previous issue date: 2021

O uso de genótipos resistentes é um dos principais métodos de controle de doenças no Brasil, sendo fundamental o melhoramento genético visando a obter novos genótipos resistentes, para suprir essa demanda. Assim, o objetivo deste trabalho foi estimar os parâmetros genéticos das variáveis resistência ao cancro, causado por Chrysoporthe cubensis e resistência à mancha foliar, causada por Cylindrocladium spp. e Kirramyces epicoccoides, bem como avaliar suas implicações na estratégia de melhoramento genético de Eucalyptus grandis. Foi instalado um teste de progênies de polinização aberta, em dois locais no Estado de São Paulo, nas regiões de Anhembi e Itatinga. O teste foi realizado em blocos casualizados, com 176 progênies e três testemunhas, uma por parcela, com 30 repetições em Itatinga e 28 repetições na região de Anhembi. A resistência ao cancro foi avaliada aos 12, 24 e 29 meses de idade na região de Anhembi e aos 15, 27 e 32 meses de idade, na região de Itatinga. A resistência à mancha foliar foi avaliada aos 12 e 24 meses de idade na região de Anhembi e aos 15 e 27 meses de idade, na região de Itatinga. Os parâmetros genéticos foram estimados, utilizando o software SELEGEN REML/BLUP®. Com a mesma população de seleção, verificou-se que, para a região de Itatinga, as estimativas de parâmetros genéticos indicam maior potencial para a seleção de genótipos resistentes ao cancro e à mancha foliar. Porém, para as condições edafoclimáticas da região de Anhembi, essa população apresenta potencial de seleção inferior, o que fica evidenciado pelos baixos valores de herdabilidade média individual de progênies estimados. Na região de Itatinga, foram obtidos valores de herdabilidade média individual de progênies para a resistência ao cancro e à mancha foliar, que variaram de moderado a alto, indicando que pode haver bons ganhos com a seleção neste local. Made available in DSpace on 2021-11-17T18:00:24Z (GMT). No. of bitstreams: 1 Celso-Auer-56935-304903-1-PB.pdf: 667287 bytes, checksum: 7bd84f5918fb256edebeb35f07d8643c (MD5) Previous issue date: 2021

The essential oil (EO) from different genotypes of Lippia gracilis Schauer (Verbenaceae) present two distinctive chemotypes containing either thymol or its isomer carvacrol as major compounds, both of which have proven bioactivity against several agricultural pests. Recently, we have shown that L. gracilis accession LGRA 106 and its major compound thymol are toxic and repellent against the coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae), a key pest of coconut plantations in Asia, Africa and America. Since intraspecific variation affects the chemical composition of EO and hence, its bioactivity, here we assessed the acaricidal and repellent effects of L. gracilis accession LGRA109 to A. guerreronis. Leaves of this accession contain carvacrol (49.35%) as major compound. The LC50 of the EO and of carvacrol estimated for A. guerreronis were 28.01 and 6.84 mg/mL, respectively. Carvacrol, at its LC50, as well as the EO and carvacrol at their LC99, repelled the mite. Our results indicated that carvacrol and the EO of L. gracilis accession LGRA109 were bioactive against A. guerreronis; however, the EO was less effective than its major compound. Made available in DSpace on 2021-12-06T19:01:03Z (GMT). No. of bitstreams: 1 Teodoro-et-al2021-IJA.pdf: 644832 bytes, checksum: 90fd69cfc371be37e5ff9361d37b0a2b (MD5) Previous issue date: 2021

Delineating species and epidemic lineages in fungal plant pathogens is critical to our understanding of disease emergence and the structure of fungal biodiversity, and also informs international regulatory decisions.Pyricularia oryzae (syn. Magnaporthe oryzae)is a multi-host pathogen that infects multiple grasses and cereals, is responsible for the most damaging rice disease (rice blast), and of growing concern due to the recent introduction of wheat blast to Bangladesh from South America. However, the genetic structure and evolutionary history ofM. oryzae, including the possible existence of cryptic phylogenetic species, remain poorly defined. Here, we use whole-genome sequence information for76 M. oryzaeisolates sampled from 12 grass and cereal genera to infer the population structure ofM. oryzae, and to reassess the species status of wheat-infecting populations of the fungus. Species recognition based on genealogical concordance, using published data or extracting previously-used loci from genome assemblies, failed to confirm a prior assignment of wheat blast isolates to a new species (Pyricularia graminis tritici). Inference of population subdivisions revealed multiple divergent lineages withinM. oryzae, each preferentially associated with one host genus, suggesting incipient speciation following host shift or host range expansion. Analyses of gene flow, taking into account the possibility of incomplete lineage sorting, revealed that genetic exchanges have contributed to the makeup of multiple lineages withinM. oryzae. These findings provide greater understanding of the eco-evolutionary factors that underlie the diversification ofM. oryzaeand highlight the practicality of genomic data for epidemiological surveillance in this important multi-host pathogen.ImportanceInfection of novel hosts is a major route for disease emergence by pathogenic micro-organisms. Understanding the evolutionary history of multi-host pathogens is therefore important to better predict the likely spread and emergence of new diseases.Magnaporthe oryzaeis a multi-host fungus that causes serious cereal diseases, including the devastating rice blast disease, and wheat blast, a cause of growing concern due to its recent spread from South America to Asia. Using whole genome analysis of 76 fungal strains from different hosts, we have documented the divergence ofM. oryzaeinto numerous lineages, each infecting a limited number of host species. Our analyses provide evidence that inter-lineage gene flow has contributed to the genetic makeup of multipleM. oryzaelineages within the same species. Plant health surveillance is therefore warranted to safeguard against disease emergence in regions where multiple lineages of the fungus are in contact with one another.

The severity of plant diseases, traditionally the proportion of the plant tissue exhibiting symptoms, is a key quantitative variable to know for many diseases and is prone to error. Good quality disease severity data should be accurate (close to the true value). Earliest quantification of disease severity was by visual estimates. Sensor-based image analysis including visible spectrum and hyperspectral and multispectral sensors are established technologies that promise to substitute, or complement visual ratings. Indeed, these technologies have measured disease severity accurately under controlled conditions but are yet to demonstrate their full potential for accurate measurement under field conditions. Sensor technology is advancing rapidly, and artificial intelligence may help overcome issues for automating severity measurement under hyper-variable field conditions. The adoption of appropriate scales, training, instruction and aids (standard area diagrams) has contributed to improved accuracy of visual estimates. The apogee of accuracy for visual estimation is likely being approached, and any remaining increases in accuracy are likely to be small. Due to automation and rapidity, sensor-based measurement offers potential advantages compared with visual estimates, but the latter will remain important for years to come. Mobile, automated sensor-based systems will become increasingly common in controlled conditions and, eventually, in the field for measuring plant disease severity for the purpose of research and decision making. Made available in DSpace on 2020-05-12T04:39:44Z (GMT). No. of bitstreams: 1 AP-Phytopathology-Research-2020.pdf: 3687278 bytes, checksum: 1cc4d05c8d98608d3ce2e7d1d2e1b252 (MD5) Previous issue date: 2020 Article 9.

A ocorrência da mancha preta do amendoim está diretamente relacionada com os elementos climáticos. Desta maneira, a elaboração de mapas de distribuição geográfica e temporal contribui informações sobre o comportamento de patossistemas frente às mudanças climáticas. Assim, o objetivo deste trabalho foi avaliar a evolução da favorabilidade climática à ocorrência da mancha preta para as principais regiões produtoras de amendoim da Argentina e do Brasil em função das mudanças climáticas. Na elaboração dos mapas foram consideradas as principais áreas produtoras de amendoim da Argentina e do Brasil e os meses de janeiro a março. Para a elaboração dos mapas foi empregada a metodologia de análise integrada das projeções climáticas e do problema fitossanitário com suporte do geoprocessamento. Foram considerados o clima normal (1961-1990) e o clima futuro (201-2040, 2041-270 e 2071-2100). Diferentes regras foram adotadas para cada a Argentina e o Brasil, pois elas incorporam as particularidades da doença nas áreas produtoras de cada país, como efeito da interação das características próprias do patógeno virulento, hospedeiro suscetível e ambiente. Os cenários climáticos futuros apontam o aumento da favorabilidade para a ocorrência da mancha preta do amendoim para a Argentina e para o Brasil. Made available in DSpace on 2020-11-11T11:23:37Z (GMT). No. of bitstreams: 1 Evolucao-da-mancha-preta-do-amendoim-nas-principais-regioes-2020.pdf: 1387315 bytes, checksum: 1732127f2cf730d076502b10d472a57c (MD5) Previous issue date: 2020

Made available in DSpace on 2020-04-24T00:44:10Z (GMT). No. of bitstreams: 1 Cultivarabr..pdf: 1366188 bytes, checksum: 33590932bac007119f0f09e9bfbfb188 (MD5) Previous issue date: 2020 Titulo alternativo (revista impressa): Cana: novo cenário.

In Mali, the economy is mainly based on agriculture. Rice contributes about 5% of the GDP and constitutes a strategic sector with enormous potential. Despite its strategic importance, rice cultivation faces multiple biotic constraints among which rice yellow mottle virus disease is the most important one with an incidence varying from 60 to 100%. To reduce yield loses due to this disease, we determined the mode of action of two rice yellow Mottle virus (RYMV) pathotypes previously isolated in rice fields in Mali, and identified by Reverse transcription polymerase chain reaction (RT-PCR). Both types significantly decrease rice height with a more pronounced effect with the type A, which showed more aggressivity even on the SK20-28 genotype recognized as RYMV disease-tolerant variety. Root dry weight, grain production and tiller number were the most affected by the disease. Except for tiller number, the virus type A was always more virulent than the type B. Significant positive correlation was found between disease severity and % reduction in tiller number, percentage reduction in plant height, and grain production. The data presented root inhibition as a mode of action of the two RYMV pathotypes isolated in Mali. This information should be used in order to improve the management strategies for these pathogens on field rice in Mali. Made available in DSpace on 2020-08-27T04:10:26Z (GMT). No. of bitstreams: 1 CNPAF-2020-ajar.pdf: 542909 bytes, checksum: d699de979c76bd44c2608e020e6e4517 (MD5) Previous issue date: 2020 Article number: 71BD88564593.

Bacterial leaf blight is a major disease of eucalypt, especially under nursery conditions. Different bacterial species have been associated with the disease in several countries, and despite its importance worldwide, it is not clear to date whether similar disease symptoms are caused by the same or by different etiological agents. In this study, 43 bacterial strains were isolated from blighted eucalypt leaves collected in different geographic areas of Brazil and inoculated onto a susceptible eucalypt clone. Polyphasic taxonomy, including morphological, physiological, biochemical, molecular, and pathogenicity tests showed that only certain strains of Xanthomonas axonopodis caused symptoms of the disease. Strains varied in their aggressiveness, but no correlation with geographic origin was observed. MLSA-based phylogenetic analysis using concatenated dnaK, fyuA, gyrB and rpoD gene sequences allocated the strains in a well-defined clade, corresponding to Rademarker?s group RG 9.6. Inoculation of nineteen plant species belonging to seven botanical families with representative strain LPF 602 showed it to be pathogenic only on Eucalyptus spp, and Corymbia spp. Based on distinct biochemical and pathogenic characteristics that differentiate the eucalypt strains from other pathovars of the X. axonopodis species, here we propose their allocation into the new pathovar X. axonopodis pv. eucalyptorum pv. nov. Made available in DSpace on 2019-01-02T23:39:23Z (GMT). No. of bitstreams: 1 26755.pdf: 1921182 bytes, checksum: 5475bd39cdda97a1767406d95440d333 (MD5) Previous issue date: 2019-01-02

The growing demand for alternative strategies for plant disease management has sought a reduction in the use of fungicides via the employment of resistance inducers and foliar fertilizers, among others. Therefore, this study aimed at evaluating the following foliar fertilizers for the management of phoma leaf spot: a foliar fertilizer based on macro-and micronutrients (Fmm: 10% N, 4% S, B, 5% Fe and 5% Zn); one based on cobalt and molybdenum (Fcm: 2% Co and 3% Mo); manganese phosphite (FMn: 30% P2O5 and 9% Mn); and the FMn+Fmm, Fcm+Fmm and FMn+Fcm+Fmm associations compared to a boscalid fungicide and a control with no treatment. The disease severity, the chlorophyll a and b contents, the net photosynthetic rate (LPR), the phenylalanine ammonia lyase (PAL) activity and the lignin content in leaves were assessment. Based on the severity, the area under the disease severity progress curve (AUSPC) and the efficiency of disease control in relation to untreated plants were calculated. The experimental design was in randomized blocks with eight treatments and three replications. Treatments FMn+Fmm and Fcm were the most effective in reducing the AUPSC in comparison with the control and promoted an increased activity of PAL. FMn was the treatment that promoted the highest increase in the LPR. There were no effects of the treatments on the lignin content compared to the control. Made available in DSpace on 2019-02-06T23:36:30Z (GMT). No. of bitstreams: 1 Pedro2018.pdf: 967520 bytes, checksum: 1c4e1a572068c0bebb808e691a10457f (MD5) Previous issue date: 2018-11-28