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Passion fruit plants are self-incompatible and fruiting is exclusively dependent on cross-pollination, which in nature is performed by carpenter (mamangava) bees, especially Xylocopa spp. (family Apidae). To ensure satisfactory productivity, daily manual pollination is a common practice among passionflower growers. Therefore, we studied whether manual pollination mechanically transmits the cowpea aphid-borne mosaic virus (CABMV), the causal agent of the passion fruit woodiness disease. None of the eight healthy passion fruit plants manually pollinated with pollen from CABMV field-infected plants were infected, as confirmed by PTA-ELISA and RT-PCR. Healthy passion fruit plants mechanically inoculated with extracts of pollen collected from flowers of CABMV field-infected plants were not infected. CABMV was only detected by RT-PCR in groups of three anthers, and in pollen from groups of 20 anthers collected from flowers of infected passion fruit plants. RT-qPCR conducted with different amounts of pollen grains and anthers indicated extremely low virus titers. In addition to low virus titers, transmission failure may be associated with an absence of virus particles outside the pollen grains and/or absence of enough wounding produced on the stigmas by the fingertips. The improbability of CABMV transmission via pollen during manual pollination showed that this widely used cultural practice is a negligible factor in the epidemiology of passion fruit woodiness disease.

Made available in DSpace on 2019-10-06T15:48:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-12-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Begomovirus infections in Passiflora plants in Brazil have increased in recent years. This contribution reports natural infection of Passiflora plants by Melochia yellow mosaic virus (MelYMV) in the state of Mato Grosso do Sul. MelYMV was transmitted to Passiflora plants by biolistics but not by Bemisia tabaci MEAM1 and MED. To our knowledge this is the first report of MelYMV infecting Passiflora plants. Departamento de Fitopatologia e Nematologia ESALQ-USP Departamento de Proteção Vegetal FCA-UNESP AGRAER/CEPAER Departamento de Proteção Vegetal FCA-UNESP FAPESP: 2016/08573-8

The antidote vines or nhandirobas (Fevillea trilobata L. [Cucurbitaceae]) are dioecious plant species native to the South American Neotropics (1). Genetic materials of these species are now being domesticated and evaluated as potential crops for seed-oil extraction aiming to produce biodiesel fuel (2). Plants of F. trilobata (Accession No. CNPH-001) were cultivated from seeds under open field conditions during the years 2008 through 2011 in Brasília-DF, Brazil. Approximately 200 plants exhibiting mosaic symptoms and severe leaf malformation (with typical bubble-like patches) were found in all fields every year. Apical mosaic was slightly more severe in female than in male plants. Electron microscopy examination of negatively stained extracts of symptomatic leaf tissue showed the presence of filamentous particles about 700 to 800 nm long. Analysis of ultra-thin sections of the same tissues revealed the presence of lamellar inclusions typical of a potyvirus infection. No aphid colonies were observed on field-grown F. trilobata plants. The virus was mechanically transmitted to healthy Cucurbita pepo cv. Caserta and Luffa cylindrica, causing systemic mosaic. Sap from these infected plants reacted in PTA-ELISA with polyclonal antiserum against Zucchini yellow mosaic virus (ZYMV), but not with antisera against Papaya ringspot virus – type W (PRSV-W), Cucumber mosaic virus (CMV), and Zucchini lethal chlorosis virus (ZLCV). Total RNA extracted from experimentally infected C. pepo was analyzed by RT-PCR using specific pairs of primers for the coat protein gene of ZYMV (3). A cDNA fragment of approximately 1,186 bp was amplified and the nucleotide sequence obtained by direct sequencing. Comparisons of the nucleotide (837 nt) and deduced amino acid (279 aa) sequences of the coat protein genomic segment (GenBank Accession No. JX502677) revealed 93 to 98% and 97 to 98% identity, respectively, with the corresponding nucleotide and amino acid sequences of a group of ZYMV isolates from distinct hosts (AY188994, AY279000, and NC_003224). The infection by ZYMV might cause fruit yield losses to F. trilobata. In addition, the infected F. trilobata crops might work as a reservoir of ZYMV providing inoculum to other cucurbit hosts since it has been managed as a semi-perennial crop. To our knowledge, this is the first report of the genus Fevillea as a natural host of ZYMV. References: (1) M. Nee et al. Syst. Bot. 34:704, 2009. (2) E. G. Shay. Biomass Bioenergy 4:227, 1993. (3) K. G. Thomson et al. J. Virol. Meth. 55:83, 1995.

In Brazil, passion flower is grown across almost the entire country. The predominant disease of the passion flower cropis passion fruit woodiness, caused by the potyvirus cowpea aphid-borne mosaic virus (CABMV), and transmitted byaphids in a nonpersistent manner. The disease reduces the useful life of the orchard from 36 months to approximately18 months. Up to now, there has not been an efficient method for disease management. The aim of this work was toevaluate the efficiency of systematic roguing of diseased plants through weekly inspections, for disease management inthe field. The latent and incubation periods of CABMV in passion flower vines were determined in order to optimizeroguing efficiency. Passion fruit plants inoculated with CABMV started to act as sources of inoculum from 3 days afterinoculation (DAI), and the symptoms were expressed, on average, at 8 DAI. Five field experiments, conducted in thestates of S~ao Paulo and Bahia, Brazil, demonstrated that systematic roguing of diseased plants was significantly efficientfor managing passion fruit woodiness disease. In order to facilitate identification and subsequent removal of theinfected plants, they need to be grown separately. This cultural practice can be recommended for managing passionfruit woodiness disease, provided it is applied on a regional scale by all passion fruit growers. The development ofsome pilot plantings for the application of roguing in a passion flower-producing region is recommended to validatethe use of this technique for managing passion fruit woodiness disease. Made available in DSpace on 2020-02-12T18:09:33Z (GMT). No. of bitstreams: 1 Longlastingsystematicroguing2019.pdf: 557891 bytes, checksum: 92a54d52de1484d1506a3b1545811030 (MD5) Previous issue date: 2019

Made available in DSpace on 2018-11-26T17:52:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-01-01. Added 1 bitstream(s) on 2019-10-09T18:27:33Z : No. of bitstreams: 1 S1516-89132017000100454.pdf: 633133 bytes, checksum: 863802737accb4c798370ebe32c2a764 (MD5) Identification of Thysanoptera is based mainly on external morphology examination that can be time-consuming and difficult for non taxonomic experts. In this work, we propose a rapid and efficient molecular method to identify Frankliniella schultzei, an important and widespread pest thrips vector of tospoviruses in South America countries. Species-specific primers designed in the mitochondrial cytochrome oxidase I gene (mtCOI) were optimized for detection by conventional PCR and real-time PCR. The primers were tested on immature and adult thrips collected from crops and weeds found in Sao Paulo State. All samples collected were identified as F. schultzei, indicating the high prevalence of this species as vector of tospoviruses in Brazilian fields. Univ Estadual Sao Paulo, Fac Ciencias Agron, Dept Protecao Vegetal Botucatu, Sao Paulo, Brazil Univ Fed Piaui, UFPI, Dept Biol, Ctr Ciencias Nat, Teresina, Piaui, Brazil Univ Turin, Scuola Agr & Med Vet, Dipartimento Sci Agr Forestali & Alimentari, ULF Entomol Gen & Appl Grugliasco, Turin, Italy Ist Protez Sostenibile Piante Turin, Consiglio Nazl Ric, Curitiba, Parana, Brazil Univ Estadual Paulista, Dept Protecao Vegetal, Botucatu, SP, Brazil Univ Estadual Paulista, Dept Protecao Vegetal, Botucatu, SP, Brazil

Zucchini yellow mosaic virus (ZYMV) causes substantial economic losses in cucurbit crops. Although ZYMV has been present in Brazil for more than 20 years, there is little information about the biological and molecular characteristics of the isolates found in the country. This study aimed to characterize the experimental hosts, pathotypes and genetic diversity of a collection of eleven Brazilian ZYMV isolates within the coat protein gene. For biological analysis, plant species from Amaranthaceae, Chenopodiaceae, Cucurbitaceae, Fabaceae, Solanaceae, and Pedaliaceae were mechanically inoculated and pathotypes were identified based on the reaction of a resistant Cucumis melo, accession PI414723. All of the cucurbit species/varieties and Sesamum indicum were systemically infected with all isolates. The nucleotide sequence variability of the coat protein gene ranged from 82 % to 99 % compared to the corresponding sequences of ZYMV isolates from different geographical locations. No recombination event was detected in the coat protein gene of the isolates.

Zucchini lethal chlorosis virus (ZLCV), genus Orthotospovirus, so far was only reported in Brasil. The main natural hosts of ZLCV are in the cucurbit family. Pumpkin (Cucurbita maxima) cultivar Exposicao was previously reported as highly resistant to ZLCV infection. The objectives of this work were to better characterize the resistance of the Exposicao cultivar to ZLCV and to evaluate the interference of potyviruses (papaya ringspot virus type W, PRSV-W, and zucchini yellow mosaic virus, ZYMV) in the ZLCV resistance of this cultivar. C. maxima ‘Exposicao’ and zucchini (C. pepo) ‘Caserta’ (susceptible control) plants were mechanically inoculated with ZLCV in the cotyledons. Resistance to infection and systemic virus movement were evaluated at 7 and 20 days later. Virus detection was performed using PTA-ELISA and RT-PCR in the cotyledons and upper leaves. The interference of the potyviruses in ZLCV resistance was evaluated in greenhouse and field assays. ZLCV was detected in the inoculated cotyledons of both cultivars, but it did not move systemically in C. maxima ‘Exposicao’. The potyviruses PRSV-W and ZYMV did not interfere in the response of C. maxima ‘Exposicao’ to infection with ZLCV. The resistance of ‘Exposicao’ to ZLCV can be explored in future cucurbitaceae breeding programs.

A doença conhecida como enfezamento vermelho, associada a um fitoplasma do grupo 16SrI, subgrupo B, foi relatada em áreas brasileiras cultivadas com milho ainda no início da década de setenta. A importância econômica da doença se expressou a partir da década seguinte, com a introdução dos plantios de safrinha. O patossistema tem sido muito explorado em termos de pesquisa, porém falhas no conhecimento ainda são significativas. No presente trabalho foi investigada a sobrevivência do fitoplasma e da sua cigarrinha vetora Dalbulus maidis em algumas espécies forrageiras de alto interesse agronômico. Para isto, foram utilizadas cinco variedades de capim Panicum maximum cv. Mombaça, P. maximum x P. infestum cv. Massai, Brachiaria bizantha cv Marandu, B. brizantha cv. Piatã e B. decumbens cv. Basilisk (popularmente conhecida por Decumbens), os quais foram inoculados com o fitoplasma por meio de insetos infectivos alimentados em plantas de milho comprovadamente portadoras do patógeno. As avaliações foram realizadas tomando-se como critérios a detecção do fitoplasma nos tecidos dos capins, usando a técnica molecular de PCR, e a contagem diária do número de cigarrinhas mortas encontradas nas plantas forrageiras inoculadas. Amostragens de tecidos para a detecção do patógeno foram feitas aos 28, 56, 84, 112 e 140 dias após a inoculação, sendo as plantas cortadas para posterior rebrota, após cada amostragem. Também foi conduzido um ensaio em que cigarrinhas foram alimentadas em todas as variedades de forrageiras, portadoras do fitoplasma e, em seguida, confinadas em plantas sadias de milho. Os resultados revelaram que o fitoplasma estava presente em todas as plantas das diferentes variedades de capim, aos 28 dias após a inoculação. Aos 56 dias após a inoculação, o fitoplasma foi detectado em 66% das plantas de Marandu, 50% das plantas de Massai e 16% das plantas de Decumbens, Mombaça e Piatã. Aos 84, 112 e 140 dias após a inoculação, o patógeno não foi mais detectado nos tecidos rebrotados das plantas amostradas. Quanto à sobrevivência da cigarrinha, os capins se comportaram similarmente, dentro de cada um dos períodos de avaliação correspondentes a 24, 48, 72, 96 e 120 horas após o confinamento dos insetos nas plantas; no período de 120 horas, praticamente todos os insetos estavam mortos. Em relação à infecção de plantas de milho por insetos alimentados em plantas forrageiras portadoras do patógeno, os dados evidenciaram ausência do fitoplasma em todas as plantas de milho inoculadas. Estes resultados evidenciaram que, em condições naturais, provavelmente, as forrageiras podem servir como reservatórios; no entanto, sugerem que estas forrageiras podem não atuar como fonte de inóculo do patógeno para plantas de milho. Ainda, os dados apontaram que nenhuma das variedades testadas se destacou como sendo mais favorável à sobrevivência do vetor. Maize bushy stunt, associated with a phytoplasma of the group 16SrI, subgroup B, has been reported in Brazilian areas cultivated with corn since 1970s.The economic importance of the disease was expressed from 1980s, with the introduction of a cultivation system named \"safrinha\" maize. The pathosystem has long been explored, but failures of knowledge are yet significant. In the present work it was investigated the survival of the fitoplasma and its vector, the leafhopper Dalbulus maidis, in various forage species of high agronomic interest. So, five varieties of forage (Panicum maximum cv. Mombaça, P. maximum x P. infestum cv. Massai, Brachiaria bizantha cv Marandu, B. brizantha cv. Piatã e B. decumbens cv. Basilisk (popularly known by Decumbens) were used, which were inoculated with the phytoplasma via infective insects fed in corn plants infected by the pathogen. Assessment was conducted based on the detection of phytoplasma using PCR tecnique and daily counting of dead leafhoppers found in the inoculated forage plants. Tissues were collected for detection 28, 56, 84, 112 and 140 days after inoculation and plants were cut immediately after each sampling. In addition, an assay was conducted, in which insects were fed in infected plants belonging to all forage varieties and, subsequently, confined in healthy corn plants. The results allowed to detect the phytoplasma in all distinct forage varieties, 28 days after inoculation. Assesment made to the 56 days allowed to detect the pathogen in 66% of the plants of Marandu, in 50% of Massai, and 16% of plants of the varieties Decumbens, Mombaça and Piatã. In evaluations conducted to the 84, 112, and 140 days after inoculation, the phytoplasma was not more detected in the new tissues from forage plants. Concerning survival of leafhoppers, the different forage showed the same behavior, within each period corresponding to 24, 48, 72, 96 e 120 hours after confining of the insects in the plants; in the period of 120 hours, almost all insects were dead. In relation to the infection of corn plants by insects fed in forage plants infected with the pathogen, the analysis showed absence of the phytoplasma in all inoculated corn plants. These results pointed that, in natural conditions, probably the forages to serve as reservoir; however, they also suggested that these forages probably do not act as inoculum sources of the pathogen for corn plants. In addition, the results also demonstrated that none variety stood out as more favorable to survival of the leafhopper.

As viroses causadas pelo Tomato severe rugose virus (ToSRV) e Tomato chlorosis virus (ToCV) têm sido relatadas com frequência em cultivos de tomateiro e outras solanáceas no Brasil. Por compartilharem o mesmo vetor, a mosca-branca B. tabaci MEAM1, hospedeiros comuns e estarem presentes nas principais regiões produtoras, infecções mistas desses dois vírus são comuns em tomateiros. Em uma infecção mista, as diferentes espécies de vírus podem interagir, resultando em sinergismo, antagonismo ou neutralismo. Estudos referentes às interações destes dois vírus quando em infecções mistas, ainda são escassos. Este trabalho teve como objetivo avaliar o efeito da prévia aquisição do ToSRV por B. tabaci MEAM1 na subsequente taxa de transmissão e no período de retenção do ToCV pelo inseto. Além disso, avaliou-se o efeito dos princípios ativos cloridrato de cartape, ciantraniliprole e flupiradifurone no controle das transmissões primária e secundária desses vírus por B. tabaci para tomateiros. Para avaliar o efeito do begomovírus em parâmetros de transmissão do crinivírus por B. tabaci MEAM1 foram comparados os seguintes tratamentos: 1) plantas inoculadas com insetos que adquiriram apenas o ToSRV; 2) plantas inoculadas com insetos que adquiriram somente o ToCV; 3) plantas inoculadas com insetos que adquiriram inicialmente o ToSRV e em seguida o ToCV (ToSRV → ToCV); 4) plantas inoculadas com insetos que adquiriram os vírus simultaneamente de uma mesma planta fonte (ToSRV+ToCV) e 5) plantas inoculadas com insetos livres de vírus (controle). Quarenta dias após, as plantas foram avaliadas por RT-PCR e RCA-PCR para a detecção do ToCV e do ToSRV, respectivamente. Nos ensaios para avaliar a eficiência dos inseticidas no controle da simulação da transmissão primária dos vírus, insetos virulíferos foram liberados em gaiolas individuais contendo plantas de tomate sadias pulverizadas com os inseticidas de acordo com cada tratamento. A simulação da transmissão secundária foi feita através da liberação de adultos de B. tabaci MEAM1 livres de vírus, em gaiolas contendo tomateiros sadios e infectados por ToSRV+ToCV pulverizados com cada inseticida. Da mesma forma, aos 40 dias após a primeira liberação, amostras de todas as plantas foram coletadas e posteriormente avaliadas por RT-PCR e RCA-PCR para detecção do ToCV e ToSRV, respectivamente. O ToSRV previamente ou simultaneamente adquirido pela B. tabaci MEAM1 não interferiu significativamente na taxa de transmissão do ToCV para tomateiros, 24 h após a aquisição. No entanto, quando o vetor adquiriu os vírus simultaneamente, a taxa de transmissão do ToCV foi incrementada no 2° e 3° dias após a aquisição por B. tabaci. O período de retenção do crinivírus foi de três dias conforme relatado anteriormente. Nenhum dos inseticidas foi eficiente em controlar as simulações das transmissões primária e secundária do ToSRV+ToCV por B. tabaci MEAM1 para tomateiros. Os resultados obtidos neste trabalho demostram a importância em conhecer as interações vírus-vetor-planta para que as estratégias de manejo sejam melhor delineadas e efetivas. Demostram também que o uso de inseticidas deve fazer parte de um manejo integrado com outras medidas que devem ser adotadas em larga escala. Virus diseases caused by Tomato severe rugose virus (ToSRV) and Tomato chlorosis virus (ToCV) have been reported frequently in tomato and other solanaceous crops in Brazil. By sharing the same vector, the whitefly B. tabaci MEAM1, common hosts and present in the major producing regions, tomato plants infected with both viruses is common. In a mixed infection, different virus species may interact, resulting in synergism, antagonism or neutralism. Studies regarding the interactions between these two viruses when in mixed infections are still scarce. The objective of this work was to evaluate the effect of the previous acquisition of ToSRV by B. tabaci MEAM1 on the subsequent transmission rate and on the retention period of ToCV by the adult whitefly. In addition, the effect of the insecticides cartape chloridate, cyantraniliprole and flupiradifurone on the control of the simultaneous transmission of these viruses by B. tabaci to tomatoes was evaluated. To evaluate the effect of the begomovirus on the transmission parameters of the crinivirus by B. tabaci, the following treatments were compared: 1) plants inoculated with whiteflies that only acquired ToSRV; 2) plants inoculated with whiteflies that only acquired ToCV; 3) plants inoculated with whiteflies that acquired ToSRV followed by ToCV (ToSRV → ToCV); 4) plants inoculated with whiteflies that acquired both viruses simultaneously (ToSRV + ToCV) and 5) plants inoculated with virus-free whitelflies (control). Forty days after inoculation all plants were evaluated by RT-PCR and RCA-PCR for the detection of ToCV and ToSRV, respectively. In assays to evaluate the efficiency of insecticides in controlling the simulation of the primary transmission of ToSRV+ToCV, viruliferous insects were released into individual cages containing healthy tomato plants sprayed with the insecticides according to each treatment. Simulation of the secondary transmission was done by the release of virus free B. tabaci in cages containing ToSRV + ToCV infected and healthy tomato plants sprayed with each insecticide. In the same way, at 40 days after the first whiteflies release, samples from all plants were collected and evaluated by RT-PCR and RCA-PCR for the detection of ToCV and ToSRV, respectively. When B. tabaci MEAM1 acquired ToCV simultaneously or after ToSRV acquisition, the gegomovirus did not interfere with the ToCV transmission rate in tomato plants 24 h after aquisition. When the vector acquired the virus simultaneously, the ToCV transmission rate was increased on the 2nd and 3rd days after B. tabaci virus acquisition. The retention period of the crinivirus was three days, as previously reported. None of the insecticides were efficient in controlling the simulations of the primary and secondary transmissions of ToSRV+ToCV by B. tabaci MEAM1 to tomato plants. The results obtained in this work demonstrate the importance of knowing the virus-vector-plant interactions, so that the management strategies are better delineated and effective. They also show that the use of insecticides should be part of integrated management with other measures that should be adopted on a large scale.