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Resistência de cultivares de algodoeiro ao vírus do Mosaico das Nervuras transmitido pelo pulg?o Aphis gossypii (Glover) (Hemiptera: Aphididae)
Santos, Karen B. dos;Neves, Pedro M.J.;Santos, Walter J. dos;
Neotropical Entomology , 2004, DOI: 10.1590/S1519-566X2004000400013
Abstract: the aphid aphis gossypii glover is a vector of cotton vein mosaic virus (v.m.n.), which can cause reduced or null yields in cotton crops. the objective of this study was to identify cotton cultivars resistant to v.m.n. when exposed to the action of aphids. the experiments were conducted at the experimental farm of the instituto agron?mico do paraná, iapar, in londrina, pr, brazil, in a randomized blocks statistical design. the cultivars compared were: delta opal, deltapine a90, cnpa ita 90, coodetec 401, iac 22, ipr 95, ipr 96, and ipr 94. twenty-five plants were selected for evaluation; the presence of aphids and v.m.n. symptoms were recorded. two experiments were conducted under the same conditions; in one of them, insecticides were applied to control aphids when their presence was detected on 10% of the plants. the other experiment received no insecticides for aphid control. the vector was present on the plants from all cultivars. high v.m.n. rates occurred in cultivar cnpa ita 90 even under lower aphid infestations, with a yield reduction of 68% when compared with delta opal. the cultivars delta opal and coodetec 401 proved very resistant to v.m.n. based on the absence of plants with symptoms; iac 22 was susceptible, while deltapine a90 and cnpa ita 90 were very susceptible. the insecticides provided reasonable protection against the action of the vector, but data allowed to infer that in areas with high levels of v.m.n. infection, the most suitable control method would be the adoption of cultivars resistant to the disease, such as delta opal and coodetec 401.
Predatory Efficacy of Coccinella septempunctata L. on Cotton Aphids, Aphis gossypii Glov.
Anjum Suhail,Arshed Makhdoom Sabir,Adil Hussain,Asif Saeed
Pakistan Journal of Biological Sciences , 1999,
Abstract: Predatory potential of Coccinella septempunctata L. on cotton aphids (Aphis gossypii Glov.) was studied under laboratory conditions at 21 1 C and 70 5 per cent relative humidity. Both adult and larva of predator voraciously consumed on an average, 60.56 and 141.01 aphids per day, respectively and the total developmental period was noted to be 18.75 days.
Identifica o sorológica do vírus do mosaico das nervuras da videira no Brasil  [cached]
Fitopatologia Brasileira , 2002,
Abstract: Em S o Paulo, ocorrem quatro isolados do vírus que induz o mosaico das nervuras da videira (Vitis spp.), os quais s o diferenciados pelos sintomas que provocam em algumas variedades. Para confirmar a identidade desse vírus e o relacionamento existente entre os quatro isolados, foram aplicados os testes DAS-ELISA e TAS-ELISA usando anti-soros comerciais contra o Grapevine fleckvirus (GFkV). As fontes de antígeno foram tecidos de floema de ramos dormentes e de folhas jovens da brota o de primavera de videiras sabidamente infetadas. As rea es nos testes imuno-enzimáticos envolvendo os quatro isolados do vírus foram positivas para o anti-soro contra o GFkV. Os resultados foram também positivos para amostras de 66 plantas infetadas de 26 variedades de videira procedentes de 11 regi es vitícolas de S o Paulo e de 24 plantas de 12 variedades provenientes dos estados de Minas Gerais, Paraná, Pernambuco, Rio Grande do Norte e Santa Catarina. Extratos de folhas novas e tenras apresentaram valores de absorbancia mais consistentes do que extratos de ramos dormentes. Plantas n o infetadas foram empregadas como controle negativo. Os resultados obtidos confirmaram que os quatro isolados virais possuem relacionamento sorológico com o GFkV, sugerindo que os mesmos pertencem ao complexo viral que causa o "grapevine fleck disease".
Biologia de aphis gossypii em plantas infectadas pelo vírus do mosaico das nervuras do algodoeiro
Michelotto, Marcos Doniseti;Busoli, Antonio Carlos;
Bragantia , 2009, DOI: 10.1590/S0006-87052009000400023
Abstract: the objective of this work was to study the biology of cotton aphid, aphis gossypii glover (hemiptera: aphididae) on cotton plants (gossypium hirsutum l.) healthy and infected by cotton vein mosaic virus. the assay was performed in climatic chambers at 25±1oc, under relative humidity of 70±10% and photophase of 12h. the treatments corresponded to aphids fed on leaves of healthy and infected by virus plants. cages consisted of petri dishes containing agar-water (1%) solidified and one leaf disc from either healthy or infected plants. aphids fed on infected cotton plant had a significantly shorter nymphal phase (4.5 days) than aphids fed on noninfected cotton plant (4.9 days). no significant differences were observed in a. gossypii prereproductive, reproductive and postreproductive periods and longevity when fed on infected or noninfected plants. the highest mortality rate of aphids occurred on infected plants. the time interval between generations (t) and the time needed for the population to double in size (td) were lower for aphids feeding on infected plants (9.74 and 1.66 days, respectively). the net reproductive rate (ro), the intrinsic rate of population increase (rm) and finite rate of increase (λ) were higher for aphids feeding on infected plants. aphids that fed on noninfected cotton plants showed better indices of development. in the reproduction of aphids the best indices were observed in aphids kept in infected plants.
Aphid Transmission of Two Important Potato Viruses, PVY and PLRV by Myzus persicae (Sulz.) and Aphis gossypii (Glov.) in Hatay Province of Turkey
Erdal Sertkaya,Gulsen Sertkaya
Pakistan Journal of Biological Sciences , 2005,
Abstract: Transmission assays by using aphid vectors were established to determine the effects of two aphid species (Myzus persicae Sulz. and Aphis gossypii Glov. on four solanacaeous test plant species (Capsicum annum L., Lycopersicon esculentum L., Physalis floridana Rydb. and Solanum tuberosum L.). Transmission rates of PVY and PLRV from potato to other test plants were investigated by DAS-ELISA assays. All experiments were carried out at 26:22±2°C (day:night) under a 16:8 h (light:dark) photoperiod conditions. Late 4th instar or early adult M. persicae and A. gossypii apterae were used in the transmission experiments. The aphids were not subjected to preacquisition starving in the assays. Each aphid species were reared on PVY-infected source potato plants for 5 h as Acquisition Access Period (AAP). Then, aphid group including 10 individuals were taken from donor plants were transplanted on to healthy receptor test plants for 15 h as Inoculation Period (IP). For PLRV transmissions, two aphid species reared on source potato plants for 24 h as AAP were transferred on to each healthy test plants as a group including 10 individuals for 24 h as IP. After IP, the aphids were removed from plants mechanically. PVY and PLRV were transmitted in higher rates by M. persicae. PVY and PLRV were more efficiently transmitted from potato to pepper seedlings among the other inoculated solanaceous test plants by both aphid species. The lowest transmission was occurred in tomato (2/15) and P. floridana (3/15) by using A. gossypii. Seed transmission of viruses were not determined by DAS-ELISA in seedlings re-obtained from experimentally infected test plants.
Efeito da época de inocula??o do vírus do mosaico das nervuras por Aphis gossypii Glover (Hemiptera: Aphididae) no desenvolvimento e na produ??o do algodoeiro
Michelotto, Marcos D.;Busoli, Antonio C.;
Neotropical Entomology , 2006, DOI: 10.1590/S1519-566X2006000200015
Abstract: aphis gossypii glover is the vector of the cotton vein mosaic virus (cvmv), which causes serious damages to cotton. this work was carried out in a greenhouse at unesp - universidade estadual paulista, in jaboticabal, s?o paulo state, brazil, to evaluate the effect of inoculation date of the cvmv on growth and yield of cotton plants. cotton plants of cultivar cnpa ita 90 at 20, 27, 34, 41, 48 and 55 days after the emergency (dae) received one wingless viruliferous adult of a. gossypii, which remained confined in the plants for 48h. the percentage of plants with the symptoms of the disease and its influence in the phenological aspects of cotton plant were evaluated. the age of the plants did not influence the transmission efficiency of cvmv by a. gossypii. percentages of plants showing disease symptoms varied from 40% to 65% when inoculated at 20 and 48 dae, respectively. plant height was reduced in 54.5% when they were infected 20 dae and 1.3% when infection occurred at 55 dae, as compared to the control. the number and diameter of the bolls were also influenced by the age the plants were infected. plants inoculated 20 dae did not produce cotton. plants inoculated 55 dae produced 20.7 g of cotton/plant, significantly less than control plants (35.9 g/plant). the severity of the symptoms was directly associated to the age the plants were infected with cvmv.
Nota sobre a molestia de virus do fumo denominada faixa das nervuras
Costa, A. S.;Forster, R.;
Bragantia , 1942, DOI: 10.1590/S0006-87051942000200002
Abstract: the present paper deals with the virus disease of the tobacco plant recently described by kramer & silberschmidt (12) under the name "faixa das nervuras" (veinbanding). new host plants are added to the list of suscepts, as follows : nicotiana repanda willd., jv. angustifolia (*), n. gossey domin, n. sanderae hort. ex. w. watson, n. glutinosa l., n. longiflora cav., n. paniculata l., lycopersicon esculentum mill., l. pimpinellifolium mill., and cyphomandra betacea sendt. datura stramonium l., already studied by kramer & silberschmidt (12) and nicotiana glauca grah., nicandra physaloides gaertn., solanum nodiflorum (**), s. nigrum l., lactuca sativa l., brassica oleracea l., vigna sinensis endl. var. black., and dolichos lablab l., var. purpurens were found not to be susceptible to the virus. (*) this species was received with this name from the division of tobacco and plant nutrition, u.s.d.a. (**) one plant of s. nodiflorum out of 22 which were inoculated gave symptoms of veinbanding. however as no backinoculation was made it can not be stated with certainty if it was truly affected by this virus. the symptomatology on tobacco described by the above mentioned authors agrees as a whole with which has been observed that is : clearing of the veins, chlorotic spotting and veinbanding. in addition it is stated that the white necrotic spotting found associated with the disease on certain tobacco varieties, v. g. sumatra and turkish must be attributed to the same virus. on potato plants of the varieties president and green mountain the virus causes local streak-like symptoms followed by chlorotic mottling of young leaves. late symptoms take the form of leaf-drop streak. the virus of "faixa das nervuras" is easily transmissible through the sap giving practically 100% of success. the physical properties of the virus are : tolerance to dilution 1:10.000, thermal death point 54°c. and logevity in vitro 72 hours. no vector of the virus is known. the statement of kramer & silber
Efeito do deslintamento químico sobre a ocorrência e desenvolvimento de Colletotrichum gossypii associado às sementes de algodoeiro  [cached]
Fitopatologia Brasileira , 2002,
Abstract: A primeira fase do trabalho objetivou avaliar o efeito do tempo de deslintamento químico, 1:30 e 4:30 min, sobre o nível de infec o de Colletotrichum gossypii inoculado artificialmente em sementes de algodoeiro (Gossypium hirsutum). Sementes de algodoeiro com línter foram inoculadas com C. gossypii, mediante contato das mesmas com col nias do fungo em placas de Petri de 9 cm de diametro, por 30 h. Os parametros avaliados foram a ocorrência de fungos e o poder germinativo das sementes. Na segunda fase, o objetivo foi avaliar a influência do exsudato de sementes de algodoeiro, em fun o do tempo da dura o do deslintamento com ácido sulfúrico, considerando-se as fra es de sedimenta o de sementes e diferentes condi es de envelhecimento artificial sobre o desenvolvimento de C. gossypii, em condi es de laboratório. As sementes foram deslintadas quimicamente com ácido sulfúrico comercial concentrado pelos períodos de 1:30 e 4:30 min, separadas em fra es de sedimenta o em água e submetidas ao envelhecimento artificial por 0, 72 e 96 h. Os substratos foram obtidos a partir do exsudato resultante da embebi o contendo os eletrólitos lixiviados das sementes. O desenvolvimento de C. gossypii na presen a do exsudato das sementes foi avaliado em meio agarizado, através da medi o do crescimento micelial e da esporula o do fungo. O deslintamento químico, pelo período de 1:30 min, propiciou aumento do percentual de ocorrência de C. gossypii em sementes n o-desinfestadas superficialmente, e o crescimento micelial e a esporula o do fungo foram favorecidos pelo substrato proveniente de sementes deslintadas por 4:30 e 1:30 min, respectivamente.
ASPECTOS EPIDEMIOLóGICOS DA RAMULOSE (Colletotrichum gossypii South. var. cephalosporioides Costa) DO ALGODOEIRO (Gossypium hirsutum L.) EPIDEMIOLOGICAL ASPECTS OF COTTON RAMULOSIS (Colletotrichum gossypii SOUTH. Var. cephalosporioides COSTA)  [cached]
Yvo de Carvalho,Jo?o de Deus Moraes,Fuad Calil,Quimico Iamamoto Pacheco
Pesquisa Agropecuária Tropical , 2007, DOI: 10.5216/pat.v8i1.2300
Abstract: Estudaram-se os efeitos da incidência precoce, mediana e tardia de ramulose sobre o peso e altura das plantas, número de capulhos, peso das sementes e da pluma de algodoeiro do cultivar IAC-l3.l em três épocas de semeadura (21/10/75, 21/11/75 e 23/12/75) no município de Itau u (GO). O experimento foi instalado em regi o plana com latossolo vermelho. Foram utilizados blocos casualizados com seis repeti es e plantas no final do ciclo vegetativo foram classificadas em quatro tipos: sadias, com ramulose precoce, com ramulose mediana ou com ramulose tardia. Concluiu-se que a forma precoce e também a mediana foram as que afetaram mais significativamente os parametros aferidos, e que cultivares tidos como de razoável comportamento em rela o à ramulose, podem ser severamente afetados em anos agrícolas muito chuvosos como foi o de 1975/76. These experiments deal with the effects of outbreak of early, medium and late developing ramulosis on the IAC-13.l variety of cotton, which was seeded at three different intervals in Itau u (Goiás—Brazil). The effects of the ramulosis on the height and weight of the plants, on the number of bolls, and on the weight of the cotton seeds and lints, were studied. The experiments were installed in a flat area of red latosoil. The experimental design was one of random blocks with six repetitions and the plants were classified, at the end of their vegetative growth, into the following categories: healthy, early ramulosis, medium ramulosis and late developing ramulosis. The early and medium ramulosis affected more significantly the studied parameters, and it was observed that varieties of cotton which were moderately resistant in relation to ramulosis, can be severely affected during growing seasons of heavy rains such as the 1975/76 season.
Influência de tricomas do algodoeiro sobre os aspectos biológicos e capacidade predatória de Chrysoperla externa (Hagen) alimentada com Aphis gossypii Glover  [cached]
Santos Terezinha Monteiro dos,Boi?a Júnior Arlindo Leal,Soares José Janduí
Bragantia , 2003,
Abstract: Os tricomas do algodoeiro atuam como um dos fatores de resistência a Aphis gossypii Glover, e podem afetar também seus inimigos naturais, reduzindo a eficiência desses agentes de controle e aumentando o tempo de procura pela presa. Neste trabalho, em condi es de laboratório, avaliou-se a influência da densidade de tricomas das cultivares de algodoeiro Antares (pouco pilosa), CNPA 7H (hirsuta) e Deltapine Acala 90 (pilosa) sobre os aspectos biológicos e a capacidade predatória de Chrysoperla externa (Hagen) alimentada com A. gossypii criado em plantulas da cultivar de algodoeiro IAC 22. Verificou-se que a dura o e a viabilidade das fases de desenvolvimento de C. externa n o foram influenciadas pelos tricomas das cultivares. O período de oviposi o de C. externa foi maior quando suas larvas se alimentaram de A. gossypii sobre folhas da cultivar Antares. A capacidade diária e a total de oviposi o de C. externa n o sofreram influência das cultivares de algodoeiro nas quais essa espécie foi mantida durante a fase larval. Fêmeas de C. externa, alimentadas durante a fase larval com A. gossypii e mantidas sobre folhas da cultivar Antares, apresentaram maior longevidade. Durante o período larval, C. externa consumiu respectivamente, 544,0; 494,3 e 454,8 pulg es, quando mantida sobre folhas das cultivares CNPA 7H, Antares e Deltapine Acala 90. As cultivares de algodoeiro demonstraram compatibilidade com esse predador, o que indica a possibilidade de integra o de cultivares resistentes com diferentes níveis de densidade de tricomas com C. externa para controle do pulg o A. gossypii.
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