The objective of the present work was to determine the inheritance and stability of transgenes of a transgenic bean line expressing the genes rep-trap-ren from Bean golden mosaic virus and the bar ...gene. Crosses were done between the transgenic line and four commercial bean cultivars, followed by four backcrosses to the commercial cultivars. Progenies from each cross were evaluated for the presence of the transgenes by brushing the leaves with glufosinate ammonium and by polymerase chain reaction using specific oligonucleotides. Advanced generations were rub-inoculated with an isolate of Bean common mosaic necrosis virus (BCMNV). The transgenes were inherited consistently in a Mendelian pattern in the four crosses studied. The analyzed lines recovered close to 80% of the characteristics of the recurrent parent, as determined by the random amplified DNA markers used, besides maintaining important traits such as resistance to BCMNV. The presence of the transgene did not cause any detectable undesirable effect in the evaluated progenies.O objetivo do presente trabalho foi determinar a herança e a estabilidade de transgenes de uma linhagem de feijoeiro-comum com expressão dos genes rep-trap-ren, do Bean golden mosaic virus, e do gene bar. Foram realizados cruzamentos entre a linhagem transgênica e quatro cultivares comerciais de feijão, seguidos de quatro retrocruzamentos. As progênies de cada cruzamento foram avaliadas quanto à presença dos transgenes, com aplicação do glifosinato de amônia nas folhas e por meio da reação da polimerase em cadeia com uso de oligonucleotídeos específicos. O vírus do mosaico comum necrótico do feijoeiro, Bean common mosaic necrosis virus (BCMNV), foi inoculado mecanicamente nas gerações avançadas. Os transgenes foram herdados em padrão mendeliano nos quatro cruzamentos estudados. As linhagens analisadas apresentaram cerca de 80% das características do parental recorrente, conforme determinado por análises com uso de marcadores de DNA, além de manter caracteres importantes, tais como resistência ao BCMNV. A presença do transgene não causou efeitos indesejáveis que pudessem ser detectados nas progênies avaliadas.
The antifeedant and insecticidal effects of two commercial neem (Azadirachta indica) oil formulations (Dalneem and Nim-I-Go) to Oebalus poecilus were evaluated on irrigated rice. To evaluate the ...antifeedant effect, both formulations were tested at 1% and 2% (v/v) concentration levels. The insecticidal effect was evaluated at 0.5%, 1%, 2%, and 4% (v/v) concentrations of Dalneem, by ingestion. Both experiments were conducted with four replications by treatment, containing one panicle and adult insects segregated by gender (two insects per plot for the antifeedant effect and five for the insecticidal effect). Both products were efficient, reducing the damage caused by insects. Insects fed less on the panicles treated with neem oil, causing lower number of feeding sheaths per panicle and lower percentage of damaged grains than the control. Spikelets weight was higher in panicles treated with neem oils. Females caused significantly higher damage than males in controls, for numbers of feeding sheaths and for the feeding deterrence index. Only at the 4% (v/v) concentration level, Dalneem caused adult mortality higher than in the control. Results showed that neem oil formulations, at > 1% (v/v) concentration, can be used to reduce the quantitative and qualitative damages caused by O. poecilus in lowland rice.
Avaliou-se o efeito das formulações comerciais de óleo de nim (Azadirachta indica) Dalneem e Nim-I-Go sobre a alimentação e sobrevivência de O. poecilus, em arroz irrigado. O efeito sobre a alimentação foi avaliado nas concentrações de 1% e 2% (v/v) das formulações. O efeito inseticida foi avaliado nas concentrações de 0,5%; 1%; 2%; e 4% (v/v) de Dalneem, por ingestão. Os experimentos foram realizados com quatro repetições por tratamento, contendo uma panícula e insetos adultos separados por sexo (dois insetos por parcela, para o efeito sobre a alimentação, e cinco, para o efeito inseticida). Os dois produtos foram igualmente eficientes na redução dos danos causados pelos insetos. Os insetos alimentaram-se menos das panículas tratadas, causando menor número de bainhas de estilete/grão e menos grãos danificados do que no controle. A massa das espiguetas foi maior nas panículas tratadas. Na testemunha, as fêmeas causaram danos significativamente maiores que os machos, para número de bainhas de estilete e Índice de Deterrência da Alimentação. Apenas na concentração de 4% (v/v), o Dalneem causou mortalidade de adultos significativamente superior à da testemunha. Conclui-se que os óleos de nim testados, em concentrações > 1% (v/v), podem ser utilizados para reduzir os danos quantitativos e qualitativos causados por O. poecilus, em arroz.
The antifeedant and insecticidal effects of two commercial neem (Azadirachta indica) oil formulations (Dalneem and Nim-I-Go) to Oebalus poecilus were evaluated on irrigated rice. To evaluate the ...antifeedant effect, both formulations were tested at 1% and 2% (v/v) concentration levels. The insecticidal effect was evaluated at 0.5%, 1%, 2%, and 4% (v/v) concentrations of Dalneem, by ingestion. Both experiments were conducted with four replications by treatment, containing one panicle and adult insects segregated by gender (two insects per plot for the antifeedant effect and five for the insecticidal effect). Both products were efficient, reducing the damage caused by insects. Insects fed less on the panicles treated with neem oil, causing lower number of feeding sheaths per panicle and lower percentage of damaged grains than the control. Spikelets weight was higher in panicles treated with neem oils. Females caused significantly higher damage than males in controls, for numbers of feeding sheaths and for the feeding deterrence index. Only at the 4% (v/v) concentration level, Dalneem caused adult mortality higher than in the control. Results showed that neem oil formulations, at >= 1% (v/v) concentration, can be used to reduce the quantitative and qualitative damages caused by O. poecilus in lowland rice. KEY-WORDS: Small rice stink bug; Azadirachta indica; qualitative damages; Oryza sativa; botanical extract.
The antifeedant and insecticidal effects of two commercial neem ( Azadirachta indica ) oil formulations (Dalneem and Nim-I-Go) to Oebalus poecilus were evaluated on irrigated rice. To evaluate the ...antifeedant effect, both formulations were tested at 1% and 2% (v/v) concentration levels. The insecticidal effect was evaluated at 0.5%, 1%, 2%, and 4% (v/v) concentrations of Dalneem, by ingestion. Both experiments were conducted with four replications by treatment, containing one panicle and adult insects segregated by gender (two insects per plot for the antifeedant effect and five for the insecticidal effect). Both products were efficient, reducing the damage caused by insects. Insects fed less on the panicles treated with neem oil, causing lower number of feeding sheaths per panicle and lower percentage of damaged grains than the control. Spikelets weight was higher in panicles treated with neem oils. Females caused significantly higher damage than males in controls, for numbers of feeding sheaths and for the feeding deterrence index. Only at the 4% (v/v) concentration level, Dalneem caused adult mortality higher than in the control. Results showed that neem oil formulations, at >= 1% (v/v) concentration, can be used to reduce the quantitative and qualitative damages caused by O. poecilus in lowland rice.
KEY-WORDS: Small rice stink bug; Azadirachta indica ; qualitative damages; Oryza sativa ; botanical extract.
Avaliou-se o efeito das formulações comerciais de óleo de nim ( Azadirachta indica ) Dalneem e Nim-I-Go sobre a alimentação e sobrevivência de O. poecilus , em arroz irrigado. O efeito sobre a alimentação foi avaliado nas concentrações de 1% e 2% (v/v) das formulações. O efeito inseticida foi avaliado nas concentrações de 0,5%; 1%; 2%; e 4% (v/v) de Dalneem, por ingestão. Os experimentos foram realizados com quatro repetições por tratamento, contendo uma panícula e insetos adultos separados por sexo (dois insetos por parcela, para o efeito sobre a alimentação, e cinco, para o efeito inseticida). Os dois produtos foram igualmente eficientes na redução dos danos causados pelos insetos. Os insetos alimentaram-se menos das panículas tratadas, causando menor número de bainhas de estilete/grão e menos grãos danificados do que no controle. A massa das espiguetas foi maior nas panículas tratadas. Na testemunha, as fêmeas causaram danos significativamente maiores que os machos, para número de bainhas de estilete e Índice de Deterrência da Alimentação. Apenas na concentração de 4% (v/v), o Dalneem causou mortalidade de adultos significativamente superior à da testemunha. Conclui-se que os óleos de nim testados, em concentrações >= 1% (v/v), podem ser utilizados para reduzir os danos quantitativos e qualitativos causados por O. poecilus , em arroz.
PALAVRAS-CHAVE: Percevejo da panícula; Azadirachta indica ; danos qualitativos; Oryza sativa ; extrato botânico.
The objective of this work was to determine the most susceptible nymphal stage of Bemisia tabaci biotype B to neem (Azadirachta indica A. Juss.) oil applied to dry bean (Phaseolus vulgaris L.) in a ...screenhouse. A solution of commercial oil (Dalneem) extracted from neem seeds was sprayed directly on each nymphal instar at 0, 0.1, 0.25, 0.5, 1 and 2% concentrations for lethal concentration (LC) determination, and at 0, 0.5 and 1% concentrations for lethal time (LT) determination. The number of living and dead nymphs was recorded five days after spraying for LC determination, and daily during six days for LT determination. The LC50 estimated for fourth instar nymphs occurred at 0.56% concentration. For all instars, LC50 and LC95 were estimated at 0.32 and 2.78% concentrations, respectively. The estimated values of LT50 at 1% concentration were 2.46, 4.45, 3.02 and 6.98 days for the first to fourth instars, respectively. The LT50 occurred at five days for 0.5% and at four days for 1% concentration in all instars. A mortality rate of over 80% was observed on the 6th day for the first to third instars at 1% concentration. The first three nymphal stages were more susceptible to neem oil when compared to the fourth nymphal stage.O objetivo deste trabalho foi determinar o estágio ninfal de Bemisia tabaci biótipo B mais suscetível ao óleo de nim (Azadirachta indica A. Juss.) aplicado em feijoeiro (Phaseolus vulgaris L.), em casa telada. Foram avaliados o tempo letal (TL) e concentração letal (CL) do óleo comercial de sementes de nim Dalneem. Para CL, concentrações de 0, 0,1, 0,25, 0,5, 1 e 2% do produto foram pulverizadas diretamente sobre as ninfas em cada ínstar. Para TL, o produto foi avaliado a 0, 0,5 e 1% de óleo de nim em cada ínstar. Ninfas vivas e mortas foram contadas cinco dias após a pulverização para CL e diariamente para TL durante seis dias. Para o quarto ínstar, a CL50 foi de 0,56% de óleo de nim. Considerando todos os ínstares, CL50 e CL95 foram estimadas em 0,32 e 2,78% de óleo de nim, respectivamente. Os TL50 para 1% de nim foram estimados em 2,46, 4,45, 3,02 e 6,98 dias para o primeiro, segundo, terceiro e quarto ínstares, respectivamente. Os TL50 estimados para 0,5 e 1% de óleo de nim foram de cinco e quatro dias, respectivamente, considerando todos os ínstares. No sexto dia, foi observada mortalidade superior a 80% para o primeiro, segundo e terceiro ínstares a 1% de óleo de nim. Os três primeiros ínstares foram mais suscetíveis ao óleo de nim que o quarto ínstar.
Background: The whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) is among the 100 worst invasive species in the world. As one of the most important crop pests and virus vectors, B. tabaci causes ...substantial crop losses and poses a serious threat to global food security. Results: We report the 615-Mb high-quality genome sequence of B. tabaci Middle East-Asia Minor 1 (MEAM1), the first genome sequence in the Aleyrodidae family, which contains 15,664 protein-coding genes. The B. tabaci genome is highly divergent from other sequenced hemipteran genomes, sharing no detectable synteny. A number of known detoxification gene families, including cytochrome P450s and UDP-glucuronosyltransferases, are significantly expanded in B. tabaci. Other expanded gene families, including cathepsins, large clusters of tandemly duplicated B. tabaci-specific genes, and phosphatidylethanolamine-binding proteins (PEBPs), were found to be associated with virus acquisition and transmission and/or insecticide resistance, likely contributing to the global invasiveness and efficient virus transmission capacity of B. tabaci. The presence of 142 horizontally transferred genes from bacteria or fungi in the B. tabaci genome, including genes encoding hopanoid/sterol synthesis and xenobiotic detoxification enzymes that are not present in other insects, offers novel insights into the unique biological adaptations of this insect such as polyphagy and insecticide resistance. Interestingly, two adjacent bacterial pantothenate biosynthesis genes, panB and panC, have been co-transferred into B. tabaci and fused into a single gene that has acquired introns during its evolution. Conclusions: The B. tabaci genome contains numerous genetic novelties, including expansions in gene families associated with insecticide resistance, detoxification and virus transmission, as well as numerous horizontally transferred genes from bacteria and fungi. We believe these novelties likely have shaped B. tabaci as a highly invasive polyphagous crop pest and efficient vector of plant viruses. The genome serves as a reference for resolving the B. tabaci cryptic species complex, understanding fundamental biological novelties, and providing valuable genetic information to assist the development of novel strategies for controlling whiteflies and the viruses they transmit.
We evaluated the efficacy of the growth regulator triflumuron (TFM) in inducing mortality and disrupting both oviposition and egg hatching in Rhodnius prolixus adult females. TFM was administered via ...feeding, topically or by continuous contact with impregnated surfaces. Feeding resulted in mild biological effects compared with topical and impregnated surfaces. One day after treatment, the highest mortality levels were observed with topical surface and 30 days later both topical and impregnated surfaces induced higher mortalities than feeding. Oral treatment inhibited oviposition even at lower doses, and hatching of eggs deposited by treated females was similarly affected by the three delivery modes. Topical treatment of eggs deposited by nontreated females significantly reduced hatching. However, treatment per contact of eggs oviposited by untreated females did not disrupt eclosion. Additionally, oral treatment increased the number of immature oocytes per female, and topical treatment reduced the mean size of oocytes. TFM also affected carcass chitin content, diuresis, and innate immunity of treated insects. These results suggest that TFM acts as a potent growth inhibitor of R. prolixus adult females and has the potential to be used in integrated vector control programs against hematophagous triatomine species.
Nas Ciências Agrárias, uma grande quantidade de experimentos científicos é efetuada em laboratórios e casas de vegetação. Enquanto que os de campo, muitas vezes, são realizados nas dependências da ...universidade. A implantação de pesquisas em áreas de produtores rurais permitiria que, além da obtenção do seu resultado final, várias etapas de conhecimento fossem disponibilizadas aos produtores, tornando-se uma verdadeira unidade demonstrativa. Assim, por meio de um relato de experiência, é demonstrada a importância de se estabelecer a pesquisa participativa, ligada a área de ciência do solo, visando o intercâmbio entre o meio acadêmico e o meio rural, com o intuito de se consolidar ensino e extensão dentro da ação de pesquisa. Durante o período de 2006 a 2011, a UFRA campus de Parauapebas - PA desenvolveu projeto de pesquisa participativa na Área de proteção Ambiental do Igarapé Gelado. Como fruto de um trabalho participativo de pesquisa, foi estabelecida uma parceria de confiança da universidade (professores e estudantes) com o produtor, a partir da qual, diariamente, num processo contínuo de transformação de seu conhecimento, foram constatadas mudanças na
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