Orientador: Reinaldo José Fazzio Feres / Banca: Marineide Rosa Vieira / Banca: Marcel Ricardo Tanzini / Resumo: Esse trabalho teve como objetivo estudar o ciclo biológico de T. heveae em folíolos de seringueira dos clones RRIM 600, PB 235 e GT 1. Inicialmente foi estabelecida uma colônia de manutenção de T. heveae. As arenas de criação e para estudos da biologia foram confeccionadas a partir de folíolos de seringueira dos clones acima citados sendo mantidas sob condições controladas em câmara climatizada do tipo BOD com umidade relativa de 70+10%, fotoperíodo de 12 h, 28+0,1oC na fotofase e 25+0,1oC na escotofase. Três observações diárias foram realizadas, acompanhando-se o desenvolvimento de 60 ovos em folíolos de cada clone para verificação do estágio de desenvolvimento em que o ácaro se encontrava, assim como a oviposição das fêmeas. A fase mais longa registrada nos três clones foi a de ovo e o período mais curto foi o protoninfal. Em todos os clones estudados a fase de maior viabilidade foi a deutoninfal, e a menor, a larval. Quatorze fêmeas e quatro machos atingiram a fase adulta no clone PB 235, sendo observada uma taxa média de oviposição de 1,2 ovo/dia/fêmea. No clone RRIM 600, nove fêmeas e dois machos foram observados, sendo registrada a taxa de oviposição de 0,7 ovo/dia/fêmea. No clone GT 1, sete fêmeas chegaram à fase adulta com taxa média de 0,51 ovo/dia/fêmea. O ciclo completo da incubação do ovo até a morte do adulto durou 25 dias, em média, nos clones RRIM 600 e PB 235. A taxa intrínseca de crescimento populacional (rm) foi de 0,09; 0,08 e 0,02 nos clones PB 235, RRIM 600 e GT 1, respectivamente. O clone PB 235 possibilitou um melhor desenvolvimento de T. heveae, seguido pelo clone RRIM 600. O clone GT 1 foi o menos favorável ao desenvolvimento. / Abstract: This work aims to study the biological cycle of T. heveae in rubber tree leaflets of clones RRIM 600, PB235 and GT 1. Initially, a maintenance colony was established. The breeding arenas and those for the study of the biology were created using leaflets of the aforementioned rubber tree clones, which had been kept under controlled conditions in a climatic chamber. Three daily observations were done, following the development of 60 eggs in each clone to check the developmental stage and female oviposition. The egg was the longest-lasting phase registered and the protonymph was the shortest period. The deutonymph was the most viable phase in all clones, whereas the least viable was the larval stage. Fourteen females and four males reached the adult stage in the clone PB 235, an average oviposition rate of 1.2 egg per day per female. In the RRIM 600 clone, nine females and two males were viable, and an oviposition rate of 0.70 egg per day per female was observed. In the GT 1 clone, seven females reached the adult stage, the average ovoposition rate was 0.51 egg per day per female. The complete cycle of incubation of the egg until the death of the adult lasted, on average, 25 days in RRIM 600 and PB 235 clones. The intrinsic rate of population increase (rm) was 0.09; 0.08 and 0.02 in clones PB 235, RRIM 600 and GT1, respectively. The clone PB 235 allowed a better development of T. heveae, followed by RRIM 600. The clone GT 1 was the least favourable for the development of that mite species. / Mestre

Orientador: Edson Luiz Lopes Baldin / Banca: Carlos Frederico Wilcken / Banca: Arlindo Leal Boica Junior / Banca: José Djair Vendramim / Banca: Paulo Marçal Fernandes / Resumo: Desde sua introdução no Brasil, em 2003, o psilídeo-de-concha Glycaspis brimblecombei Moore (Hemiptera: Psyllidae) vem ocasionando sérios danos ao eucalipto, principalmente através de desfolha, desenvolvimento de fumagina e secamento de ponteiros. Como estratégia no controle deste inseto, o uso de genótipos resistentes pode ser uma ferramenta valiosa. Neste trabalho, avaliou-se a resistência das espécies Eucalyptus camaldulensis (VM e IPEF), E. grandis e E. urophylla e dos híbridos de E. grandis x E. camaldulensis - gracam 'HGC' (3025 e 1277), de E. urophylla x E. camaldulensis - urocam 'HUC' (VM-1), de E. urophylla x E. grandis - urograndis 'HUG' (H-13, I-144, C-219 e GG-100) e de E. grandis (EG-01, EG-02 e EG-03) a G. brimblecombei, através de testes de atratividade, preferência para oviposição e preferência para alimentação e/ou antibiose sob condições de laboratório e campo. Foram realizados testes preliminares, a fim de verificar a ocorrência de condicionamento pré-imaginal, além de ajustar a melhor densidade para infestação com adultos para testes de atratividade e a melhor posição nas mudas para avaliações de preferência para oviposição. Em laboratório, verificou-se que os adultos de G. brimblecombei não apresentaram condicionamento pré-imaginal, independentemente do hospedeiro de criação ser o híbrido 3025 ou E. camaldulensis IPEF. As densidades de 10 e 15 adultos de psilídeo-de-concha por muda de eucalipto proporcionaram maior número de ovos. As folhas próximas ao ápice foram preferidas para oviposição, sendo que o número de ovos decresceu do ápice para a base. No teste com chance de escolha, os genótipos E. grandis, E. urophylla, C-219 e H-13 foram menos atrativos ao psilídeo-de-concha, expressando não-preferência. Em teste com chance de escolha, o número de ovos depositados nas folhas dos genótipos H-13, E. grandis... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Since its introduction in Brazil in 2003, the red gum lerp psyllid Glycaspis brimblecombei Moore (Hemiptera: Psyllidae) has been causing serious damages in eucalyptus trees, especially through defoliation, development of sooty mold and dieback. The use of resistant genotypes as a strategy to control this insect may be a valuable tool. In this study, the resistance of species Eucalyptus camaldulensis (VM e IPEF), E. grandis and E. urophylla and hybrids E. grandis x E. camaldulensis - gracam 'HGC' (3025 and 1277), E. urophylla x E. camaldulensis - urocam 'HUC' (VM-1), E. urophylla x E. grandis - urograndis 'HUG' (H-13, I-144, C-219 and GG-100) and E. grandis (EG-01, EG-02 and EG-03) on G. brimblecombei, through attractiveness, oviposition preference and feeding preference and/or antibiosis tests under laboratory and field conditions evaluated. Initially preliminary tests were carried out, using eucalyptus seedlings, in order to verify the occurrence of preimaginal conditioning, and also adjust the best density for adult infestation for attractiveness tests and the best position in the seedlings for the evaluation of oviposition preference. In laboratory conditions, that G. brimblecombei adults did not present preimaginal conditioning, despite the fact that the rearing host was a 3025 hybrid or E. camaldulensis IPEF. The densities of 10 and 15 psyllid adults per eucalyptus seedlings showed a higher number of eggs. The insects showed preference for the leaves close the apex for oviposition, being that the number of eggs decreased from the apex to the basis. In the choice test concerning attractiveness, genotypes E. grandis, E. urophylla, C-219 and H-13 were less attractive to psyllid, showing non-preference. In a choice test, the number of eggs oviposited in leaves of genotypes H-13, E. grandis and E. urophylla were lower when compared... (Complete abstract click electronic access below) / Doutor

As plantas respondem ao ataque de insetos pela indução e acumulação de um conjunto grande de proteínas de defesa. Nesse trabalho foi feita uma investigação sobre as modificações transcricionais que ocorrem em plantas de cana-de-açúcar, em resposta ao ataque de lagartas de Diatraea saccharalis. A primeira abordagem foi o estudo detalhado da indução de duas isoformas do homólogo de cana-de-açúcar do gene de cevada induzido por dano barwin (barley woundinducible), chamado de sugarwin (sugarcane wound-inducible). A indução de transcritos de sugarwin ocorreu em resposta ao ferimento mecânico, dano provocado por D. saccharalis e tratamento com metil jasmonato. Além disso, sua expressão foi restrita ao local de dano. Sugarwins fazem parte do grupo de genes induzidos tardiamente por dano. A localização subcelular do peptídeo sinal fusionado à gfp (green fluorescent protein) mostra que essas proteínas são secretadas. Embora a função do domínio barwin não esteja completamente elucidada, atividades anti-patogênicas têm sido descritas para um grande número de homólogos. Alinhamentos múltiplos de seqüências do domínio barwin das proteínas de cana-de-açúcar e de outras proteínas de mono e dicotiledôneas revelaram altos índices de similaridade, sugerindo que sua função é conservada entre espécies. Esse é o primeiro relato da indução de uma proteína da família Barwin por herbivoria. A atividade dessas proteínas contra insetos nunca foi estudada. Os resultados apresentados aqui sugerem que as SUGARWINS fazem parte da estratégia de defesa de cana-de-açúcar. A segunda abordagem para estudar a resposta da cana-de-açúcar ao dano por D. saccharalis foi a análise em larga-escala, usando macroarranjos de DNA, de serino proteases e inibidores de serino proteases de cana-de-açúcar diferencialmente expressos em resposta a herbivoria. Enquanto que a função dos inibidores de proteases na defesa de plantas contra insetos e patógenos está bem estabelecida, o envolvimento de proteases na defesa tem sido proposto recentemente. O monitoramento de transcritos de serino proteases de cana-de-açúcar responsivos a herbivoria revelou vários genes cuja função precisa ser investigada. Uma das aplicações desses resultados é a identificação de genes para uso em estratégias biotecnológicas que visam aumentar a resistência de cana-de-açúcar a insetos. / Plants respond to insect damage by induction and accumulation of a large set of defense proteins. An investigation was undertaken to study the sugarcane transcriptional changes following Diatraea saccharalis damage. The first approach was a detailed study about the induction of two isoforms of a sugarcane homologue of a barley wound inducible gene, barwin, named sugarwin (sugarcane wound-inducible). Induction of sugarwin transcripts occurs in response to mechanical wounding, D. saccharalis feeding and methyl jasmonate treatment. Their expression is restricted to the site of damage. Sugarwins are members of the late wound-inducible genes. The subcellular localization of the signal peptide fused to the gfp (green fluorescent protein) shows that these proteins are secreted. Although the exact function of the barwin domain has not been completely elucidated, antipathogenic activities has been described for a number of homologues. Multiple sequence alignment of barwin domain-containing sugarcane proteins and of mono and dicotiledoneous proteins reveals high similarity, suggesting that their function is conserved among species. This is the first report of a barwin-like protein induced by herbivory. The activity of this type of proteins against insects has never been studied. Based on the results presented here, it can be concluded that SUGARWINS are part of the sugarcane defense response strategy. The second approach to study the sugarcane response to D. saccharalis damage was the large-scale analysis, using DNA macroarrays, of serine proteases and serine protease inhibitors differently expressed in response to herbivory. While the protease inhibitors function in defense is well-established, the involvement of proteases in defense has been recently proposed. The transcript monitoring of sugarcane serine proteases in response to herbivory revealed several candidate genes for further functional studies. One of the greatest applications of these results is the identification of genes for use in biotechnological strategies to improve sugarcane insect resistance.

O uso de marcadores moleculares tem contribuído para o estudo da domesticação das espécies de Phaseolus, origem e diversidade das cultivares atuais de feijão-comum (P. vulgaris), e do controle genético da resistência a diversas doenças. Mapas de ligação têm sido estabelecidos em feijão-comum com base em marcas de RFLP, RAPD, SCAR, isoenzimas e locos fenotípicos, sendo que alguns deles foram reunidos em um mapa mais denso e completo do genoma do feijão, chamado mapa núcleo. No entanto, para o uso efetivo de mapas de ligação em programas de melhoramento estes devem ser suficientemente saturados. O presente trabalho se insere neste contexto, visando saturar o mapa núcleo de P. vulgaris a partir do mapeamento de novos marcadores moleculares como AFLP e SSR baseados em EST. Assim, buscou-se desenvolver e caracterizar marcadores SSR oriundos de uma biblioteca de EST, testar a transferibilidade destes para outros cultivares e espécies relacionadas, gerar marcadores AFLP e integrá-los ao mapa consenso da espécie. Também, construir um mapa genético para uma população de interesse no Brasil (Carioca x Flor de Mayo), e promover o seu alinhamento com o mapa consenso, complementando desta forma, a caracterização genômica da espécie. Pares de primers foram desenhados para 156 SSR-EST. Destes, 138 SSR-EST amplificaram locos claros e reprodutíveis e foram caracterizados usando um conjunto de 26 genótipos de feijões cultivados. Dos locos analisados, 85 se mostraram polimórficos entre os genótipos estudados e apresentaram em média 2,96 alelos por loco e um PIC médio de 0,38. Entre todos os SSR-EST analisados, 50 locos segregaram na população de mapeamento Bat 93 x Jalo EEP558, 20 locos segregaram na população Carioca x Flor de Mayo e 12 locos foram polimórficos nas duas populações. Marcadores AFLP foram gerados e genotipados nas duas populações. Os 262 locos microssatélites e AFLP genotipados na população Bat 93 x Jalo EEP558 foram integrados ao mapa núcleo da espécie. Foi obtido um mapa de 1353 cM de comprimento total, contendo 357 marcas, incluindo 9 SSR-genômico, 47 SSR-EST e 190 AFLP. Além disso, outro mapa foi gerado a partir da análise de segregação de 252 marcadores na população Carioca x Flor de Mayo. Este mapa teve 807,5 cM de comprimento, com uma distância média de 5,3 cM entre marcas. Os marcadores microssatélites comuns foram usados como ponte para alinhar e comparar os mapas das duas populações estudadas. / The use of molecular markers has contributed to the studies regarding domestication of Phaseolus species, origin and diversity of current common bean cultivars (P. vulgaris), and the genetic control of resistance to several diseases. Linkage maps have been constructed for common bean by using RFLP, RADP, SCAR, isoenzymes and phenotypic markers, some of which were meeting in a more dense and complete map of bean genome, called core map. However, for the effective use of linkage maps in breeding programs they must be sufficiently saturated. This work fits in this context, aiming to saturate the core map of P. vulgaris from the mapping of new molecular markers as AFLP and SSR EST-based. Thus, it was tried to develop and characterize SSR markers from a EST library, to test the transferability of these markers to other cultivars and related species, to generate AFLP markers and integrate them to the consensus map of the species. Also, build a genetic map for a population of interest in Brazil ( \'Carioca\' x \'Flor de Mayo\'), and promoting its alignment with the consensus map, thus complementing the genomic characterization of the species. Pairs of primers were designed for 156 EST-SSR. Of these, 138 EST-SSR amplified clear and reproducible loci and were characterized using a set of 26 genotypes of cultivated beans. Of the loci tested, 85 were polymorphic between the genotypes studied and showed an average 2.96 alleles per locus and a PIC average of 0.38. Among all examined EST-SSR, 50 loci segregated in \'Bat 93\' x \'Jalo EEP558\' mapping population, 20 loci segregated in \'Carioca\' x \'Flor de Mayo\' population and 12 loci were polymorphic in both two populations. AFLP markers were generated and genotyped in the two populations. The 262 microsatellites and AFLP loci genotyped in \'Bat 93\' x \'Jalo EEP558\' population were integrated onto the core map of the species. A map of 1353 cM total length was obtained, containing 357 markers, including 9 genomic-SSR, 47 EST-SSR and 190 AFLP. Moreover, another map was generated from the analysis of segregation of 252 markers in \'Carioca\' x \'Flor de Mayo population. This map was 807.5 cM long, with an average distance of 5.3 cM between markers. The common microsatellites markers were used as a bridge to align and compare the maps of the two studied populations.

<p>I have, in this thesis, studied the interactions between gray-sided voles (Clethrionomys rufocanus) and tundra vegetation, on islands in, and mainland sites close to the lake Iešjávri, in northern Norway. As isolated islands are virtually free of predation, I have been able to compare plant-herbivore interactions in the presence and absence of predators. I transplanted vegetation from an island with predators and voles, to predator-free islands with and with out voles. The results reveal the existence of a terrestrial trophic cascade as voles had a severe impact on the transplanted vegetation on the predator-free islands, but only minor effects on the mainland where predators are present. Moreover, this study shows that plant defence was only a successful strategy when predators were present. Voles reduced the abundance of all available plants during winter on the predator-free islands. The results imply that cascading effects of predation are most important for well-defended plants with grazing-sensitive morphology as these plants escape herbivore impacts in the presence of predators but are vulnerable in their absence</p><p>I studied the recovery of intensively grazed vegetation by building exclosures on islands that have been heavily grazed by voles for almost a decade.This study shows that the collective biomass of vascular plants recovered completely on three years, when voles were excluded. Although most species that are dominating the ungrazed vegetation recovered rapidly in the exclosures, the vegetation did not simply return to its ungrazed state. Herbaceous plants increased and there were pronounced differences in response among evergreen dwarf-shrub species. The semi-prostrate and tannin rich crowberry (Empetrum nigrum), showed the strongest recovery of all species, while the erect lingonberry (Vaccinium vitis-idaea) only showed weak signs of recovery. Thus, growth form determined the potential of plants to recover, whereas the trade-off between defensive investments and capacity to recover was weak or absent.</p><p>I studied the interaction between gray-sided voles and their main winter food plant, bilberry (Vaccinium myrtillus) on islands in and mainland sites close to the lake Iešjávri. I compared the abundance, population structure and palatability of bilberry ramets between vole-free islands, islands with voles but no predators and mainland sites with both voles and predators. Voles decreased the abundance of bilberry on the mainland, but the effect was much stronger on predator-free islands. Bilberry was fairly tolerant to grazing as it partially compensated for the lost tissue by producing more new ramets. Moreover, a cafeteria experiment showed that voles preferred the ramets from predator-free islands, which is inconsistent with conjectures emphasizing inducible plant defenses. The vole-bilberry interaction lacks features of delayed density dependence that could explain the vole cycles. I conducted a clipping and fertilization experiment to further investigate the effects of herbivory on palatability of bilberry shoots. Fertilization decreased the concentration of condensed tannins in shoots of bilberry and voles preferred fertilized and clipped shoots. I found no indication of induced defense that could reduce the palatability of bilberry twigs in response to herbivory.</p><p>The relationships between gray-sided vole densities, levels of invertebrate herbivory and chemical quality of leaves of Northern willow (Salix glauca) were studied on islands and mainland sites with contrasting vole densities. I found a positive correlation between level of invertebrate herbivory and vole density. The number of leaves per shoot, leaf size and leaf nitrogen content were also positively correlated with vole densities, while leaf C/N ratios were negatively correlated with vole densities. The positive correlation between vole densities and level of invertebrate herbivory is probably due to a facilitative effect of voles on invertebrate herbivores, mediated through changes in plant chemistry.</p>

I have, in this thesis, studied the interactions between gray-sided voles (Clethrionomys rufocanus) and tundra vegetation, on islands in, and mainland sites close to the lake Iešjávri, in northern Norway. As isolated islands are virtually free of predation, I have been able to compare plant-herbivore interactions in the presence and absence of predators. I transplanted vegetation from an island with predators and voles, to predator-free islands with and with out voles. The results reveal the existence of a terrestrial trophic cascade as voles had a severe impact on the transplanted vegetation on the predator-free islands, but only minor effects on the mainland where predators are present. Moreover, this study shows that plant defence was only a successful strategy when predators were present. Voles reduced the abundance of all available plants during winter on the predator-free islands. The results imply that cascading effects of predation are most important for well-defended plants with grazing-sensitive morphology as these plants escape herbivore impacts in the presence of predators but are vulnerable in their absence I studied the recovery of intensively grazed vegetation by building exclosures on islands that have been heavily grazed by voles for almost a decade.This study shows that the collective biomass of vascular plants recovered completely on three years, when voles were excluded. Although most species that are dominating the ungrazed vegetation recovered rapidly in the exclosures, the vegetation did not simply return to its ungrazed state. Herbaceous plants increased and there were pronounced differences in response among evergreen dwarf-shrub species. The semi-prostrate and tannin rich crowberry (Empetrum nigrum), showed the strongest recovery of all species, while the erect lingonberry (Vaccinium vitis-idaea) only showed weak signs of recovery. Thus, growth form determined the potential of plants to recover, whereas the trade-off between defensive investments and capacity to recover was weak or absent. I studied the interaction between gray-sided voles and their main winter food plant, bilberry (Vaccinium myrtillus) on islands in and mainland sites close to the lake Iešjávri. I compared the abundance, population structure and palatability of bilberry ramets between vole-free islands, islands with voles but no predators and mainland sites with both voles and predators. Voles decreased the abundance of bilberry on the mainland, but the effect was much stronger on predator-free islands. Bilberry was fairly tolerant to grazing as it partially compensated for the lost tissue by producing more new ramets. Moreover, a cafeteria experiment showed that voles preferred the ramets from predator-free islands, which is inconsistent with conjectures emphasizing inducible plant defenses. The vole-bilberry interaction lacks features of delayed density dependence that could explain the vole cycles. I conducted a clipping and fertilization experiment to further investigate the effects of herbivory on palatability of bilberry shoots. Fertilization decreased the concentration of condensed tannins in shoots of bilberry and voles preferred fertilized and clipped shoots. I found no indication of induced defense that could reduce the palatability of bilberry twigs in response to herbivory. The relationships between gray-sided vole densities, levels of invertebrate herbivory and chemical quality of leaves of Northern willow (Salix glauca) were studied on islands and mainland sites with contrasting vole densities. I found a positive correlation between level of invertebrate herbivory and vole density. The number of leaves per shoot, leaf size and leaf nitrogen content were also positively correlated with vole densities, while leaf C/N ratios were negatively correlated with vole densities. The positive correlation between vole densities and level of invertebrate herbivory is probably due to a facilitative effect of voles on invertebrate herbivores, mediated through changes in plant chemistry.

The aim of this thesis project was to elucidate patterns and processes associated with the biotic interactions in a natural plant–herbivore–parasitoid food web characterized by spatial and temporal heterogeneity with regard to species composition. The system examined is based on island populations of the perennial herb Meadowsweet (Filipendula ulmaria, Rosaceae), located in the Skeppsvik Archipelago. The area is subject to isostatic rebound, amounting to 0.85 cm per year; this makes it possible to calculate the age of the rising islands. Meadowsweet colonizes new islands when they are about 100 years old. Meadowsweet is consumed by two major herbivores in the study area: Galerucella tenella and Altica engstroemi (Coleoptera: Chrysomelidae). Both herbivores overwinter in the topsoil and successful colonization occurs when the islands reach a height that prevents the beetles from being removed or killed as a result of wave wash during the winter. I found that both herbivores significantly reduced individual plant fitness and population growth rate. A “cafeteria experiment” with Galerucella showed that this beetle discriminated between plants from different islands, avoiding plants from old islands which contained high concentrations of putative defence compounds, while readily accepting plants from younger islands which contained lower concentrations of these chemicals. Further, the plant species exhibited a trade-off between growth and production of the putative defence compounds. Taken together, these results were interpreted as providing evidence of herbivore-driven evolution of resistance in Meadowsweet. Further, laboratory studies suggested that Galerucella gradually includes a less preferred host plant (Rubus arcticus, Rosaceae) in its diet as Meadowsweet resistance increases. This implies that Galerucella drives its own host-breadth enlargement by selectively inducing a ‘rent rise’ in the original host, Meadowsweet. In a number of field studies I showed that the oligophagous parasitoid Asecodes mento (Hymenoptera: Eulophidae) has a strong positive effect on Meadowsweet seed set by removing large numbers of G. tenella larvae. This top-down effect is, however, altered by the presence of a close relative of G. tenella, namely G. calmariensis, which is monophagous on Purple loosestrife (Lythrum salicaria, Lythraceae). G. tenella experiences associational susceptibility when coexisting with G. calmariensis since the latter supports a higher and more fit pool of shared parasitoids and because Meadowsweet attracts a higher proportion of the shared parasitoid females than Purple loosestrife. This implies that G. tenella densities are very low in coexisting populations and that Meadowsweet experiences associational resistance and produces more seeds when co-occurring with Purple loosestrife. Thus, selection for increased resistance in Meadowsweet is likely to be relaxed in populations mixed with Purple loosestrife. I conclude that the evolution of plant resistance is likely to depend on the length of time and intensity of selection. When Meadowsweet colonizes new islands it experiences a period of enemy-free space; followed by a midlife and ageing with selection by herbivores. The intensity of this selection does, however, depend on the presence of additional plant and herbivore species.

Made available in DSpace on 2015-03-26T13:30:22Z (GMT). No. of bitstreams: 1 texto completo.pdf: 584816 bytes, checksum: f4330ebbc024b36a1ab766369b97b738 (MD5) Previous issue date: 2008-07-07 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Plants previously attacked by herbivores may have their defense system activated. The defense forms may occur by different routes. Some of the unleashed routes take place right after the herbivory, when the plant starts responding in an indirect way through the production of volatile substances attractive to natural enemies of the infesting phytophagous. Another route would be the direct response from the plant through the synthesis of proteinase inhibitors produced post-injury, which can affect the development and growth of the infesting phytophagous. The plants can present specificity in the induced responses, that is, the defenses may intimidate a subsequent herbivory; however, in some cases the re- infesting species do not have their performance affected. Recent studies have shown resistance mechanisms in plants of commercial interest against the attack of pests. Strawberry plants which are cultivated in large scale in Brazil have suffered serious damage by the two spotted mite Tetranychus urticae, which is a primary pest for the culture. Therefore, the present study had as an aim to study induced direct resistance in strawberry plants (Fragaria x ananassa Duch.) upon the population dynamics of the two-spotted mite T. urticae. In the experimental studies clean strawberry plants (control), plants that were mechanically injured as well as plants pre-infected with the two-spotted mite T. urticae were used. In order to determine the proteinase inhibitors, samples of each treatment were used. Based on these methods, in test 1 the hypothesis that the pre-infestation of T. urticae would induce the production of proteinase inhibitors reducing the population growth of their co-specifics was tested. In test 2, the specificity of the defensive compounds was studied, testing then the hypothesis that the pre- infestation of T. urticae would induce the production of proteinase inhibitors which would affect the development of red mite Tetranychus mexicanus, a species of spider mite that also occur in strawberry plants. In test 3, the hypothesis that the infestation by T. urticae in the mother strawberry plants would induce the production of proteinase inhibitors and these would be translocated through stolons unt il the strawberry runners injuring the development of T. urticae in these daughter plants was tested. According to the results a smaller number of individuals of T. urticae were found in plants previously infected with the co-specific. The spider mite T. mexicanus did not have its development affected by the induced response due to the pre-infestation of T. urticae. The plant response had contrasting effect to T. mexicanus, apparently the induced defenses in strawberry plants do not act in reinfestations of hetero-specifics, ate least for T. mexicanus. The population growth of T. urticae was also smaller in the strawberry runners of strawberry plants. The induced defense by T. urticae in mother strawberry plants presented systemic defense signals through the stolon, affecting the performance of the phytophagous of the strawberry runners. In the results of the concentrations of proteinase inhibitors, one could verify that they varied among the treatments in the experiments, but were not correlated to phytophagous performance. Possibly, other phytochemicals compounds produced by the plants might be involved in the induced responses by T. urticae. These results support the hypothesis that the plants that present direct defense can reduce the performance of co-specific phytophagous in the following generation. / Plantas previamente atacadas por herbívoros podem ter o seu sistema de defesa ativado. As formas de defesa podem ocorrer por diferentes rotas. Algumas das rotas desencadeadas ocorrem logo após a herbivoria, quando a planta passa a responder de forma indireta através da produção de substâncias voláteis atrativas aos inimigos naturais dos fitófagos infestantes. Uma outra rota seria a resposta direta da planta através da síntese de inibidores de proteases produzidos após a injúria, o que pode afetar o desenvolvimento e crescimento de fitófagos infestantes. As plantas, por sua vez, podem apresentar especifidade nas respostas induzidas, ou seja, as defesas podem intimidar a herbivoria posterior, porém em alguns casos as espécies re- infestantes não tem o desempenho afetado. Estudos recentes têm demonstrado mecanismos de resistência em plantas de interesse comercial contra o ataque de pragas. Plantas de morangueiro que são cultivadas em larga escala no Brasil têm sofrido sérios danos pelo ácaro-rajado Tetranychus urticae, que é praga primária para a cultura. Desse modo, o presente estudo teve como objetivo estudar a resistência induzida direta em plantas de morangueiro (Fragaria x ananassa Duch.) sobre populações de T. urticae. Nos estudos experimentais foram utlizadas plantas de morangueiro limpas (controle), plantas injuriadas mecanicamente e plantas pré-infestadas por T. urticae. Para determinação dos inibidores de proteases foram utilizadas amostras de folhas limpas de cada tratamento. Baseado nestes métodos, testou-se no ensaio 1 a hipótese de que a pré-infestação de T. urticae induziria a produção de inibidores de proteases reduzindo o crescimento populacional de seus coespecíficos. No ensaio 2, estudou-se a especificidade dos compostos defensivos, testando a hipótese de que a pré-infestação de T. urticae induziria a produção de inibidores de proteases que afetariam o desenvolvimento do ácaro-vermelho Tetranychus mexicanus, uma espécie de ácaro que também ocorre em morangueiro. No ensaio 3, foi testada a hipótese de que a infestação por T. urticae nas plantas matrizes de morangueiro induziria a produção de inibidores de proteases e estes seriam translocados através dos estolões até as plantas-filhas prejudicando o desenvolvimento de T. urticae nestes propágulos. De acordo com os resultados, menor número de indíviduos de T. urticae foram encontrados em plantas previamente infestadas com o coespecífico. O ácaro T. mexicanus não teve seu desenvolvimento afetado pela resposta induzida decorrente da pré-infestação de T. urticae. A resposta da planta teve efeito contrastante a T. mexicanus , aparentemente as defesas induzidas em morangueiro não atuam em re-infestações de heteroespecíficos, pelo menos para T. mexicanus. O crescimento populacional de T. urticae também foi menor nos propágulos de morangueiro. A defesa induzida por T. urticae em plantas matrizes de morangueiro apresentou sistemicidade, através do estolão, afetando o desempenho dos fitófagos nos propágulos. Nos resultados das concentrações de inibidores de proteases, verificou-se em geral, que as mesmas variaram entre os tratamentos nos experimentos, mas não foram correlacionados ao desempenho dos fitófagos. Possivelmente, outros compostos fitoquímicos produzidos pelas plantas estejam envolvidos nas respostas induzidas por T. urticae. Estes resultados suportam a hipótese de que as plantas que apresentam defesa direta podem reduzir o desempenho de fitófagos coespecíficos na geração seguinte.

The genetically modified cotton to produce toxins from the bacterium Bacillus thuringiensis (Bt) has the objective of offering plant resistance against lepidopteran larvae. The cotton crop cultivated in the Semiarid region can be subjected to the condition of water stress. Thus, this work investigated the expression of the Cry1Ac toxin in two varieties of Bt-cotton Acala 90B and NuOpal cultivated under the conditions of irrigated and water stress. In addition, the oviposition and feeding preference of adults and larvae of the cotton leafworm, Alabama Argillacea (Hübner), caged on these plants were studied. Cotton plants were cultivated under controlled conditions of irrigation to obtain water stress treatment in microparcels inside an open-sided greenhouse. Higher levels of Cry1Ac expression was found on top leaves of Bt-cotton for both varieties under water stress condition, and similar levels between plants with and without water stress in the other plant parts such as bracts, flower petals, and boll. Adults of A. argillacea did not exhibited preference for oviposition between Bt and non-Bt cotton plants. Likewise, 3- and 10-d-old A. argillacea larvae did not show food preference under a choice test comparing leaves of non-Bt and Bt-cotton plants. Otherwise, adults of A. argillacea showed lower oviposition on plants under water stress, and their larvae did not complete development fed non-Bt varieties cultivated under water stress condition. These results indicated that adults and larvae of A. argillacae do not recognize Bt-cotton plants to lay eggs and to feed, respectively. Further, cotton plants under water stress showed greater Cry1Ac toxin concentration on top leaves, interfered with the oviposition of A. argillacea irrespective of plant genotypes Bt and non-Bt, and with the larval development on non-Bt plants. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O algodoeiro geneticamente modificado para a produção de toxinas da bactéria Bacillus thuringiensis (=Bt) tem como principal objetivo oferecer a planta resistência contra larvas de lepidópteros. O cultivo do algodoeiro Bt no Semiárido pode estar submetido a diferentes condições edafoclimáticas, principalmente, ao estresse hídrico. Assim, este estudo investigou a produção da toxina Cry1Ac em algodoeiro Bt variedades Acala 90B e NuOpal com plantas submetidas ou não ao estresse hídrico e a preferência para oviposição e alimentação de Alabama Argillacea (Hübner) confinadas sobre essas plantas. Plantas de algodão foram cultivadas em microparcelas em casa telada e submetidas ao controle de irrigação para a obtenção de plantas com estresse hídrico. A produção de Cry1Ac foi maior em folhas de plantas Bt de ambas as variedades submetidas ao estresse hídrico, e similar nas demais partes como brácteas, pétalas e casca de maçãs. Mariposas de A. argillacea não apresentaram preferência para ovipositar entre plantas de algodão Bt e não-Bt. Da mesma forma, as larvas com três ou 10 dias de idade não apresentaram preferência para alimentar em folhas de variedades não-Bt comparadas a Bt, em testes com chance de escolha. Por outro lado, mariposas de A. argillacea preferiram ovipositar em plantas sem estresse hídrico e larvas não completaram o desenvolvimento em plantas não-Bt sob estresse hídrico de ambas as variedades. Estes resultados mostram que tanto mariposas quanto as larvas de A. argillacea não foram capazes de reconhecer plantas de algodão Bt para ovipositar e alimentar, respectivamente. Também, que plantas de algodoeiro submetidas ao estresse hídrico apresentam diferenças quanto à quantidade da toxina Cry1Ac nas folhas, interferiram com a preferência de oviposição de A. argillacea, bem como com o seu desenvolvimento larval.

Made available in DSpace on 2014-06-11T19:32:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-03-09Bitstream added on 2014-06-13T20:42:38Z : No. of bitstreams: 1 thuler_rt_dr_jabo.pdf: 1113556 bytes, checksum: c35811ff0eb7e1d5308e457d8e63eff5 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O trabalho foi desenvolvido no Laboratório de Biologia e Criação de Insetos (LBCI) da FCAV-UNESP, para avaliar o efeito da interação entre resistência de cultivares de brássicas, inseticidas químicos e produtos vegetais e Trichogramma no controle de P/utella xy/ostella. Para tanto, avaliou-se a biologia de P. xy/ostella nas cultivares de repolho: Chato de Quintal (CQ), Midori (MD), Roxo Precoce (RP) e Híbrido Roxo (HR) e, nas cultivares de couve, Geórgia (CM) e Híbrido Geórgia HS20 (HS20) em laboratório. Avaliou-se a toxicidade dos inseticidas lufenuron e deltametrina, bem como dos produtos vegetais óleo de nim e extrato pirolenhoso, pela adequação das concentrações letais (CLso) dos produtos. Com os mesmos produtos citados, foram avaliados os efeitos sobre Trichogramma. Finalmente, avaliou-se a associação dos métodos testados primordialmente, utilizando-se as cultivares de repolho e os inseticidas químicos e produtos vegetais, bem como o efeito sobre Trichogramma. A cultivar CQ foi classificada como moderadamente resistente; RP e MD como suscetíveis, e CM, HS20 e HR como altamente suscetíveis, sendo 'observado também, que nenhuma cultivar apresentou a substância sinigrina. Lufenuron, óleo de nim e extrato pirolenhoso, causaram até 100% de mortalidade para P. xy/ostella, e Decis não foi eficiente. Deltametrina também foi o produto mais prejudicial aos parasitóides T. exiguum e T. pretiosum, enquanto o produto Nim e o inseticida Match foram os menos prejudiciais. A associação dos métodos químicos e resistência de plantas elevam o potencial de controle para P. xy/ostella, mas essa estratégia deve ser bem avaliada, pois pode afetar o desempenho dos parasitóides, reduzindo seu potencial de controle. / The project was developed to evaluate the effect of the interaction between resistance of cabbage cultivars, insecticides and Trichogramma in the P/utella xy/ostella control. The biology of P. xy/ostella was evaluated in the following cabbage cultivars: Chato de Quintal (CQ), Midori (MD), Roxo Precoce (RP) and Roxo Hybrid (RH), and kale cultivars: Geórgia (CM) and Geórgia Hybrid HS20 (HS20), in laboratory. The toxicity of the insecticides lufenuron and deltamethrin and, of the vegetal products neem oil and pyroligneous extract, was evaluated for the adequacy of the lethal concentrations (LC50) of the products. With those products, the effect on Trichogramma was also evaluated. Finally, it was evaluated the association of the methods tested, using cabbage cultivars and chemical insecticides and vegetal products, and the effect on Trichogramma. The cultivar CQ was classified as moderately resistant; RP and MO as susceptible, and CM, HS20 and HR as highly susceptible, being also observed, that the cultivars tested did not present sinigrin. Lufenuron, Neem oil and pyroligneous extract caused up to 100% of P. xy/ostella mortality and deltabethrin was not efficient. Oeltamethrin was most harmful product to the parasitoids T exiguum and T pretiosum, while neem oil and lufenurun were less harmful. The interaction of chemical and plant resistance methods, increased the potential to P. xy/ostella control, but this strategy must be well evaluated, as it can affect negativity the parasitoid performance, reducing its control potential.