The purposes of this study were to determine the effect of the exogenous polyamines, spermidine and spermidine, on growth of crown gall tumors, to assay levels of spermidine and spermine in normal and crown gall tumor tissue and to determine the effects of selected anti-tumor compounds on growth of crown gall tumors as well as on the endogenous levels of the polyamines in those tumors.Findings1. Spermidine and spermine are present in normal potato tissue and crown gall tumor tissue grown on potato discs.2. Exogenous spermidine and spermine do affect growth of crown gall tumors depending upon the concentration of the solutions added, the type of polyamine added and the number of times the solutions are applied.3. Spermidine (1 mM) has a positive growth effect on crown gall tumors.4. Crown gall tumor tissue contains more spermidine than corresponding normal potato tissue; spermine levels are consistently low compared to spermidine levels in both crown gall tissue and normal potato tissue.5. The level of spermidine in tumor tissue increases as the tumors develop; the level of spermine remains consistently low.6. Addition of methylglyoxal bis (guanylyhdrazone) inhibits tumor growth, but the inhibitory effect is decreased by concurrent administration of spermidine.7. Both novobiocin and nalidixic acid have an inhibitory effect on tumor growth, but the effects are decreased by concurrent administration of spermidine. Reversal of the nalidixic acid effect on growth by addition of spermidine is more pronounced than reversal of the novobiocin effect.8. Methylglyoxal bis (guanylhydrazone) decreases the endogenous levels of both spermidine and spermine in crown gall tumor tissue.Conclusions1. The polyamine, spermidine, plays an important role in the growth of crown gall tumors.2. Compounds which inhibit spermidine biosynthesis or the possible mode of action of spermidine inhibit tumor growth.3. Other polyamines appear to have no significant role in crown gall tumor growth.4. The growth of crown gall tumors involves the activation of a mechanism leading to the increased biosynthesis of spermidine.5. A specific inhibitor of polyamine biosynthesis in animals also reduces endogenous levels of spermidine and spermine in crown gall tumors.6. These data further support the hypothesis that crown gall tumors are similar to animal tumors.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1967. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Plantas parasitas são aquelas que retiram os recursos necessários para a sua sobrevivência de outras plantas (hospedeiras) por meio de uma estrutura denominada haustório, que permite que a parasita se conecte ao sistema vascular da hospedeira. As plantas podem responder ao ataque parasita ativando alguns mecanismos de defesa, dentre eles, a produção de substâncias fenólicas. Os viscos constituem um grupo de plantas parasitas aéreas pertencentes a Santalales que podem ser divididos em viscos holoparasitas ou hemiparasitas. Alguns gêneros de viscos são de importância econômica, dentre eles, Phoradendron, um gênero de visco hemiparasita. Esse trabalho teve como objetivos determinar os conteúdos de taninos, flavonoides, fenilpropanoides, carboidratos solúveis, amido, lipídeos, a razão carbono/nitrogênio e avaliar como a relação parasítica afeta o metabolismo das espécies envolvidas. Para tanto, coletou−se no município de Campanha (MG) folhas e ramos de seis indivíduos não parasitados de Tapirira guianensis (FT e RT) e, a partir de nove indivíduos parasitados de T. guianensis, foram coletados ramos e folhas de Phoradendron crassifolium (FP e RP), ramos não infestados da hospedeira e suas folhas (RNI e FRNI) e ramos infestados de T. guianensis e suas folhas (RI e FRI), sendo que ramos infestados foram divididos em região proximal, galha e distal (RPRI, RGRI e RDRI). Como principais resultados estão o aumento no teor de proantocianidinas e de carboidratos solúveis em FRNI e FRI em relação a FT. Ramos infestados sofreram redução nos conteúdos de carboidratos solúveis, amido, lipídeos, nitrogênio e substâncias fenólicas, exceto na região da galha (RGRI) em que aumentos de amido e flavonoides foram verificados. Observou-se ainda que RNI parece ter sofrido um acúmulo de substâncias fenólicas. O conjunto dos resultados obtidos mostra que P. crassifolium afeta o metabolismo primário e o secundário de T. guianensis, com influência mais pronunciada nos ramos do que nas folhas da hospedeira. Pode−se sugerir que a parasita obtêm nitrogênio e carboidratos solúveis de sua hospedeira e que pode ocorrer uma possível realocação de carbono para crescimento, desenvolvimento, manutenção e, ainda, defesa de ramos ainda não infestados. Além disso, sugere−se que o acúmulo de fenólicos em ramos não infestados (RNI) possa ser um mecanismo de defesa usado pela hospedeira com o objetivo de evitar, ou mesmo diminuir, novas infestações em ramos ainda não parasitados. / Parasitic plants are those that withdraw necessary resources for its survival from other plants (hosts) through a structure so-called haustorium which enables the parasite to connect to the host\'s vascular system. Plants can respond to the parasite attack activating some defense mechanisms, including the production of phenolic compounds. Mistletoes are a group of stem parasitic plants belonging to Santalales that can be grouped into holoparasite or hemiparasite mistletoes. Some mistletoes genera are of economic importance among them Phoradendron, a hemiparasite mistletoe. This study aimed to determine the contents of tannins, flavonoids, phenylpropanoids, soluble carbohydrates, starch, lipids, the carbon⁄nitrogen ratio and evaluate how the parasitic relationship affects the metabolism of the involved species. Were collected in Camapanha (MG) leaves and branches from six non−parasitized individuals of Tapirira guianensis, host plant (LT and BT). From nine parasitized individuals of T. guianensis were collected branches and leaves of Phoradendon crassifolium, the parasitic plant (LP and BP), non-infested host branches and their leaves (NIHB and NIHB-L) and infested branches and their leaves (IHB and IHB-L). Infested branches of T. guianensis were divided into proximal, gall, and distal regions (IHB-P, IHB-G and IHB-D). Main results were an increase in the proanthocyanidin and soluble carbohydrates content in NIHB−L and IHB−L in relation to LT. There was a reduction of soluble carbohydrate, starch, lipids, nitrogen, and phenolic compounds in infested branches, except in the gall region (IHB-G), which showed an increase of flavonoids and starch contents. It was also observed that NIHB appears to accumulate phenolic compounds. Results showed that P. crassifolium affects the primary and secondary metabolism of T. guianensis, and branches were affected more intense than the leaves. It can be suggested that the parasite withdraws nitrogen and soluble carbohydrates from its host and this could result in possible carbon relocation for growth, development, maintenance, and also defense of branches not yet infested. In addition, it could be suggested the accumulation of phenolic compounds in non−infested branches (NIHB) as a defense mechanism used by the host in order to prevent or even reduce new infestations of an individual already parasitized.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1959. / Typescript. Abstracted in Dissertation abstracts, v. 20 (1959) no. 2, p. 450. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 89-93).

O efeito de borda em florestas é bastante estudado, porém pouco se sabe sobre as respostas das interações entre espécies a este efeito. O mesmo acontece quando se trata de distúrbios antrópicos, muitas vezes presentes após o processo de fragmentação. Apesar de não terem sido originadas por tal processo, as transições floresta-campo existentes nas florestas com Araucaria do sul do Brasil são submetidas aos distúrbios causados pelo pastejo e manejo por fogo, possuindo características semelhantes às bordas florestais mantidas no seu ponto de criação. No Capítulo 1, o efeito de borda e de distúrbios antrópicos sobre a fauna de insetos galhadores foi testado em transições floresta-campo, em termos de riqueza e composição destes organismos, comparando-se tanto bordas e interiores florestais quanto graus de distúrbio (com distúrbio e em regeneração), e adicionalmente foram feitas comparações entre manchas florestais naturais e a floresta contínua. Considerando as hipóteses propostas para os padrões de distribuição dos insetos galhadores, espera-se que existam mais espécies nas bordas de florestas comparadas ao interior, e que os distúrbios afetem estas respostas. Apesar das bordas em geral não terem apresentado maior riqueza de espécies que o interior, o padrão foi oposto ao esperado em locais com presença de distúrbio, com interiores mais ricos que bordas. A composição de espécies foi diferente entre os habitats e entre graus de distúrbio, e as porções de floresta contínua amostradas foram mais ricas que manchas florestais. Além disso, a fauna de insetos galhadores das manchas florestais foi um subconjunto da floresta contínua. Os resultados reforçam a relação dos padrões de distribuição da vegetação com os insetos galhadores, que indiretamente responderam ao efeito de borda e de distúrbios antrópicos atuando sobre suas plantas hospedeiras. No Capítulo 2 é apresentado de forma pioneira um inventário das galhas de insetos da Floresta com Araucária, referente às galhas coletadas para o estudo apresentado no primeiro capítulo. São listadas as espécies de insetos galhadores e suas plantas hospedeiras, com informações sobre a morfologia das galhas e a ocorrência nos locais amostrados. Foram encontradas 57 espécies de insetos galhadores (a maioria Diptera: Cecidomyiidae), em 43 espécies de plantas pertencentes a 18 famílias botânicas. As galhas foram predominantemente caulinares ou em gemas, glabras, isoladas, fusiformes e de coloração verde. Myrtaceae, Asteraceae e Melastomataceae foram as famílias de plantas mais representativas. Os valores brutos totais de galhas por habitat ou local mostraram-se semelhantes entre borda e interior, porém foram relativamente maiores na área sem distúrbio e na floresta contínua, esta última abarcando um grande número de galhas que ocorreram nas manchas. A existência de áreas sem distúrbio do pastejo e manejo por fogo se mostrou relevante para a conservação da fauna de insetos galhadores, que podem se estabelecer e manter suas populações. O conhecimento da diversidade destes organismos é um fator chave para o desenvolvimento de ações mais claras visando sua preservação. / The edge effect on forests is widely studied, however little is known about species interactions responses to this effect. The same is true for anthropogenic disturbances, many times present after the fragmentation process. Despite not originated by this process, forest-grassland boundaries of Araucaria forests in southern Brazil are under disturbance by cattle grazing and fire, presenting characteristics similar to forest edges maintained at their point of creation. In Chapter 1, edge and anthropogenic disturbance effects on the galling insect fauna were tested in forest-grassland boundaries, in terms of richness and composition of this organisms, comparing both forest edges and interiors as degrees of disturbance (disturbed and recovering), and additional comparisons were performed between natural forest patches and a continuous forest. Considering hypotheses proposed to distribution patterns of the galling insects, it is expected that forest edges would harbor more species compared to forest interior, and that disturbances would affect the outcome. Although edges in general did not present higher species richness than forest interiors, the pattern was opposite to the expected in disturbed sites, with forest interiors richer than edges. Species composition differed between habitats and disturbance degrees, and portions of continuous forest were richer than forest patches. Furthermore, the galling fauna of forest patches was a subset of the continuous forest. Results strengthen the relation between vegetation distribution patterns and galling insects, which indirectly responded to edge and disturbance effects acting on their host plants. In Chapter 2 it is pioneering presented an inventory of insect galls from Araucaria forest, referring to the galls collected to the study presented in first chapter. Galling insect species and their host plants are listed, with information about gall morphology and occurrence in sites sampled. Fifty seven galling insect species were found (mostly Diptera: Cecidomyiidae), in 43 host plants belonging to 18 plant families. Galls were predominantly induced on stem or buds, glabrous, isolated, fusiform and green. Myrtaceae, Asteraceae e Melastomataceae were the most representative plant families. Total raw values of galls per habitat or site were similar between forest edge and interior, but were relatively higher in the recovering area and in continuous forests, the latter embracing a great number of galls occurring on forest patches. The existence of areas without disturbance by cattle grazing and fire management was important to the conservation of galling insect fauna, which can establish and keep their populations. Knowledge of the diversity of these organisms is a key factor to the development of clearer actions seeking its preservation.

O efeito de borda em florestas é bastante estudado, porém pouco se sabe sobre as respostas das interações entre espécies a este efeito. O mesmo acontece quando se trata de distúrbios antrópicos, muitas vezes presentes após o processo de fragmentação. Apesar de não terem sido originadas por tal processo, as transições floresta-campo existentes nas florestas com Araucaria do sul do Brasil são submetidas aos distúrbios causados pelo pastejo e manejo por fogo, possuindo características semelhantes às bordas florestais mantidas no seu ponto de criação. No Capítulo 1, o efeito de borda e de distúrbios antrópicos sobre a fauna de insetos galhadores foi testado em transições floresta-campo, em termos de riqueza e composição destes organismos, comparando-se tanto bordas e interiores florestais quanto graus de distúrbio (com distúrbio e em regeneração), e adicionalmente foram feitas comparações entre manchas florestais naturais e a floresta contínua. Considerando as hipóteses propostas para os padrões de distribuição dos insetos galhadores, espera-se que existam mais espécies nas bordas de florestas comparadas ao interior, e que os distúrbios afetem estas respostas. Apesar das bordas em geral não terem apresentado maior riqueza de espécies que o interior, o padrão foi oposto ao esperado em locais com presença de distúrbio, com interiores mais ricos que bordas. A composição de espécies foi diferente entre os habitats e entre graus de distúrbio, e as porções de floresta contínua amostradas foram mais ricas que manchas florestais. Além disso, a fauna de insetos galhadores das manchas florestais foi um subconjunto da floresta contínua. Os resultados reforçam a relação dos padrões de distribuição da vegetação com os insetos galhadores, que indiretamente responderam ao efeito de borda e de distúrbios antrópicos atuando sobre suas plantas hospedeiras. No Capítulo 2 é apresentado de forma pioneira um inventário das galhas de insetos da Floresta com Araucária, referente às galhas coletadas para o estudo apresentado no primeiro capítulo. São listadas as espécies de insetos galhadores e suas plantas hospedeiras, com informações sobre a morfologia das galhas e a ocorrência nos locais amostrados. Foram encontradas 57 espécies de insetos galhadores (a maioria Diptera: Cecidomyiidae), em 43 espécies de plantas pertencentes a 18 famílias botânicas. As galhas foram predominantemente caulinares ou em gemas, glabras, isoladas, fusiformes e de coloração verde. Myrtaceae, Asteraceae e Melastomataceae foram as famílias de plantas mais representativas. Os valores brutos totais de galhas por habitat ou local mostraram-se semelhantes entre borda e interior, porém foram relativamente maiores na área sem distúrbio e na floresta contínua, esta última abarcando um grande número de galhas que ocorreram nas manchas. A existência de áreas sem distúrbio do pastejo e manejo por fogo se mostrou relevante para a conservação da fauna de insetos galhadores, que podem se estabelecer e manter suas populações. O conhecimento da diversidade destes organismos é um fator chave para o desenvolvimento de ações mais claras visando sua preservação. / The edge effect on forests is widely studied, however little is known about species interactions responses to this effect. The same is true for anthropogenic disturbances, many times present after the fragmentation process. Despite not originated by this process, forest-grassland boundaries of Araucaria forests in southern Brazil are under disturbance by cattle grazing and fire, presenting characteristics similar to forest edges maintained at their point of creation. In Chapter 1, edge and anthropogenic disturbance effects on the galling insect fauna were tested in forest-grassland boundaries, in terms of richness and composition of this organisms, comparing both forest edges and interiors as degrees of disturbance (disturbed and recovering), and additional comparisons were performed between natural forest patches and a continuous forest. Considering hypotheses proposed to distribution patterns of the galling insects, it is expected that forest edges would harbor more species compared to forest interior, and that disturbances would affect the outcome. Although edges in general did not present higher species richness than forest interiors, the pattern was opposite to the expected in disturbed sites, with forest interiors richer than edges. Species composition differed between habitats and disturbance degrees, and portions of continuous forest were richer than forest patches. Furthermore, the galling fauna of forest patches was a subset of the continuous forest. Results strengthen the relation between vegetation distribution patterns and galling insects, which indirectly responded to edge and disturbance effects acting on their host plants. In Chapter 2 it is pioneering presented an inventory of insect galls from Araucaria forest, referring to the galls collected to the study presented in first chapter. Galling insect species and their host plants are listed, with information about gall morphology and occurrence in sites sampled. Fifty seven galling insect species were found (mostly Diptera: Cecidomyiidae), in 43 host plants belonging to 18 plant families. Galls were predominantly induced on stem or buds, glabrous, isolated, fusiform and green. Myrtaceae, Asteraceae e Melastomataceae were the most representative plant families. Total raw values of galls per habitat or site were similar between forest edge and interior, but were relatively higher in the recovering area and in continuous forests, the latter embracing a great number of galls occurring on forest patches. The existence of areas without disturbance by cattle grazing and fire management was important to the conservation of galling insect fauna, which can establish and keep their populations. Knowledge of the diversity of these organisms is a key factor to the development of clearer actions seeking its preservation.

O efeito de borda em florestas é bastante estudado, porém pouco se sabe sobre as respostas das interações entre espécies a este efeito. O mesmo acontece quando se trata de distúrbios antrópicos, muitas vezes presentes após o processo de fragmentação. Apesar de não terem sido originadas por tal processo, as transições floresta-campo existentes nas florestas com Araucaria do sul do Brasil são submetidas aos distúrbios causados pelo pastejo e manejo por fogo, possuindo características semelhantes às bordas florestais mantidas no seu ponto de criação. No Capítulo 1, o efeito de borda e de distúrbios antrópicos sobre a fauna de insetos galhadores foi testado em transições floresta-campo, em termos de riqueza e composição destes organismos, comparando-se tanto bordas e interiores florestais quanto graus de distúrbio (com distúrbio e em regeneração), e adicionalmente foram feitas comparações entre manchas florestais naturais e a floresta contínua. Considerando as hipóteses propostas para os padrões de distribuição dos insetos galhadores, espera-se que existam mais espécies nas bordas de florestas comparadas ao interior, e que os distúrbios afetem estas respostas. Apesar das bordas em geral não terem apresentado maior riqueza de espécies que o interior, o padrão foi oposto ao esperado em locais com presença de distúrbio, com interiores mais ricos que bordas. A composição de espécies foi diferente entre os habitats e entre graus de distúrbio, e as porções de floresta contínua amostradas foram mais ricas que manchas florestais. Além disso, a fauna de insetos galhadores das manchas florestais foi um subconjunto da floresta contínua. Os resultados reforçam a relação dos padrões de distribuição da vegetação com os insetos galhadores, que indiretamente responderam ao efeito de borda e de distúrbios antrópicos atuando sobre suas plantas hospedeiras. No Capítulo 2 é apresentado de forma pioneira um inventário das galhas de insetos da Floresta com Araucária, referente às galhas coletadas para o estudo apresentado no primeiro capítulo. São listadas as espécies de insetos galhadores e suas plantas hospedeiras, com informações sobre a morfologia das galhas e a ocorrência nos locais amostrados. Foram encontradas 57 espécies de insetos galhadores (a maioria Diptera: Cecidomyiidae), em 43 espécies de plantas pertencentes a 18 famílias botânicas. As galhas foram predominantemente caulinares ou em gemas, glabras, isoladas, fusiformes e de coloração verde. Myrtaceae, Asteraceae e Melastomataceae foram as famílias de plantas mais representativas. Os valores brutos totais de galhas por habitat ou local mostraram-se semelhantes entre borda e interior, porém foram relativamente maiores na área sem distúrbio e na floresta contínua, esta última abarcando um grande número de galhas que ocorreram nas manchas. A existência de áreas sem distúrbio do pastejo e manejo por fogo se mostrou relevante para a conservação da fauna de insetos galhadores, que podem se estabelecer e manter suas populações. O conhecimento da diversidade destes organismos é um fator chave para o desenvolvimento de ações mais claras visando sua preservação. / The edge effect on forests is widely studied, however little is known about species interactions responses to this effect. The same is true for anthropogenic disturbances, many times present after the fragmentation process. Despite not originated by this process, forest-grassland boundaries of Araucaria forests in southern Brazil are under disturbance by cattle grazing and fire, presenting characteristics similar to forest edges maintained at their point of creation. In Chapter 1, edge and anthropogenic disturbance effects on the galling insect fauna were tested in forest-grassland boundaries, in terms of richness and composition of this organisms, comparing both forest edges and interiors as degrees of disturbance (disturbed and recovering), and additional comparisons were performed between natural forest patches and a continuous forest. Considering hypotheses proposed to distribution patterns of the galling insects, it is expected that forest edges would harbor more species compared to forest interior, and that disturbances would affect the outcome. Although edges in general did not present higher species richness than forest interiors, the pattern was opposite to the expected in disturbed sites, with forest interiors richer than edges. Species composition differed between habitats and disturbance degrees, and portions of continuous forest were richer than forest patches. Furthermore, the galling fauna of forest patches was a subset of the continuous forest. Results strengthen the relation between vegetation distribution patterns and galling insects, which indirectly responded to edge and disturbance effects acting on their host plants. In Chapter 2 it is pioneering presented an inventory of insect galls from Araucaria forest, referring to the galls collected to the study presented in first chapter. Galling insect species and their host plants are listed, with information about gall morphology and occurrence in sites sampled. Fifty seven galling insect species were found (mostly Diptera: Cecidomyiidae), in 43 host plants belonging to 18 plant families. Galls were predominantly induced on stem or buds, glabrous, isolated, fusiform and green. Myrtaceae, Asteraceae e Melastomataceae were the most representative plant families. Total raw values of galls per habitat or site were similar between forest edge and interior, but were relatively higher in the recovering area and in continuous forests, the latter embracing a great number of galls occurring on forest patches. The existence of areas without disturbance by cattle grazing and fire management was important to the conservation of galling insect fauna, which can establish and keep their populations. Knowledge of the diversity of these organisms is a key factor to the development of clearer actions seeking its preservation.

Bacterial galls on Douglas-fir (Pseudotsuga menzeisii [Mirb.] Franco), collected from the southern tip of Vancouver Island, the Greater Vancouver area and the Hope region of British Columbia, were generally globose in shape with rough, irregular surfaces and measured between 0.5 and 2.0 cm in diameter. The galls were generally located on the tips of branches or twigs of 10- to 20-year old Douglas-fir trees. The bacterial gall disease appeared to affect few Douglas-fir trees in the collection areas and bacterial galls were not found on any other coniferous species. Furthermore, there have been no reports of serious damage to natural forests in British Columbia due to bacterial gall disease. Young, greenhouse-grown Douglas-fir seedlings occasionally died if the tip of the main stem was artificially inoculated. Often new growing tips would be produced affecting the growth form of the seedlings. Two types of gall-forming Erwinia spp. were isolated from Douglas-fir galls. Typical isolates, tentatively identified by fatty acid analysis as Erwinia salicis, produced galls which were rough and irregular in shape composed of multiple outgrowths marked by a single or cross-shaped fissure. The atypical isolate, tentatively identified by fatty acid analysis as Erwinia herbicola subsp. herbicola, produced galls which were smooth and generally round in shape with the surface cracking as the gall expanded. Colonies of the typical isolates grown on casein-peptone-glucose media were characteristically round, slightly domed with somewhat concentric ridging observed near the margins of the colonies. Three to 4 day old colonies of the atypical isolates grown on casein-peptone-glucose media were characteristically round and concave while older colonies produced an extracellular slime and were more irregular in shape. In Luria Broth, the typical isolates grew at temperatures of up to 32°C while the atypical isolate grew at temperatures of up 34°C. The typical isolate was resistant to a wider range of antibiotics than the atypical isolate. Polyclonal antisera were produced against glutaraldehyde-fixed whole cells of both the typical T-2789 and atypical A-0181 gall-forming Erwinia isolates. The purified antisera were isolate specific as tested by immunodiffusion and an indirect ELISA against several different phytopathogenic bacteria including Pseudomonas syringae pv. syringae, Erwinia herbicola subsp. herbicola, Agrobacterium tumefaciens, Rhizobium leguminosarum and Erwinia carotovora subsp. carotovora. Plasmid profiles of the typical Erwinia isolates contained one band while the atypical isolate characteristically contained 4 to 5 bands which appeared to be different forms of at least one plasmid. Restriction digests of the typical isolates suggested a size of approximately 50 kb while complex digestion profiles were obtained for the atypical isolates because of the difficulty in isolating individual plasmid types. From visual estimates against Hindlll-digested lambda DNA, a size of between 10 and 20 kb was suggested for the fastest moving plasmid band of the atypical isolate. No homology was observed between the different plasmid types characteristic of the two isolates. The role of the plasmid DNA of the atypical isolate in pathogenesis was not determined because curing of the plasmid(s) was not successful using high temperature treatments plus chemical curing agents. Heat treatment experiments, in which the pathogen was selectively killed at various times after inoculation, demonstrated that the bacteria are required to be present for gall induction and continued development of the gall for both of the gall-forming Erwinia isolate types. Pathogenicity of the isolated bacteria was tested on 14 conifer species, other than Douglas-fir, including Abies, Chamaecyparis, Pinus and Thuja spp. The typical isolates were weakly pathogenic on Abies, Larix and Picea spp. The atypical isolate was weakly pathogenic on Abies, Chamaecyparis, Larix, Picea and Pinus spp. Due to the limited damage caused on the conifers tested and to their infrequent occurrence, these gall-forming pathogens do not appear to be of economic importance to the forestry industry. / Land and Food Systems, Faculty of / Graduate

Plantas parasitas são aquelas que retiram os recursos necessários para a sua sobrevivência de outras plantas (hospedeiras) por meio de uma estrutura denominada haustório, que permite que a parasita se conecte ao sistema vascular da hospedeira. As plantas podem responder ao ataque parasita ativando alguns mecanismos de defesa, dentre eles, a produção de substâncias fenólicas. Os viscos constituem um grupo de plantas parasitas aéreas pertencentes a Santalales que podem ser divididos em viscos holoparasitas ou hemiparasitas. Alguns gêneros de viscos são de importância econômica, dentre eles, Phoradendron, um gênero de visco hemiparasita. Esse trabalho teve como objetivos determinar os conteúdos de taninos, flavonoides, fenilpropanoides, carboidratos solúveis, amido, lipídeos, a razão carbono/nitrogênio e avaliar como a relação parasítica afeta o metabolismo das espécies envolvidas. Para tanto, coletou−se no município de Campanha (MG) folhas e ramos de seis indivíduos não parasitados de Tapirira guianensis (FT e RT) e, a partir de nove indivíduos parasitados de T. guianensis, foram coletados ramos e folhas de Phoradendron crassifolium (FP e RP), ramos não infestados da hospedeira e suas folhas (RNI e FRNI) e ramos infestados de T. guianensis e suas folhas (RI e FRI), sendo que ramos infestados foram divididos em região proximal, galha e distal (RPRI, RGRI e RDRI). Como principais resultados estão o aumento no teor de proantocianidinas e de carboidratos solúveis em FRNI e FRI em relação a FT. Ramos infestados sofreram redução nos conteúdos de carboidratos solúveis, amido, lipídeos, nitrogênio e substâncias fenólicas, exceto na região da galha (RGRI) em que aumentos de amido e flavonoides foram verificados. Observou-se ainda que RNI parece ter sofrido um acúmulo de substâncias fenólicas. O conjunto dos resultados obtidos mostra que P. crassifolium afeta o metabolismo primário e o secundário de T. guianensis, com influência mais pronunciada nos ramos do que nas folhas da hospedeira. Pode−se sugerir que a parasita obtêm nitrogênio e carboidratos solúveis de sua hospedeira e que pode ocorrer uma possível realocação de carbono para crescimento, desenvolvimento, manutenção e, ainda, defesa de ramos ainda não infestados. Além disso, sugere−se que o acúmulo de fenólicos em ramos não infestados (RNI) possa ser um mecanismo de defesa usado pela hospedeira com o objetivo de evitar, ou mesmo diminuir, novas infestações em ramos ainda não parasitados. / Parasitic plants are those that withdraw necessary resources for its survival from other plants (hosts) through a structure so-called haustorium which enables the parasite to connect to the host\'s vascular system. Plants can respond to the parasite attack activating some defense mechanisms, including the production of phenolic compounds. Mistletoes are a group of stem parasitic plants belonging to Santalales that can be grouped into holoparasite or hemiparasite mistletoes. Some mistletoes genera are of economic importance among them Phoradendron, a hemiparasite mistletoe. This study aimed to determine the contents of tannins, flavonoids, phenylpropanoids, soluble carbohydrates, starch, lipids, the carbon⁄nitrogen ratio and evaluate how the parasitic relationship affects the metabolism of the involved species. Were collected in Camapanha (MG) leaves and branches from six non−parasitized individuals of Tapirira guianensis, host plant (LT and BT). From nine parasitized individuals of T. guianensis were collected branches and leaves of Phoradendon crassifolium, the parasitic plant (LP and BP), non-infested host branches and their leaves (NIHB and NIHB-L) and infested branches and their leaves (IHB and IHB-L). Infested branches of T. guianensis were divided into proximal, gall, and distal regions (IHB-P, IHB-G and IHB-D). Main results were an increase in the proanthocyanidin and soluble carbohydrates content in NIHB−L and IHB−L in relation to LT. There was a reduction of soluble carbohydrate, starch, lipids, nitrogen, and phenolic compounds in infested branches, except in the gall region (IHB-G), which showed an increase of flavonoids and starch contents. It was also observed that NIHB appears to accumulate phenolic compounds. Results showed that P. crassifolium affects the primary and secondary metabolism of T. guianensis, and branches were affected more intense than the leaves. It can be suggested that the parasite withdraws nitrogen and soluble carbohydrates from its host and this could result in possible carbon relocation for growth, development, maintenance, and also defense of branches not yet infested. In addition, it could be suggested the accumulation of phenolic compounds in non−infested branches (NIHB) as a defense mechanism used by the host in order to prevent or even reduce new infestations of an individual already parasitized.

Galls of Artemisia tridentata Nutt. of Utah County were collected and described in detail. Of the ten galls collected, seven were caused by members of the Itonididae, two by members of the Trypetidae, and one by a member of the Curculionidae. Of the seven Itonid galls, six were caused by species of Diarthronomyia, and one by a species of Rhopalomyia. Two of the galls were caused by new species of Diarthronomyia. Three genera of the Scelionidae (Hymenoptera) and four genera of the Chalcidoidea (Hymenoptera) were also reared from the galls. A key to the ten galls was constructed, but does not necessarily include all the galls of big sagebrush of Utah County. To the writer's knowledce this is a first report of Eutreta diana O. S. (U. S. Geol. Sur. of Terr., 1877) in Utah. The position of the galls in their relationships as to complexity and specialization and possible origin has been pointed out.