Call number: LD2668 .T4 1978 W42 / Master of Science

Bibliography: 129-139 / iv, 139 leaves, [14] leaves of plates : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Pathology, 1984

Bibliography: leaves 96-112 / iv, 156 leaves : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Agronomy, Waite Agricultural Research Institute, 1986

Submitted by Carlos Cesar De Oliveira Guarnieri (carloscesarguarnieri@gmail.com) on 2018-08-02T18:26:04Z No. of bitstreams: 1 EFICÁCIA DE TIODICARBE, CADUSAFÓS E CONDICIONADOR DE SOLO VIA TRATAMENTO DE SEMENTES E OU SULCO DE PLANTIO NO CONTROLE DE NEMATOIDES NA CULTURA DE SOJA.pdf: 756636 bytes, checksum: 89d88ef49a1b212168332c38507a27e0 (MD5) / Approved for entry into archive by Neli Silvia Pereira null (nelisps@fcav.unesp.br) on 2018-08-03T17:20:53Z (GMT) No. of bitstreams: 1 guarnieri_cco_me_jabo.pdf: 756636 bytes, checksum: 89d88ef49a1b212168332c38507a27e0 (MD5) / Made available in DSpace on 2018-08-03T17:20:53Z (GMT). No. of bitstreams: 1 guarnieri_cco_me_jabo.pdf: 756636 bytes, checksum: 89d88ef49a1b212168332c38507a27e0 (MD5) Previous issue date: 2018-06-14 / Os principais métodos de controle de nematoides na cultura de soja atualmente utilizados são a resistência ou tolerância genética da planta, a rotação/sucessão de culturas resistentes/não hospedeiras e poucos são os estudos com o uso de produtos químicos/biológico e condicionadores de solo. Um dos métodos adotados para a aplicação de nematicida químico nas lavouras de soja é a aplicação via tratamento de sementes, porém os estudos de controle com este método, na grande maioria dos casos, apontam período de proteção de até 30 dias após a emergência das plantas, e na maioria das vezes tem trazido resultados insatisfatórios. A aplicação de nematicida químico, no sulco de plantio, ou associação do tratamento de sementes com a aplicação no sulco de plantio, pode melhorar os resultados de eficácia e eficiência, todavia esta técnica é pouco estudada no Brasil para a cultura de soja, consequentemente são poucos trabalhos que comprovem essas características nos produtos disponíveis atualmente. Também, o uso de um condicionador de solo poderá contribuir com um melhor desenvolvimento radicular, da planta e na eficácia e eficiência do produto nematicida químico. O objetivo deste estudo foi avaliar a eficácia e eficiência do nematicidas químicos tiodicarbe, cadusafós e do condicionador de solo Maskio, usados em tratamento de sementes e/ou aplicados no de sulco de plantio, no controle dos nematoides de galha (Meloidogyne incognita), de cisto da soja (Heterodera glycines) e das lesões radiculares (Pratylenchus brachyurus) na cultura de soja. Foram instalados ensaios a campo em áreas naturalmente infestadas pelos nematoides, e em vasos onde foram avaliados o desenvolvimento e produtividade da cultura e a redução na população de nematoides. Nenhum dos tratamentos testados causou sintomas visuais de intoxicação na cultura. Isoladamente, o tratamento de sementes com tiodicarbe (600 mL 100 kg sementes-1) é tão eficaz na redução da população total de P. brachyurus nas raízes da soja, quanto o tratamento de sulco com cadusafós (4,0 L ha-1) ou cadusafós + Maskio (4,0 L ha-1 + 2,0 L ha-1). Porém nenhum tratamento aumentou significativamente a produtividade da cultura. Para que haja incremento significativo em produtividade foi necessário associar a aplicação de tiodicarbe na semente e no sulco de plantio para áreas infestadas por P. brachyurus. Para áreas com M. incognita os tratamentos, de semente ou de sulco, podem ser eficazes no controle e incrementar em produtividade a cultura da soja se utilizados em área com alta infestação de nematoides de galha. A aplicação de tiodicarbe nas sementes foi tão eficaz na redução de cistos de Heterodera glycines quanto a aplicação no sulco de plantio de tiodicarbe, cadusafós, Maskio e suas associações. A associação de tiodicarbe nas sementes e uma aplicação no sulco melhorou a eficácia de controle de cistos de H. glycines, saindo de 27% de eficácia para tratamento de sementes isolado, para 75% de eficácia para o tratamento com tiodicarbe nas sementes associado ao uso da mesma molécula no sulco de plantio. / The main methods of nematode control in soybean crop currently used are resistance or genetic tolerance, rotation / succession of resistant / non - host crops, and few studies with the use of chemical / biological and soil conditioners. One of the methods adopted for the application of chemical nematicide in soybean crops is the application through seed treatment, but the studies in the control of this method, in the great majority of cases, indicate protection period up to 30 days after the emergence of the plants, in the most of the time it has brought unsatisfactory results. The application of chemical nematicide, in the planting groove, or association of the treatment of seeds with the application in the planting groove, can improve the results of efficacy and efficiency, however this technique is little studied in Brazil for the soybean crop, consequently are few works that prove the effectiveness and efficiency of the currently available products. Also, the use of a soil conditioner may contribute to a better root development of the plant and to the effectiveness and efficiency of the chemical nematicide product. The objective of this study was to evaluate the efficacy and efficiency of the chemical nematicides thiodicarb, cadusafos and the Maskio soil conditioner, used in seed treatment and / or applied to the planting groove, in the control of root-knot nematode (Meloidogyne incognita), soybean cist nematode (Heterodera glycines) and root-lesion nematode (Pratylenchus brachyurus) on soybean crop. Field trials were carried out in areas naturally infested by nematodes, and in pots where the development and productivity of the crop and the reduction in the nematode population were evaluated. None of the treatments tested causes visual symptoms of intoxication in the culture. Seed treatment with thiodicarb (600 mL 100 kg seed-1) is as effective in reducing the total population of P. brachyurus in soybean roots as in grouper treatment with cadusafos (4.0 L ha-1) or cadusafos + Maskio (4.0 L ha-1 + 2.0 L ha-1). However, no treatment significantly increases the productivity of the crop. In order to have a significant increase in productivity it is necessary to associate the application of thiodicarb in the seed and in the planting groove to areas infested by P. brachyurus. For areas with M. incognita, seed or planting groove treatments may be effective in controlling and increasing soybean productivity if used in an area with high root-knot nematode infestation. The application of thiodicarb in the seeds is as effective in the reduction of Heterodera glycines cysts as the application in the planting groove of thiodicarb, cadusafos, Maskio and their associations. The association of thiodicarb in seeds and a planting groove treatment improves the control efficacy of H. glycines. Leaving 27% efficacy for isolated seed treatment, to 75% efficacy for treatment with thiodicarb in seeds associated with the use of the same molecule in the planting groove.

Submitted by Reginaldo Soares de Freitas (reginaldo.freitas@ufv.br) on 2016-09-21T11:29:40Z No. of bitstreams: 1 texto completo.pdf: 414321 bytes, checksum: 1217b68cf39d80cb3ce2b85b1eae2eea (MD5) / Made available in DSpace on 2016-09-21T11:29:40Z (GMT). No. of bitstreams: 1 texto completo.pdf: 414321 bytes, checksum: 1217b68cf39d80cb3ce2b85b1eae2eea (MD5) Previous issue date: 1999-07-14 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Neste trabalho foram sintetizados a timoquinona [15] e os éteres derivados do timol, 2-benziloxi-1-isopropil-4-metilbenzeno [8; 35,8%], 2-etoxi- 1-isopropil-4-metilbenzeno [9; 18,8%], 1-isopropil-4-metil-2-octiloxibenzeno [10; 23,6%], 1-isopropil-4-metil-2-octadeciloxibenzeno [11; 33,0%], 2- (2’,3’,4’,5’,6’-pentafluorobenziloxi)-1-isopropil-4-metilbenzeno [12; 32,0%] e 1- isopropil-4-metil-2-metoxibenzeno [13; 75,8%]. Foram também sintetizados os sais derivados de piperazina: cloreto de piperazina [17], citrato de piperazina [18], fosfato de piperazina [19], oxalato de piperazina [20] e sulfato de piperazina [21]. Os éteres derivados do timol foram preparados através da síntese de Williamson, entre o timol e os compostos halogenados aromáticos e alifáticos. A timoquinona [15] foi obtida como produto da nitração do timol, utilizando ácido sulfúrico/nitrato de sódio. Os sais derivados da piperazina foram sintetizados mediante reação entre a piperazina e um ácido, apresentando rendimento quantitativo. Os ensaios biológicos dos produtos sintetizados e do timol foram realizados in vitro, com os nematóides Meloidogyne incognita raça 3 e Heterodera glycines, utilizando-se doses de 5 e 50 μg mL-1 dos compostos sintetizados. Nestes bioensaios, os índices de mortalidade para o Meloidogyne incognita variaram de 1,8 a 81,8% na concentração de 5 μg mL-1 e de 5,3 a 86,7% na concentração de 50 μg mL-1. Para Heterodera glycines estes índices variaram de 0 a 83% na concentração de 5 μg mL-1 e de 0 a 88% na concentração de 50 μg mL-1. Estes resultados permitiram observar a influência dos diferentes grupos substituintes, dos ânions e da concentração dos compostos sintetizados sobre sua atividade nematicida. Observou-se também diferença entre os mecanismos de ação destes compostos nas espécies Meloidogyne incognita e Heterodera glycines, sugerindo que uma abordagem diferente deve ser feita para a síntese de nematicidas que visam ao controle de Heterodera glycines. / In this work were synthesized the thymoquinone [15] and the derivatives ethers of the thymol, 2-benzyloxy-1-isopropyl-4-methylbenzene [8; 35.8%], 2- ethoxy-1-isopropyl-4-methylbenzene [9; 18.8%], 1-isopropyl-4-methyl-2- octyloxybenzene [10; 23.6%], 1-isopropyl-4-methyl-2-octadecyloxybenzene [11; 33.0%], 2-(2',3',4',5',6'-pentafluorobenzyloxy)-1-isopropyl-4-methylbenzene [12; 32.0%] and 1-isopropyl-4-methyl-2-methoxybenzene [13; 75.8%]. they were also synthesized the derived salts of piperazine: piperazine chloride [17], piperazine citrate [18], piperazine phosphate [19], piperazine oxalate [20] and piperazine sulphate [21]. The derived ethers of the thymol were prepared through the Williamson synthesis, between the thymol and the halogenates compounds aromatics and aliphatics. The thymoquinone [15] was obtained as product of the nitration of the thymol, using sulfuric acid/sodium nitrate. The derived salts of the piperazine were synthesized by means of reaction between the piperazine and an acid, presenting quantitative yeld. The biological assays of the synthesized products and of the thimol were carried in vitro, with the nematodes Meloidogyne incognita strain 3 and Heterodera glycines, using doses of 5 and 50 mg mL-1 of the synthesized compounds. In these bioassays, the mortality rate for Meloidogyne incognita varied from 1.8 to 81.8% at a 5 mg mL-1 concentration and of 5.3 to 86.7% at a 50 mg mL-1 concentration. For Heterodera glycines these rates varied from 0 to 83% at a 5 mg mL-1 concentration and from 0 to 88% at a 50 mg mL-1 concentration. These results allowed to observe the influence of the different substituents groups, of the anions and of the concentration of the synthesized compounds, on its nematicidal activity. It was also observed difference among the action mechanism of these compounds in Meloidogyne incognita and Heterodera glycines, suggesting that a different approach should be made for the synthesis of nematicides that seek the control of Heterodera glycines.

Submitted by Reginaldo Soares de Freitas (reginaldo.freitas@ufv.br) on 2016-10-05T18:17:05Z No. of bitstreams: 1 texto completo.pdf: 1361747 bytes, checksum: 02f07a1a422620aeb4025cd1437df02b (MD5) / Made available in DSpace on 2016-10-05T18:17:05Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1361747 bytes, checksum: 02f07a1a422620aeb4025cd1437df02b (MD5) Previous issue date: 2005-01-20 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Os extratos brutos de nim foram preparados a partir de sementes extraídas seqüencialmente com hexano, metanol e água. O extrato metanólico foi particionado com acetato de etila e água seguido por tratamento com carvão ativo, repetindo-se 3 vezes e obtendo-se o extrato concentrado enriquecido com 60% de azadiractina A (Aza- A 60). Primeiramente, isolou-se azadiractina A através da injeção de 700 mg de Aza-A 60 no cromatógrafo em contracorrente (CCC), com coluna de politetrafluoretileno e 116mL de capacidade, utilizando-se o sistema bifásico hexano:butanol:metanol:água (1:0.9:1:0.9, v/v) eluído a 2mL/min, na direção cabeça-cauda. Coletaram-se 30 frações recuperando-se 95% do material injetado. Após monitoramento por cromatografia em camada delgada (CCD) usando-se tolueno:acetato de etila:metanol (10:1:2, v/v/v) como sistema eluente, as frações (9-13) foram purificadas por cromatografia líquida de alta eficiência de fase reversa (CLAE-FR) preparativa, utilizando-se uma coluna LC-8 (250 x 21 mm di, 5 μm) e metanol:água (50:50 v/v) a 6mL/min, sendo os efluentes monitorados num comprimento de onda de 217 nm. Assim, obteve-se Aza-A com 96% de pureza, segundo CLAE-FR analítica e sua estrutura foi confirmada por RMN 13 C. Num segundo estudo foram isolados azadiractina B (Aza-B), azadiractina H (Aza-H), desacetilnimbim (Dnim), desacetilsalanim (Dsal), nimbim (Nim) e salanim (Sal) injetando-se 4.2 g de Aza-A 60 (700 mg/corrida) no CCC seguindo as mesmas condições relatadas no isolamento de Aza-A. Após as 6 injeções, obtiveram-se duas frações principais que foram reunidas após monitoramento por (CCD), havendo recuperação de 97% do material injetado. A primeira delas, correspondendo à soma das frações (9-13) de cada injeção, foi purificada por CLAE-FR preparativa nas mesmas condições do isolamento de Aza-A, obtendo-se Aza-B e Aza-H, ambas com 97% de pureza, segundo análises por CLAE. A segunda fração, referente à soma das frações (17-30) de cada injeção, foi purificada utilizando-se metanol:água (60:40 v/v) a 8 mL/min, obtendo-se Dnim, Dsal, Nim e Sal, todos 97% puros após análises por CLAE analítica, sendo todas estruturas confirmadas por RMN 13 C. Todos os compostos purificados bem como extratos brutos de sementes de nim foram submetidos a ensaios de atividade nematicida sobre Heterodera glycines. Avaliando-se a mobilidade de juvenis do segundo estádio (J2), seguindo a metodologia do tubo invertido, verificou-se que ocorreu menor recuperação (P 0,05) dos J2 tratados com os extratos brutos aquoso (1/2 e 1/10 v/v) e metanólico (1000 ppm), sendo que o extrato hexânico não apresentou efeito nematicida. A atividade dos extratos brutos aquoso e metanólico foi atribuída, respectivamente, à presença de saponinas e triterpenóides (limonóides). Nos ensaios em casa de vegetação, plantas de soja inoculadas com juvenis tratados com os extratos aquoso (1/2 e 1/10 v/v) ou metanólico (1000 ppm) produziram menos fêmeas e ovos (P 0,05), se comparada à testemunha. O extrato de Aza-A 60 (70 ppm) causou maior imobilidade (P 0,05) dos J2 (92%), sendo esta proporcional às concentrações estudadas. A mortalidade dos J2 foi avaliada para todos os triterpenóides isolados nas concentrações de 0,8, 8 e 80 ppm, havendo redução do número de J2 recuperados com aumento das dosagens aplicadas. Nim e Sal a 80 ppm foram os mais efetivos causando 99% de mortalidade. Plantas de soja inoculadas com J2 tratados com os triterpenóides a 80 ppm apresentaram um efeito nematicida médio de 95% na redução do número de fêmeas e ovos (P 0,05), se comparados à testemunha. Com relação à eclosão dos ovos, os triterpenóides testados a 100 ppm apresentaram uma atividade ovicida média (P 0,05) de 50 %, em relação à testemunha, e não se observou ação nematostática até 96 horas após o tratamento. / Crude extracts were prepared from Neem seeds by sequential extraction with n- hexane, methanol and water. The methanolic extract was partitioned three times between ethyl acetate and water and treated with activated charcoal to obtain a concentrate (Aza-A 60) containing 60% azadirachtin A (aza-A). In the first study, aza- A (the major triterpenoid) was isolated by countercurrent chromatography (CCC) fitted with polytetrafluorethylene coil (116 mL volume) using the biphasic solvent system n- hexane:butanol:methanol:water (l:0.9:l:0.9,v/v) by injecting 700 mg of Aza-A 60 and eluting with 2mL/min, in the head to tail direction. Thirty fractions (3 mL each) were collected with 95% of the material being recovered. After monitoring by thin-layer chromatography (TLC) using toluene:ethyl acetate:methanol (10:1:2, v/v) as the developing solvent, the fractions (9-13) were purified by preparative reverse phase high performance liquid chromatography (RP-HPLC) using the LC-8 stainless-steel column (5 μm, 250 x 21 mm id, Supelco) and methanol:water (50:50 v/v) as eluent at a flow rate of 6mL/min. The effluents were monitored at 217 nm. Aza-A thus obtained was about 96% pure according to HPLC analysis. The structure of aza-A was confirmed by NMR (13C). In the second study, six minor triterpenoids, i.e., azadirachtin B (aza-B), azadirachtin H (aza-H), desacetylnimbin (Dnim), desacetylsalannin (Dsal), nimbin (Nim) and salannin (Sal) were isolated by injecting 4.2 g of Aza-A 60 (700 mg/run) in CCC, using the same conditions as described for the isolation of aza-A. After the six injections, two main fractions were obtained and monitored by TLC with 97% of the injected material being recovered. The first fractions (9-13) were purified by RP-HPLC as described above to obtain aza-B and aza-H, both 97% pure as attested by analytical HPLC. The second fraction (17-30) was purified using methanol:water (60:40 v/v) at a flow rate of 8 mL/min, with dnim, dsal, nim and sal being obtained (each 97% pure) according to HPLC analysis and their structures being confirmed by NMR (13C). The nematicidal activity against Heterodera glycines of all the above-purified compounds and crude extracts was evaluated. The mobility of the second stage juveniles (J2) was evaluated by the inverted tube methodology. A smaller recovery (P 0.05) of J2 treated with the aqueous crude (l/2 and 1/10 v/v) and methanolic (1000 ppm) extract was obtained while the hexane extract did not present activity. The activity of the aqueous crude and methanolic extracts was likely due to the presence of saponins and triterpenoids (limonoids), respectively. In the greenhouse assay, soy plants inoculated with juveniles treated with the aqueous (l/2 and 1/10 v/v) or methanolic (1000 ppm) extract produced less females and eggs (P 0,05) as compared to the control. The extract Aza-A 60 (70 ppm) caused larger immobility (P 0,05) of J2 (92%), proportional to the studied concentrations. The mortality of J2 for all the isolated triterpenoids at concentrations of 0.8, 8 and 80 ppm was evaluated with a reduction in the number of the J2 recovered, observed with increase of the applied dosages. Nim and Sal at 80 ppm were the most effective causing 99% mortality. Soy plants inoculated with J2 treated with the triterpenoids at 80 ppm presented medium nematicidal effect of 95%, reducing the number of females and eggs (P 0,05) as compared to the control. In regard to egg hatching, the triterpenoids tested at 100 ppm showed medium ovicide activity (P 0,05) of 50% as compared to the control with no nematostatic activity being observed 96 h after treatment.

The understanding of plant defense response in plant-pathogen interaction provides useful information to combat the disease. Soybean cyst nematode (SCN), Heterodera glycines, and charcoal rot causing fungus, Macrophomina phaseolina, are major pathogens of soybean, Glycine max, and infestation with SCN has found to aggravate the fungal disease severity. The gene expression analysis in resistant and susceptible interactions between H. glycines and G. max has identified some candidate resistance genes and signaling pathways but they are yet to be fully characterized. This dissertation aims to characterize one such gene, Conserved Oligomeric Golgi (COG) complex. The COG complex is important in structural and functional integrity of Golgi complex among eukaryotes, but very little is understood about its role in plants. This study demonstrated a defensive role of the COG complex in G. max against H. glycines. The transgenic plants for overexpression of COG genes, which were originally susceptible to the pathogen, showed reduced parasitism. In contrast, the RNA interference (RNAi) in originally resistant soybean lines showed a marked increase in parasitism. Further, these COG genes were found to be inducible by harpin elicitor molecules. In another study, the already proven resistance genes (NDR1, NPR1, EDS1 and TGA2) against H. glycines were investigated against the fungal pathogen. The transgenic plants for overexpression of these genes showed reduced disease severity, while the RNAi resulted increased severity compared to control lines. In addition, the H. glycines parasitism study and the candidate gene expression analysis in M. Phaseolina susceptible and moderately resistant G. max indicate that there are some cross communications between the defense processes of G. max to H. glycines and M. phaseolina.

Plant-parasitic nematodes represent a substantial constraint on global food security by reducing the yield potential of all major crops, including soybean (Glycine max L.). The soybean cyst nematode (SCN) (Heterodera glycines I.) is widely distributed across all soybean production areas of the US, and is the major yield-limiting factor, especially in the Midwestern US. Double cropping (DC) is defined as producing more than one crop on the same parcel of land in a single growing season. Compared to conventional single annual crops, DC provides many advantages, including improving soil health, enhanced nutrient provisioning to plants, improvement of soil physical properties, control of erosion, decrease in tillage requirements, and enhanced profitability. In some double-cropping systems, soybean is planted following winter wheat (Triticum aestivum L.), and several reports suggest the potential of wheat to suppress SCN populations. Field trials were conducted from 2017 to 2018 to investigate the effect of wheat on SCN populations in double-cropping soybean. Nine fields with three levels of initial SCN populations (low, moderate, and high) were selected in Illinois. Wheat was planted in strips alternating with strips-maintained weed-free and under fallow over winter and early spring. Soybean was planted in all strips after the wheat harvest. Soybean cyst nematode egg densities were acquired at four time points: wheat establishment, post-wheat/pre-soybean, mid-soybean (R1 growth stage or beginning of flowering), and post-soybean harvest. Wheat strips reduced SCN egg densities compared with fallow strips at the R1 stage (−31.8%) and after soybean harvest (−32.7%). Field locations with noted SCN suppression were selected for a metagenomics study. The structure of fungal communities differed significantly between DC and fallow plots at soybean planting and after harvest (P<0.001). Fungal populations were affected by location at all sampling times and by treatments before planting and after soybean harvest. Several enriched fungal and bacterial taxa in wheat plots, including Mortierella, Exophiala, Conocybe, Rhizobacter spp., and others, were previously reported to parasitize SCN and other plant-parasitic nematodes. Knowing that phytocompounds with potential nematicidal activity are released via the root system of plants, we implemented a gas chromatography–mass spectrometry (GC-MS) pipeline to investigate the profile of phytochemicals in soil samples collected from these fields and reviewed the potential nematicidal activity of compounds with higher concentration in double cropping fields. A total of 51 compounds were detected with the GSMS analysis, 8 with unknown identification. Several compounds, including multiple fatty acids, had greater relative peak areas in double-cropping samples compared to fallow. This multi-approach study provides a better understanding of the mechanisms governing wheat's effect on SCN populations. Rather than a single mechanism, the suppression of SCN in soybean fields double-cropped with winter wheat is potentially linked to enriched microbial communities, increased populations of beneficial organisms, and higher concentrations of phytochemicals with nematicidal activity. This is the first study implementing metagenomics and GCMS to characterize soil microbial and chemical profiles in soybean fields double-cropped with winter wheat. Finally, a set of studies were conducted to evaluate the effect of two seed-applied succinate dehydrogenase inhibitors (SDHI) compounds, fluopyram and pydiflumetofen, on SCN population densities, plant injury, and plant growth. Next-generation sequencing was later employed to identify transcriptomic shifts in gene expression profiles of soybean seedlings treated with fluopyram and pydiflumetofen. Fluopyram reduced both SCN egg and cyst counts in comparison to pydiflumetofen and the untreated control. RNA expression patterns of seed treatments clustered by sampling time (5 DAP vs 10 DAP). Multiple DEGs identified in soybean seedlings treated with fluopyram are reported to be linked to systemic resistance, suggesting a role of systemic resistance on the suppression of SCN by fluopyram. The non-target inhibition of soybean succinate dehydrogenase genes by fluopyram may be the origin of the phytotoxicity symptoms observed and potentially the cause of the systemic resistance activation reported in the current study. To our knowledge, this is the first report of systemic resistance being activated by fluopyram in addition to the suppression of soybean succinate dehydrogenase (SDH) and ubiquinone oxidoreductase genes. This work helps to elucidate the mechanisms of suppression of SCN by fluopyram

Made available in DSpace on 2017-07-10T17:37:10Z (GMT). No. of bitstreams: 1 Hamilton Santana.pdf: 702139 bytes, checksum: d0ac4361cec105b090cd85a79db56ad3 (MD5) Previous issue date: 2007-08-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The Cyst Nematode is one of the main soybean crop pathogens in the world levels. In Brazil, such nematode is spread throughout Brazilian regions in which soybean is grown and its damage for soybean crops is dependent on the infestation level on the field. In Paraná State, this species is widely distributed, and it has been reported in 11 counties in the western region. The physiological race determination in such species is fundamentally important for the recommendation of resistant soybean cultivars to H. glycines. This work aimed to study the genetic variability in H. glycines polycystic populations collected from infested areas, through the identification of physiological races in monocystic populations by tests in soybean differential plants. It was also aimed at testing the reaction of soybean commercial cultivars to H. glycines to race 3. Field population and monocystic isolates from H. glycines, collected in Cruz Alta (RS), Porto Mendes (PR) and Novo Horizonte (PR), were developed in CD 202 soybean plants. Soybean differentials and soybean commercial cultivars were seeded in tubes, inoculated in the V1 stage with 5.000 eggs and J2 and kept in a greenhouse under temperature ranging from 28 to 30oC. The greenhouse essays followed a completely randomized design with seven replications. The physiological race identification was carried out with two field populations and nine monocystic isolates whereas the resistance test was developed on 18 commercial cultivars. The evaluation procedure was accomplished at 28 days apart the inoculation and based on the Parasitism Index (PI). The PI was calculated on the number of females and cysts found on the differentials and the cultivars tested in relation to the check cultivar LEE . The tests in differential plants with monocystic isolates revealed the presence of the races 2, 5 and 6 to Porto Mendes, 3 and 6 to Cruz Alta and 5 and 6 to Novo Horizonte. Field populations showed the presence of race 6 in Porto Mendes and race 3 in Cruz Alta. Most of commercial cultivars tested were resistant to H. glycines race 3 while the cv. Liderança and the CD 217 presented susceptibility. The results showed that the race identification from monocystic isolates assists in the identification of genetic variability in field populations of H. glycines, what is not possible according to the race scheme based in polycystic populations extracted from the soybean crop fields / O nematóide de cisto é um dos principais patógenos da cultura da soja a nível mundial. No Brasil, este nematóide encontra-se disseminado em praticamente todas as regiões produtoras de soja, sendo responsável por perdas de produtividade variáveis, dependendo do nível de infestação a campo. No Paraná, esta espécie encontra-se amplamente distribuída, tendo sido relatada em 11 municípios somente da região oeste do estado. A determinação de raças fisiológicas de H. Glycines é de fundamental importância para a recomendação de cultivares de soja resistentes a este patógeno. Objetivou-se com o presente trabalho, estudar a variabilidade genética presente em populações policísticas de H. glycines coletadas a campo, através da identificação de raças fisiológicas de populações monocísticas, a partir de testes em plantas hospedeiro-diferenciadoras. Objetivou-se também testar a reação de cultivares comerciais de soja à raça 3 de H. glycines. Populações de campo e isolados monocísticos de H. glycines, provenientes dos municípios de Cruz Alta (RS), Porto Mendes (PR) e Novo Horizonte (PR), foram multiplicados em plantas de soja CD 202 . Plantas hospedeiro-diferenciadoras e cultivares comerciais de soja foram semeados em tubetes, inoculados no estádio V1 com 5.000 ovos e J2 e mantidos em casa-de-vegetação com temperatura variando de 28 a 30 oC. Os testes em casa-de-vegetação seguiram o delineamento inteiramente casualizados com sete repetições. A identificação de raças fisiológicas foi realizada em duas populações de campo e nove isolados monocísticos e o teste de resistência em 18 cultivares. comerciais. As avaliações foram feitas aos 28 dias após a inoculação com base no Índice de Parasitismo (IP). O IP foi calculado em função do número de fêmeas e cistos encontrados nas diferenciadoras e cultivares testados em relação ao padrão de suscetibilidade e multiplicado por 100. Os testes em plantas diferenciadoras com isolados monocísticos revelou a presença das raças 2, 5 e 6 para Porto Mendes, 3 e 6 para Cruz Alta e 5 e 6 para Novo Horizonte. Populações de campo revelaram a presença da raça 6 para Porto Mendes e da raça 3 para Cruz Alta. A maioria dos cultivares comerciais testados foram resistentes à H. glycines raça 3, enquanto que a cv. Liderança e a CD 217 apresentaram-se suscetíveis. Os resultados mostraram que a identificação de raças a partir de isolados monocísticos de H. glycines auxilia na identificação da variabilidade genética presente em populações de campo, o que não é possível mediante a determinação de raças com base em populações policísticas obtidas a campo

Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2014-10-14T14:34:16Z No. of bitstreams: 2 Tese - Fernando Godinho de Araujo - Agronomia.pdf: 1300550 bytes, checksum: 2fcb22f0659c2649971101a837569973 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Jaqueline Silva (jtas29@gmail.com) on 2014-10-17T21:38:21Z (GMT) No. of bitstreams: 2 Tese - Fernando Godinho de Araujo - Agronomia.pdf: 1300550 bytes, checksum: 2fcb22f0659c2649971101a837569973 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-10-17T21:38:21Z (GMT). No. of bitstreams: 2 Tese - Fernando Godinho de Araujo - Agronomia.pdf: 1300550 bytes, checksum: 2fcb22f0659c2649971101a837569973 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2013-07-04 / Soybean is the most important oilseed crop grown in the world and Brazil is the second largest producer. Many pest problems can affect soybean, including the soybean cyst nematode, Heterodera glycines. The search for efficient management alternatives of this nematode and understanding of their biology have been largely studied, but still lacking information. Experiments were conducted under greenhouse conditions and naturally infested field aiming to better understand the behavior of H. glycines and to propose management alternatives. The first study had the purpose to evaluate the penetration and life cycle of H. glycines, race 3 (HG Type 0 -) in soybean cultivars resistant (BRSGO 8860RR) and susceptible (BRS Valiosa RR) under greenhouse conditions. Evaluations in stained roots were made at 2, 4, 6, 9, 12, 15, 18, 21, 24 and 30 days after inoculation (DAI). The penetration of H glycines occurred throughout the period of evaluation in both cultivars. The H. glycines life cycle was completed in 15 days, both in the susceptible and resistant cultivars. Resistant cultivar had the peak period of formation of J3, J4 and females delayed in comparison with the susceptible cultivar. The second study aimed to evaluate effectiveness of the resistance to H. glycines under high inoculum concentration, and the effect of increasing inoculum rates on the penetration of juveniles and H. glycines survival. Two experiments were conducted using three soybean cultivars (BRS Valiosa RR, susceptible to H. glycines; BRSGO Chapadoes and BRSGO 8860RR, both resistant to H. glycines) under four inoculum concentrations (1.000, 2.500, 5.000 and 10.000 eggs and J2 per plant). The increase in the H. glycines inoculum concentration increased the final nematode population in the susceptible cultivar. The cultivar resistance was not affected by high inoculum concentration. The root penetration of J2 increased as the inoculum concentration increased regardless the cultivar. The survival rate was higher in the susceptible cultivar decreasing with increasing of inoculum concentration. The third study evaluated the effect of seed treatment two soybean cultivars (resistant BRSGO 8860RR and susceptible BRS Valiosa RR). Two experiments were conducted, one in a naturally infested field and other under greenhouse conditions. The seed treatments did not affect the stand and the plant height of the resistant soybean cultivar. There was no effect of seed treatments on the nematode population in the field experiment. Under greenhouse, seeds treated with abamectin (50 and 75 mL a.i. 100 kg seed-1) + thiamethoxam (70 mL a.i.), imidacloprid + thiodicarb (105+315 mL a.i.) and thiodicarb + imidacloprid with carbendazim + thiram (75+225 e 30+70 mL a.i.) reduced the number of females per gram of roots on the susceptible cultivar. Seed treatment with imidacloprid + thiodicarb (75+225 mL a.i.) also reduced the number of eggs per female on the resistant cultivar BRSGO 8860RR. / A soja é a mais importante oleaginosa cultivada no mundo sendo o Brasil o segundo maior produtor. Diversos problemas fitossanitários afetam a cultura da soja, dentre eles o nematoide de cisto da soja, Heterodera glycines. A busca por alternativas de manejo eficiente desse nematoide e a compreensão de sua biologia têm sido temas muito difundidos, mas ainda carente de estudos. Dessa forma, foram conduzidos experimentos em condições de casa de vegetação e campo naturalmente infestado visando conhecer melhor o comportamento de H. glycines e propor alternativas para seu manejo. O primeiro estudo teve como objetivo avaliar a penetração e a duração do ciclo de H. glycines, raça 3 (HG tipo 0-), em cultivares de soja resistente (BRSGO 8860RR) e suscetível (BRS Valiosa RR) em condições controladas de casa de vegetação. Foram realizadas avaliações de coloração de raiz aos 2, 4, 6, 9, 12, 15, 18, 21, 24 e 30 dias após a inoculação (DAI). A penetração do H. glycines ocorreu durante todo o período de avaliação nas duas cultivares. O ciclo do H. glycines se completou em 15 dias, tanto na cultivar suscetível como na cultivar resistente. Na cultivar resistente o período de pico de formação de J3, J4 e fêmeas foi atrasado em relação a cultivar suscetível. O segundo estudo teve como objetivo avaliar se a resistência ao H. glycines é eficiente na redução do desenvolvimento do nematoide, mesmo sob elevada concentração de inóculo, bem como se esse aumento na concentração de inóculo e a resistência afetam a penetração de juvenis e a taxa de sobrevivência do H. glycines. Foram conduzidos dois ensaios utilizando-se três cultivares de soja, uma suscetível (BRS Valiosa RR) e duas resistentes (BRSGO Chapadões e BRSGO 8860RR), submetidas a quatro concentrações de inóculo (1.000, 2.500, 5.000 e 10.000 ovos e J2 por vaso). O aumento na concentração inicial de inóculo de H. glycines resultou no aumento da população final do nematoide na cultivar suscetível. A reação de resistência das cultivares não foi afetada por altas concentrações de inóculo e a penetração de J2 nas raízes aumentou com o aumento da concentração de inóculo independentemente da cultivar. A taxa de sobrevivência do nematoide foi maior na cultivar suscetível diminuindo com o aumento da concentração do inóculo, não sendo influenciada pela concentração de inóculo para cultivares resistentes. O terceiro estudo teve como objetivo avaliar o efeito do tratamento de sementes de duas cultivares de soja resistente (BRSGO 8860RR) e suscetível (BRS Valiosa RR), com produtos a base de abamectina e tiodicarbe no manejo de H. glycines. Foram conduzidos dois experimentos, sendo um em campo naturalmente infestado e outro em condições de casa de vegetação. Os tratamentos de sementes não afetaram o estande e a altura das plantas de soja. Não foi observado efeito dos tratamentos de sementes sobre o nematoide no experimento conduzido em campo. Em condições de casa de vegetação os tratamentos de sementes com produtos a base de abamectina, nas dosagens de 50 e 75 mL i.a. 100 kg sementes-1 acrescido de tiametoxam (70 mL i.a.) e os tratamentos imidacloprido + tiodicarbe (105+315 mL i.a.) e imidacloprido + tiodicarbe e carbendazim + tiram (75+225 e 30+70 mL i.a.) reduziram o número de fêmeas por grama de raiz na cultivar suscetível. O tratamento de sementes com imidacloprido + tiodicarbe (75+225 mL i.a.) também reduziu o número de ovos por fêmea na cultivar resistente, BRSGO 8860RR.