O gênero Eucalyptus possui diversas espécies que apresentam grande valor comercial, sendo utilizado principalmente para produção de energia (carvão e lenha) e celulose-papel. Na literatura, entretanto, existem poucas informações acerca de nematoses nessa cultura. Além dessa carência e de sua importância econômica, o eucalipto é comumente cultivado em locais de alta incidência de Pratylenchus brachyurus e Meloidogyne incognita, além de ser consorciado com diversas outras culturas intolerantes, como por exemplo a soja. Dessa forma há uma necessidade de conhecer a reação das espécies de eucalipto a estes nematoides. Dito isso, o presente trabalho teve por objetivo testar a reação de algumas espécies de eucalipto a P. brachyurus e M.incognita. Foram realizados 6 experimentos, 5 envolvendo o nematoide das lesões e 1 com o nematoide de galhas. Os tratamentos foram inoculados com uma população inicial de nematoides e, após 90 dias, estimava-se o fator de reprodução (FR) e nematoides por grama de raiz (Nem/g). Adotou-se o critério baseado em Oostenbrink (1966), onde a espécie foi considerada suscetível quando apresenta FR >= 1 e resistente quando FR < 1. Dos eucaliptos testados, 6 apresentaram reação suscetível e 4 reação resistente para P. brachyurus. As espécies com maiores FR estão entre as mais utilizadas no Brasil, exceto E. saligna. Ressalta-se que estas não necessariamente são resistentes, necessitando apenas de um período maior para o estabelecimento do patógeno. Observou-se indícios de que E. saligna e E. camaldulensis sejam intolerantes a P.brachyurus. Para M. incognita raça 3 todas as espécies testadas foram resistentes. Aconselha-se a realização de experimentos com períodos superiores a 100 dias para uma correta classificação da reação de hospedeiro. O eucalipto é uma opção para aproveitamento de áreas infestadas com M. incognita raça 3, porém seu uso mostra-se um risco em áreas infestadas com P. brachyurus. / The Eucalyptus has several species with high commercial value and is used mainly for energy purpose (Charcoal and firewood) and paper. In the literature, however, there is little information about plant parasitic nematodes in this woody specie. In addition to this lack and its economic importance, eucalypts is also commonly cultivated in areas with high incidence of Pratylenchus brachyurus and Meloidogyne incognita, and consorted with several intolerant crops, such as soybean. Thus, there is a need to know the host status of the eucalypts species to these nematodes. With that, this work aimed to test the reaction of some Eucalyptus species to P.brachyurus and M. incognita. For this purpose six experiments were performed, five to test the lesion nematode and one to test the root-knot nematode. The treatments were inoculated and, after 90 days, it was estimated the reproduction factor (FR) and nematodes per gram of root (Nem/g). The present work adopted the criteria based on Oostenbrink (1966), where the species was considered susceptible when presenting FR >= 1 and resistant when FR < 1. Of species tested, six were susceptible hosts and four resistant host to P. brachyurus. The species with highest FR are among the most used eucalypts in Brazil, except E. saligna. It is emphasized that those species with FR < 1 are not necessarily resistant, requiring only a longer period for the pathogen establishment. There was some evidence that E. saligna and E. camaldulensis are intolerant hosts to P. brachyurus. To M. incognita Race 3 all tested species were resistant. It is advisable to perform experiments for periods longer than 100 days to a correct classification of host status. Eucalyptus is an option for utilization of areas infested with M. incognita race 3, but its use appears to be a risk in Pratylenchus brachyurus infested areas.

Submitted by (lucia.rodrigues@ufrpe.br) on 2017-02-17T13:25:26Z No. of bitstreams: 1 Arinaldo Pereira da Silva.pdf: 466696 bytes, checksum: 29af3e3cc868a579886430ae6457c0e1 (MD5) / Made available in DSpace on 2017-02-17T13:25:26Z (GMT). No. of bitstreams: 1 Arinaldo Pereira da Silva.pdf: 466696 bytes, checksum: 29af3e3cc868a579886430ae6457c0e1 (MD5) Previous issue date: 2012-02-29 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The development of resistant varieties is one of the most important alternative for rot-knot management on sugarcane fields. The present work had as objective to evaluate the development of the sugarcane varieties RB92579, RB93509, RB867515 and SP81–3250 under different densities of M. incognita and M. enterolobii, as well the genotypes effect on nematode reproduction, under greenhouse. One month old plants had the soil infested with increasing inoculum densities (0, 5000, 10000 and 20000eggs and juveniles per plant), in a completely randomized design, with evaluations 90 days after. The RB varieties presented higher fresh shoots biomass weight than SP813250 when parasited by M. enterolobii. Meloidogyne enterolobii had the life cycle completed in RB863129, SP813250 and RB867515, in contrast to RB92579. In relation to M. incognita, RB92579 stood out presenting the highest height, stalk number, stalk diameter and fresh root biomass weight. RB863129 presented lower gall index than the other varieties and lower number of eggs per root than RB867515 and SP813250. SP813250 showed the lowest stalk diameter and number, the lowest number of shoot and fresh root biomass and the highest number of eggs per plant. Plant growth was not affect by inoculum density of M. incognita or M. enterolobii. Inversely to M. enterolobii, plants parasited by M. incognita presented gall index higher than 3 and high reproduction factors. No models fitted either M. incognita or M. enterolobii population density to evaluated variables. / O desenvolvimento de variedades resistentes constitui uma das principais alternativas para o manejo dos nematoides formadores de galhas em cana-de-açúcar. O presente trabalho teve como objetivo avaliar o desenvolvimento das variedades, RB92-579, RB93-509, RB86-7515 e SP81–3250 sob diferentes densidades de M. incognita e M. enterolobii, e o efeito dos genótipos sobre a reprodução dos nematoides, em condições de casa de vegetação. Plantas com um mês de cultivo, tiveram o solo infestado com crescentes densidades de inoculo (0, 5000, 10000 e 20000 ovos e juvenis por planta) e foram avaliados ao 90 dias em delineamento inteiramente casualizado. As variedades RB apresentaram maior peso da biomassa fresca da parte aérea do que SP81-3250 quando parasitadas por M. enterolobii. RB86-3129, SP81-3250 e RB86-7515 garantiram o ciclo de vida de M. enterolobbi, enquanto que RB92579, não permitiu o seu completo desenvolvimento. Em relação a M. incognita, a variedade RB92-579 destacou-se das demais por apresentar significativamente maior altura do que RB86-3129 e RB86-7515, maior diâmetro do colmo que RB86-7515, maior número de colmos, número de perfilho e peso da biomassa fresca da parte aérea do que RB86-7515. RB86-3129 apresentou menor número e índice de galhas que as demais variedades e menor número de ovos por sistema radicular do que RB86-7515 e SP81-3250. SP81-3250 apresentou menor diâmetro e número de colmo, menor número de perfilho, menor biomassa fresca da raiz e maior número de ovos por planta. O desenvolvimento das plantas parasitadas por M. incognita ou M. enterolobii não foi afetado pela densidade de inoculo. No entanto, ao contrário de M. enterolobii, as plantas parasitadas por M. incognita apresentaram índices de galhas superiores a três e altos fatores de reprodução. Nenhum dos modelos testados descreveu significativamente as relações entre as variáveis analisadas e as densidades populacionais de M. incognita ou M. enterolobii.

Submitted by (lucia.rodrigues@ufrpe.br) on 2017-03-22T16:07:26Z No. of bitstreams: 1 Natalya Monique Ribeiro Barbosa.pdf: 540479 bytes, checksum: b3638a01426e2f087c88f8f1d9ef73d3 (MD5) / Made available in DSpace on 2017-03-22T16:07:26Z (GMT). No. of bitstreams: 1 Natalya Monique Ribeiro Barbosa.pdf: 540479 bytes, checksum: b3638a01426e2f087c88f8f1d9ef73d3 (MD5) Previous issue date: 2013-02-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Considering Meloidogyne incognita and M. javanica importance for sugarcane and reports of M. enterolobii in the crop in Northeastern Brazil, this study had as objective identifying through biochemical methods the species of Meloidogyne occurring in sugarcane fields of Pernambuco and Paraíba States and evaluating reproduction of this three species in association or individually on the variety RB 867515. It was identified 19 nematode populations, mostly constituted exclusively by M. incognita phenotype I1(Rm: 1.0) and I2 (Rm: 1.0, 1.1). Meloidogyne incognita, M. javanica and M. enterolobii, in association or individually, did not affect plant growth variables. RB 867515 was a good host for M. incognita and M. javanica, but not for M. enterolobii, permitting free reproductions for the former nematodes. Esterease phenotypes at the end of the experiment presented quantitative variations in the species ratios used for inoculation, indicating M. incognita prevalence over the other species. The second study evaluated Meloidogyne enterolobii penetration, development and life cycle length on sugarcane variety RB 98710 as well the reaction of the variety to the nematode parasitism. After soil infestation with M. enterolobii and M. javanica (control), roots were evaluated at 3, 7, 10, 17, 24, 31, 38 and 45 days after inoculation for nematode development. At 45 days, M. javanica complete the life cycle in contrast to the low number of vermiform and swollen juveniles and no adult female of M. enterolobii found in roots. Using different nematode initial population densities, M. enterolobii did not affect initial sugarcane development at 120 days after inoculation. In contrast to M. javanica, M. enterolobii reproduction was inhibited presenting reproductive factor always lower than 1. / Considerando a importância de Meloidogyne incognita e M. javanica em cana-de-açúcar e o assinalamento de M. enterolobii em canaviais do Nordeste, o primeiro estudo teve como objetivo identificar por métodos bioquímicos espécies de Meloidogyne ocorrentes em canaviais nos Estados de Pernambuco e Paraíba e avaliar a reprodução das três espécies, isoladamente e conjuntas, na variedade RB 867515. Foram identificadas 19 populações do nematoide, através da eletroforese de isoenzimas, a maioria constituída exclusivamente por M. incognita fenótipo I1(Rm: 1.0) e I2 (Rm: 1.0, 1.1). Meloidogyne incognita, M. javanica e M. enterolobii, isoladamente ou em população conjunta, não afetaram as variáveis de crescimento da planta avaliadas. RB 867515 mostrou-se boa hospedeira para M. incognita e M. javanica, mas não para M. enterolobii, permitindo que as duas primeiras espécies se multiplicassem livremente. Os fenótipos de esterase obtidos após a realização do experimento mostraram variações quantitativas nas proporções das espécies inoculadas, indicando prevalência de M. incognita sobre as demais. O segundo estudo avaliou a penetração, o desenvolvimento e o comprimento do ciclo de Meloidogyne enterolobii em cana-de-açúcar variedade RB 98710 e o comportamento dessa variedade em relação ao parasitismo do nematoide. Após a infestação do solo com M. enterolobii e M. javanica (testemunha), raízes foram avaliadas aos 3, 7, 10, 17, 24, 31, 38 e 45 dias após inoculação dos nematoides. Aos 45 dias, M. javanica conseguiu completar o ciclo, enquanto o número de formas vermiformes, salsichóides e ovoides de M. enterolobii foram reduzidos, não sendo encontradas fêmeas imaturas ou com massas de ovos. Utilizando diferentes densidades de inóculo, M. enterolobii não afetou o desenvolvimento inicial da cana-de-açúcar aos 120 dias após a inoculação. Ao contrário de M. javanica, M. enterololobii teve a reprodução inibida, apresentando sempre fatores de reprodução menores do que 1.

Made available in DSpace on 2017-07-10T17:36:55Z (GMT). No. of bitstreams: 1 2014_Diss_Rafael_Augusto_Swarowsky.pdf: 1265471 bytes, checksum: b7b6c650055a2ba1f2346656fda7a03d (MD5) Previous issue date: 2014-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Considering the importance of the tomato crop and the high costs of the control of Meloidogyne incognita with resistant cultivar or nematicides, grows the search of new alternatives to control the root-knot disease. The homeopathy may be an alternative way of control, by inducing resistance. This study aimed to evaluate the influence of the homeopathic drug Cina in the number of root galls, eggs and J2 present in the roots of tomato and soil, as well as the growth of tomato plants. The dynamizations used were 12, 24, 50, 100, 200, and 400CH (centesimal hahnemanian dilutions). It was also used the chemical carbofuran, 70% ethanol and water as control treatments. The assay was conducted in pots in greenhouse for the in vivo assay and in laboratory for the in vitro ones. In both assays, homeopathic treatments were diluted with distilled water to 0.1% before application. On the in vivo assay, the homeopathic drug was applied weekly by foliar spray. The first treatments were done three days before pathogen inoculation with approximately 5000 eggs and 500 J2 per pot. The evaluations were made 50 days after transplanting of the tomato seedlings and 44 days after inoculation. The Cina demonstrated effectiveness in stimulating root development, once the results of root volume were higher in homeopathic treatments than in control. Cina 100CH also favored the growth of the stalk diameter of the plants. However, the homeopathic product showed no nematostatic nor nematicide effect / Considerando a importância da cultura do tomateiro e os custos com variedades resistentes e com nematicidas para controle de Meloidogyne incognita, são necessárias alternativas para manejo da doença das galhas radiculares. A homeopatia pode ser uma alternativa de controle, através da indução de resistência de plantas. Este trabalho objetivou avaliar a influência do medicamento homeopático Cina quanto ao número de galhas radiculares, ovos e J2 presentes nas raízes do tomateiro e no solo, bem como variáveis de crescimento das plantas de tomate. As dinamizações usadas foram 12, 24, 50, 100, 200 e 400CH (centesimal hahnemanniana). Também foram utilizados como tratamentos para comparação o nematicida carbofurano, etanol 70% e água. O experimento foi conduzido em vasos dentro de estufa climatizada para ensaio in vivo e em laboratório para o ensaio in vitro. Em ambos os ensaios, os tratamentos homeopáticos foram diluídos em água destilada a 0,1% antes da aplicação. No ensaio in vivo o medicamento homeopático foi aplicado semanalmente por aspersão foliar. A primeira aplicação dos tratamentos foi realizada três dias antes da inoculação, com aproximadamente 5000 ovos e 500 J2 por vaso. As avaliações foram feitas 50 dias após o transplante das mudas de tomate e 44 dias após a inoculação. A Cina demonstrou eficiência em estimular o desenvolvimento radicular, pois os resultados de volume de raiz foram maiores nos tratamentos homeopáticos do que nas testemunhas. Cina a 100CH também favoreceu o crescimento do diâmetro de caule das plantas. Contudo, o medicamento homeopático não demonstrou nenhum efeito nematostático e nem nematicida

Abamectin is a blend of B1a and B1b avermectins that is being used as a seed treatment to control plant-parasitic nematodes on cotton. Data on the toxicity of abamectin and its effectiveness as a seed treatment to control Meloidogyne incognita or Rotylenchulus reniformis on cotton are lacking. The toxicity of abamectin was based on an assay of nematode mobility, LD50 values of 1.56 µg/ml and 32.9 µg/ml were calculated based on 2 hr exposure for M. incognita and R. reniformis, respectively. There was no recovery of either nematode after exposure for 1 hr to its LD50 concentration. Sublethal concentrations greater than 0.39 µg/ml for M. incognita and 8.2 µg/ml for R. reniformis reduced (P = 0.05) infectivity on tomato. In field trials, suppression (P = 0.05) of M. incognita was observed 32 DAP by abamectin seed treatment whereas no suppression of R. reniformis was observed. No suppression of M. incognita was perceived by abamectin seed treatment in microplots. Suppression of M. incognita was observed in microplots by harpinEA and harpingαβ as a seed treatment and foliar spray, respectively. Seed cotton yields were variable for abamectin-treated seed, but numerically positive for harpin-treated cotton. Initial gall formation on developing taproots was suppressed (P = 0.001), and penetration of 5-cm long taproots by M. incognita and R. reniformis was numerically suppressed by abamectin-treated compared to non-treated seed, but infection increased with root development. Using an assay of nematode mobility, the proportion of dead second-stage juveniles (J2) was higher (P = 0.05) following exposure to an excised radicle from abamectin-treated seed than non-treated seed, but lower (P = 0.05) than J2 exposed to the abamectin-treated seed coat. Thus a higher concentration of abamectin remained on the seed coat than emerging radicle. The concentration of abamectin transferred from the seed coat to the developing roots was limited, which contributed to the variability in suppression of plant-parasitic nematodes on cotton.

Abamectin is a blend of B1a and B1b avermectins that is being used as a seed treatment to control plant-parasitic nematodes on cotton. Data on the toxicity of abamectin and its effectiveness as a seed treatment to control Meloidogyne incognita or Rotylenchulus reniformis on cotton are lacking. The toxicity of abamectin was based on an assay of nematode mobility, LD50 values of 1.56 µg/ml and 32.9 µg/ml were calculated based on 2 hr exposure for M. incognita and R. reniformis, respectively. There was no recovery of either nematode after exposure for 1 hr to its LD50 concentration. Sublethal concentrations greater than 0.39 µg/ml for M. incognita and 8.2 µg/ml for R. reniformis reduced (P = 0.05) infectivity on tomato. In field trials, suppression (P = 0.05) of M. incognita was observed 32 DAP by abamectin seed treatment whereas no suppression of R. reniformis was observed. No suppression of M. incognita was perceived by abamectin seed treatment in microplots. Suppression of M. incognita was observed in microplots by harpinEA and harpingαβ as a seed treatment and foliar spray, respectively. Seed cotton yields were variable for abamectin-treated seed, but numerically positive for harpin-treated cotton. Initial gall formation on developing taproots was suppressed (P = 0.001), and penetration of 5-cm long taproots by M. incognita and R. reniformis was numerically suppressed by abamectin-treated compared to non-treated seed, but infection increased with root development. Using an assay of nematode mobility, the proportion of dead second-stage juveniles (J2) was higher (P = 0.05) following exposure to an excised radicle from abamectin-treated seed than non-treated seed, but lower (P = 0.05) than J2 exposed to the abamectin-treated seed coat. Thus a higher concentration of abamectin remained on the seed coat than emerging radicle. The concentration of abamectin transferred from the seed coat to the developing roots was limited, which contributed to the variability in suppression of plant-parasitic nematodes on cotton.

Root-knot disease caused by Meloidogyne spp. is the most important nematode disease of peanut. Even though many management strategies have been applied to control this disease on peanut, resistance is the most recommendable. Marker-assisted selection has been used as a useful tool for screening of resistant individuals in segregating populations. However, it requires many laborious steps. Thus, there is a need for PCR - based markers, which are more practical, rapid, and efficient. In this study, we tried to develop a SCAR marker linked to root-knot nematode resistance locus in peanut based on the RFLP marker R2430E. The entire sequence of R2430E was 2217 bp and contained one putative open reading frame (ORF) of 713 nucleotides. Thirteen primers including 5 forward and 8 reverse primers were synthesized to sequence the entireR2430E. Based on the results of BLAST searches, R2430E appeared to encode an AAA ATPase containing von Willebrand factor type A (VWA) domain from Magnetococcus sp. MC-1 (106 bits). To determine if there is a portion of the R2430E that hybridizes only to a band co-segregating with the resistance locus, we generated 4 probes spanning different parts of the gene. Southern analysis using these probes revealed identical banding patterns for each probe. Therefore, we concluded that there is very limited if any sequence polymorphism between different alleles detected by the R2430E probe. Additionally, this conclusion is supported by the experiment in which we tested 25 primer pairs derived from the R2430E using genomic DNA from both resistance and susceptible genotypes. In this experiment, all primer pairs amplified identical PCR fragments, suggesting again that there is little or no sequence divergence between putative alleles as differentiated by southern blotting. To identify possible single nucleotide polymorphisms (SNPs) between polymorphic R2430E RFLP bands, we cloned several fragments that span the entire R2430E transcribed sequence. Surprisingly, no SNPs were identified in the transcribed region of this gene. We propose that polymorphism detected by this RFLP marker is outside of the R2430E.

No description available.

No description available.

Thesis (M.S.)--University of Delaware, 2006. / Principal faculty advisor: Darla J. Sherrier, Dept. of Plant and Soil Science. Includes bibliographical references.