A study was undertaken to investigate the morphological host-parasite interactions of selected resistant and susceptible lines of tomato to Meloidogyne incognita, M. incognita var. acrita, M. javanica, M. hapla and M. arenaria and to determine the mode of inheritance of nematode resistance and the number of genetic factors controlling resistance to the root-knot nematodes. Four resistant varieties of tomato were crossed with one susceptible variety. The F₁ populations showed hybrid vigor for height, yield, and fresh weight of roots, stems, and leaves. Resistance to M. javanica, M. incognita, M. incognita var. acrita was dominant and susceptibility was recessive. The F₂ populations segregated in a 3:1 ratio showing resistance is a monofactorial dominant character and controlled by the same gene. The resistant parents, and the F₁ and F₂ populations did not show resistance to M. hapla and M. arenaria. Anatomical studies showed that there were some slight differences between resistant and susceptible varieties. In resistant varieties a compact layer of cells was formed around the body of the nematode which may have caused the noticeable reduction in nematode development and egg-formation. Giant cells formed in resistant varieties were much smaller and fewer in number than in susceptible varieties. The contrast between these two reactions by the resistant and the susceptible hosts suggests that resistance is related to the cellular response of the host to the parasite. In the root penetration and attraction study it was observed that when 2000 larvae were used as inoculum, they freely penetrated the roots of susceptible seedlings whereas in resistant roots very few larvae entered and most remained half embedded in the roots even at the 96 hour interval after inoculation. When the concentration of the larvae inoculum was increased from 2000 to 8000 per seedling, the larvae entered the roots of resistant seedlings as freely and as rapidly as they entered the roots of susceptible ones, demonstrating that the concentration of inoculum is an important factor in penetration. / Ph. D.

Thesis (M. A. Agriculture (Plant Protection)) -- University of Limpopo, 2019 / Available potato (Solanum tuberosum L.) cultivars do not have any genotype that is resistant to the root-knot (Meloidogyne species) nematodes. Due to the susceptibility of potato cultivars to Meloidogyne species, alternative management strategies had to be researched and developed after the withdrawal of methyl bromide from the agro-chemical markets, amongst which were the cucurbitacin-containing phytonematicides. However, of the available application methods of phytonematicides, the ground leaching technology (GLT) and botinemagation technology were not suitable for use in most high-rainfall potato-producing regions, where production is under rain-fed conditions. The objective of the study, therefore, was to determine whether pre- and post-emergent application of Nemafric-BG phytonematicide would have effects on growth of potato and suppression of M. javanica population densities. Parallel pot trials of pre- and post-emergent application of Nemafric-BL phytonematicide were conducted under greenhouse conditions in autumn (February-April: Experiment 1) 2017 and validated (Experiment 2) in 2018. Each plant was inoculated with 3000 M. javanica eggs and second-stage juveniles (J2). Five treatments, namely, 0, 2, 4, 8 and 16 g concentration of Nemafric-BG phytonematicide, arranged in randomised complete block design, were either applied mixed with seed tubers for pre-emergent or spread on the soil surface after emergence for post-emergent trials. In all cases, plant growth variables were assessed using the Curve-fitting Allelochemical Response Data (CARD) model, whereas nutrient elements (Fe, K, Na and Zn) and nematode variables were assessed using analysis of variance, with data subjected to lines of the best fit. In pre-emergent application trial, plant height (R2 = 0.98) and fresh root mass (R2 = 0.99) exhibited quadratic relations, characterised by density dependent growth patterns with increasing concentrations of Nemafric-BG xv phytonematicide in Experiment 1, similar trends were also observed on plant height (R2 = 0.99) and root mass (R2 = 0.99) in Experiment 2. In contrast, in post-emergent application trial, plant height (R2 = 0.97), fresh root mass (R2 = 0.99) and dry shoot (R2 = 0.98) exhibited quadratic relations in Experiment 1, which ascribed to DDG patterns, similar trends were also observed in Experiment 2 on plant height (R2 = 0.99), fresh root mass (R2 = 0.96) and dry shoot (R2 = 0.99) of potato cv. ꞌMondial G3ꞌ. In pre-emergent application trials, Mean Concentration Stimulation Point (MCSP) = 24.18 and 7.82 g, respectively, in Experiment 1 and Experiment 2, with ∑k being equivalent to 20 and 6 units for potato to the product, respectively, in Experiment 1 and Experiment 2. In contrast, post-emergent application trials, MCSP = 9.87 and 12.10 g, respectively, in Experiment 1 and Experiment 2, whereas the ∑k value for potato to the product was 11 and 6 units, respectively in Experiment 1 and Experiment 2. Increasing concentrations of the phytonematicide significantly (P ≤ 0.05) affected the selected nutrient elements. In pre emergent application trials, K (R2  =  0.96) Na (R2  =  0.90) and Zn (R2  =  0.83) each with increasing Nemafric-BG phytonematicide concentrations exhibited positive quadratic fashion, while Fe (R2  =  0.87) exhibited negative quadratic relations in Experiment 1. In Experiment 2, K (R2  = 0.99), Na (R2  = 0.90) and Zn (R2 =  0.97) contents each in leaf tissues against the increasing concentrations of the phytonematicide exhibited negative quadratic relations, while Fe (R2  = 0.88) exhibited positive quadratic relations. In post emergent trials, Fe (R2 = 0.91, Na (R2 = 0.90) and Zn (R2 = 0.99) contents in leaf tissues against increasing Nemafric-BG phytonematicide concentration exhibited negative quadratic relations, whereas K (R2 = 0.86) exhibited positive quadratic relation in Experiment 1. In Experiment 2, Fe (R2 = 0.93), K (R2 = 0.92), Na ( R2  = 0.79) and Zn (R2 xvi = 0.89) contents in leaf tissues of potato exhibited positive quadratic, respectively. In pre emergent trial for Experiment 1, eggs in roots (R2 = 0.78), J2 in roots (R2 = 0.85), J2 in soil (R2 = 0.97) and Pf (R2 = 0.78) of M. javanica against increasing pre-emergent application concentrations of Nemafric-BG phytonematicide exhibited negative quadratic relations, characterised by DDG patterns. Similar trends were observed on eggs in roots (R2 = 0.82), J2 in roots (R2 = 0.99), J2 in soil (R2 = 0.84) and Pf (R2 = 0.85) in Experiment 2. In contrast, in post-emergent application trial, eggs in roots (R2 = 0.87), J2 in roots (R2 = 0.99), J2 in soil (R2 = 0.91) and Pf (R2 = 0.99) of M. javanica against increasing post emergent application concentrations of Nemafric-BG phytonematicide also exhibited negative quadratic relations in Experiment 1, which ascribed to DDG patterns. Similar trends were also observed on eggs in roots (R2 = 0.72), J2 in roots (R2 = 0.68), J2 in soil (R2 = 0.85) and Pf (R2 = 0.83) in Experiment 2. Results from the study demonstrated that Nemafric-BG phytonematicide stimulated plant growth at lower concentration and the product does not have any detrimental effects in accumulation of nutrient elements in leaf tissues. Therefore, it is concluded, that the product could be applied at the recommended rates of 7.82 and 9.87 g/plant in pre and post-emergent application, respectively, for the management of root-knot nematodes, provided the active ingredient does not accumulate in potato tubers or have any detrimental effects in accumulation of nutrient elements in tubers and temper with nutritional value of potatoes.

Thesis (M.Sc. Agriculture (Soil Science)) -- University of Limpopo, 2019 / Nutritional water productivity (NWP) is an assessment tool, which describes the amount of water that has been used to produce selected mineral malnutrition (MMN) elements and micronutrient malnutrition (MNMN) substances. Therefore, it links agricultural production to human nutrition. Deficiencies in MMN elements and/or MNMN substances in human nutrition referred to as malnutrition, had been linked with fatal diseases. Agricultural soils could be affected by soil-borne pathogens such as plant-parasitic nematodes, which could limit the availability of MMN elements and MNMN substances. In some communities, vegetable crops, including chilli are regarded as a major source of MMN elements and MNMN substances. Effects of root-knot (Meloidogyne species) nematodes on NWP of chilli (Capsicum annuum L.) have not been documented. The objective of the study was to determine the effects of increasing population densities of M. incognita race 2 and M. javanica on the NWP of hot chilli plants. A microplot trial was conducted at the Green Biotechnologies Research Centre of Excellence (GBRCE), University of Limpopo, South Africa. Pots were filled with 10-L steam-pasteurised (300oC) sandy clay loam soil sourced from GBRCE and Hygromix-T (Hygrotech, Pretoria North) growth medium in the ratio 3:1 (v/v). Thereafter, three-week-old hot chilli cv. 'Serrano' seedlings were transplanted into each pot, with inoculum prepared by extracting eggs and second-stage juveniles (J2) of M. incognita race 2 and M. javanica from roots of grown nematode susceptible tomato cv. 'Floradade' (Solanum lycopersicum L.) in a 1% NaOCl solution. Fourteen days after transplanting, treatments 0, 50, 125, 250, 625, 1250 and 2000 eggs and second-stage juveniles (J2) of M. incognita race 2 and M. javanica were separately inoculated using a 20 ml plastic syringe into 5-cm-deep holes in pots. At 56 days after the initiation of the treatments, Meloidogyne species xiv decreased soil pH and increased organic carbon, contributing 29 and 43% in total treatment variation (TTV) of the respective variables. Treatment effects caused the pH to decrease. NWP variables against increasing nematode numbers exhibited quadratic relations, with coefficients of determination ranging from 59 to 86% for M. incognita race 2 trial and 80 to 98% for M. javanica trial. Meloidogyne species population densities against plant variables did not show any significant relationship, except for root galling and chlorophyll content where treatments contributed 76, 98 and 47% TTV of the respective variables. Generally, root galling increased with increase in Meloidogyne species population densities, whereas chlorophyll content decreased with increasing inoculum levels. Nematode variables against their increasing population exhibited quadratic relationship with the model explained by 44 to 95% for M. incognita race 2 and 28 to 82%, association, respectively for M. javanica. In conclusion, Meloidogyne species interfered with NWP of mineral elements in chilli plant and therefore, nematode management practices should be done to reduce the nematode population densities that would confer quality to agricultural produce for human health benefits.

Thesis (M. Sc. (Plant Protection)) -- University of Limpopo, 2021 / Worldwide, root-knot (Meloidogyne species) nematodes are considered to be the most important and damaging genus in crop husbandry. The existence of a wide host range, over 2000 plants, and several biological races, makes the management of this nematode genus difficult with nematode-resistant crop Hybrid Sorghum Sudan grass (Sorghum bicolor × Sorghum Sundanese) has been classified as being resistant to certain Meloidogyne species and races, with a wide range of uses in crop rotation intended to manage nematode population densities. However, due to the ability of nematodes to enter chemiobiosis when gradually exposed to chemicals, this hybrid might not be effective in managing nematode population densities for the subsequent highly susceptible sweet potato (Ipomoea batatas L.) cultivars. The objective of the study was to determine whether hybrid Sorghum-Sudan grass would suppress M. javanica (Trial 1), M. incognita race 2 (Trial 2) and M. incognita race 4 (Trial 3) population densities, allowing a nematode susceptible sweet potato cv. ′Beauregard′ as successor crop to be cultivated without suffering nematode damage. The hybrid Sorghum-Sudan grass study was conducted under greenhouse conditions, with seven inoculation levels, namely, 0; 5; 25; 125; 625; 3 125 and 15 625 eggs and second-stage juveniles (J2) of each nematode species or race, arranged in randomised complete block design, with six replications and validated in time. Plant growth, foliar nutrient elements and nematodes were collected at 56 days after inoculation and prepared for analysis using standard methods. The reproductive factor (RF) at all levels was zero, whereas nematode inoculation at all levels did not have any effect on plant growth of the hybrid Sorghum-Sudan grass. However, the nematode levels affected the accumulation of nutrient elements and the quality of forage. After cultivating the susceptible sweet potato cultivar in pots xxx previously with hybrid Sorghum-Sudan grass at increasing levels of M. javanica alone, that is in Trial 1, similar results were observed with respect to RF and lack of nematode damage to plant growth. Consequently, the hybrid was suitable for use in crop rotation with sweet potato for the purpose of managing nematode population densities of thermophilic Meloidogyne species and/or races. / National Research Foundation of South Africa (NRF) and the Agricultural Research Council (ARC)

No description available.

Plant parasitic nematodes cause billons of dollars in annual crop losses. One of the most damaging is the root-knot nematode, Meloidogyne incognita, which is known to attack more than 3000 plants. This research will contribute to the understanding of host-plant resistance through characterization of the early infection processes of Meloidogyne incognita race 3 in susceptible (Lahontan) and resistant (Moapa) alfalfa cultivars by light microscopy and transmission electron microscopy. Neither differential penetration of M. incognita J2 into Lahontan, nor migration of J2 from Moapa, played a significant role in the resistance mechanism(s). Coiled nematodes in the cortex were observed in greater numbers in the Moapa 48 hours after inoculation. This position was interpreted as a sign of disorientation and starvation. By 96 hours after inoculation, no coiled nematodes were observed in Lahontan. In Moapa, resistance probably depends not only on the failure of the J2 to identify a suitable feeding site and initiate giant cells, but also on its inability to maintain the giant cells, once they are initiated. At the ultrastructural level, 48 hours after inoculation, the most evident change in both cultivars was the appearance of a uniform interstitial material (IM) between the nematode cuticle and the root cell wall. At 96 hours, IM in Moapa was completely agglutinated while in Lahontan it was still uniform or only slightly agglutinated. Due to these clear differences between both cultivars I propose that the IM plays a role in the resistance of Moapa to M. incognita. Immunolabeling techniques were employed to determine if the distribution of the nematode's surface coat, deposited in host tissues, differs in resistant and susceptible alfalfa cultivars. At 72 hours after inoculation, labeling of surface coat epitopes in Moapa was stronger than at 24 and 48 hours after inoculation. Labeling was observed on the nematode's cuticle, the plant cell wall, and the IM. In Lahontan, 72 and 96 hours after penetration, labeling of the surface coat epitopes was observed on the nematode's cuticle, the root cell walls, and the cell wall junctions of cells near the nematode, but not in direct contact with the cell.

Submitted by Michele Mologni (mologni@unoeste.br) on 2019-01-24T16:37:31Z No. of bitstreams: 1 Lorrayne Guimarães Bavaresco.pdf: 1579894 bytes, checksum: be828e9da52619462a559db48496ff9a (MD5) / Made available in DSpace on 2019-01-24T16:37:31Z (GMT). No. of bitstreams: 1 Lorrayne Guimarães Bavaresco.pdf: 1579894 bytes, checksum: be828e9da52619462a559db48496ff9a (MD5) Previous issue date: 2018-08-08 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Among the forms of biological control, the use of rhizobacteria has shown to be promising in the suppression and protection of plants against the attack of phytonematoids. The objective of this work was to evaluate the effect of Bacillus subtilis on the reproduction of Meloidogyne spp., associated to changes in rhizosphere colonization and growth, nutrition and enzymatic activity of tomato cultivars tolerant and susceptible to root-knot nematodes. The methods of application consisted of the inoculation of Bacillus subtilis (AP-3) in pre-planting and post-planting of the tomato. Two experiments were conducted in a plant growth chamber. In the first experiment the tomato plants were cultivated on a sterile substrate, inoculating 5000 eggs of Meloidogyne incognita. In the second, tomato cultivation was carried out in sandy soil naturally infested with root-knot nematodes. The plant growth, nematode reproduction, soil and rhizosphere colonization by bacteria of the genus Bacillus spp., and biochemical changes were evaluated at 40 days after transplanting of the tomato. In both modes of application, the Bacillus subtilis was efficient in increasing root mass and in reducing the reproduction of the root-knot nematode in susceptible tomato cultivated in naturally infested soil. In sterile substrate, inoculation of B. subtilis in post-planting promoted reduction of the number of active forms of the nematode and both applications promoted the decrease of eggs of Meloidogyne incognita in the roots of the tomato. The application of B. subtilis, as a sterile substrate, induced changes in the nutritional uptake of tomato plants, increasing calcium levels and reducing leaf potassium. The application of B. subtilis contributed to the reduction of the peroxidase activity in leaves of the tomato susceptible to root-knot nematodes, in sterile condition. The rhizobacteria, after planting, allowed the increase in the proline content in the leaves of the tomato, cultivated in soil naturally infested with root-knot nematodes. Inoculations with B. subtilis promoted an increase in the number of Bacillus spp. in the sterile substratum and in the rhizosphere of the tomato, being confirmed the persistence of these bacteria at 40 DAP. / Dentre as formas de controle biológico, a utilização de rizobactérias tem se mostrado promissora na supressão e proteção de plantas ao ataque de fitonematoides. O presente trabalho teve como objetivo avaliar o efeito da aplicação de Bacillus subtilis na reprodução de Meloidogyne spp., associado as alterações na colonização da rizosfera e no crescimento, nutrição e atividade enzimática de cultivares de tomateiro tolerante e suscetível aos nematoides-das-galhas. Os modos de aplicação estudados consistiram na inoculação do Bacillus subtilis (AP-3) em pré-plantio e pós-plantio do tomateiro. Foram conduzidos dois experimentos em câmara de crescimento de plantas. No primeiro experimento as plantas de tomateiro foram cultivadas em substrato esterilizado, com inoculação de 5000 ovos de Meloidogyne incognita. No segundo, o cultivo do tomateiro foi realizado em solo arenoso naturalmente infestado por nematoides-das-galhas. Aos 40 dias após o transplantio das mudas, foram avaliados o crescimento das plantas, a reprodução do nematoide, a colonização do solo e da rizosfera por bactérias do gênero Bacillus spp. e as alterações bioquímicas do tomateiro. Em ambos os modos de aplicação, o Bacillus subtilis foi eficiente em aumentar a massa radicular e em reduzir a reprodução do nematoide-das-galhas em tomateiro suscetível, cultivado em solo naturalmente infestado. Em substrato estéril, a inoculação de B. subtilis em pós-plantio promoveu redução do número de formas ativas do nematoide e ambas as aplicações promoveram a diminuição de ovos de Meloidogyne incognita nas raízes do tomateiro. A aplicação de B. subtilis, na condição de substrato estéril, induziu mudanças na absorção nutricional do tomateiro, aumentando os teores de cálcio e reduzindo o potássio foliar. A aplicação de B. subtilis contribuiu para redução da atividade peroxidase nas folhas do tomateiro suscetível a nematoides-das-galhas, em condição estéril. A rizobactéria, em pós-plantio, possibilitou o aumento no teor de prolina nas folhas do tomateiro, cultivado em solo naturalmente infestado com nematoides-das-galhas. As inoculações com B. subtilis promoveram aumento do número de Bacillus spp. no substrato estéril e na rizosfera do tomateiro, sendo comprovada a persistência destas bactérias aos 40 DAP.

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.