Objective – research the pine wood nematodes Bursaphelenchus sp. situation in Lithuania. Goals: 1. Research of native pine wood nematode species composition in Lithuania; 2. Research of preconditions for harmful pine wood nematode species to enter Lithuania; 3. Research of conditions for non-native pine wood nematode species to establish, breed and spread; 4. Research of consequences if harmful species becomes established in Lithuania, anticipate pest management options. Object of the study – coniferous (pine) forests in Lithuania and companies, processing imported wood. Methods. Samples were taken in coniferous clearcuts and wood processing companies from the stained wood or wood with evidence of Monochamus activities. Nematodes were extracted sing Baermann method. Preconditions for nematodes to enter Lithuania, establish and spread were analysed using statistical and literature sources. Strengths, weaknesses, opportunities, threats (SWOT) analysis was applied to the situation of Bursaphelenchus in Lithuania. Results. 27 forest enterprises and 62 wood processing companies were studied. For the first time in Lithuania non-pathogenic species Bursaphelenchus mucronatus was found. Assessement of conditions for wood nematodes in the country (import assortment and volume, countries, host plants and potential vectors), real probability for harmful species, particularly Bursaphelenchus xylophilus, to enter, establish and spread was defined. Existing quarantine system might... [to full text]

Root-lesion nematodes, Pratylenchus spp., are serious pathogens of potato plants worldwide. Several management practices can control Pratylenchus spp.; however, they all have shown some limitations. Therefore, environmentally-safe, low-cost, and effective control strategies are needed as possible alternative to currently used strategies. This thesis was designed to assess if liquid hog manure (LHM) holds such potential. The objectives of this thesis were to determine: (i) the prevalence and identity of species of Pratylenchus spp. in Manitoba potato fields, (ii) if short-chain volatile fatty acids (VFA) in LHM are the constituents responsible for the manure’s toxicity to Pratylenchus spp. using solution exposure experiments (iii) the effectiveness of LHM in killing Pratylenchus spp. in soil, and (iv) the impact of LHM on nematode communities. Pratylenchus spp. were detected in 39% of 31 potato fields surveyed in Manitoba with population densities ranging, for positive fields, from 45 to 631 nematodes kg-1 fresh soil. Morphometrics of female nematodes and molecular diagnosis (using species-specific PCR primers) showed that the species of Pratylenchus present in the potato fields to be P. neglectus. Potato, cv. Russet Burbank, showed to be a poor host to two populations of Pratylenchus spp. from Manitoba potato fields. Accordingly, P. neglectus does not seem to be a limitation to potato production in Manitoba; thus, P. penetrans, the most widely spread and damaging species to potato was used in the successive studies of assessing the use of LHM to control Pratylenchus spp. in potato fields. VFA (acetic, propionic, n-butyric, isobutyric, n-valeric, isovaleric, and n-caproic acids) accounted for the majority of the lethal effect of LHM to P. penetrans under acidic conditions. VFA in LHM killed Pratylenchus spp. in soil and acidification seemed to enhance its ability when VFA concentration in the manure is low. LHM did not act as a soil fumigant eliminating soil trophic interactions but increased bottom-up food web interactions. VFA in LHM persisted in the soil for four days with biological degradation being their mode of loss. In conclusion, LHM is potentially an effective and low-cost strategy to control Pratylenchus spp. and its efficacy can be improved by acidification.

Platinum mining activities contribute substantially to South Africa's economy since it exceeded gold as economical contributor in 2001. Mining activities contribute to large amounts of waste production in the form of tailings and rock waste, deposited in the surrounding environment of the mine premises. Mining companies are held responsible for damages caused to the surrounding environment. These companies are required to introduce the cost of ecological rehabilitation in their operation costs as well as compile an environmental management plan. Numerous attempts to rehabilitate mine waste have proven unsuccessful. New and improved rehabilitation techniques are required to facilitate in the rehabilitation of these mine spoils. Woodchip-vermicompost produced from platinum mining wastes (woodchips and sewage sludge) was used as an alternative amendment to inorganic fertilisers during the rehabilitation of platinum mine tailings. The effectiveness of the woodchip-vermicompost as an alternative amendment during the platinum mine tailings rehabilitation were monitored using different ecosystem components. A natural veldt in the vicinity of the mine area was randomly selected to serve as a reference site. These ecosystem components selected have previously been shown to be effective as indicators of ecosystem quality. The components selected for this study includes the use of microbial enzymatic activity, microbial community structure, nematode trophic structures, and other mesofaunal groups such as micro-arthropods. The physical and chemical properties of the platinum mine tailings and reference area as well as the vegetation cover of the platinum mine tailings were determined. Statistical and multivariate analyses were use to determine the correlation between the dependent microbial components and dominate independent chemical properties. Nematode trophic structure, Maturity Index, and Plant-Parasitic nematode Index were used to compare the two rehabilitation techniques in terms of nematodes as indicators. Microarthropods family structures were used to compare the two amendments in terms of diversity and abundance. Enzymatic activity was positively affected by the addition of woodchip-vermicompost, than in the sites treated with inorganic fertilisers. The microbial community structure showed no statistically significant (p < 0.05) differences between the two amendments. A higher abundance of nematodes especially plant-parasitic nematodes and bacterivorous nematodes were observed in the woodchip-vermicompost sites than in the inorganic fertilised sites. According to the Maturity Index, both amendments became more enriched during the study period, while the Plant-Parasitic nematode Index showed that the carrying capacity for plantparasitic nematodes on the woodchip-vermicompost sites increased while it decreased in the inorganic fertilised sites, which can be related to the decrease in vegetation cover on the inorganic fertilised sites. Both coloniser (Prostigmata) and persister (Cryptostigmata and Mesostigmata) groups of the micro-arthropods, as well as a higher diversity of micro-arthropods, were present on the woodchip-vermicompost sites whereas the inorganic fertilised sites showed only the presence of colonisers, with a decrease in diversity and abundance of micro-arthropods over the study. The colonisation of micro-arthropods may have been affected by the addition of woodchip-vermicompost and vegetation cover, which contribute to the establishment of suitable microhabitats for these soil biota. By intercorrelating the results, it may be concluded that the addition of woodchip-vermicompost may be an essential part of the rehabilitation process, by contributing to soil organic material to the ecosystem system, which may improve the recolonisation of soil biota and ecosystem processes. However further studies need to be conducted in order to determine the long-term sustainability of the woodchip-vermicompost in providing organic material and sustaining the ecosystem processes. The study also showed the necessity to integrate various ecosystem components when evaluating ecosystem development due to the unique role each component plays and the impact it may have on other components. / Thesis (M. Environmental Science)--North-West University, Potchefstroom Campus, 2006.

Root-lesion nematodes, Pratylenchus spp., are serious pathogens of potato plants worldwide. Several management practices can control Pratylenchus spp.; however, they all have shown some limitations. Therefore, environmentally-safe, low-cost, and effective control strategies are needed as possible alternative to currently used strategies. This thesis was designed to assess if liquid hog manure (LHM) holds such potential. The objectives of this thesis were to determine: (i) the prevalence and identity of species of Pratylenchus spp. in Manitoba potato fields, (ii) if short-chain volatile fatty acids (VFA) in LHM are the constituents responsible for the manure’s toxicity to Pratylenchus spp. using solution exposure experiments (iii) the effectiveness of LHM in killing Pratylenchus spp. in soil, and (iv) the impact of LHM on nematode communities. Pratylenchus spp. were detected in 39% of 31 potato fields surveyed in Manitoba with population densities ranging, for positive fields, from 45 to 631 nematodes kg-1 fresh soil. Morphometrics of female nematodes and molecular diagnosis (using species-specific PCR primers) showed that the species of Pratylenchus present in the potato fields to be P. neglectus. Potato, cv. Russet Burbank, showed to be a poor host to two populations of Pratylenchus spp. from Manitoba potato fields. Accordingly, P. neglectus does not seem to be a limitation to potato production in Manitoba; thus, P. penetrans, the most widely spread and damaging species to potato was used in the successive studies of assessing the use of LHM to control Pratylenchus spp. in potato fields. VFA (acetic, propionic, n-butyric, isobutyric, n-valeric, isovaleric, and n-caproic acids) accounted for the majority of the lethal effect of LHM to P. penetrans under acidic conditions. VFA in LHM killed Pratylenchus spp. in soil and acidification seemed to enhance its ability when VFA concentration in the manure is low. LHM did not act as a soil fumigant eliminating soil trophic interactions but increased bottom-up food web interactions. VFA in LHM persisted in the soil for four days with biological degradation being their mode of loss. In conclusion, LHM is potentially an effective and low-cost strategy to control Pratylenchus spp. and its efficacy can be improved by acidification.

Soybean [Glycine max (L.) Merr.] is an important crop worldwide. It has been widely consumed for protein, oil and other soy products. To develop soybean cultivars with greater resistance against pests and improved meal quality, it is important to elucidate the molecular bases of these traits. This dissertation aims to investigate the biochemical and biological functions of soybean genes from four gene families, which are hypothesized to be associated with soybean defense against pests and soybean meal quality. There are three specific objectives in this dissertation. The first one is to determine the function of components in the salicylic acid (SA) signaling pathway in soybean resistance against soybean cyst nematode (Heterodera glycines, SCN). The second one is to determine whether insect herbivory induce the emission of volatiles from soybean, and if so, how these volatiles are biosynthesized. The third objective is to identify and characterize soybean mannanase genes that can be used for the improvement of soybean meal quality. The soybean genome has been fully sequenced, which provides opportunities for cross-species comparison of gene families of interest and identification of candidate genes in soybean. The cloned cDNAs of putative genes were expressed in Escherichia coli to produce recombinant enzymes. Through biochemical assays, these proteins were proved to be soybean salicylic acid methyltransferase (GmSAMT1), methyl salicylate esterase (GmSABP2-1), α[alpha]-farnesene synthase (GmTPS1) and E-β[beta]-caryophyllene synthase (GmTPS2), and endo-β[beta]-mannanase (GmMAN1). Through a transgenic hairy root system harboring overexpression of GmSAMT1 and GmSABP2-1, both of these two genes were evaluated for their biological function related to resistance against SCN. The results showed that the over-expression of GmSAMT1 and GmSABP2-1 in the susceptible soybean background lead to enhanced resistance against SCN. Among four putative soybean mannanase genes, one gene was cloned and characterized. GmMAN1 showed the endo-β[beta]-mannanase hydrolyse activity and can hydrolyze cell walls isolated from soybean seeds. In summary, using comparative and functional genomics, a number of genes involved in soybean defense and meal quality were isolated and characterized. This study provides novel knowledge and molecular tools for the genetic improvement of soybean for enhanced resistance and improved meal quality.

Includes bibliographies. / xiv, 175, [96] leaves, [17] leaves of plates : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis reports on the generation of molecular tools for the analysis of chromosome 6R of rye and the application of these tools in structural analysis of 6RL. Results presented include physical and genetic maps of chromosome 6RL incorporating RFLP and PCR markers and CreR, the locus conferring resistance to cereal cyst nematode (CCN). The ability to detect small introgessions of rye chromatin in wheat is demonstrated. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Science, 1997

Bibliography: leaves 133-152 / iv, 152 leaves, [47] leaves of plates : ill. (1 col.) ; 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, 1987

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2006. / Härtill 5 uppsatser.

Thesis (Ph.D.)--Uniformed Services University of the Health Sciences, 2006 / Typescript (photocopy)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The aim of this study was to evaluate the effect of cadusafos and Fluensulfone nematicides applied at three different depths and positions in the soybean planting in furrow, in order to control Meloidogyne javanica, Pratylenchus brachyurus end Heterodera glycines. The experiments were cared out in the field naturally infested by nematodes, Júlio de Castilhos city - RS. It was nine treatments and five replications in a randomized block design, totaling 45 experimental units per experiment. The treatments were: 1 check treatment; 2 - position 1 (nozzle installed on the upper furrower); 3 - Position 2 (nozzle installed at the bottom of the open furrow); 4 - Position 3 (nozzle installed in the distribution disc of seeds); 5 - Positions 1 and 2 associates; 6 - The positions 2 and 3 associates; 7 - Positions 1 and 3 associates; 8 Full seed treatment by Avicta completo (abamectin (30 g ai.ha-1) + thiamethoxam (42 g ai.ha-1) + fludioxonil (1.5 g ai.ha-1) + metalaxyl-M (1.2 g ai.ha-1 ) + thiabendazole (9 g ai.ha-1) and 9 - position 1 and Avicta completo treatment seeds associated. The variables measured in the experiment were: number of nematodes in the soil, number of nematodes on the roots, shoot dry weight, plant height (pre-harvest); number of pods per plant and Yield. The results showed significant reduction in the population of nematodes in the both soil and the roots, regardless of the nematicide. For the deposition positions in soil, the responses were vary according to the species of nematodes in the soil. / O objetivo do presente trabalho foi avaliar o efeito dos nematicidas Fluensulfone e Cadusafós aplicados no sulco de semeadura da soja, em três diferentes profundidades no solo para o controle de Meloidogyne javanica, Pratylenchus brachyurus e Heterodera glycines. Os experimentos foram conduzidos a campo, no município de Júlio de Castilhos RS, em área comercial de soja naturalmente infestada. Os tratamentos foram dispostos no delineamento de blocos ao acaso, contendo nove tratamentos e cinco repetições, totalizando 45 unidades experimentais por experimentos. Os tratamentos foram: 1 - Testemunha sem produto; 2 - Posição 1 (Ponta instalada na parte superior do sulcador); 3 - Posição 2 (Ponta instalada na parte inferior do sulcador); 4 - Posição 3 (Ponta instalada na haste do disco de distribuição das sementes) 5 - As pontas 1 e 2 associadas; 6 - As pontas 2 e 3 associadas; 7 - As pontas 1 e 3 associadas; 8 - Tratamento de semente com Avicta completo (abamectina + tiametoxam + fludioxonil + metalaxil-M + tiabendazol - 30 + 42 + 1,5 + 1,2 + 9 g de i.a./ha) e 9 - A ponta 1 associada ao tratamento de semente com Avicta completo. As variáveis resposta medidas no experimento foram: número de nematoides presentes no solo, aos 30 dias após a emergência (D.A.E.); número de nematoides nas raízes (30 D.A.E.); massa seca de parte aérea (MSPA), aos 30 DAE; estatura de plantas (Pré-colheita); número de legumes por planta e produtividade. Os resultados mostraram que houve redução significativa na população dos nematoides, tanto no solo quanto nas raízes, independente do nematicida aplicado. No entanto, foram observadas diferentes respostas de controle em função dos pontos de deposição dos nematicidas no solo.