Thesis (M.Sc. Agriculture (Plant Protection)) -- University of Limpopo, 2021 / In use of phytonematicides as an alternative to synthetic chemical nematicides, the major challenge had been the development of appropriate application technologies, which are currently limited to the ground leaching technology (GLT) and botinemagation (BNT) systems. The former is labour-intensive, whereas the latter requires infrastructure that could be costly for smallholder farmers. The priming of seeds with hypogenous germination properties in phytonematicide solutions could serve as an alternative method of the application of phytonematicides, where the cotyledons would serve as carriers of the active ingredients that are leached into the rhizosphere for suppression of nematode numbers. However, since germination is a chemical process, it is not known whether the active ingredients in cucurbitacin containing phytonematicides would interfere with germination and the subsequent emergence of the seedlings through the incidence of phytotoxicity as observed in the use of the products in crop production. The objectives of the study, therefore, were (1) to investigate the sensitivity and overall sensitivity of pea (Pisum sativum L.) plants to Nemarioc-AL and Nemafric-BL phytonematicides, and (2) to determine the mean concentration point (MCSP) for pea-inoculated with Meloidogyne incognita under greenhouse and microplot conditions, where seeds were previously primed in phytonematicide solutions. Two separate trials were conducted with seven treatments, namely, 0, 2, 4, 8, 16, 32 and 64% Nemarioc-AL or Nemafric-BL phytonematicide, arranged in completely randomised design (CRD), with 8 replications each. Pea seeds were primed in Nemarioc-AL and Nemafric-BL phytonematicide solutions for two hours and shade dried prior to sowing. In vitro trial, 10 seeds were spread uniformly on a moistened filter paper in sterilised petri-dishes with lids and placed in an incubator at 25oC. In vivo trials were under greenhouse and micro-plot conditions, pea seeds were sown in 25-cm and 30-cm diameter plastic pots, respectively. Pots were filled with pasteurised loam soil. Seedlings were inoculated with 5 000 eggs + second-stage juveniles (J2) of M. incognita. Treatments in each case included priming seeds as explained earlier, arranged in a randomised complete block design (RCBD), with 6 replications under greenhouse conditions and 8 replications under micro-plot conditions. In all cases, plant growth variables were assessed using the Curve-fitting Allelochemical Response Dose (CARD) model to generate biological indices which were used to calculate MCSP and the overall sensitivity (Σk). Nematode variables in inoculated trials were assessed using the regression model. In vitro trials, germination variables had positive quadratic relation versus Nemafric-BL phytonematicide, with MCSP= 0.62 % and ∑k = 34 units. In contrast, tested germination variables exhibited negative quadratic relations versus Nemarioc-AL phytonematicide. In greenhouse trials, MCSP values for Nemarioc-AL and Nemafric-BL phytonematicides were 0.62 and 2.18 %, respectively, with ∑k = 0. Plant height (R2 = 0.86), stem diameter (R2 = 0.93) and chlorophyll content (R2 = 0.85), exhibited positive quadratic relationship against Nemarioc-AL phytonematicide, whereas, plant height (R2 = 0.95), stem diameter (R2 = 0.92), chlorophyll content (R2 = 0.89), number of flowers (R2 = 0.93) and dry shoot mass (R2 = 0.94), exhibited positive quadratic relationship against Nemafric-BL phytonematicide. In micro-plot trials, MCSP values for Nemarioc-AL and Nemafric-BL phytonematicides were 0.71 and 2.45 %, respectively, with ∑k = 0. Plant height (R2 = 0.95), stem diameter (R2 = 0.98), chlorophyll content (R2 = 0.98), and gall ratings (R2 = 0.98), exhibited positive quadratic relationships against Nemarioc-AL phytonematicide, while chlorophyll content (R2 = 0.97) and gall ratings (R2 = 0.96) exhibited positive quadratic relationships against Nemafric-BL phytonematicide. All degrees of Nemarioc-AL and Nemafric-BL phytonematicides profoundly reduced nematode numbers under greenhouse and micro-plot trials. In conclusion, both Nemarioc-AL and Nemafric-BL phytonematicides could be applied through the priming technology on pea seeds which have hypogenous germination properties in suppression of nematode population densities. / National Research Foundation (NRF)

[Truncated abstract] Field pea (Pisum sativum) has many benefits when included in the crop rotation system in broadacre grain farming. These benefits include a disease break and improved weed control for cereals and less dependence on nitrogenous fertilisers due to the leguminous nature of pea. Currently, field pea adoption in Australia is low because the crop is susceptible to the fungal disease `black spot’ (Mycosphaerella pinodes) and has low stem strength and a lodged canopy. Black spot causes yield losses averaging 10-15% per year. Lodging results in difficult and costly harvesting, increased disease pressure and increased wind erosion from exposed soil surface when stems break at the basal nodes. This project aimed to address these problems through breeding, and through the application of quantitative genetics theory to a recurrent selection program. A quantitative measurement of relative stem strength was developed which could be used effectively in the field on single plants. Accurate laboratory measurements of stem strength were closely correlated with the field measure of compressed stem thickness in the basal node region. A diallel analysis of stem strength of the progeny of crosses among a range of pea lines with different values of compressed stem thickness concluded that the genetic control of stem strength was additive, with no maternal inheritance or dominance or epistasis effects.

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No. of bitstreams: 1 sideiamariliadoamaralteles.pdf: 1399779 bytes, checksum: fb6901015dca8f0d97c9c94262d6406e (MD5) Previous issue date: 2013-12-19 / Esta dissertação, intitulada "A implementação do Programa Educacional de Atenção ao Jovem – PEAS Juventude: o Estudo de Caso de Gestão de duas Escolas Estaduais em Patos de Minas, MG”, tem por objetivo identificar como os gestores e demais agentes dessas duas escolas se envolvem com o PEAS Juventude e quais são os pontos positivos e negativos detectados na implementação do programa. A pesquisa foi realizada em duas escolas públicas da rede estadual de ensino do Estado de Minas Gerais pertencentes à Superintendência Regional de Ensino de Patos de Minas. O critério de escolha para a pesquisa nessas escolas fundamentou-se no fato de ambas terem implementado o PEAS Juventude, em 1999, quando ele deixa de ser projeto piloto na região metropolitana de Belo Horizonte e se institucionaliza como um Programa da Secretaria de Estado de Educação de MG, sendo estendido às 47 Superintendências Regionais de Ensino da rede pública estadual. Desde o ano de 2002, atuo na função de coordenadora regional do programa. Na referida função, tive a oportunidade de acompanhar as duas escolas pesquisadas em todas as mudanças de operacionalização e gerenciamento que o PEAS Juventude sofreu, ao longo do seu contexto histórico. Escolhendo a gestão escolar como campo de investigação, realizei uma pesquisa qualitativa nessas duas escolas, através de entrevistas semiestruturadas, feitas com a equipe gestora, com os coordenadores e professores do GDPEAS, com a coordenação central do PEAS Juventude, na SEE/MG, e com a diretora educacional de ensino da SRE de Patos de Minas. Esse instrumento de pesquisa articulado à pesquisa bibliográfica e à análise dos dados coletados me permitiu confrontar a realidade da gestão dessas escolas com os resultados esperados pelo programa, tendo em vista o objetivo da presente dissertação. O acervo teórico sobre gestão escolar que subsidiou este trabalho foi fundamentado nos estudos de José Carlos Libâneo (2003, 2009), Heloisa Lück (2000, 2007, 2009, 2010, 2011), Márcia Cristina da Silva Machado (2010), Marcelo Tadeu Baumann Burgos (2011), José Luis Neves (1996), Henry Mintzberg (2009, 2010), Maria Lúcia Miranda Afonso (2000), Maria Helena Michel (2009), Cecília de Souza Minayo (1994), Gilberto de Andrade Martins (2008), Thaís Cristina Rodrigues Tezani (2004). / This dissertation, titled “Implementation of the Educational Program of Attention to the Young One - PEAS Youth: The Case Study on Management of Two State Schools in Patos de Minas, MG”, aims to identify how the managers and other agents on these two schools are involved with the PEAS Youth program, and which are the positive and negative aspects detected in the program implementation. The research was done on two public schools which belong to Patos de Minas´ Regional Scholarship Superintendence, part of the Minas Gerais state educational network. These two schools were chosen for the research due to the fact that both of them implemented PEAS Youth in 1999, when it left the status of a pilot program in Belo Horizonte´s metropolitan area and established itself as an MG State Secretary for Education program, being then extended to the 47 regional scholarship superintendences in the state´s educational network. Since 2002, I have been working as one of the program´s regional coordinator. In such job, I had the opportunity of following the two chosen schools through all the management and operational changes the PEAS Youth program had suffered in its historical context. With scholar management chosen as investigation field, I had relatively structured interviews, as a form of qualitative research, with the schools management personnel, with coordinators and teachers of GDPEAS, with PEAS Youth coordination central in SSE/MG, and also with the Patos de Minas regional scholarship director. This research instrument, along with bibliographic research and analysis of collected data, allowed the direct comparison between the program expectations and the reality in the management of these schools, in the light of the goals of this thesis. The theoretical basis on scholar management used in this work is founded on the studies of José Carlos Libâneo (2003, 2009), Heloisa Lück (2000, 2007, 2009, 2010, 2011), Márcia Cristina da Silva Machado (2010), Marcelo Tadeu Baumann Burgos (2011), José Luis Neves (1996), Henry Mintzberg (2009, 2010), Maria Lúcia Miranda Afonso (2000), Maria Helena Michel (2009), Cecília de Souza Minayo (1994), Gilberto de Andrade Martins (2008), Thaís Cristina Rodrigues Tezani (2004).

A ervilha é considerada uma fonte nutritiva de proteína vegetal de alta qualidade, sendo também reconhecida como boa fonte de vitaminas, minerais, compostos fenólicos e carboidratos. Considerando que nem todos os nutrientes presentes no alimento tornam-se acessíveis para absorção pelo organismo e considerando ainda que a irradiação é uma técnica que permite garantir a segurança e a qualidade de um alimento, controlando microrganismos patogênicos, sem afetar significativamente qualquer atributo organoléptico e sensorial, estudou-se comparativamente os efeitos gerados na bioacessibilidade de Fe e Zn, tomando como base, uma amostra controle, o processo tradicional de ervilhas congeladas e o processo utilizando radiação gama na dose de 1 kGy. As ervilhas foram avaliadas em duas condições de tempo: tempo inicial, correspondente ao tempo após o término do processamento e tempo após quinze dias de armazenamento. Verificou-se que para as amostras controle e irradiada, a bioacessibilidade do Fe foi inferior à das amostras congeladas. A bioacessibilidade do Zn para as amostras de ervilhas analisadas (controle, irradiada e congelada), apresentou um teor médio de 71%, de acordo com os testes estatísticos de ANOVA e Tukey, não houve diferença significativa entre as amostras. Este trabalho avaliou também os aspectos sensoriais (cor, textura e sabor), microbiológicos e a composição centesimal dos produtos obtidos por esses tratamentos. Nos aspectos sensoriais observou-se pela análise de variância (ANOVA) em um nível de significância de p>0,05, que não houve diferença significativa entre as amostras analisadas. Nos aspectos microbiológicos, para as análises de bolores e leveduras, contagem de aeróbios mesófilos, coliformes a 45°C, E. coli e Salmonella, verificou-se que a irradiação trouxe melhor preservação microbiológica às ervilhas quando comparadas com o congelamento e com as ervilhas apenas refrigeradas (controle). Em relação à composição centesimal, constatou-se que os resultados encontrados estão alinhados aos referenciados na literatura. / The pea is considered a nutritious source of high quality vegetable protein and is also recognized as a good source of vitamins, minerals, phenolic compounds and carbohydrates. Considering that not all the nutrients present in the food become accessible for absorption by the body, and also considering that irradiation is a technique that ensures the safety and quality of a food by controlling pathogenic microorganisms without significantly affecting any sensory attributes, this work evolved the effects generated in the bio accessibility of Fe and Zn. The study performed the comparison between the control sample (the traditional process of frozen peas) and those submitted to the process using gamma radiation at 1 kGy dose. The peas were evaluated in two conditions: initial time, corresponding to time after processing, and after fifteen days of storage. For both samples - control and the irradiated - the bioaccessibility of Fe was lower than that of the frozen samples. Considering the initial time and after 15 days of storage, the bioaccessibility of the Zn to the analyzed (control, irradiated and frozen) pea samples, was about 71% and according to the statistical tests of ANOVA and Tukey there was no difference between the samples. This work also evaluated the sensory aspects (color, texture and flavor), microbiological and the centesimal composition of the products obtained by these treatments. Sensory aspects presented no statistical differences among analyzed samples (p> 0.05). Microbiological aspects (for yeast and mold counts, aerobic mesophilic counts, Salmonella, coliforms organisms and Escherichia coli) demonstrated that the irradiation brought better microbiological preservation to the peas when compared with the freezing and the chilled peas (control). In relation to the centesimal composition, results found are in agreement with those referenced in the literature.

The maternal rearing environment (MRE) of an organism can be a key determinant of an organism's host choice decisions, its own fitness, or the fitness of its offspring. Here, it is investigated if the MRE of an organism can influence lower or higher trophic levels. A series of reciprocal cross-over experiments was conducted using pea aphids (Acyrthosiphon pisum), bean (Vicia faba) or pea (Pisum sativum) plants, and an aphid natural enemy, the parasitoid wasp Aphidius ervi, as model organisms. In each experiment, pea aphid offspring experienced either the same or an alternative plant host to that experienced by their mothers. This PhD showed that the MRE of pea aphids and parasitoid wasps was not a main contributory factor of host choice decisions or offspring fitness but influenced mother parasitoid wasp fecundity. Additionally, the MRE of pea aphids influenced the foliar nutrient concentration of pea plants when infested with the aphid's offspring. First, over shorter infestation periods, variation in foliar nitrogen and essential amino acid concentrations of pea leaves could be explained by pea aphid MRE. Over longer infestation periods, variation in foliar nitrogen and essential amino acid concentrations of pea leaves was explained by a combination of pea aphid MRE and aphid genotype. Second, the 13C concentration of pea leaf tissue, an indicator of stomatal aperture and leaf water stress, varied with pea aphid MREs over longer infestation periods. However, stomatal conductance and the expression of abscisic acid-responsive genes did not vary in a manner that was consistent with leaf water stress. Additional components of an organism's maternal rearing conditions are considered, including symbioses, as a more realistic MRE compared with that observed in nature. Taking account of MREs could provide a better understanding of the factors influencing the fitness of many organisms interacting in natural and managed ecosystems.

Includes bibliographical references (leaves 82-92). Five isolates of pea seed-borne mosaic virus were compared by host range and symptomatology on 16 pisum sativum cultivars lines, 21 lines of Lathyrus and Lens spp. and several indicator species

Corrigendum inserted at the back. Includes bibliographical references (leaves 133-158). Ch. 1. General introduction -- ch. 2. General materials and methods -- ch. 3. Biological characterisation of Australian PSbMV isolates -- ch. 4. Developing nucleic acid based diagnostics for PSbMV -- ch. 5. Detection of PSbMV isolates by RT-PCR and RFLP analysis -- ch. 6. Developing an internal control for PSbMV RT-PCR -- ch. 7. Molecular analysis of the PSbMV VPG -- ch. 8. PSbMV sequence and phylogenetic analysis -- ch. 9. General discussion Sixteen pea seed borne mosaic virus (PSbMV) isolates were collected between 1995 and 1998. These isolates were biologically distinct yet serologically indistinguishable. The conclusion is that PSbMV is widespread and occurs at a low incidence in Australia. Reports sequence information on new isolates of PSbMV which has allowed genomic regions to be identified which distinguish PSbMV pathotypes and isolates; and, to the development of PSbMV nucleic acid hybridisation and RT-PCR assays.

Includes bibliographical references (leaves 82-92). / xii, 92 leaves : ill., photos ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Five isolates of pea seed-borne mosaic virus were compared by host range and symptomatology on 16 pisum sativum cultivars lines, 21 lines of Lathyrus and Lens spp. and several indicator species / Thesis (Ph.D.)--University of Adelaide, Dept. of Crop Protection, 1993

Corrigendum inserted at the back. / Includes bibliographical references (leaves 133-158). / xvi, 158 leaves : ill., col. map ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Sixteen pea seed borne mosaic virus (PSbMV) isolates were collected between 1995 and 1998. These isolates were biologically distinct yet serologically indistinguishable. The conclusion is that PSbMV is widespread and occurs at a low incidence in Australia. Reports sequence information on new isolates of PSbMV which has allowed genomic regions to be identified which distinguish PSbMV pathotypes and isolates; and, to the development of PSbMV nucleic acid hybridisation and RT-PCR assays. / Thesis (Ph.D.)--University of Adelaide, Dept. of Applied and Molecular Ecology, 2001

Lowther and Boll in the study of the effect of 2,4,5-TCPAA on etiolated bean leaf discs observed that inhibition of expansion at low concentrations was relieved at high concentrations where growth was equal to that of the light plus Co control. This means that at appropriate concentrations, TCPAA completely replaced Co in the expansion of light-treated leaf discs. [...]