Graduation date: 1972

Submitted by Reginaldo Soares de Freitas (reginaldo.freitas@ufv.br) on 2017-05-11T18:21:11Z No. of bitstreams: 1 texto completo.pdf: 507768 bytes, checksum: c1a5b4fb947ae111d0a7a14225630109 (MD5) / Made available in DSpace on 2017-05-11T18:21:11Z (GMT). No. of bitstreams: 1 texto completo.pdf: 507768 bytes, checksum: c1a5b4fb947ae111d0a7a14225630109 (MD5) Previous issue date: 2003-03-12 / Programa de Modernización del Sector Agropecuario / Um dos maiores problemas na comercialização de bananas é o destacamento individual dos frutos das pencas, fazendo que estes percam ou diminuam seus valores comercial e nutricional, além de contribuir para que as perdas pós-colheita atinjam cerca de 40% da produção brasileira. O presente trabalho teve como objetivos caracterizar o comportamento dos componentes da parede celular, de amido e açúcares solúveis; determinar a atividade enzimática de poligalacturonase (PG), pectinametilesterase (PME) e xilanase na região do pedicelo de duas variedades e um híbrido de banana resistente e suscetível ao despencamento natural durante o amadurecimento; e estabelecer a relação entre o comportamento dos componentes da parede celular e a atividade enzimática, bem como a suscetibilidade de bananas à queda natural. Foram utilizados os genótipos triplóides ‘Terra’ (AAB) e ‘Prata’ (AAB) e o híbrido tetraplóide SH-3640 (AAAB). Os resultados evidenciaram uma diferença de comportamento na consistência da polpa entre os genótipos estudados, com a ressalva de que ‘Terra’ apresentou a maior consistência em todos os seus estádios de amadurecimento, seguido de ‘Prata’ e ‘SH-3640’. Verificou-se também que o genótipo ‘Terra’ mostrou resistência ao despencamento, mesmo estando seus frutos maduros, ao contrário de ‘SH-3640’, que, já a partir do estádio 5 (fruto amarelo com pontas verdes), exibiu suscetibilidade à queda. Em todos os estádios de amadurecimento, o genótipo ‘Terra’ teve os maiores teores de matéria seca. Por sua vez, o genótipo ‘SH-3640’ sempre manteve os mais baixos teores. Quanto à taxa respiratória, embora se tenha elevado com o amadurecimento, em nenhum dos três genótipos estudados foi observado comportamento climatérico típico. Do total das frações dos carboidratos estruturais (celulose, hemicelulose e pectina) e não-estruturais (amido, açúcares solúveis redutores e não-redutores), os genótipos ‘SH-3640’ e ‘Prata’ tiveram por volta de 80 e 70% de carboidratos estruturais no fruto verde, mantendo-se relativamente constantes durante o amadurecimento. Nesses cultivares, houve redução na proporção de amido e aumento na de açúcares solúveis, principalmente dos redutores. Já o genótipo ‘Terra’ apresentou variações mais evidentes com relação aos outros dois. Nesse genótipo, diminuíram os teores de pectinas no decorrer do amadurecimento, enquanto os de amido se mantiveram altos mesmo no fruto maduro. Entre as enzimas estudadas, os resultados evidenciaram um papel mais importante de PME e PG na queda de fruto e confirmaram a maior resistência do genótipo ‘Terra’ ao despencamento, permitindo concluir que PG e PME são as enzimas-chave na solubilização da parede celular que acompanha o amadurecimento e, portanto, têm papel fundamental na indução do despencamento natural. A alta suscetibilidade ao genótipo SH-3640 ao despencamento está associada à elevada atividade de PG e PME e ao baixo teor de matéria seca; a maior resistência ao despencamento do genótipo ‘Terra’ está relacionada com o maior acúmulo de matéria seca e amido no pedicelo. / One of the greatest problems for banana commercialization is finger drop of ripe bananas from the bunch since the market as well as the nutritional value of such isolated fruits is reduced or lost. This contributes to post-harvest losses of about 40% of the Brazilian production. In this study, the behavior of the cell wall components, starch, and soluble sugars was characterized; the enzymatic activity of polygalacturonase (PG), pectinmetylesterase (PME), and xylanase in the pedicel region of two varieties and one hybrid determined; and the relation between the behavior of cell wall components, enzyme activities in the pedicel, and the susceptibility of bananas to natural fruit dropping established. The triploid genotypes ‘Terra’ (AAB) and ‘Prata’ (AAB), and the tetraploid hybrid SH- 3640 (AAAB) were used. Results showed a difference in the pulp consistence of the studied genotypes. ‘Terra’ presented the highest consistence throughout all ripening stages, followed by ‘Prata’ and then ‘SH-3640’. Even when the fruits were ripe, ‘Terra’ was most resistant against fruit dropping, while ‘SH-3640’ began to present a high susceptibility to fruit dropping from stage 5 on (yellow fruits with green tips). At all ripening stages, ‘Terra’ presented the highest dry matter content, while ‘SH-3640’ continuously maintained the lowest content. In none of the studied genotypes the respiration rate obeyed a typical climacteric behavior, in spite of increases during the ripening process. Of all carbohydrate structural (cellulose, hemicellulose, and pectin) and non-structural (starch, soluble reducing and non-reducing sugars) fractions, the genotypes ‘SH-3640’ and ‘Prata’ contained around 70 and 80%, respectively, of structural carbohydrates in the green fruits. This proportion remained relatively constant during the ripening process. In these cultivars, there was a reduction in the starch proportion and an increase of soluble sugars, mainly of reducing sugars. The genotype ‘Terra’, on the other hand, presented more evident variations than the other two: there was a reduction of pectin contents during the ripening process (from 2.1 to 0.47%), while the starch contents remained above 2% even in ripe fruit. The ’Terra’ genotype proved to be the most resistant against fruit dropping. Results evidenced the importance of PG and PME for the degradation, or simply, the solubilization of cell wall components during the ripening process, and, therefore, for natural fruit dropping. The high susceptibility of the SH-3640 genotype is related to the high PG and PME activity and the low dry matter content. In the case of ‘Terra’, the high resistance to finger drop is related to a greater accumulation of dry matter and starch in the pedicel. / Não foram localizados o cpf e o curriculo lattes do autor.

Bananas and plantains (Musa spp.) are cultivated commercially as a dessert fruit and by small-scale farmers as a staple food crop in many countries of the world. Sustainable production, however, is threatened by a number of diseases and pests such as Fusarium wilt (Fusarium oxysporum f.sp. cubense), black Sigatoka (Mycosphaerella fijiensis), the banana weevil (Cosmopolitus sordidus) and the burrowing nematode (Radopholus similis). Many diseases and pests of banana cannot be managed by conventional control methods, and replacement cultivars are often not acceptable to local industries. Resistance can be introduced into banana by means of conventional and unconventional improvement methods. Conventional breeding programs have many limitations, due to sterility of cultivated bananas, long growth cycles, low seed set and hybrids that are often not accepted by consumers. Unconventional improvement for enhanced resistance involves methods such as in vitro mutagenesis, protoplast culture, and genetic modification. During genetic modification, foreign genes are introduced into banana by means of Agrobacterium-mediated transformation or by particle bombardment. One of the most powerful means to reduce the impact of pests and diseases is the use of somatic embryogenesis for unconventional plant improvement and the propagation of disease-free plants. In this thesis, immature male flowers of Grande Naine (Musa acuminata, Cavendish subgroup, AAA) were isolated and incubated on MA1 medium to form somatic embryos with ideal callus. When ideal callus was transferred to liquid MA2 medium, a heterogeneous cell suspension was formed. Non-embryogenic aggregates were removed to ensure a cell suspension constituted of small embryogenic clusters only. Somatic embryos were obtained from the cell suspension after plating the embryogenic clusters on solid MA3 medium. These somatic embryos were transferred to MA4 medium for germination, and to P6 medium to develop into in vitro plantlets. Embryogenic cell suspension can be used for genetic engineering of disease and pest resistant plants, in vitro mutagenesis, germplasm conservation and protoplast culture. An Agrobacterium-mediated transformation system was established for the improvement of Cavendish banana cultivars, the only bananas produced for the fresh fruit market in South Africa. Embryogenic cell suspensions from the cultivar Grande Naine were co-cultivated with Agrobacterium strains harbouring the plasmids pCambia1305.1, pART-TEST7 and pKYΩOCI. Antibiotic-resistant embryos derived from transgenic cell suspensions developed into banana plantlets 12 weeks after cultivation on MA4 medium. In total, 145 putative transgenic plants were produced. Molecular analysis revealed that the Gus gene was integrated into the genome of transformed plants, and a histochemical GUS assay showed that the Gus gene was expressed in putative transgenic plants. In future, southern blot assays will be performed to determine copy numbers of the transgenes, and the putative transgenic plants containing the OcI gene tested in the greenhouse and the field for resistance to the banana weevil and the burrowing nematode. The successful transformation of Grande Naine reported in this work will contribute significantly towards improving Cavendish bananas in South Africa, and offers the opportunity to modify banana and plantain varieties cultivated in Africa for enhanced disease and pest resistance. A highly discriminative fingerprinting technique, called amplified fragment length polymorphisms (AFLPs), was used to differentiate between closely related species within the Cavendish banana subgroup. AFLP profiles of eight banana varieties, cultivars and hybrids were generated on a Licor analyser using seven different primer combinations. Results showed that the banana plants were subdivided in clades according to their genomic composition. More importantly, the AFLP technique was able to separate the different cultivars within the Cavendish subgroup. Hopefully this technique could eventually be applied to accurately detect somaclonal variants in banana due to micropropagation and genetic modification. / Dissertation (MSc)--University of Pretoria, 2006. / Microbiology and Plant Pathology / unrestricted

No description available.

Soluble and insoluble non-starch polysaccharide (NSP) fractions have been isolated from the pulp of ripe banana fruit. Attempts to determine the composition of the insoluble NSP indicated the fraction to be exceptionally complex and difficult to analyze. Only about 44% of the dry weight could be accounted for as NSP, the protein content was high (26%) and about 22% of the dry weight appeared to be a complex mixture of phenolic and other unknown components. One interesting property of the insoluble NSP was its unusually high water-holding capacity. The soluble NSP (isolated by extraction from fresh pulp with water at 25°C and not dried prior to analysis) contained about 48% pectin, 20% hemicellulose, 21% partially hydrolyzable polysaccharides and 11% protein. The hemicellulose represented about 0.05% of the banana fresh weight or about 0.2% of dry weight. Hydrolysis of the hemicellulose and analysis of the resulting sugars via gas chromatography revealed the hemicellulose to be made up predominantly (84%) of mannose, the remainder being 12% arabinose and 4% xylose. After removal of most of the pectin via treatment with anion exchange resin, the major hemicellulose component was isolated by gel filtration. The isolated hemicellulose was a homomannan as demonstrated by gas chromatography and high performance liquid chromatography of acid hydrolysates. The banana homomannan appears to be unique among plant mannans. All previously isolated plant homomannans were reported to be insoluble in water. Further studies will be required to establish the exact structure of the banana mannan. The molecular weight (MW) of the mannan in solution appears to be exceptionally high, the peak MW being about 5 million, as determined by gel filtration. / Master of Science

No description available.

No description available.

Thesis (Th. M.)--Nairobi Evangelical Graduate School of Theology, 1990. / Includes bibliographical references (leaves 113-118).

Thesis (Ph. D.)--John Hopkins University, 1928. / Vita. From the Zeitschrift für zellforschung und mikroskopische anatomie, bd. 7, 1928. "Literature cited": p. 731-733.

Orientador: Sarita Leonel / Banca: Elizabeth Orika Ono / Banca: Jackson Mirellys Azevêdo Souza / Resumo: O Brasil é o quarto maior produtor mundial de banana, no entanto, apresenta dificuldades quanto à participação expressiva no mercado internacional, o que por sua vez, está diretamente relacionada aos fatores de padrões tradicionais de produção, com baixos investimentos de capital e tecnologia na maioria das regiões produtoras no país. Para que se tenham frutos de alta qualidade, há necessidade da adoção de inúmeras técnicas culturais e dentre estas, está o ensacamento dos cachos, que, apesar de onerar o custo de produção, é uma prática que vem sendo recomendada em plantios comerciais de bananeira que produzem frutos com melhor qualidade. Diante do exposto, o presente trabalho teve como objetivo avaliar a influência de tipos de materiais para ensacamento de cachos de banana, no desenvolvimento e qualidade dos frutos de bananeira „BRS Platina‟. O experimento foi realizado na Fazenda Experimental Lageado, pertencente à UNESP, campus de Botucatu. O delineamento estatístico experimental utilizado foi em blocos casualizados, composto por seis tratamentos, quatro blocos e quatro plantas por parcela, sendo os tratamentos: T1 - testemunha (sem ensacamento); T2 - Saco de polipropileno (TNT), cor preta + Papel kraft; T3 - Saco de polietileno, cor preta + Papel kraft; T4 - Papel kraft; T5 - Saco de polipropileno (TNT), cor branca; T6 - Saco de polietileno, cor branca. Foram feitas avaliações de características fenológicas, desempenho agronômico produtivo, qualidade pós-colheita dos fruto... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Brazil is the fourth largest producer of banana in the world, however, it presents difficulties in expressive participation in the international market, which in turn is directly related to the factors of traditional production patterns, with low investments of capital and technology in the majority of producing regions in the country. In order to have high quality fruits, there is a need to adopt numerous cultural techniques, among which is the bagging of bunches, which, despite costing the production, is a practice that has been recommended in commercial banana plantations that produce better quality fruits. In view of the above, the present work had the objective of evaluating the influence of types of materials for banana bagging on the development and quality of 'BRS Platina' banana fruits. The experiment was carried out at Experimental Farm Lageado, belonging to UNESP, Botucatu campus. The experimental design was a randomized block design, consisting of six treatments, four blocks and four plants per plot. The treatments were: T1 - control (without bagging); T2 - Polypropylene bag (TNT), black color + Kraft paper; T3 - Polyethylene bag, black color + Kraft paper; T4 - Kraft paper; T5 - Polypropylene bag (TNT), white color; T6 - Polyethylene bag, white color. Evaluations of phenological characteristics, productive agronomic performance, post-harvest quality of fruits and economic analysis were performed. The results were statistically evaluated by analysis of variance with application of the F test at 5% probability (p <0.05) and the means compared by the Scott-Knott test at the 5% probability level. It was concluded that the bagging is effective in the control of thrips of the eruption and in the reduction of defects or injuries, not affecting the production, besides promoting few changes in the physical and chemical characteristics of the fruits. The treatment with bagging using ... / Mestre