Thesis (Ph.D)-University of KwaZulu-Natal, Pietermaritzburg, 2008. / Full text also available online. Scroll down for electronic link.

Digitized by Kansas State University Libraries

No description available.

No description available.

No description available.

No description available.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Resumo: A cultura da goiabeira ocupa importante espaço no agronegócio do país, um dos maiores produtores mundiais de goiaba. O araçazeiro, nativo do Brasil, embora não apresente a mesma importância econômica da goiaba, tem sido explorado em algumas regiões como alternativa de plantio devido à boa aceitação do seu fruto e também por apresentar características de interesse comercial e social. Dentre as características compartilhadas por goiabas e araçás estão a diversidade de uso, desde o consumo in natura até diferentes formas processadas, e a riqueza em nutrientes e em compostos fenólicos. Este trabalho visou à caracterização química e bioquímica de frutos de araçazeiros e goiabeiras do banco ativo de germoplasma (BAG) da Embrapa Semiárido, provenientes de diferentes regiões do Brasil, bem como a caracterização genética de parte dos acessos. Foram determinados os teores de açúcares, proteínas, sólidos solúveis, acidez titulável, "ratio" e umidade, além dos minerais: cálcio, magnésio, ferro, fósforo e potássio. Foram também analisados os antioxidantes: ácido ascórbico, fenóis totais, flavonóides totais, licopeno e β-caroteno, bem como a atividade antioxidante. Para a caracterização genética,, utilizou-se o marcador molecular AFLP (Amplified Fragment Length Polymorphism). Frutos de cinco acessos de goiabeira provenientes do Maranhão (G01MA, G12MA, G14MA, G16MA e G20MA), e dos acessos A08MA, A42PE, A45PE, A80RO e A100AM, de araçazeiros, se destacaram nas avaliações bioquímicas por apresentarem, no conjunto, os maiores teores de sólidos solúveis, açúcares, proteínas e minerais, além de estarem entre aqueles com menores teores de acidez titulável, no caso das goiabas, e maiores no caso dos araçás. Quanto aos antioxidantes, verificou-se que goiabas e araçás são ricos em compostos fenólicos, os quais apresentaram forte correlação... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The culture of guava has an important position in the agribusiness in the country, one of the largest producers of guava of the world. Brazilian guava tree, native of Brazil, although not present the same economic importance of guava has been explored in some regions as an alternative planting due to the high acceptance of its fruit and also present characteristics of commercial and social interest. The diversity of use, since the fresh market to different forms processed forms, and wealth of nutrients and phenolic compounds are among the characteristics shared by guavas and Brazilian guava. This work aimed at the chemical and biochemical characterization of Brazilian guava and guava fruit of the active germplasm bank (AGB) of Embrapa Semiarid, from different regions of Brazil and the genetic characterization of some accessions. The levels of sugars, proteins, soluble solids, titratable acidity, "ratio" and moisture, and minerals calcium, magnesium, iron, phosphorus and potassium were analyzed. There were also analyzed antioxidants: Ascorbic acid, total phenols, total flavonoids, lycopene and β-carotene, besides antioxidant activity. For the genetic characterization, was used the molecular marker AFLP (Amplified Fragment Length Polymorphism). Fruits of five accessions of guava from Maranhão state (G01MA, G12MA, G14MA, G16MA and G20MA), and the accessions A08MA, A42PE, A45PE, A80RO and A100AM of Brazilian guava highlighted in the biochemical assessment by presenting, in general, the larger soluble solids, sugars, proteins and minerals, and are among those with lower levels of acidity, in the case of guavas, and higher in the case of Brazilian guava. As for antioxidants, it was found that guavas and Brazilian guavas are rich in phenolic compounds, which showed strong correlation with antioxidant activity, showing be your main contributor. It was also observed that part of accesses... (Complete abstract click electronic access below) / Orientador: Giuseppina Pace Pereira Lima / Coorientador: Carlos Antonio Fernandes Santos / Banca: Ricardo Alfredo Kluge / Banca: Luis Fernando Durigam / Banca: João Domingos Rodrigues / Banca: Sarita Leonel / Doutor

Graduation date: 1994

The purpose of this study was to examine the molecular evolution of floral developmental MADS-box genes in diploid and allotetraploid cotton (Gossypium, Malvaceae). We isolated and characterized both cDNA and genomic DNA sequences of four MADS-box genes, B-sister, APETALA3 (AP3), PISTILLATA (PI, two copies) and AGAMOUS (AG), in seven Gossypium species (2 A-genome species, 2 D-genome species, 1 C-genome species and 2 AD-genome species) as well as an outgroup species, Gossypioides kirkii. We then studied the expression patterns of each gene by reverse-transcriptase PCR (RT-PCR) in each flower part for different flower stages of G. arboreum (A-genome), G. raimondii (D-genome) and G. hirsutum (AD-genome). We found that these MADS-box genes are evolving independently at the DNA sequence level but exhibit highly variable expression patterns in allotetraploid G. hirsutum. These MADS-box genes contain highly conserved exon lengths and exon/intron structures, high nucleotide identity with homologs in Arabidopsis thaliana and Antirrhinum majus, and conserved gene phylogeny within the genus Gossypium. All the genes exhibit evidence of codon bias. The AP3 gene in Gossypium appears to be subject to positive selection, while the PI-small copy of the PI gene appears to be subject to strong functional constraints together with a very low mutation rate. Within G. hirsutum, the B-sister gene exhibits gene silencing of the A-subgenomic homoeolog and the PI-big copy of the PI gene has experienced pseudogenization by insertion of a copia-like retroelement. The AP3, PI-small and AG genes show biased expression patterns in G. hirsutum. These MADS-box genes also demonstrated developmentally regulated expression patterns in G. arboreum, G. raimondii and G. hirsutum.