Typescript (photocopy). / Digitized by Kansas Correctional Industries

Orientador: Catalina Romero Lopes / Banca: Edson Seizo Mori / Banca: Rogério Abdallah Curi / Resumo: O Arachis Pintoi é uma leguminosa forrageira de alta qualidade, apresentando valores de 18 a 25% de proteína bruta, 60 a 67% de digestibilidade "in vitro" da matéria seca e 60 a 72% de digestibilidade da energia bruta, além de apresentar grande aceitabilidade pelos animais. O valor nutritivo do A. Pintoi é mais alto quando comparado com gramíneas e leguminosas tropicais. No sistema de produção animal em pasto a utilização de leguminosa forrageira deve ser valorizada pela qualidade de produção e pelo alto valor nutritivo que é oferecido à dieta e também pelo aporte de nitrogênio atmosférico incorporado aos ecossistemas das pastagens. O uso de leguminosas em pastagens, no Brasil, ainda é muito limitado, seja porque o portfólio de cultivares é pequeno, ou porque o preço da semente ou do material vegetativo é elevado. Neste trabalho foram avaliados quatro genótipos de A. Pintoi (G1, G2, G3 e G4) oriundos de pré-seleção de um híbrido natural da espécie, utilizando o marcador molecular microssatélite visando à seleção de plantas homozigotas para, a partir delas, seguir o processo de melhoramento em cada genótipo para obtenção de linhagens puras. Foram utilizados nesta avaliação 14 locos de microssatélites dos quais, dez mostraram-se polimórficos e quatro monomórficos. O número de alelos observado variou de 1 a 11 por loco, com um total de 85 alelos e média de 8,5 por loco. A heterozigose observada variou de 0,3377 no loco AP183CV a 0,8701 no loco AP190CV com média de 0,6403. As plantas de maior homozigose foram selecionadas para dar continuidade ao processo de melhoramento e após avaliação agronômica poderão ser lançadas como potenciais cultivares de A. Pintoi. Considerando-se somente as plantas com homozigose superior a 70%, foi possível selecionar cinco plantas do genótipo G1 ...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Not available. / Mestre

Resumo: A cafeína é um alcalóide do grupo das metilxantinas. Em café, sua síntese depende da ação de três enzimas: Metilxanthosina sintase (MS), Teobromina sintase (TS) e Cafeina sintase (CS). A crença de que o consumo de cafeína pode trazer problemas à saúde como também a sensibilidade aos efeitos da cafeína, em alguns consumidores, determinou um crescimento do mercado dos cafés descafeinados em pelo menos 10%. O processo de descafeinização hoje é baseado no uso de solventes, que acarreta em significante perda de compostos essenciais ao sabor e qualidade de bebida. Recentemente, foram descobertas três plantas de Coffea arabica naturalmente descafeinadas no banco de germoplasma do Instituto Agronômico de Campinas (IAC). Estas plantas foram nomeadas AC. Análises bioquímicas nas folhas de AC1 mostraram que esta planta acumula teobromina, percussor da cafeína, não sendo detectada atividade da cafeína sintase. Maluf em 2009 descreveu, a existência de transcritos extras em todas as fases de desenvolvimento de frutos de AC1. Estes transcritos também estão presentes nos estágios verde-cana e cereja de frutos do cultivar mundo novo. Esses resultados obtidos sugerem que o transcrito extra está relacionado ao mecanismo de não produção de cafeína em frutos maduros. Tais resultados representam a possibilidade do desenvolvimento de um cultivar naturalmente descafeinado, e estratégias de melhoramento vêm sendo utilizadas para a transferência desta característica para outros cultivares. O presente trabalho caracterizou as plantas com baixos teores de cafeína através de análises genéticas e moleculares. Através da analise da regulação da expressão do gene caffeine sinthase (CCS), em folhas de café com teores normais e baixos de cafeína. As quantificação dos níveis de expressão, analisados via PCR quantitativo em tempo real revelaram baixa expressão do gene em folhas... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Caffeine is an alkaloid from the methilxanthine group. In coffee the synthesis of caffeine is carried out by three enzymes, methylxanthosine synthase (MS), theobromine synthase (TS) and caffeine synthase (CS). Due to the belief that the caffeine could cause health problems and also to consumers sensitivity to caffeine, the consumption of decaffeinated coffee increased in about 10%. The decaffeination process is based on the use of solvents, this process results in a loss of essentials compounds of flavor and cup quality. Recently, three coffee plants with extremely low levels of caffeine were identified in the IAC Coffea Germoplasm Collection, among non-cultivated C. arabica accessions. They are named AC's. Bioquimistry assays in AC1 leaves show teobromine accumulation, caffeine precursor, no activity of caffeine synthase was detected. Maluf in 2009 described the existence of extra transcript in all development of AC1 fruit. Those transcripts are also present on latter development stages, yellowish-green and cherry. The Author suggest that this extra transcript is related to non-synthesis of caffeine in mature fruits of cultivar MN and during the development of AC1 fruits. These results represent the possibility of the development of low-caffeine cultivars and coffee breeding programs are been used due to transfer this characteristic to others cultivars. In this work, the naturally caffeine free plants have been caracterizated by molecular and genetics assays. Throught the characterization of the regulation of caffeine synthase gene expression. The quantification of expression by qRT PCR show low expression in leaves of ACs plants comparing the expression of MN and ET4, same cultivar of AC. Expression assays show that abramulosa mutant has low expression comparing to MN cultivar but seperflorens mutant showed a normal expression... (Complete abstract click electronic access below) / Orientador: Ivan de Godoy Maia / Coorientador: Mirian Perez Maluf / Banca: Celso Luis Marino / Banca: Oliveiro Guerreiro Filho / Mestre

Genetic consistency within varieties is essential to quality assurance for any agricultural product. While the Australian coffee industry targets high quality coffee, there is observed morphological variation within coffee varieties in New South Wales plantations. This variability may result from environmental, genetic and/or management factors. Genetic factors can be tested by molecular markers which can also shed light on the questions concerning crop quality management. A review of the literature showed low genetic variation in C. arabica. Hence four different molecular marker systems were used in this study to detect possible genetic variation within and between varieties of local coffee grown in Northern New South Wales (NNSW), Australia. Genetic variation in eighty-four seed propagated coffee (C. arabica) accessions, mainly from two commercial varieties (K7 and CRB) in NNSW, were tested using various PCR-based marker systems (RAPDs, ISSRs, SSRs and AFLPs). Eleven accessions from Central Highland, Vietnam, were used as reference material. While RAPD and ISSR did not distinguish intra-varietal molecular variation, SSR and AFLP data revealed the degree of genetic variability and the relationship among individuals within and between coffee varieties. Despite observed morphological variation within supposedly single variety plantations in NNSW, the genetic variation, measured by genetic distance, revealed in this study was very low (K7: 0.193; CRB: 0.205). There exists genetic variation between different farms sharing the same cultivar (K7) which suggests differences in the management of plantation establishment and sourcing of trees. The genetic variability is not aligned with off-type individuals observed in K7, but is with off-type CRB plants which is probably due to inter-varietal hybrids from unintentional outcrossing. The mean level of genetic identity between cultivars derived from the two distinct types of C. arabica is moderate (0.641). Although genetic variation within and among arabica cultivars is low, sufficient DNA polymorphism was found among some C. arabica accessions to allow differentiation. The results in this study suggested that even the elite cultivars, which have been exposed to intensive selection, still show a certain degree of genetic variation amongst individuals within each cultivar even though C. arabica is a predominantly selfing species and has a narrow genetic foundation. The congruence between AFLP and SSR data sets suggests that either method individually, or a combination, is applicable to genetic studies of coffee. SSR alone clearly distinguished and revealed inter-varietal heterogeneity but were more powerful when combined with AFLP.

Title from container. Includes bibliographies and indexes. Contributions to quantitative and population genetics -- The biochemical genetics of man -- The theory of plant breeding -- Natural selection and its constraints.

Bibliography: leaves 132-159. Boron efficiency in oilseed rape (Brassica napua L. and B. juncea L.) was investigated in a wide range of genotypes. Using a solution culture screening of 10 day old seedlings, root length best described shoot growth response, and was used to characterise a total of 65 genotypes. Varieties and breeders lines tolerant of B-deficient growing conditions were identified, and the screening process validated through field trials. B responses in plants sampled at the 'green bud' stage indicated that vegetative growth is important in B efficiency. Studies were conducted to investigate the mechanism of B efficiency in oilseed rape. Results suggest no association between B efficiency and the capacity to acidify the root rhizosphere, or an increased translocation of B from root to shoot. Boron retranslocation was also studied as a mechanism of B efficiency.

<p>Ethiopian mustard (<i>Brassica carinata</i> A. Braun) or gomenzer is an oilseed crop that is well adapted to the highlands of Ethiopia. Evaluation of the local germplasm has resulted in the registration of high yielding cultivars, such as Dodolla and S-67. The oil of gomenzer contains about 40% erucic acid and the meal is high in glucosinolates. The objective of this research was to study the inheritance of erucic acid content in gomenzer and to introgress genes for the non2-propenyl glucosinolate trait from <i>B. napus</i> and <i>B. juncea</i>. The erucic acid content of F₁ seed from reciprocal crosses between the high erucic acid cultivars Dodolla and S-67 and zero erucic acid line C90-14 was intermediate between the parents indicating that erucic acid content in B. carinata was controlled by two nondominant genes with two alleles acting in an additive manner. Backcross F₁ seed derived from the backcross to the low erucic acid parent fell into three erucic acid classes with $<$0.5%, 6 to 16% and $>$16% erucic acid at the ratio of 1:2:1 indicating that erucic acid was under the control of two alleles each of at two loci. F₂ seed segregation data supported this observation. Each allele contributed approximately 10% erucic acid. The high glucosinolate B. carinata line C90-14, low glucosinolate <i>B. napus</i> cultivar Westar and <i>B. juncea</i> line J90-4253 were chosen as parents for the development of non2-propenyl glucosinolate <i>B. carinata</i>. The objective was to transfer genes for non2-propenyl glucosinolate content from <i>B. napus</i> and <i>B. juncea</i> into <i>B. carinata.</i> Interspecific crosses were made between <i>B. carinata</i> and <i>B. napus</i>, <i>B. carinata</i> and <i>B. juncea</i> and the interspecific F₁ generations were backcrossed to <i>B. carinata</i>. Backcross F₁ plants from the two interspecific crosses were intercrossed in an attempt to combine the two sources for non2-propenyl glucosinolate content in one genotype. Seed of backcross F₁ plants of the cropss ((<i>B. carinata</i> x <i>B. napus</i>) x <i>B. carinata</i>) contained a high concentration of 2-propenyl glucosinolate similar to those of <i>B. carinata</i>. Introgression of C genome chromosomes of <i>B. napus</i> into <i>B. carinata</i> was not effective in redirecting glucosinolate synthesis away from 2-propenyl and into 3-butenyl glucosinolate. This indicated that C genome chromosomes do not contain genetic factors for C3 $\to$ C4 glucosinolate precursor chain elongation, and that 2-propenyl glucosinolate synthesis is primarily controlled by genes on B genome chromosomes. Seed of ackcross F₂ plants of the cross ((<i>B. carinata</i> x <i>B. juncea</i>) x <i>B. carinata</i>) contained much reduced levels of 2-propenyl glucosinolate indicating that genetic factors for C3 $\to$ C4 glucosinolate precursor chain elongation were introgressed from the B genome of <i>B. juncea</i> into the B genome of <i>B. carinata</i>. However, a complete diversion of glucosinolate synthesis from 2-propenyl to 3-butenyl was not achieved. Further selections in segregating F₄ and F₅ generations of <i>B. juncea</i> derived <i>B. carinata</i> populations could yield the desired zero 2-propenyl glucosinolate B. carinata. The double interspecific cross was unsuccessful.

No description available.

No abstract available. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 2003.

When imbibed at their optimum germination temperature of 25°C, achenes of Tagetes minuta L. germinate over a period of approximately 48 h. At temperatures of between 35°C and 39°C, the achenes do not germinate but enter into a state of thermoinhibition. These supra-optimal conditions do not harm the achenes, however, and when the temperature is reduced below 35°C radicle emergence may be observed within 4 h. Achenes which have been thermoinhibited for periods of 24 h or more show "accelerated germination" which takes only 24 h, although the actual germination curve is identical to that of normally germinated achenes. This suggests that the achenes are metabolically active at thermoinhibitory temperatures and undergo most of the processes of normal germination, but that at some point any further development is halted, preventing radicle emergence. When the temperature is reduced, this block on germination is removed and since the achenes are already primed for germination, this occurs within a short time. An analysis of the proteins produced by germinating and thermoinhibited achenes was conducted using SDS-polyacrylamide gel electrophoresis (SDS-PAGE). This procedure was able to resolve approximately 40 different protein bands, but no differences were observed between thermoinhibited and germinating achenes. Two dimensional polyacrylamide gel electrophoresis (20-PAGE) was able to resolve approximately 200 individual polypeptides. The vast majority of polypeptides in T. minuta achenes are acidic, although the number of neutral to basic polypeptides increases as germination progresses. Ten polypeptides were identified which were specific to thermoinhibited achenes. These formed two distinct groups on the twodimensional gels. The larger group contained seven proteins, ranging in size from 22 kDa to 26.7 kDa and with isoelectric points of between 3.0 and 4.0. The smaller group contained three polypeptides with molecular weights of about 14 kDA and a pi of approximately 3.0. These polypeptides were all extremely specific to thermoinhibited achenes and declined rapidly when the incubation temperature was reduced, in a manner which correlated with an increase in the germinability of the achenes. Several characteristics of the expression of these polypeptides were similar to characteristics of embryo-dormancy in seeds where dormancy is thought to be actively imposed by the expression of specific dormancy-associated genes. This, along with the very tightly-regulated nature of these 10 polypeptides, suggests that thermoinhibition in T. minuta may be regulated through gene expression and that these ten polypeptides may represent the products of genes responsible for preventing radicle emergence at unfavourable temperatures. Since these polypeptides were only resolved using silver-staining and could not therefore be used for amino acid sequence analysis, this hypothesis was further investigated using differential display of mRNA to isolate genes which are expressed specifically in thermoinhibited achenes. A large number of cDNA fragments which were specific to either germinating or thermoinhibited achenes were identified and extracted from the differential display gels. Those cDNAs specific to the thermoinhibited achenes were taken for further analysis. Of the 62 fragments excised from the gels, 25 could be reamplified to generate single bands of the correct size on agarose gels. A further 22 cDNAs produced multiple bands, where one band was much brighter than the others and correlated with the size of the original fragment. Thirteen of the cDNAs which' generated single bands were cloned into the plasmid vector pGEM®-T Easy and transformed into either Escherichia coli JM109 or E. coli XL1-Blue. Recombinant colonies were identified using blue-white colour selection and the presence of the insert confirmed by colony blotting and restriction analysis. Three clones were chosen for each of the cDNAs. Reverse northern analysis confirmed that all 39 clones were specific to the mRNA pool of thermoinhibited achenes. High quality sequence data were obtained for 27 of the cDNA samples, the remainder appeared to have been degraded in transit. Alignment of the various sequences revealed that a total of 14 different sequences had been cloned, indicating that several of the bands isolated from the differential display gels contained multiple sequences. Electronic homology searches tentatively identified three of the sequences, whilst the remainder did not show significant homology to any known sequences. Of the cDNAs identified in this way, one may encode a plant transcription factor-like or nuclear RNA-binding protein whilst the other two may encode an RNase-L Inhibitor-like protein and a miraculin homologue. The potential roles of such genes in the imposition or maintenance of the thermoinhibited state are discussed. Although further research needs to be conducted to isolate full length cDNA sequences and to determine their exact expression patterns in germinating and thermoinhibited achenes, these results are consistent with the hypothesis that thermoinhibition in T. minuta achenes is under positive genetic control in a manner analogous to embryo dormancy. This thesis represents the first molecular study of thermoinhibition as well as the first report of active control over this phenomenon in any species. Since thermoinhibition, unlike dormancy, can be rapidly imposed and released under strictly controlled conditions without the need for any dormancy breaking treatment, T. minuta achenes represent an excellent model system for studies on the molecular control of seed germination. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 2003.