This dissertation presents the result of two separate research programs. The first elucidates the phylogeny, biogeography and systematics of the genus Menodora in the olive family. A phylogeny based on the internal transcribed spacer (ITS) of nuclear ribosomal DNA and the chloroplast rps16 and trnL introns and trnL-F intergenic spacer demonstrates that the genus is monophyletic. Within the genus, M. robusta of Patagonia is the first taxon to branch, followed by a monophyletic African clade and M. spinescens of California, though the placement of the latter does not have strong support. Most North American species are nested within the derived South Americans. A South American origin is hypothesized, with two independent dispersals to North America, and a single dispersal to Africa. The phylogeny provided new insights for the systematic treatment, where 24 species, one subspecies and six varieties are recognized, with major realignments of the intregrifolia and scabra species complexes, and a single new species described. In the second area of research, the chloroplast genome of Pelargonium × hortorum has been completely sequenced. At 217,942 base pairs (bp), it is both the largest and most rearranged land plant chloroplast genome yet sequenced. It features two copies of a greatly expanded inverted repeat (IR) of 75,741 bp each, and diminished single copy regions of 59,710 bp and 6,750 bp. Gene content is similar to other angiosperms, with the exceptions of a large number of pseudogenes, two open reading frames (ORF56 and ORF42), and the losses of accD, trnT-ggu, and possibly rpoA. The latter may be represented, however, by highly divergent set of rpoA-like ORFs. The IR expansion accounts for most of the size increase of the genome, but an additional 10% is related to the large number of repeats found. Most of these occur near rearrangement hotspots, and two different repeat associations (characterized by full or partial duplications of several genes) are localized in these regions. We propose simple models that account for the major rearrangements with a minimum of eight IR boundary changes and 12 inversions in addition to several sequence duplications. / text

Submitted by Reginaldo Soares de Freitas (reginaldo.freitas@ufv.br) on 2017-06-13T16:59:09Z No. of bitstreams: 1 texto completo.pdf: 819791 bytes, checksum: cb03aa7b2159a45745634e2ef7e54bc9 (MD5) / Made available in DSpace on 2017-06-13T16:59:09Z (GMT). No. of bitstreams: 1 texto completo.pdf: 819791 bytes, checksum: cb03aa7b2159a45745634e2ef7e54bc9 (MD5) Previous issue date: 2005-12-13 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Retardantes de crescimento são comumente utilizados em culturas ornamentais para manipulação da arquitetura das plantas. Os objetivos deste trabalho foram avaliar as doses e formas de aplicação dos retardantes clormequat, daminozide e paclobutrazol nas características fitotécnicas de plantas de gerânio zonal (Pelargonium x hortorum L.H.Bailey). Plantas de gerânio de três cultivares foram submetidas à aplicação de daminozide ou da mistura contendo daminozide + clormequat via pulverizações foliares e de clormequat ou paclobutrazol via pulverizações ou aplicação da solução diretamente no substrato. Os experimentos foram conduzidos no Setor de Floricultura da UFV, em blocos casualizados com 3 repetições em esquema fatorial. Pelos resultados experimentais obtidos, concluiu-se que os retardantes não proporcionaram aumento no ciclo das plantas. As concentrações de 1000 ou 1500 mg i.a./l de clormequat ou 20 mg i.a./l de paclobutrazol, aplicadas via pulverizações foliares por 3 vezes, resultaram em plantas com as dimensões adequadas, entretanto o aparecimento de sintomas de fitotoxidez limita o uso do clormequat próximo ao final do ciclo da cultura. A aplicação do clormequat diretamente no substrato proporcionou resultados semelhantes aos encontrados nas plantas submetidas às pulverizações foliares, porém com custos mais elevados. Soluções contendo paclobutrazol nas doses 0,018; 0,036 e 0,072 mg i.a./planta aplicadas via solo proporcionaram controle excessivo do alongamento das hastes. Elevadas concentrações de daminozide necessárias para obtenção de plantas com as dimensões desejadas podem restringir o uso desse retardante na cultura do gerânio. O uso da mistura de retardantes clormequat + daminozide resultou em plantas com características adequadas, porém manejo mais trabalhoso quando comparado aos outros retardantes. / Growth retardants are commonly used at ornamentals to manipulate plant’s architecture. The objectives of this study were to evaluate the growth retardants chlormequat, daminozide and paclobutrazol applied as drenches or foliar sprays at different rates over zonal geranium (Pelargonium x hortorum L.H.Bailey) characteristics. The experiments were conducted at Floriculture Section of UFV and arranged in a randomized block design with 3 single plant replications. There were no significant differences in time to flower. Plants treated with foliar sprays at 1000 or 1500 ppm of chlormequat or 20 ppm of paclobutrazol had the desired shape, but phytotoxic symptoms limits chlormequat ́s use close to the end of culture ́s cycle. Chlormequat drenches provided similar results as foliar sprays, but with higher costs. Paclobutrazol drenches at 0,018; 0,036 and 0,072 mg a.i./plant caused excessive retardation of vegetative growth and total plant height. High rates of daminozide needed to attain plants with desired shape may restrict the use of this retardant on geranium plants. Tank mix of chlormequat + daminozide results in plants with suitable characteristics, but requires more labour than the other retardants.