Made available in DSpace on 2015-03-26T13:51:44Z (GMT). No. of bitstreams: 1 01 - capa_abstract.pdf: 58664 bytes, checksum: 66cb47131cc46bcd2d5d263065f54c20 (MD5) Previous issue date: 2008-07-29 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The objective of this work was to evaluate the effects of the arbuscular mycorrhizal fungus (AMF), Glomus clarum, multiplied monoxenically in transformed carrot roots, on the growth, survival, mycorrhizal colonization and root development of micropropagated plantlets in different stages of rooting. Inoculation was performed in vitro and ex vitro conditions. Micropropagated plantlets with 0, 14 or 21 days maintained in rooting medium, supplemented or not with 1 mg L-1 of Indolbutiric acid (IBA), were transferred to a substrate composed by sand:soil:vermiculite (1:1/2:1). The in vitro system allowed the establishing mycorrhizal association, but no stimulatory effect on the development of shoot or root by mycorrhizal inoculation was observed. The period of time and addition of IBA did not affect plant growth. In ex vitro system, the stimulatory effects of arbuscular mycorrhizal association were evident in all evaluated characteristics, except to plant height. Plants that were not submitted to rooting showed growth similar or superior to those that were maintained in the rooting media, independent of IBA addition. Inoculated plants were shown to be more efficient at nutrient absorption, especially to phosphate. The arbuscular mycorrhizal association promotes beneficial effects when inoculation is performed ex vitro and the best period for inoculation of physic nut seedlings is in the beginning of acclimatization, without in vitro rooting phase. Inoculation of physic nut with arbuscular mycorrhizal fungi showed to be an important tool for micropropagated seedlings production. / O objetivo deste trabalho foi avaliar o efeito da inoculação do fungo micorrízico arbuscular (FMA), Glomus clarum, multiplicado monoxenicamente em raízes de cenoura transformadas, sobre o crescimento, a sobrevivência, a colonização micorrízica e o desenvolvimento radicular de plantas micropropagadas de pinhão-manso em diferentes estádios de enraizamento. A inoculação foi efetuada em condições in vitro e ex vitro. Plantas micropropagadas de pinhão-manso com 0, 14 ou 21 dias de permanência em meio de enraizamento, suplementado ou não com 1 mg L-1 de ácido indol-butírico (AIB), foram transferidas para substrato areia lavada:solo:vermiculita (1:1/2:1). O sistema in vitro utilizado permitiu o estabelecimento da associação micorrízica, mas não foi possível observar efeitos estimuladores da inoculação sobre o crescimento e desenvolvimento radicular das plantas. O tempo de permanência em meio de enraizamento e a adição de AIB também não afetaram o crescimento das plantas. No sistema ex vitro os efeitos estimuladores das micorrizas arbusculares foram evidenciados em todas as características relacionadas ao crescimento, com exceção da altura das plantas. As plantas que não foram submetidas à etapa de enraizamento mostraram crescimento semelhante ou superiores àquelas submetidas à etapa de enraizamento, independente da adição do AIB. As plantas inoculadas com G. clarum mostraram-se também eficientes na absorção de nutrientes, principalmente de fósforo. Pode-se concluir que os efeitos estimuladores das micorrizas arbusculares foram evidenciados quando foi realizada a inoculação ex vitro dessas plantas e que a melhor época de inoculação de J. curcas corresponde à fase de início da aclimatização, sem necessidade de passar pela fase de enraizamento in vitro. A inoculação com FMAs pode representar importante ferramenta para a produção de mudas micropropagadas de qualidade.

From the Proceedings of the 1971 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 22-23, 1971, Tempe, Arizona / The development of tree-ring chronology for bristlecone pine (Pinus aristata), stretching over 8,200 years, has been used to calibrate the radiocarbon time scale. An extensive deposit of driftwood in Stanton's cave in the grand canyon was estimated to have been deposited on the cave floor about 12,000 years ago on the basis of the 4,095-year radiocarbon age of a split-twig figurine on the surface of the cave floor. However, the initial driftwood specimen gave the surprising C-14 age of 35,000 years. A tree-ring dating study was therefore undertaken on driftwood in the grand canyon in order to: (1) evaluate the driftwood deposit in Stanton's cave; (2) provide a basis for interpreting c-14 dates from canyon archaeological sites; and (3) document a technique for deriving some concept of pre-dam hydrology, especially maximum high water levels. The percentage of dated specimens found indicated that the approach was feasible. A likely interpretation of the seemingly early c-14 dates at archaeological sites is that prehistoric man used old driftwood, as does modern man in the canyon. Tree-ring dates from wood above the pre-dam high water mark indicate that maximum 100-year flood evidence can be obtained.