Avaliação ecofisiológica e metabólica de quatro variedades de cana-de-açúcar

• Autor(a) principal: Sousa, João Paulo Silva
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFS
• Texto Completo: https://ri.ufs.br/handle/riufs/6561
• topic: Cana-de-açúcar; Biometria; Ecofisiologia; Cana-de-açúcar; Avaliação; Fotoquímica; Saccharumofficinarum; Mancha de curvularia; Fisiologia vegetal; Biometry; Ecophysiology; Sugarcane; Sugarcane; Sugarcane; Curvularia leaf spot; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA

The purpose of this work was to evaluate biometric, metabolic and physiological four of the most promising varieties of RIDESA s sugar cane at 150 and 240 days, where in this second period, under the influence of the fungus Curvularia inaequalis, causal agent of the Curvularia s spot.The gas exchange, fluorescence, chlorophyll content and biometry of varieties of sugar cane (Saccharumofficinarum) RB 872552, RB 962962, RB 98710 and RB 92579 were assessed under controlled conditions in vessels, maintained in a greenhouse. The measurements of gas exchange were made at 8:00 am using the following parameters: photosynthetic assimilation of CO2 (A), stomatal conductance (gS), the internal concentration of carbon (Ci), transpiration (E) and vapor pressure deficit between leaf and air (DPVairleaf). Fluorescence measurements were performed at 9:00 am being used the initial fluorescence (Fo), maximum (Fm), variable (Fv), the ratio between variable and maximum fluorescence (Fv / Fm), photochemical quenching (qP) and quenching non-photochemical (qN). The content of chlorophyll a, b and total was collected after elapsed previous analyzes. The quantification of the PAL enzyme was subsequently performed in the laboratory using the leaf +1 of sugar cane.At 150 days of gas exchange, the parameters of photosynthetic CO2 assimilation and transpiration showed abnormalities, and the variety 98710 presented the best results. The same tendency was repeated in the data of chlorophyllous pigments and biometrics. The data of chlorophyll fluorescence did not change.At 240 days of the gas exchange showed difference for the parameters of photosynthetic assimilation CO2, stomatal conductance and internal carbon, and the varieties 872552 and 962962 had values that indicate infection by the fungus.The same tendency occurred in fluorescence of chlorophyll a, in the parameters minimal fluorescence, maximal fluorescence, maximum quantum yield (Fv / Fm), photochemical quenching and non-photochemical quenching. The chlorophyllous pigments showed no change.Confirming the trend, quantified the enzyme phenylalanine ammonia-lyase showed variation, with varieties RB 872552 and 962962 with the major activity of this enzyme in the inoculated treatment.Biometrically varieties RB 92579 and 98710 showed the best development in both treatments. We conclude that under optimal conditions, the varieties generally had the same trends at 150 and 240 days after transplanting, already under the influence of the fungus Curvularia inaequalis, the varieties RB 92579 and 98710 were resistant, the varieties and RB 872552 and 962962 presented symptoms.