Respostas do feijoeiro comum ao d?ficit h?drico

• Autor(a) principal: Macedo, David Cabral
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFRRJ
• Texto Completo: https://tede.ufrrj.br/jspui/handle/jspui/2464
• topic: Fluoresc?ncia da clorofila a; seca; fotoinibi??o; Drought; photoinibition; Phaseolus vulgaris L; Fisiologia

The aim of this work was evaluate the effect of water deficit on two common bean (Phaseolus vulgaris L.) cultivars. For that, an experiment was carried out in greenhouse, with Ouro Negro and Diplomata cultivars, on Plant Science sector of Federal Rural University of Rio de Janeiro. The two cultivars were submitted to eight days of drought and four days of rehydration in a completely randomized design. The results show that the cultivar Diplomata has a better performance under water deficit conditions, presenting leaf base water potential values (?a) higher than the black gold in the last days of stress. Analysis of the fluorescence of chlorophyll a demonstrated statistically significant variation between cultivars, with the cultivar Diplomata presenting higher values for most of the parameters analyzed, such as Fv/Fm, ?F/F'm and lower values of the NPQ variable. About photoinhibition, the diplomat genotype showed a significant difference with lower values on the seventh day of stress and on the second day of rehydration, indicating a higher reversal of damage from photoinhibition throughout the day. Regarding the content of starch, the cultivar Ouro negro showed high values before stress (AE), but there was no significant difference among both cultivars during (DE) and in rehydration (R). In relation to the protein content, the cultivar Diplomata showed significantly higher values (AE) and in (R). Also, for the potential of biological nitrogen fixation (PFBN), the cultivar Diplomata showed a significantly higher number of nodules and nodules mass (AE) and (DE), as for the morphologic parameters, the Ouro negro showed higher root dry weight (MSR) at the (R), but Diplomata had a higher leaf dry weight (MSF) at the (R) too. For the yield components of the cultivar Diplomata had a significantly higher grain mass/plant under stress compared to the cultivar Ouro negro. Therefore, these results indicate a better adaptation to drought cultivar Diplomata.