Ecofisiologia e Bioquímica da cultivar BRS-Xiquexique: [Vigna unguiculata (L.) Walp], sob deficiência hídrica

• Autor(a) principal: Silva, Carlos Davi Santos e
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFS
• Texto Completo: https://ri.ufs.br/handle/riufs/4325
• topic: Feijão-caupi; Déficit hídrico; Vigna unguiculata; Agricultura familiar; Cowpea bean; Water deficit; Family farming; Food safety; CNPQ::OUTROS

The cowpea culture has a huge alimentary importance; it is one of the most cultivated by the rural zone population of North/Northeastern of Brazil. Abiotic stress such as droughts can reduce the crop yield. Therefore, the identification and understanding of the drought tolerance mechanisms are fundamental when selecting cultivars more tolerant to water deficit. This paperwork had as objective the study of ecophysiological and biochemical responses showed by the cultivation of cowpea ´BRS-xiquexique´ when submitted to different water regimes. The studies of the ecophysilogical responses and biochemical analyses were realized in the agricultural greenhouse and in the Botany Department of Biology applied laboratory at the Federal University of Sergipe, located in São Cristóvão-SE. For the cultivation were used vases with 10 litres containing soil composed of vegetal land and washed sand in a proportion of 2:1. There were sown 4 seeds by vase but after 15 days the 2 more vigorous were chosen. By the 46th day of cultivation the irrigation was suspended. The trial design was made with three treatments and five repetitions (T0 = 100% repositioning of the daily lost water by the plant, T1 = 50% repositioning of the daily lost water by the plant, T2 = 25% repositioning of the daily lost water by the plant). Always in the interval of 8am to 8:30am the vases were weighed and the water lost in the last 24 hours was the answer for the established proportions for each treatment. During the experiments, ecophysiological analyses were done every two days and the biochemical analyses, every four days. The ecophysiological studied variables were transpiration (E), stomatal conductance (gs), liquid photosynthesis (A), leaf water potential (ψ), CO2 concentration (Ci) and total chlorophyll. Establishing the ratio of photosynthesis and transpiration it was determined the efficiency of water use (A/E). For the biochemical studies, the variables were the soluble sugar content, level of proline, level of proteins, level of chlorophylls a and b. Every cophsyological and biochemical data was submitted to variance analyses and the averages were compared through Tukey test, by the level of 5% significance with the aid of the statistical programme GraphPad Prism. Version 4.0. Through the results analysis it was possible to identify correlation between water abolition and the ecophysiological responses presented. There was decline in the following values: water potential, transpiration rate, stomatal conductance, liquid photosynthesis and efficient use of water. There was increase in: internal concentration of CO2 and leaf temperature. For the stomatal conductance there was no significant differences between the plants of the treatments T1 and T2, however, there were differences among them and treatment T0 (witness). For the other variables, it could be observed important differences even though in isolated days. Concerning to the biochemical responses, in general there were no changes in levels of the studied variables, susceptible to correlation to the water disability.