Fluorescencia inducida en hojas de espinaca sujetas a deshidratación.

Abstract

In this work, chlorophyll a fluorescence induction curves were obtained from spinach leaves subjected to dehydrataion at 25 °C. The experimental results found showed that due to the loss of water in the leaves, the fluorescence curves shifted towards higher fluorescence values. In addition, it was found that there is a threshold in the loss of mass above which the effects of dehydratation are significant. If the leaf loses more than 20% of its mass, the IP region is not present in induced fluorescence curves. Additionally, the fitting of the experimental curves was carried out using a variant of the stochastic model proposed in previous works. For this study, the contribution of the connectivity parameters (pα) was considered directly and not as part of the statistical weights. With the change made, it was obtained that if pα is equal to 1 then the region associated with a specific domain is absent. In fact, in this work it was found with values of chi-square reduced less than 4 that the connectivity parameter associated with the IP region (p3) took values close to 1 (0.94 ± 0.051) which is consistent with the experimental curves obtained, where the IP region is not present. Importantly, this parameter only increased as the leaf loses water.