Photosynthetic performance and gas exchange of eucalyptus genotypes in the early development phase under water deficit

Abstract

Brazil has been cultivating eucalyptus since the beginning of the 20th century and with the development of eucalyptus plantations, over the years there has been an expansion of these planted areas to other regions of the country, where strong environmental tensions can negatively impact survival and/or growth of these species. In this sense, the objective of this work was to evaluate the photosynthetic performance and gas exchange in six eucalyptus genotypes in the initial phase under water deficit. The experiment was carried out in a greenhouse at the Universidade Federal do Acre and a completely randomized design, in a 6x2 factorial scheme, was adopted, with six eucalyptus genotypes, two water regimes (irrigated and non-irrigated) and five replications. Gas exchange and chlorophyll a parameters were evaluated after 15 days, using the IRGA, model Li-6400XT (LI-COR Inc., CA, USA) with a fluorometer (model Li-6400-40) attached. Also measured were: DM, R/Pa and ABM. The data obtained by the base experiment showed significant differences between the water treatments studied. In the gas exchange and chlorophyll “a” fluorescence analyses, the RIP01 and AEC0601 genotypes stood out. As for R/Pa, the genotypes AEC0601 and LCFA030 showed better results and as for ABM, LCFA030 presented a statistically significant relationship.