Photosynthetic performance in Eucalyptus clones cultivated in saline soil

Abstract

The aim of this study was to evaluate the photosynthetic performance of Eucalyptus clones with the aim of identifying their tolerance to soil saline stress conditions. The experiment was arranged in a randomized block design with a 3 × 4 factorial arrangement: in five replications, totaling 60 plots, three Eucalyptus clones were used, VC865, I224, and I144, which were exposed to four concentrations of NaCl (0, 1, 2 and 3 g NaCl kg-1 of soil). Clone I144 shows mechanisms of salinity tolerance as smaller reductions in the stomatal conductance, transpiration, photosynthesis, photochemical efficiency of PSII, photosynthetic pigment content and total dry mass. On the other hand, clone I224 presents greater physiological damage, indicating high susceptibility to salt stress, while VC865 shows moderate sensitivity to salinity. Variables related to photosynthetic performance, such as gas exchange, photochemical efficiency of PSII and photosynthetic pigments are potentially reliable physiological indicators for selecting of tolerant Eucalyptus clones to salt stress.

EFFECTS OF ARTIFICIAL SHADING AND IRRIGATION WITH BRACKISH WATER ON THE INITIAL DEVELOPMENT OF Anadenanthera colubrina (Vell.) Brenan PLANTS

“…The high values of internal CO 2 concentration associated with the increase in stomatal conductance at the higher levels of shading, can justify the higher instantaneous carboxylation effi ciency, which occurred due to the availability of ATP and NADPH and substrate for RuBisCo (Silva et al, 2015;Tan et al, 2017). Similar results were observed by Andrade et al (2019), who observed reductions in carboxylation effi ciency in Eucalyptus spp. clones with increasing soil salinity levels, observing strong correlation with photosynthesis data, which was also observed in the present study.…”

Emergência e crescimento inicial de plântulas de Libidibia ferrea (Mart. exTul.) em diferentes níveis de salinidade na água de irrigação

“…A degradação das clorofilas também indica perturbações fotoquímicas no complexo coletor de luz e nos centros de reação do PSII, ocasionadas pela salinidade (BHARGAVA et al, 2014;CAVALVANTE et al, 2018). Diversos autores observaram redução no índice SPAD em mudas de espécies florestais submetidas à salinidade tais como Lima et al, (2015) e Andrade et al, (2019).…”