Eucalyptus urocan drought tolerance mechanisms

Abstract

The present study was designed to identify strategies for tolerance to hydric deficit in Eucalyptus urocan seedlings. The experiment was conducted in a green house with 100% solar radiation capture. The completely randomized block design was used with five treatments (plants irrigated daily with water corresponding to 25, 50, 75, 100 and 125% daily evapotranspiration) and five replications. 120-day-old E. urocan seedlings (hybrid result from the crossing between Eucalyptus Urophylla x Eucalyptus camaldulensis) were planted in pots containing 8 L of substrate composed by oxisol, sand and muck at 3:1:0.5 ratio, respectively. The seedlings were irrigated with different volumes of water for 13 days and then analyzed. Under hydric deficit condition, E. urocan plants showed significant investment in the root system, reduced the breathing rate and kept enough turgor for growth. E. urocan plants at initial growth stage are tolerant to hydric deficit and show dehydration delay as a strategy to tolerate drought.

Growth of Eucalyptus urocam Under Different Irrigation Managements

“…The principal component analysis (PCA) (Figure 1) explained 79.8% of the data variance, and formed two groups: the first for the right of axis 1, with plants irrigated with water depths corresponding to 50%, and the second for the left of axis 1, with plants irrigated with 100% of the retention capacity of the substrate. This indicates that the difference in water supply was sufficient to alter the growth of E. urocam plants, which, in general, have an isohydric mechanism to maintain tissue hydration, minimizing transpiration by reducing stomatal opening (Matos et al, 2016).…”

Initial growth of Jatropha curcas plants subjected to drought stress and silicon (Si) fertilization

“…Reduced transpiration in plants subject to drought stress is associated with high stomatal sensitivity and less biomass partitioning to the leaves. Low transpiration enables sufficient hydration for plant metabolism and growth (Matos et al, 2016).…”

An overview of adaptative responses to drought stress in Eucalyptus spp.

“…Eucalyptus presented investment in the root system to access water (e.g. E. urocan) (Matos et al, 2016). Susiluoto & Berninger (2007) studied the response of E. microtheca F.Muell.…”