Impact of drought stress on some physiological traits in five Eucalypt species

In order to investigate the impact of drought stress, a trail was carried out in a factorial experiment in the base of randomized complete design on traits such as pigments and photosynthesis in five Eucalyptus species (E. globulus, E. largiflorens, E. robusta, E. sideroxylon, E. tereticornis). Drought treatments contained polyethylene glycol solution with five levels (0, -1, -3, -6, -12 bar). In this investigation characteristics such as: chlorophyll and carotenoids, photosynthesis rate, leaf water potential and stomata number were studied. Most of the traits were significantly decreased under water stress condition. The highest amount of chlorophyll, carotenoids, photosynthesis and leaf water potential were related to control plants of different species. Results showed that these traits caused lower reduce under drought stress condition in E. largiflorens. Whereas these traits have positive correlation with resistance to drought, consequently E. largiflorens were most resistance species to drought stress. E. sideroxylon and E. tereticornis with high reduce in traits were sensitive species to drought under drought stress condition. E. globulus and E. robusta were relative high resistance species to drought stress.