Leaf osmotic potential of Eucalyptus hybrids responds differently to freezing and drought, with little clonal variation.

摘要: Concentrations of solutes, and thus leaf osmotic potential (Psi pi), often increase when plants are subject to drought or sub-zero (frost) temperatures. We measured Psi pi concentrations individual solutes in leaves 3-year-old Eucalyptus camaldulensis Dehn., E. globulus Labill., grandis W. Hill ex Maid. 29 hybrid clones on a site subjected both summer winter frost. sought characterize seasonal genetic variations determine whether turgor is related bole volume increment. Leaf at full pi(100)) was 0.7 MPa more negative than late summer, this trend uniform across genotypes. Soluble carbohydrates were confirmed as key contributors pi, accounting for 40-44% total osmolality. The pi(100) facilitated by changes morphology, such reduced turgid mass:dry mass ratio increased apoplastic water fraction winter. Cell wall elasticity significantly from summer. Our results suggest that elastic adjustment may be important exposed drought. Although reasonable predictor situ turgor, we found no relationship between any physiological trait Clone-within-family variation small unrelated conclude that, the study species, tree improvement under water-limited conditions should concentrate direct selection growth rather indirect based potential.