ESJ56 一般講演（口頭発表） B1-08

Responses of the Growth and Physiology to Salt Stress in Hydropically Cultured Salix psammophila and Salix matsudana Cuttings

Mao H.P., Okada Y., Michimata S., Yamamoto F.

Salix spp. is one of main tree species grown in Maowusu sand dune in northwest China. There has been little research into physiological reactions to salt stress and into different salt tolerance in Salix psammophila and Salix matsudana. In this study, growth, photosynthesis, and Na⁺, K⁺, Ca²⁺ and Mg²⁺ distributions were investigated in 2-year-old hydroponically cultured S. psammophila and S. matsudana cuttings exposed to salt stresses (0, 25, 50, 75 or 100mM) for 4 weeks in 2/5 Hoagland solution. Growth and biomass was strongly depressed by 100mM NaCl treatment in S. psammophila but by 50mM, 75mM or 100mM NaCl in S. matsudana. S. matsudana showed higher photosynthesis than S. psammophila in salt-free condition. However, the photosynthesis in S. matsudana was more sensitive than S. psammophila in salt treatment condition. Different ions exhibited different distributions in different parts of the plant. S. psammophila exhibited stronger Na⁺ exclusion ability in roots comparison with S. matsudana. K⁺ content increased in leaves and decreased in roots in both species with the increase in the salt concentration in the growth solutions. The distributions of Ca²⁺ and Mg²⁺ in the leaves and roots of each species were also analyzed.