不同干旱胁迫后复水对侧柏和元宝枫幼树渗透调节的影响

Based on the measurements of leaf electric conductivity and proline content with two-year-old pot-cultured seedlings of Platycladus orientalis and Acer truncatum, osmotic adjustment ability under different growth stages (early growth stage, fast growth stage and late growth stage), drought stress severity (moderate and severe water stress) and stress duration (15d, 30d, 45d), restoration degree after re-watering (24h and 48h) were studied. The results showed that there are positive relationships between the plasma-membrane permeability and drought stress severity. The Osmotic Adjustment ability of saplings during drought stress was late growth stage > fast growth stage> early growth stage. The main trend of recovery after re-watering at different growth stage was late growth stage > fast growth stage> early growth stage also, and for the two tree species was Acer truncatum >Platycladus orientalis. With the increase in severity of drought stress, proline content increased firstly and then decreased gradually, which showed that adjustment ability of proline was not strong enough to endure the drought stress. The trend of recovery for proline content existed diversity according to the different growth stage, different drought stress severity after re-watering from 24 hours to 48 hours. Plasma-membrane permeability of both saplings all existed extra-compensation after moderate water stress followed by re-watering.