山黧豆幼苗对干旱胁迫的生理响应

用PEG6000模拟干旱对山黧豆进行胁迫。结果发现，胁迫初期（0~48 h），突然的水分亏缺使气孔导度（Sc）和蒸腾速率（Tr）迅速下降，而净光合速率（Pn）和水分有效利用率（WUE）基本维持稳定。胁迫后期（48~108 h），上述四个光合指标均不同程度地向对照水平恢复；脯氨酸和相对电导率（REC）受胁迫强度影响较小，但与胁迫时间呈明显正相关，分别在48和60 h增幅最大，而且当REC上升至对照的50%左右时，脯氨酸含量已达对照的14倍之多。由此认为，山黧豆可能主要通过迅速减小Sc和Tr以及大量而急剧的积累脯氨酸来减轻干旱所造成的伤害。

Physiological Response of Lathyrus sativus L. to Drought Stress

Lathyrus sativus L. was used as experimental material and treated by PEG6000. The results showed that at the beginning of stress(0~48 h), stomatal conductance(Sc) and transpiration(Tr) decreased sharply, while net photosynthesis rate(Pn) and water use efficiency(WUE) fluctuated at a certain level. But these photosynthetic indexes recovered near to normal soon after 48 h. Moreover, the content of free proline showed a significant elevation, especially at 48 h and 60 h. When REC increased nearly 50 percent of control, proline had accumulated 14 times more than the control. All data above suggests that the seedlings of L. sativus L. could alleviate its stress damage by declining Sc/Tr and accumulating plenty of proline, which might be some of drought-resistant mechanisms.