NaCl胁迫对榉树种子萌发及幼苗生理指标的影响

Effects of NaCl Stress on Seed Germination and Seedlings'Physiological Index of Zelkova schneideriana

研究了0.1%、0.2%、0.4%、0.6%和0.8%NaCl浓度处理对榉树种子萌发和幼苗生理指标的影响。结果显示:榉树种子的发芽率,发芽指数和活力指数在较低NaCl浓度(0.1%)处理下即有显著降低;萌发后幼苗的苗高、根长在较低NaCl浓度(≤0.2%)处理下变化不显著,当NaCl浓度达到0.4%及更高时幼苗的苗高和根长显著减小;幼苗SOD、POD活性随NaCl处理浓度的增加呈先升后降的单峰曲线,MDA含量变化不明显。由此推断,榉树在种子萌发阶段对NaCl胁迫较为敏感,但萌发后的幼苗在较低NaCl浓度(0.2%)下可通过增加保护酶的活性来减少NaCl胁迫产生的危害,从而得以正常生长。

The effects of NaCl with concentrations of 0. 1%, 0.2%, 0.4%, 0.6% and 0.8% on seed germination and seedlings＇ physiological indices of Zelkova schneideriana were studied in this paper. The results showed that germination rate, germination index and seed vigor index were all significantly decreased even under low NaCI concentration （0. 1% ）. While seedling heights and root lengths were significantly decreased only under high NaCI concentrations （ ≥0.4% ）. Compared with the control, the activity of SOD and POD appeared a single peak in the curve with the increase of NaCl concentration whiel the content of MDA had no obviously change. It was inferred that Z. schneideriana was more sensitive to NaCl stress during seed germination than during seedling growth period. Under low NaCl concentration （ ≤ 0.2% ）, seedlings of Z. schneideriana might mitigate the inhibition induced by NaCl stress by increasing the activity of SOD and POD.