NaCl胁迫对构树种子发芽及幼苗生理生化指标的影响

Effects of NaCl solution stress on seed germination and seedling physiological indexes of Broussonetia papyrifera

研究了不同浓度NaC l(0,25,50,75,100,125 mmol/L)对构树种子发芽和幼苗生长及生理效应的影响。结果表明:低浓度(25 mmol/L)盐胁迫下,构树种子的发芽率比对照升高了7.7%,同时幼苗根长亦有显著增加,比对照高23%,苗高、发芽指数、活力指数虽有所下降但不显著;随着NaC l浓度的增大,构树种子的发芽率、发芽指数、活力指数均呈下降趋势,发芽后幼苗的根长、苗高、鲜质量等也呈下降趋势,幼苗生长被抑制。对幼苗的生理指标测定显示:细胞膜透性随着盐浓度的增加逐渐升高,细胞膜稳定性受到破坏;MDA含量、SOD、POD活性随盐浓度的增加呈现先升高后降低的趋势,膜透性和MDA含量与SOD活性呈极显著相关。

The effects of NaCl stress on the seed germination and seedlings growth of Broussonetia papyrifera were studied by treating the seeds with different NaCI concentrations （0, 25, 50, 75, 100 and 125 mmol/L, respectively）. Results showed that comparing to the control treatment, the germination of Broussonetia papyrifera seed under light concentration salt stress （25 mmol/L） had gone up 7.7%. Length of the root of young seedlings had increased by 23% significantly. Length of the stem, germination index and vigor index dropped inconspicuously. With the increasing NaCl concentration, the germination of Broussonetia papyrifera seed, germination index and vigor index had a significant decrease. Length of the root and stem, fresh weight declined after germination, the growth of seedlings was inhibited. The physiological indexes of seedlings showed that the membrane permeability gone up gradually with the increasing NaCl concentration and the membrane stability was destroyed. The activities of SOD, POD and MDA contents had similar trends, increasing firstly and then decreasing. There were significant correlations among the membrane permeability, MDA contents and the activity of SOD