内生真菌对干旱胁迫下金钗石斛生理生化特性的影响

Effects of endophytic fungi on physiological and biochemical characteristics of Dendrobium nobile under drought stress

以从野生金钗石斛内分离到的内生真菌37号、117号和120号菌株为材料,探讨在干旱胁迫下3种菌株对金钗石斛的生长、生理特性和抗氧化酶活性的影响。结果表明,随着15%PEG6000溶液胁迫时间的延长,各处理组较对照组相比生长减缓,渗透调节增加,抗氧化酶活性增强。3株内生真菌处理下能减少植株鲜重的下降,其中120号菌株能有效降低根长、提高抗氧化酶(SOD、CAT、POD)的活性;117号能增加渗透调节物质脯氨酸和可溶性糖含量;37号能增强抗氧化酶(SOD、CAT)活性。3株菌株均能增强金钗石斛抗旱能力,但作用效果各不相同,生产中混合使用效果更佳。

In this study, No.37, No.117 and No.120 strains isolated from Dendrobium nobile were used to detect the influence of these endophytic fungi on physiological and biochemical characteristics of Dendrobium nobile under drought stress. The results showed that the growth of Dendrobium nobile was slower than that of the control, and the osmotic regulation as well as the activities of antioxidant enzymes was increased with the increasing time of the stress induced by 15% PEG6000 solution. Under the treatment of the above-mentioned endophytic fungi, the fresh weight of Dendrobium nobile was reduced. Among them, No.120 strain effectively reduced the root length and improved the activity of antioxidant enzymes（SOD, CAT and POD）; No.117 strain increased the content of osmotic substances（proline） and soluble sugar; No.37 strain also enhanced the activities of antioxidant enzymes（SOD and CAT）. In conclusion, all these endophytic fungi can significantly improve the drought resistance of Dendrobium nobile with different effects. Therefore, combining the three endophytic fungi will result a much better effect in production.