干旱胁迫对桔梗生长特性、生理特性及总皂苷成分积累的影响

目的]探讨干旱胁迫对桔梗种子萌发及幼苗生长的影响,并初步分析干旱胁迫下桔梗生长发育的生理机制和对总皂苷成分的诱导影响。方法]分别采用5%、10%、15%、20%、25%聚乙二醇6000(PEG6000)处理桔梗种子及幼苗,测量种子萌发及幼苗生长过程中的生长性状指标和生理指标,以及次生产物桔梗总皂苷成分含量。结果]随着PEG胁迫浓度的增加,桔梗种子萌发和幼苗生长受到抑制。种子发芽率、相对发芽率显著降低;幼苗各生理指标中脯氨酸,丙二醛和总皂苷含量呈上升趋势,超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性均不同程度地表现为先上升后下降的趋势。结论]桔梗能够耐受一定程度的干旱胁迫,适度的干旱胁迫有助于桔梗幼苗总皂苷的积累。

Effects of drought stress on growth and physiological characteristics, and total saponins accumulation of Ballonflower

Objective] To explore the effects of drought stress on seed germination and seedling growth of ballonflower, and to analyze the physiological mechanism of drought stress on growth and development of ballonflower and the accumulation characteristics of saponins. Methods] The seeds of ballonflower and the seedling were treated with 5%, 10%, 15%, 20% and 25% PEG 6000, then the growth traits index and physiologic index in the process of seed germination and seedling growth and the secondary product, i.e. ballonflower total saponins were measured. Results] With the increase of PEG stress concentration, seed germination was inhibited, the germination rate and relative germination rate were decreased;among the various physiological indexes, proline, MDA, and total saponins showed increasing trends. The activities of SOD, CAT and POD all presented a rising and then decreasing tendency. Conclusion] Ballonflower can tolerate some degree of drought stress. Moderate drought stress is good for the accumulation of total saponins of ballonflower seedlings.