菘蓝内生细菌对其生长生理及药用品质的影响

Effects of endophytic bacteria on the growth and medicinal quality of Isatis indigotica Fort.

摘要:

目的 从菘蓝(Isatis indigotica Fort.)根中分离内生菌，研究内生菌对菘蓝生长生理及药用品质的影响，为其栽培生产中微生物调控提供参考。方法 选择相应的培养基分析内生菌的促生活性；随后进行盆栽试验，选取3株具促生作用的内生菌(Bacillus sp. BC00、Bacillus sp. BV11、Pseudomonas sp. PA28)单施菘蓝4次，最后一次处理后不同时间测定叶片的相关生理指标，并于采收期测定其根与叶的生长生理、活性成分等指标。结果 各处理组菘蓝叶的光合色素含量、营养代谢酶活性在每个时间点均高于对照组。3株内生菌对其生长和生物量积累均有显著促进作用，其中BC00对地上部分干重的促进效果最佳，与对照相比提升了74.16%；BV11对地下部分干重的促进效果最显著，与对照相比提升了216.02%。内生菌处理对其内源激素和可溶性物质含量有显著影响。3株内生菌对活性成分的影响各有不同，BC00与对照相比靛蓝和(R,S)-告依春含量分别增加了7.83%和5.64%；BV11的靛蓝和(R,S)-告依春含量略低于对照，但处理组各指标成分的总活性生物量均显著高于对照。结论 菘蓝内生细菌BC00、BV11和PA28对其生长生理及活性成分均有显著促进作用，其中BC00的综合促进效果最佳，为后期研发有利于菘蓝生长的微生物菌肥提供了依据。

Abstract:

Objective We isolated endophytes from the roots of Isatis indigotica Fort. and investigated the effects of endophytes on the growth, physiology, and medicinal quality of I. indigotica, aiming to provide a reference for microbial regulation of the cultivation and production of this plant.Methods The relevant culture media were selected to analyze the plant growth-promoting activities of the endophytes. Three endophyte strains (Bacillus sp. BC00, Bacillus sp. BV11, and Pseudomonas sp. PA28) were selected and applied singly to I. indigotica four times. The physiological indexes of the leaves were measured at different time points after the last treatment, and the growth and physiological indexes and the content of active ingredients of the roots and the leaves were measured at the harvesting stage.Results The photosynthetic pigment content and nutrient-metabolizing enzyme activities of I. indigotica leaves in each treatment group were higher than those in the control group at each time point. The three strains of endophytic bacteria significantly promoted the growth and biomass accumulation of I. indigotica. Strain BC00 had the best promoting effect on the dry weight of the above-ground part, which was increased by 74.16% compared with that of the control. Strain BV11 had the most significant promoting effect on the dry weight of the below-ground part, which was increased by 216.02% compared that of the control. The treatments with endophytic bacteria significantly affected the content of endogenous hormones and soluble substances. The three strains of endophytic bacteria had different effects on the active ingredients. Compared with the control, strain BC00 increased the content of indigo and epigoitrin by 7.83% and 5.64%, respectively, while strain BV11 slightly decreased the content of indigo and epigoitrin. The total active biomass of each index ingredient in the strain treatments was significantly higher than that of the control.Conclusion The endophytic bacterial strains BC00, BV11, and PA28 had significant promoting effects on the growth, physiological indexes, and active ingredients of I. indigotica, and strain BC00 demonstrated the best comprehensive promoting effect. The findings provide a basis for the later development of microbial fertilizers conducive to the growth of I. indigotica.