Welcome to Chinese Agricultural Science Bulletin,

Chinese Agricultural Science Bulletin ›› 2022, Vol. 38 ›› Issue (21): 129-135.doi: 10.11924/j.issn.1000-6850.casb2022-0190

Special Issue: 生物技术 植物保护

Previous Articles     Next Articles

Quality Promotion and Disease Control Effects of Bacillus Strain R57 on Astragalus membranaceus var. mongholicus and Its Identification

ZU Weixi1(), ZHAO Xiaoxia2, GAO Fen2()   

  1. 1Taiyuan Tourism College, Taiyuan 030032
    2Institute of Applied Chemistry, Shanxi University, Taiyuan 030006
  • Received:2022-03-22 Revised:2022-04-27 Online:2022-07-25 Published:2022-08-23
  • Contact: GAO Fen E-mail:zuweixi@163.com;gaofen@sxu.edu.cn

Abstract:

The study aims to explore the quality promotion and disease control effects of strain R57 on root rot of Astragalus membranaceus var. mongholicus (AMM), and identify its classification status. The antifungal activity of bacteria-free filtrate was determined by Oxford cup method, the control effect in detached roots was evaluated by seedling root dipping method, and the control effect in potted plants was tested by conventional root-irrigation method. The changes of main active components in roots of AMM irrigated with the fermentation broth of strain R57 were tested by HPLC-UV-ELSD. The strain R57 was identified by means of morphology, physio-biochemical characteristics and 16S rDNA sequence analysis. In the inhibition test in vitro, the diameters of inhibition zone of R57 bacteria-free filtrate to F. solani and F. acuminatum were (18.02 ±1.71) mm and (19.96±2.42) mm, respectively. In the detached roots test, the therapeutic treatments using R57 bacteria-free filtrate showed significant control effect on F. solani and F. acuminatum infection on both 7 d and 15 d; the protective treatments showed significant control effect on F. solani infection on 7 d and on F. acuminatum infection on 15 d, respectively; the antagonistic treatments had obvious control effect on F. solani infection only on 7 d. In the pot experiment, the protective effects of the fermentation broth of strain R57 on the root rot caused by F. solani and F. acuminatum were 61.27%±4.89% and 64.33%±8.25%, respectively; no significant therapeutic effect on root rot was observed for all the treatments. The fermentation broth of strain R57 had obvious promotion effect on the accumulation of two main active components in AMM: calycosin-7-O-β-D-glucoside and ononin. The strain R57 was identified as Bacillus subtilis. The Bacillus subtilis strain R57 can reduce the incidence of root rot disease and promote the accumulation of main flavonoids active components in the AMM root; therefore, it can be further studied as a muti-functional strain for the development of microbial agent.

Key words: Astragalus membranaceus var. mongholicus, Bacillus subtilis, control effect, HPLC-UV-ELSD, root rot, active components

CLC Number: