AUTHOR=Han Caixia , Zhou Shixing , Mei Yu , Cao Qiumei , Shi Kai , Shao Hua 

TITLE=Phytotoxic, insecticidal, and antimicrobial activities of Ajania tibetica essential oil

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.1028252

DOI=10.3389/fpls.2022.1028252

ISSN=1664-462X

ABSTRACT=<p>The chemical profile of <italic>Ajania tibetica</italic> essential oil (EO) and its phytotoxic, insecticidal, and antimicrobial activities were assessed. Monoterpenes (79.05%) and sesquiterpenes (10.33%) were dominant in the EO, with camphor, (+/-)-lavandulol and eucalyptol being the major constituents, representing 55.06% of the total EO. The EO possessed potent phytotoxicity against <italic>Poa annua</italic> and <italic>Medicago sativa</italic> starting from 0.5 mg/mL, and when the concentration rose to 5 mg/mL, seed germination of both tested species was 100% suppressed. <italic>Ajania tibetica</italic> EO displayed significant pesticidal activity against <italic>Aphis gossypii</italic> with an LC<sub>50</sub> value of 17.41 μg/mL; meanwhile, the EO also showed antimicrobial activity against <italic>Escherichia coli</italic>, <italic>Bacillus subtilis</italic>, <italic>Verticillium dahlia</italic> and <italic>Aspergillus niger</italic> using broth microdilution and disc diffusion methods. For the tested bacterial and fungal strains, the EO exhibited a repressing effect, with minimum inhibitory concentrations (MICs) ranging from 0.3125 to 1.25 mg/mL for bacteria and from 1.25 to 2.5 mg/mL for fungi, whereas the minimum microbicidal concentrations (MMCs) were 5 mg/mL for bacteria and 2.5 mg/mL for fungi. Our study is the first report on the chemical profile as well as the phytotoxicity, insecticidal and antimicrobic activity of <italic>A. tibetica</italic> EO, indicating its potential value as an alternative synthetic pesticide.</p>