Allelopathy and potential allelochemicals of Ligularia sagitta as an invasive plant

ABSTRACT

Allelopathy is the main chemical means in the invasion process of exotic plants and one of the key factors in grassland degradation. In this experiment, we investigated the effects of ethyl acetate phase extract (EAE), n-butanol phase extract (BE) and aqueous phase extract (AE) from the aboveground (stems and leaves) and roots of Ligularia sagitta on seed germination and seedling growth of four Gramineae forages (Poa pratensis L. Festuca ovina L. Elymus nutans Griseb. Agropyron cristatum (L.) Gaertn.) in their sympatric domains and one Legosuminae forage (Medicago sativa L.). The chemical components in each phase extract of L. sagitta were determined with UHPLC-MS/MS non-targeted metabolomics, and the differential compounds were screened using Orthogonal Partial Least Squares-Discriminant Analysis (OPLS-DA). Within a set concentration range, EAE significantly inhibited seed germination and seedling growth of four Gramineae forages. BE and AE acted mainly in the seedling growth stage and did not significantly inhibit forage seed germination. P. pratensis was most sensitive to L. sagitta extracts; at 2.0 mg/mL of EAE from roots, germination energy and germination rate of P. pratensis seeds were 0. L. sagitta extracts inhibited the growth of M. sativa seedlings and did not inhibit its seed germination. A total of 904 compounds were identified with UHPLC-MS/MS, among which 31, 64, 81 and 66 metabolites displayed different accumulation patterns in the four comparison groups (R.EAE vs. R.BE, R.EAE vs. R.AE, SL.EAE vs. SL.BE, SL.EAE vs. SL.AE), respectively. In particular, 9 compounds were found to be common up-regulated differential metabolites in the four comparison groups and were enriched in EAE. Additionally, N,N-dimethylaniline, Caffeic acid, 4-Hydroxybenzoic acid, 4-Hydroxybenzaldehyde and cis-9-Octadecenoic acid as potential allelochemicals in L. sagitta. The results of this study support efforts at finding alternative control plants for the restoration of poisonous grass-type degraded grasslands.

KEYWORDS:

• Ligularia sagitta
• allelopathy
• inhibition
• allelochemical
• forage

Acknowledgments

This research was funded by the Doctoral Research Foundation Project of Gansu Agricultural University (GAU-KYQD-2019-01).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

Conceptualization, Kan Jiang and Fang Nian; methodology, Kan Jiang and Fang Nian; data collection, Shengxiao Wang, Chenyue Wang and Jun Zhang; formal analysis, Shengxiao Wang; writing and original draft preparation, Shengxiao Wang; writing and editing, Kan Jiang; supervision, Kan Jiang and Fang Nian. All authors have read and agreed to the published version of this manuscript.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/15592324.2024.2335025

Additional information

Funding

The work was supported by the Gansu Agricultural University [GAU-KYQD-2019-01].