Artemisia baimaensis allelopathy has a negative effect on the establishment of Elymus nutans artificial grassland in natural grassland

ABSTRACT

Planting Elymus nutans artificial grassland to replace degraded Artemisia baimaensis grassland on the Qinghai Tibetan plateau (QTP) can effectively alleviate local grass-livestock imbalance. However, it is unknown whether the allelopathy of natural grassland plant A. baimaensis on E. nutans affects grassland establishment. Accordingly, we examined the effects of varying concentrations of aqueous extracts of A. baimaensis litter on the seed germination and early seedling growth of E. nutans, and the effects of A. baimaensis volatile organic compounds (VOCs) on the growth parameters and physiological characteristics of E. nutans. The results indicate that the aqueous extract inhibited the force, percentage, and index of germination of E. nutans and affected early seedling growth, particularly at high concentrations. Further, the VOCs significantly reduced the aboveground and root biomass of E. nutans and increased malondialdehyde concentrations. Additionally, these VOCs altered the antioxidant enzyme activities and increased the superoxide dismutase, peroxidase, ascorbic acid peroxidase, soluble sugar, and proline content but significantly decreased glutathione reductase levels. Our results indicate that the allelopathy of A. baimaensis significantly inhibited the germination and seedling growth of E. nutans . Thus, the leaching of A. baimaensis may produce allelochemicals in the soil that inhibit the germination of E. nutans seeds. Moreover, the VOCs of A. baimaensis may disrupt the growth process, resulting in a decrease in biomass and a disruption of the physiological metabolism of seedlings under field conditions.

KEYWORDS:

• Elymus nutans
• Artemisia baimaensis
• litter aqueous extracts
• volatile organic compounds
• allelopathy
• seed germination
• seedling growth
• physiological characteristics
• artificial grassland establishment

Disclosure statement

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

Author contribution statement

Hang Yang conceived and designed the experiments, performed the experiment, analyzed the data, prepared figures, authored and review draft of the paper, and approved the final draft. Jiaochao Song performed the experiments, prepared figures, and approved the final draft. Xiaojun Yu conceived and designed the experiments, authored and review draft of the paper, and approved the final draft.

Additional information

Funding

This research was funded by the Key Research and Development and Transformation Plan of Qinghai Province (2019-HZ-815).