Allelopathic Potential and Active Substances from Wedelia Chinensis (Osbeck).

Kawsar Hossen,Arihiro Iwasaki,Shun Okada,Krishna Rany Das,Hisashi Kato-Noguchi,Kiyotake Suenaga

doi:10.3390/foods9111591

Kawsar Hossen, Arihiro Iwasaki + Show 4 more

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https://doi.org/10.3390/foods9111591

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Abstract

Wedelia chinensis (Asteraceae) is a wetland herb native to India, China, and Japan. It is a valuable medicinal plant recorded to have pharmaceutical properties. However, the phytotoxic potential of Wedelia chinensis has not yet been examined. Thus, we carried out this study to establish the allelopathic effects of Wedelia chinensis and to identify its phytotoxic substances. Extracts of Wedelia chinensis exhibited high inhibitory activity against the root and shoot growth of cress, alfalfa, rapeseed, lettuce, foxtail fescue, Italian ryegrass, timothy, and barnyard grass. The inhibition was varied with species and was dependent on concentrations. The extracts were separated through several purification steps, and the two effective substances were isolated and characterized as vanillic acid and gallic acid using spectral analysis. Vanillic acid and gallic acid significantly arrested the growth of cress and Italian ryegrass seedlings. The concentrations of vanillic acid and gallic acid needed for 50% inhibition (I50 values) of the seedling growth of the cress and Italian ryegrass were 0.04–15.4 and 0.45–6.6 mM, respectively. The findings suggest that vanillic acid and gallic acid may be required for the growth inhibitory activities of Wedelia chinensis.

Highlights

IntroductionOrganic farming emerged at the beginning of the 20th century as an alternative agricultural method to demote the hazardous effect of nonnatural herbicides on the environment and people [1,2]
Organic farming emerged at the beginning of the 20th century as an alternative agricultural method to demote the hazardous effect of nonnatural herbicides on the environment and people [1,2].Natural substances are used in organic farming, and at the same time, the use of synthetic substances is banned or severely restricted [3]
The present study showed the phytotoxic activities of aqueous methanol extracts of Wedelia chinensis, which significantly restricted the seedlings growth of eight tested species: lettuce, alfalfa, cress, rapeseed, barnyard grass, Italian ryegrass, timothy, and foxtail fescue (Figure 2)

Summary

Introduction

Organic farming emerged at the beginning of the 20th century as an alternative agricultural method to demote the hazardous effect of nonnatural herbicides on the environment and people [1,2]. Natural substances are used in organic farming, and at the same time, the use of synthetic substances is banned or severely restricted [3]. Searching for nature-based product alternatives to synthetic herbicides is a pressing issue to control weeds, which is a major impediment to crop production [5,6]. In light of these concerns, allelopathy can be explored and used as alternative weed management over synthetic herbicides [7]. Many studies have reported on the use of phytotoxic substances as a nature-friendly approach to weed management [7,8,9]

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