Inhibitory effects of methanol extracts from Fallopia japonica and F. × bohemica rhizomes and selected phenolic compounds on radish germination and root growth

Abstract Allelopathic plants release secondary compounds into the soil that then suppress growth of nearby plants. Allelopathy has been shown for invasive Japanese knotweed ( Fallopia japonica ) and Bohemian F . × bohemica ). The aggressive dominant invaders represent a serious threat to local plant communities outside their native range. Here, we analysed phenols in rhizomes using nuclear magnetic resonance. We also evaluated allelopathic potential methanol extracts F. compared these with effects individual resveratrol, epicatechin emodin, mixture. Rhizomes both knotweeds contained similar amounts 24% higher resveratrol Only extract inhibited radish Raphanus sativus seed germination. After 3 days treatments 10% (w/v) knotweeds, seedlings showed up 70% shorter roots. In contrast, root treated mixture, was by 30%, 1% extracts. Biochemical parameters oxidative stress increased roots seedlings, high levels malondialdehyde particular indicating lipid peroxidation. Total antioxidative capacity exposed 0.6 mg/mL emodin. This study shows