College of Forestry, Hainan University, Haikou, 570100, Hainan, China.
College of Ecology and Environment, Hainan University, Haikou, 570100, Hainan, China.
Sci Rep. 2020 Jul 9;10(1):11332. doi: 10.1038/s41598-020-68234-5.
Mikania micrantha and Ipomoea cairica are two invasive plants widely distribute and seriously damage in Hainan island. In this study, the leaves extracts of two weeds were collected and determined for their allelopathic potentials on Chrysanthemum coronarium. The phytotoxicity bioassay showed that when the extract concentration was 50 and 100 mg/ml, the inhibited effects of M. micrantha on growth of C. coronarium were greater than by I. cairica. However, when the extract concertation at 400 mg/ml, the opposite inhibited effects were observed. We speculated this phenomenon was caused by different allelopathic compounds. Therefore, using gas chromatography-mass spectrometry, 19 and 23 compounds were identified respectively, benzoic acid and cinnamic acid were the main components in the two leaves extracts, which were selected to carry out the further bioassays. Subsequent bioassay results showed the effects of two allelochemicals on morphological index and chlorophyll content and POD activity were all negative to C. coronarium, whereas the content of MDA and activity of SOD, CAT represented adverse changes. Moreover, the inhibitions by cinnamic acid were generally greater than those by benzoic acid. Thus, the phenolic acids played the most crucial roles in the allelopathic effccts of M. micrantha and I. cairica leaves extracts.
薇甘菊和假臭草是两种广泛分布并对海南岛造成严重危害的入侵植物。本研究采集了两种杂草的叶片提取物，并测定其对菊花的化感潜力。植物毒性生物测定表明，当提取物浓度为 50 和 100 mg/ml 时，薇甘菊对菊花生长的抑制作用大于假臭草。然而，当提取物浓度为 400 mg/ml 时，观察到相反的抑制作用。我们推测这种现象是由不同的化感化合物引起的。因此，使用气相色谱-质谱联用仪分别鉴定了 19 种和 23 种化合物，苯丙酸和肉桂酸是两种叶片提取物中的主要成分，选择这两种成分进行进一步的生物测定。随后的生物测定结果表明，两种化感物质对菊花形态指标、叶绿素含量和 POD 活性的影响均为负向，而 MDA 含量和 SOD、CAT 活性则表现为不利变化。此外，肉桂酸的抑制作用通常大于苯甲酸。因此，酚酸在薇甘菊和假臭草叶片提取物的化感效应中起着至关重要的作用。
