Cheng Shipu, Xu Fanru, Lu Zhiyong, Xu Huairui, Cai Mengqi, Sun Juan, Xu Yufang
College of Grassland Science, Qingdao Agricultural University, Qingdao, Shandong, China.
Shandong Key Laboratory for Germplasm Innovation of Saline-alkaline Tolerant Grasses and Trees, Qingdao, Shandong, China.
PeerJ. 2025 May 8;13:e19378. doi: 10.7717/peerj.19378. eCollection 2025.
Cav. is a high-risk invasive plant that seriously threatens the development of grasslands in southern China. However, the allelopathic effects on L. and L., which are widely cultivated forages around the world, have not been reported.
To explore the allelopathic mechanism of , the allelopathic effects of aqueous extracts from different parts of . on and were investigated. The germination rate (GR), germination potential (GP), seedling height, fresh weight, and chlorophyll content of and seedlings were measured to elucidate the allelopathy of on the two forages. Based on the five indicators, synthetical allelopathic effects (SAE) of extracts was also calculated. In addition, the allelopathic components of the extracts in were quantitatively revealed by untargeted metabolomics detection. Furthermore, two key allelopathic substances, 1,4-cyclohexanedicarboxylic acid (CHDA) and trehalose, were selected to explore the inhibitory effect on two notorious weed species in China, such as gramineous L. and broad-leaved L.
(1) The inhibitory effects of aqueous extracts from different parts of on recipient plants were different, the root was the weakest, and the whole plants was the strongest, with the values of synthetical allelopathic effects (SAE) on at the highest concentration being -0.12 and -0.40, respectively. (2) Compared with , was generally more susceptible to the extracts. (3) The differences in the content of CHDA or trehalose might be a reason why extracts from different parts of exhibited different allelopathic effects. (4) The herbicidal activity test of key allelopathic substances found that CHDA has a strong inhibitory effect on the germination of and almost does not affect and . Thus, this discovery not only revealed allelopathic effects and components in different parts of , but provided scientific evidence for weed control based on natural plant extracts in the future.
空心莲子草是一种高风险的入侵植物，严重威胁中国南方草原的发展。然而，其对世界各地广泛种植的黑麦草和三叶草的化感作用尚未见报道。
为探究空心莲子草的化感作用机制，研究了空心莲子草不同部位水提物对黑麦草和三叶草的化感效应。测定黑麦草和三叶草幼苗的发芽率（GR）、发芽势（GP）、苗高、鲜重和叶绿素含量，以阐明空心莲子草对这两种牧草的化感作用。基于这五个指标，还计算了提取物的综合化感效应（SAE）。此外，通过非靶向代谢组学检测定量揭示了空心莲子草提取物中的化感成分。此外，选择两种关键化感物质1,4-环己烷二甲酸（CHDA）和海藻糖，探究其对中国两种恶性杂草禾本科的马唐和阔叶的小飞蓬的抑制作用。
（1）空心莲子草不同部位水提物对受体植物的抑制作用不同，根部最弱，全株最强，最高浓度下对黑麦草和三叶草的综合化感效应（SAE）值分别为-0.12和-0.40。（2）与黑麦草相比，三叶草通常对提取物更敏感。（3）CHDA或海藻糖含量的差异可能是空心莲子草不同部位提取物表现出不同化感效应的原因之一。（4）关键化感物质的除草活性试验发现，CHDA对马唐的萌发有较强的抑制作用，对小飞蓬几乎无影响。因此，这一发现不仅揭示了空心莲子草不同部位的化感效应和成分，也为未来基于天然植物提取物的杂草防治提供了科学依据。
