关键词: 猪繁殖与呼吸综合征病毒, 猪繁殖与呼吸综合征病毒, 细胞培养, Marc-145, RT-PCR, 诊断, 防制

Abstract:

To evaluate the allelopathic effects of ginseng root exudates on seed germination of four important medicinal plants. Adopted complex sterile matrix substrate to cultivate ginseng, ginseng root exudates were collected in situ. The ginseng root exudates were extracted with water and MeOH, divided into the aqueous extracts and the ethyl acetate extracts two parts with ethyl acetate extract. The allelopathic effects of ginseng root exudates on seed germination, hypocotyls length and fresh weight of four medicinal plants over a range of extract concentrations were studied in vitro. Results showed that the allelopathic effects of ginseng root exudates on four medicinal plants were different. Ginseng root exudates had inhibitory action on seed germination of the Rhubarb and milk thistle, in varying degree, decreased α-amylase activity in seed. Ginseng root exudates had inhibitory effects at higher concentrations but at low to medium concentrations they had stimulatory effects on the fresh weight and hypocotyls length of Rhubarb. Aqueous extracts had stimulatory effects while ethyl acetate extracts had inhibitory effects on the fresh weight and hypocotyls length of milk thistle. The Burdock seed germination and seed α-amylase activity increased at low to medium concentrations while decreased at high concentrations of aqueous extracts. The Burdock seed germination and seed α-amylase activity decreased with ethyl acetate extracts. Aqueous extracts had inhibitory effects while ethyl acetate extracts had inhibitory effects on hypocotyl length and fresh weight of Burdock. Aqueous extracts had inhibitory effects at medium to high concentrations while at low concentrations they had stimulatory effects on seed germination and α-amylase activity of white sweetclover. Ethyl acetate extracts had stimulatory effects at medium to high concentrations while at low concentrations they had inhibitory effects on seed germination and α-amylase activity of white sweetclover. Ginseng root exudates had inhibitory effects on hypocotyl length and fresh weight of white sweetclover. Ginseng root exudates had different allelopathic effects on four medicinal plants. The close relationship existed bewteen allelopathy and the content of allelochemicals.