关键词: 羊尿斑块, 化学特性, 碳, 氮, 磷, 时间变化

Abstract: The crude toxin was extracted from Exserohilum monoceras X27, and its effects on the inhibition of seed germination, radical growth, embryo growth, and seedling growth of Echinochloa crus-gallias well as the chlorophyll content, superoxide dismutase (SOD) activity, malondiadehyde (MDA) content, and relative electrical conductivity (EEC) of E. crus-galli leaves at 2nd-leaf stage were studied by the methods of filter paper, detached leaf, and spot-spraying. The results showed that the toxin at 5.0 g·L^-1 strongly inhibited the seed germination, radical growth, and embryo growth, and made the detached leaves before 4th-leaf stage completely dead. The crude toxin also strongly affected the growth of plants at 1st- and 2ndleaf stages. On the 7th day after spraying toxin, the inhibition rate of seedling height exceeded 20%; while on the 28th day, the mass inhibition rate of above- and underground parts exceeded 40% and 70%, respectively. Within the 7 days of spraying the toxin, the chlorophyll content of 2nd leaf stage plants decreased significantly, while MDA content, SOD activity and EEC were in adverse.

Key words: Sheep urine patches, Soil chemical properties, Carbon, Nitrogen, Phosphorus, Temporal change