Abstract: In order to clarify the growth promoting effects of lactic acid bacteria on the growth， physiological characteristics and antioxidant capacity of Pennisetum americanum×P. purpureum， Enterococcus faecalis， Lactobacillus plantarum， Lactobacillus brevis， Lactococcus lactis， Leuconostoc mesenterodies and Lactococcus lactis subsp lactis isolated and identified in the laboratory， were used as the reseatch objects through pot experiment. The results showed that the plant height， leaf area， chlorophyll， soluble sugar and soluble protein of Pennisetum americanum×P. purpureum increased by 33.1%-57.9%， 44.8%-73.7%， 13.0%-25.6%， 44.2%-124.8% and 56.4%-79.9%， respectively. The activities of CAT， SOD， POD and APX in leaves increased by 7.4%-211.8%， 104.4%-176.3%， 6.2%-22.4% and 11.0%-74.4%， respectively， and the MDA content decreased by 29.6%-56.0%. The total phenolic content of leaves increased by 15.9%-36.1%. Compared with the control， L₂， L₆ and L₇ had the best effects on the growth promotion， quality improvement and antioxidant enhancement of Pennisetum americanum×P. purpureum.

Key words: Lactic acid bacteria, Pennisetum americanum×P. purpureum, Antioxidant properties, Agronomic traits, Plant growth promoting bacteria （PGPB）

摘要： 为明确乳酸菌对牧草的促生作用，以实验室分离鉴定的粪肠球菌（Enterococcus faecalis）、植物乳杆菌（Lactobacillus plantarum）、短乳杆菌（Lactobacillus brevis）、乳酸乳球菌（Lactococcus lactis）、肠膜明串珠菌（Leuconostoc mesenterodies）、乳酸乳球菌乳酸亚种（Lactococcus lactis subsp. lactis）为对象，用盆栽试验研究了其对杂交狼尾草（Pennisetum americanum×P. purpureum）生长、生理特性和抗氧化能力的影响。结果表明：喷施这7种乳酸菌菌液后，杂交狼尾草的株高、叶面积、叶绿素、可溶性糖和可溶性蛋白分别提高33.1%~57.9%，44.8%~73.7%，13.0%~25.6%，44.2%~124.8%和56.4%~79.9%；叶片的过氧化氢酶（Catalase， CAT）、超氧化物歧化酶（Superoxide dismutase， SOD）、过氧化物酶（Peroxidase， POD）和抗坏血酸过氧化物酶（Ascorbate peroxidase， APX）活性分别提高7.4%~211.8%，104.4%~176.3%，6.2%~22.4%和11.0%~74.4%，丙二醛（Malondialdehyde， MDA）含量降低29.6%~56.0%；叶片总酚含量提高15.9%~36.1%。与CK相比，植物乳杆菌、乳酸乳球菌乳酸亚种和短乳杆菌对杂交狼尾草促生、提质和增强抗氧化效果最好。

关键词: 乳酸菌, 杂交狼尾草, 抗氧化性, 农艺性状, 植物生长促进菌