Abstract: Phleum pratense is a perennial tufted grass that serves as a valuable forage crop due to its highly cold and moisture resistance, high quality, and high yield. Disease is a significant factor limiting the production of P. pratense, and systematic research on P. pratense diseases was lacking. In this study, we investigated the dynamic of P. pratense leaf spot disease caused by Cladosporium phlei, and also conducted the disease damage loss assessments. The results showed the disease mainly occurred in the middle and late growth stages of cattail grass. The highest incidence rate in the field was 83.2%, and the disease index was 42.2. The disease significantly impacted the yield and quality of P. pratense, resulting in a 50.6% reduction in fresh weight, 35.2% reduction in zinc and 58.1% reduction in chlorophyll content. The contents of phenylalanine, isoleucine, aspartic acid, alanine, glycine and arginine were decreased significantly by 42.5%-67.5%. In addition, dry weight, crude protein content and chlorogenic acid content were lost by 34.0%, 45.7%, and 23.3%, respectively. In summary, this study found that the leaf spot disease of Phleum pratense is an important disease affecting the production of Phleum pratense in Min County, and there is an urgent need to develop prevention and control technologies.

Key words: Phleum pratense, Cladosporium phlei, Leaf spot, Severity, Forage quality

摘要： 猫尾草（Phleum pratense）是一种多年生丛生型禾本科牧草,兼具抗寒耐湿、优质高产等特点,具有良好的饲用价值。病害是限制猫尾草生产的重要因素之一,目前尚缺少对猫尾草病害的系统研究。本研究以甘肃省岷县猫尾草为对象,调查了梯牧草枝孢（Cladosporium phlei）引致的猫尾草叶斑病发病动态,评定了病害危害损失。结果表明：梯牧草枝孢叶斑病主要在猫尾草生长中后期发生,田间发病率最高可达83.2%,病情指数达42.2。叶斑病显著影响了猫尾草的产量和品质,致使猫尾草鲜重显著减少50.6%,锌元素含量显著减少35.21%,以及叶绿素含量显著降低58.09%,苯丙氨酸、异亮氨酸、天冬氨酸、丙氨酸、色氨酸、甘氨酸与精氨酸含量显著减少了42.45%~67.47%,干重、粗蛋白含量和绿原酸含量分别损失了34.0%,45.7%和23.29%。综上,本研究发现梯牧草枝孢引致的猫尾草叶斑病是影响岷县猫尾草生产的重要病害,亟需研发防治技术。

关键词: 猫尾草, 梯牧草枝孢, 叶斑病, 严重度, 饲草品质