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甘肃省燕麦主产区叶斑病调查及病原鉴定

来源：花匠小妙招时间：2025-01-03 02:46

摘要： 为了明确甘肃省燕麦主产区叶斑病的发生情况及其病原种类,为防治提供理论依据。对定西市通渭县、张掖市山丹县和民乐县、武威市天祝县和甘南州合作市大面积种植的燕麦田间叶斑病发病情况进行了调查,对采集的病叶进行了病原菌的培养、分离、致病性测定及鉴定。结果表明,不同区域燕麦叶斑病的发生情况存在明显差异,其中定西市通渭县最严重,平均病叶率为96.15%,平均病情指数为70.26;武威市天祝县的叶斑病病叶率和病情指数分别为95.07%和69.16;张掖市民乐县叶斑病较轻,平均病叶率为8.78%,病情指数为2.45。分离纯化获得的真菌经致病性测定后发现发病症状与田间病害症状一致,经再次分离可得到相同的病菌。进一步通过形态学观察和rDNA-ITS序列分析表明引起甘肃省燕麦主产区叶斑病的病原菌有10种,分别为燕麦内脐蠕孢(Drechslera avenae)、燕麦核腔菌(Pyrenophora avenae)、德氏霉菌(Pyrenophora chaetomioides)、细交链格孢(Alternaria alternata)、芸薹链格孢(Alternaria brassicae)、苹果链格孢(Alternaria mali)、麦根腐平脐蠕孢(Bipolaris sorokiniana)、芽枝状枝孢菌(Cladosporium cladosporioides)、多主枝孢(Cladosporium herbarum)和黑附球菌(Epicoccum nigrum),优势菌为燕麦内脐蠕孢和细交链孢,在各调查样地均能分离出。明确了燕麦叶斑病在甘肃省主要种植区的发生情况及其病原种类,除燕麦内脐蠕孢和燕麦核腔菌外,其他均为国内燕麦叶斑病新的病原菌。

关键词: 燕麦叶斑病, 病害调查, 病原菌鉴定

Abstract: This study aimed to clarify the occurrence and pathogenic species causing oat leaf spot in the main oat producing areas of Gansu Province, and provide a theoretical foundation for prevention and control of this disease. Occurrence of oat leaf spot was investigated, and leaves were collected from the field for isolation, culture, pathogenicity testing, and pathogen identification. Collection locations included Tongwei County of Dingxi City, Shandan and Minle Counties of Zhangye City, Tianzhu County of Wuwei City, and Gannan County of Hezuo City. Regional differences in the occurrence of oat leaf spot were found. The occurrence was the most serious in Tongwei County of Dingxi City, where the mean leaf incidence was 96.15% and the average disease index was 70.26. Moderate leaf spot incidence and disease index (95.07% and 69.16, respectively) were recorded in Tianzhu County of Wuwei City. A relatively light occurrence was observed in Minle County of Zhangye City, where the leaf incidence was 8.78%, and the disease index was 2.45. Disease symptoms induced by the isolated and purified fungi were the same as the symptoms in the field after the pathogenicity test, and the same fungi could be obtained after re-isolation. Further morphological observation and rDNA-ITS sequence analysis indicated that a total of 10 pathogens caused oat leaf spot in the different localities where samples were collected. These were Drechslera avenae, Pyrenophora avenae, Pyrenophora chaetomioides, Alternaria alternata, Alternaria brassicae, Alternaria mali, Bipolaris sorokiniana, Cladosporium cladosporioides, Cladosporium herbarum and Epicoccum nigrum. The dominant fungi were D. avenae and A. alternata. This study clarified the occurrence and identity of pathogenic species causing oat leaf spot in Gansu Province. With the exception of D. avenae and P. avenae, the identified pathogens have, to our knowledge, not previously been reported as causes of domestic oat leaf spot.

Key words: oat leaf spot, disease investigation, pathogenic identification