谷子叶斑病的病原鉴定及不同品种抗病性评价

Identification of Alternaria tenuissima and evaluation of disease resistance in different varieties of foxtail millet

2021年陕西省榆林市谷子田发生的一种叶斑病对谷子产量造成了严重影响。经分离纯化,从发生叶斑病的谷子病叶上得到疑似病原菌(编号YLGZ)。经测定,该菌对谷子(品种晋谷21)具有明显的致病性;观察其菌落形态学特征,初步鉴定为链格孢属(Alternaria)真菌,结合ITS、GAPDH和TEF1多基因序列分析,将该菌鉴定为细极链格孢(Alternaria tenuissima)。通过调查病情指数,评价了14个谷子品种对于由细极链格孢引起的叶斑病的田间抗性,确定了抗病品种9个、中抗品种3个、感病品种2个,为当地种植抗病品种提供了参考依据。

In 2021,a fungus named YLGZ was isolated from the foxtail millet leaf spot in Yulin City,Shaanxi Province,which had a serious impact on the yield of millet.The fungus was found to have obvious pathogenicity to Jingu 21.It was provisionally classified as Alternaria sp.by observing the morphological characteristics of the colony and conidia.Further study,combined with ITS,gapdh,and TEF1 gene sequence analysis,identified the strain YLGZ as A.tenuissima,providing a theoretical basis for its scientific control.The disease index method was used to evaluate the leaf spot resistance in 14 foxtail millet varieties.The results showed that there were nine resistant varieties,three moderately resistant varieties,and two susceptible varieties.