Isolation,pathogenicity determination and identification of leaf blight pathogens of Poa pratensis
[Objective]To identify leaf blight of Poa pratensis in Lanzhou.[Method]The symptoms of P. pra-tensis leaf blight in Lanzhou grassland were described,and the pathogen was identified by morphological characteris-tics and molecular biology methods.[Result]Leaf blight of P. pratensis mainly affects the middle and upper leaves,often starting at the tip and leaf edge,gradually expanding inward,forming large dead spots,and forming a large num-ber of small black spots on the spots. The pathogen was initially white on PDA medium,then turned to olive green and dark brown,and produced orange granular droplets with wheel markings on the back. All the mycelium had dia-phragm,which was colorless or light brown. The conidia shape was long ellipsoidal neurons,which was single cell (colorless) and had oil balls at both ends. The size of conida was 4.2 μm×1.8 μm～7.7 μm×4.8 μm (average 5.8 μm×3.4 μm). The pycnidium shapes was globose,ovoid or oblong,even with orifice,and the sizes ranged from 48.3μm×193.1 μm to 38.5 μm×139.6 μm (average 106.0 μm×86.4 μm).[Conclusion]The pathogen of P. pratensis leaf blight disease was identified as Peyronellaea glomerata that combined with its morphological character-istics and ITS sequence analysis. These results provided the basis for the diagnosis and comprehensive control of P. pratensis leaf blight disease.
万方数据
维普
