Race identification of pathogen causing wheat tan spot in Sichuan province
[Objective]The study aimed to isolate and identify the pathogenic fungi causing wheat tan spot in the main wheat-growing regions of Sichuan province,analyze the composition of their pathogenic genes,investigate the pathogenicity of the fungi,and to clarify their physiolog-ical races,thereby providing a theoretical foundation for the control of wheat tan spot.[Method]From 2021 to 2022,wheat leaf samples were collected from major wheat producing areas in Sichuan province.Pathogens were isolated and characterized by a combination of morphological observation,internal transcribed spacer(ITS)sequence analysis,amplification of pathogenic genes(Ptr ToxA,ToxB and ToxC)and pathoge-nicity test.[Result]In the experiment,three pathogenic isolates of wheat tan spot were isolated and identified,all of which were identified as Pyrenophora tritici-repentis.These isolates accounted for a small proportion of all the isolated wheat leaf blight pathogens.Morphological obser-vation of their colonies and conidia revealed no significant differences,meeting the standards for pathogen morphological identification.Further ITS sequence analysis showed that the ITS sequences of the three isolates were 100％ identical to the reference genome(ID:AM887509).PCR amplification of the pathogenic genes Ptr ToxA,ToxB,and ToxC revealed no amplification at the ToxA and ToxB loci in any of the iso-lates,but approximately 500 bp fragments were successfully amplified at the ToxC locus in all three isolates.Pathogenicity tests showed that the local isolates exhibited strong pathogenicity on the wheat varieties Prosper and 6B365,causing widespread leaf chlorosis,while no signifi-cant leaf necrosis or chlorosis was observed on Glenlea and 6B662.In conclusion,the wheat tan spot pathogen collected from Sichuan province was identified as P.tritici-repentis race 3.[Conclusion]This is the first report about the race identification of P.tritici-repentis in China.The research will offer valuable insights for the management and prevention of wheat tan spot disease in China.
Tan spotPyrenophora tritici-repentisRace identificationPathogenicity testVirulence gene
万方数据
维普
