Identification of Pathogen,Evaluation of Rice Resistance and Studies on Chemical Control of Rice Panicle Blight in Heilongjiang Province

摘要

This study aimed to clarify the pathogen composition,biological characteristics,infection patterns,and effective control agents for panicle blight of rice in Heilongjiang Province.Diseased panicles were collected from different rice-growing areas in Heilongjiang Province and subjected to tissue isolation,pathogenicity tests,morphological observation,and molecular identification.The primary pathogens identified were Fusarium graminearum,Alternaria alternata and Nigrospora oryzae.The biological characteristics of these three pathogens were systematically investigated.Pathogenicity assays revealed that F.graminearum exhibited the strongest pathogenicity,followed by A.alternata,while N.oryzae was the weakest.In vitro toxicity tests screened highly effective fungicides:75% trifloxystrobin-tebuconazole showed the best inhibitory effect against F.graminearum (EC₅₀=0.0140 μg·mL^-1);30% tebuconazole-azoxystrobin was the most effective against A.alternata (EC₅₀=0.0060 μg·mL^-1) and N.oryzae (EC₅₀=0.0310 μg·mL^-1).

关键词

panicle blight of rice / pathogen identification / biological characteristics / resistant source screening / chemical control