嘧菌酯对石榴干腐病菌的生物学活性
Biological activity of azoxystrobin against Pilidiella granati causing pomegranate dry rot

为探究石榴干腐病的病原菌种类及嘧菌酯对石榴干腐病菌的生物学活性，采用单孢分离法对石榴病果中的病原菌进行分离纯化，然后进行分子鉴定和致病性测定，并通过室内生测法测定了嘧菌酯对其菌丝生长和孢子萌发的影响，且连续2年开展了大田防治试验。经形态学、分子生物学鉴定及致病性测定结果表明，石榴干腐病的病原菌为石榴壳座月孢Pilidiella granati。嘧菌酯在水杨肟酸（SHAM）的协同作用下，对石榴干腐病菌的菌丝生长和孢子萌发具有强烈的抑制作用，对其菌丝生长和孢子萌发的平均EC50分别为0.202 μg/mL和0.007 μg/mL（含100 μg/mL SHAM）；在大田防治试验中，嘧菌酯对石榴干腐病具有良好的防效，其中1 000倍25%嘧菌酯SC稀释液在2013和2014年的防效分别可达90.85%和81.91%，显著高于其它处理。表明嘧菌酯可作为防治石榴干腐病的候选药剂。
In order to investigate the pathogen causing pomegranate dry rot and the biological activity of fungicide azoxystrobin against this pathogen, the isolated pathogen was purified and identified by molecular methods and pathogenicity test. The activity of azoxystrobin (amended with 100 μg/mL SHAM) against mycelial growth and conidial germination was determined and the control efficacy of this fungicide was performed against pomegranate dry rot in 2013 and 2014. The results of morphological observation, pathogenicity test and molecular identification showed that the pathogen was Pilidiella granati. Azoxystrobin (amended with 100 μg/mL SHAM) exhibited strong inhibitory activity against mycelial growth and spore germination of P. granati isolates with the average EC50 values of 0.202 μg/mL and 0.007 μg/mL, respectively. In the field experiments, azoxystrobin showed excellent control efficacy against this disease in which the treatment 25% azoxystrobin SC 1 000×provided 90.85% and 81.91% control efficacy in 2013 and 2014, respectively, significantly higher than that of other treatments. Therefore, azoxystrobin could be a candidate fungicide for the control of pomegranate dry rot.