Abstract: Sesame stem rot is caused by the fungal pathogen Macrophomina phaseolina，and is the significant disease of sesame. Previous studies have found that M.phaseolina carries abundant resources of mycoviruses，while while the hypovirulent mycovirus is the green solution to control crop disease.In order to obtain the biocontrol strains against sesame stem rot，the biological characteristics of three hypovirulent strains（2012‐19，2012‐22，2012‐161）carrying mycoviruses were studied，and the strong virulent strain 2012‐63 was used as the control.The pathogenicity was compared by in vitro leaf and in vivo stem inoculation，and the control effect of three hypovirulent strains on sesame stem rot was evaluated by soil inoculation method.The results showed that the colony morphology of the highly virulent strain 2012‐63 on the PDA plate showed radial growth，the aerial mycelium was lush，and the growth rate was 20.44 mm/d；the colony morphology of hypovirulent strains 2012‐19，2012‐22 and 2012‐161 showed irregular growth，with obvious fanning area，and the growth rate was 2.94—13.19 mm/d，and the average growth rate of the three hypovirulent strains was significantly 60.54% lower than that of the highly virulent strain.After five days of inoculation of detached leaves，the lesions of the highly virulent strains had expanded to the entire leaf surface，resulting in browning and decay of the leaf surface，while the three hypovirulent strains only formed 28.26 mm2 lesions at the inoculation site. After 8 days of stem inoculation，the relative area under the disease progression curve（RAUDPC）of the three hypovirulent strains was 2.10—5.90，and the average RAUDPC of the three hypovirulent strains was reduced by 92.27% significantly than high‐virulent strains（45.55）.The indoor pot experiment showed that the control effects of three hypovirulent strains on sesame stem rot were 44.90%，56.40% and 75.30%，respectively，while the control effects of biocontrol agent（Trichoderma harzianum）and chemical agent（50% carbendazim）were 53.65% and 87.10%，respectively.It can be seen that the hypovirulent strain of M.phaseolina carrying the related virus can be used as a biological control resource to control sesame stem rot.

Key words: Sesame stem rot, Mycovirus, Macrophomina phaseolina, Biological control

摘要： 菜豆壳球孢引起的芝麻茎点枯病害是芝麻生产上的重要病害，前期研究发现菜豆壳球孢携带了大量的真菌病毒资源。为获得对芝麻茎点枯病具有生物防治效果的菜豆壳球孢菌株，以强致病力菜豆壳球孢菌株2012-63为对照，以携带真菌病毒的3个低毒力菜豆壳球孢菌株（2012-19、2012-22、2012-161）为研究对象，明确其生物学特性，并采用离体叶片和活体茎秆接种比较其致病力，同时采用菌土接种法评价3个低毒力菌株对芝麻茎点枯病的防治效果。结果表明，强毒力菌株2012-63在PDA平板上的菌落形态呈现放射状生长，气生菌丝茂盛，生长速度为20.44 mm/d；而低毒力菌株2012-19、2012-22和2012-161的菌落形态表现为不规则生长，出现明显的扇变区域，生长速度为2.94～13.19 mm/d；3个低毒力菌株的平均生长速度较强毒力菌株显著降低60.54%。离体叶片接种5 d后，强毒力菌株的病斑已经扩展至整个叶面，导致叶面褐变腐烂，而3个低毒力菌株仅在接种处形成28.26 mm2的病斑。活体茎秆接种8 d 后，3 个低毒力菌株的相对病程发展曲线下面积（RAUDPC）为2.10～5.90，三者的平均RAUDPC较强毒力菌株（45.55）显著降低92.27%。室内盆栽试验显示，3个低毒力菌株对芝麻茎点枯病的防治效果分别为44.90%、56.40%和75.30%，而生防菌剂哈茨木霉和化学药剂50%多菌灵的防治效果分别为53.65%和87.10%。可见，携带相关病毒的低毒力菜豆壳球孢菌株可以作为芝麻茎点枯病的生物防治资源。

关键词: 芝麻茎点枯病, 真菌病毒, 菜豆壳球孢, 生物防治