Austrocedrus chilensis [D.Don] Pic. Serm. et Bizarri (Pinales: Cupressaceae) is a keystone tree species in South America. Mortality of A. chilensis has been reported over most of its distribution in Argentina, and Phytophthora austrocedri has been identified as the causal agent. The aim of this work was to evaluate rhizospheric microorganisms present in A. chilensis roots as biocontrol agents against P. austrocedri. Mycelial growth of P. austrocedri was inhibited by seven fungal and four bacterial isolates in vitro. Interaction among isolates and P. austrocedri was microscopically studied. Isolates with high in vitro fungistatic or fungicide performance were molecularly identified and inoculated in plants to evaluate their ability to reduce the effect of the pathogen. Two of the bacterial isolates were able to reduce the symptoms in A. chilensis seedlings inoculated with P. austrocedri. These findings are promising since they may contribute to the development of a biocontrol strategy for the disease.

Austrocedrus chilensis [D.Don] Pic。精油 et Bizarri（Pinales：柏科）是南美的重点树种。据报道，智利曲霉的死亡率大部分分布在阿根廷，而疫霉菌已被确认为病原体。这项工作的目的是评价存在于根际微生物A. chilensis的根作为对生物防治剂P. austrocedri。在体外，七种真菌和四种细菌分离株抑制了桔梗假单胞菌的菌丝生长。分离株与P. austrocedri之间的相互作用进行了微观研究。对具有高体外抑真菌或杀真菌性能的分离物进行分子鉴定，并接种到植物中，以评估其降低病原体作用的能力。两种细菌分离物能够减轻接种桔梗的A. chilensis幼苗的症状。这些发现令人鼓舞，因为它们可能有助于该疾病的生物防治策略的发展。