Isolation and characterization of endophytic Beauveria spp. (Ascomycota: Hypocreales) from Pinusradiata in New Zealand forests

Abstract

New Zealand Pinus radiata and associated exotic and native trees were surveyed for presence of Beauveria bassiana. Samples were collected from trees located in 33 sites in four geographically distinct areas of New Zealand. Needle samples were taken at all sites, while seed samples were taken from a single tree at one site and four root samples were collected from two sites where P. radiata seedlings were present. The bulk of the needle samples were from P. radiata, but exotic and indigenous trees growing in the same vicinity were also periodically sampled. After processing plant material from 167 trees, 21 fungal isolates resembling Beauveria spp. were recovered; DNA sequence analysis of a terminal region of the EF1-α locus showed that these isolates all classified as B. bassiana Clade A. The pathogenicity of these isolates against Hylurgus ligniperda adults and Tenebrio molitor larvae was confirmed in laboratory bioassays. This study demonstrated widespread occurrence of B. bassiana as endophytes of pine in New Zealand. This association may provide new opportunities to regulate insect pests of pine using a biological control agent.