Evaluation of fungal endophytes to biological control of Dothistroma needle blight on Pinus nigra subsp. pallasiana (Crimean pine)

Abstract

Dothistroma needle blight (DNB), caused by Dothistroma septosporum and Dothistroma pini, is the most important forest disease of pine in many countries. This disease has recently emerged in Ukraine as a major threat to mostly Pinus nigra subsp. pallasiana and less to Scots pine. There is increasing evidence that some fungal and bacterial isolates can reduce the growth and pathogenicity of fungal plant pathogens. In this research, infected needles were collected from 30-year-old Crimean pine (P. nigra subsp. pallasiana) in four locations in Southern Ukraine. In total, 244 of endophytic fungi were recovered from needles of Crimean pine during summer sampling of the host’s microbiome in Ukraine in 2012-2014. Dothistroma spp. were detected using fungal isolation and species-specific priming PCR techniques. Among all endophytes, eight fungal species were selected based on the commonness of their occurrence in the foliage of the host and their antagonistic activity. All selected species were tested for their antifungal activity against Dothistroma needle blight. Good antifungal activity against Dothistroma pini was achieved with the Trichoderma sp. and Gliocladium rosea, indicating their good potential possibility in preventing the Dothistroma needle blight on young pines. Moreover, the significant reduction in numbers of conidia and spore germination was found on needles treated with Trichoderma sp. and Gliocladium rosea, compared to conidia numbers following treatment with other fungi. Thus, the use of an effective biological control agent against Dothistroma could be of value in forest nurseries, where it is essential to reduce losses to D. pini infection prior to transferring pines to field sites for planting out.

Keywords

• dnb
• dothistroma septosporum
• dothistroma pini
• pathogens
• biological control
• forest health