Pine bark beetles are typically associated with complexes of fungi that could reveal different functional interaction. Thus, previously nonaggressive bark beetle Ips acuminatus is considering now to be among the most serious pests of pine forest in Ukraine and other European countries and vectored fungal community is very important to assess total harm of this bark beetle. The aim of this study was to reveal the vectored fungal community associated with the pine engraver beetle, I. acuminatus with special emphasis on pathogenic fungi for further evaluation of harm bark-beetle - fungi association for Ukrainian forest.
In total, 288 adult beetles were collected from Scots pine trees at six different sites through Ukraine. DNA sequencing as fungal culturing from all beetles resulted in 1681 isolates and amplicons representing 42 fungal taxa. NCBI BLAST search revealed that the overall fungal community was composed of 94 species, of which 80.85% were Ascomycota, followed by Basidiomycota and unidentified fungal group, which accounted for 10.6% and 8.5 % of the total sequences, respectively. Among these, the most commonly detected fungi for pooling dataset were Sphaeropsis sapinea (23.6%), Cladosporium pini-ponderosae (19.44%), Ophiostoma ips (19.1%), Ophiostoma canum (19.1%) and Cladobotryum mycophilum (18.06%). In the pooled dataset of isolates and amplicons for each site, Shannon diversity indices ranged between 1.9 and 2.9 while Simpson diversity index varied between 0.69 and 0.89 indicating rich species diversity.
In total twelve ophiostomatoid species were detected. All ophiostomatoid fungi were showing varying degrees of virulence and O. minus was the most aggressive fungus in previous studies. It is concluded that I. acuminatus vectors a species-rich fungal community including pathogens such as ophiostomatoid fungi, Sphaeropsis sapinea, different needle pathogens and wood decay fungi that seems to be very important for the assessment of threat of I. acuminatus to the pine forest in Ukraine.
Phytotoxicities of fluoranthene and phenanthrene deposited on needle surfaces of the evergreen conifer, Japanese red pine (Pinus densiflora Sieb. et Zucc.)