A New Species of Biscogniauxia Associated with Pine Needle Blight on Pinus thunbergii in China

Abstract

In June 2020, needle blight symptoms on Pinus thunbergii were discovered in Bazhong City, Sichuan Province, China. Fungal isolates were obtained from the pine needles of P. thunbergii. After examining morphological characteristics and conducting multi-locus (ITS, ACT, TUB2 and RPB2) phylogenetic analyses, the isolates SC1–SC5 were determined to be a new species, Biscogniauxia sinensis. Genealogical Concordance Phylogenetic Species Recognition with a pairwise homoplasy index test was used to further verify the results of the phylogenetic analyses. The morphology and phylogenetic relationships between this new species and other related Biscogniauxia species were discussed. To our knowledge, this is also the first report of Biscogniauxia sinensis associated with pine needle blight on P. thunbergii in China. The needle damage of P. thunbergii associated with Biscogniauxia sinensis will detrimentally affect the carbon absorption and photosynthetic efficiency of P. thunbergii, further reduce the absorption of nutrients by Japanese black pine and may lead to the imbalance of pine forest conditions, which will have a negative impact on the forest ecological system.