Pestalotiopsis trachicarpicola, a novel pathogen causes twig blight of Pinus bungeana (Pinaceae: Pinoideae) in China.

Pinus bungeana is one of indigenous trees in China and widely distributed in poor and arid regions for vegetation and industrial woody use. However, since a high-incidence disease threatens the growth of mature P. bungeana tree in the garden and in the plantation every year, the overwintering shoots were infected and died in the next spring with a ratio over 70%, but the cause was beyond understood. A total of 120 fungal isolates were separated from symptomatic twigs by histological isolation methods, including Pestalotiopsis spp., Fusarium spp., Trichothecium spp., Penicillium and some unknown fungal species. Pestalotiopsis spp. was dominant, accounting for 85%. Morphological observation under microcopy showed all Pestalotiopsis species are identical, and six isolations among them were randomly selected for pathogenicity tests. Fulfilling Koch's postulates showed that all six isolates of Pestalotiopsis spp. were pathogens of twig blight, causing the same symptoms as observed in the field, while other non-Pestalotiopsis isolates were avirulent to P. bungeana twigs. Multi-gene (ITS, tub2 and TEF1) analysis and morphological observation revealed that all the six Pestalotiopsis isolates belonged to P. trachicarpicola. To our knowledge, this is the first study reporting P. trachicarpicola as the pathogens responsible for P. bungeana twig blight in China.

Three new species of Talaromyces sect. Talaromyces discovered from soil in China.

Three new Talaromyces species isolated from soil are reported here, namely T. dimorphus (ex-type strain AS3.15692 T), T. lentulus (ex-type strain AS3.15689 T) and T. mae (ex-type strain AS3.15690 T). T. dimorphus is characterized by biverticillate and monoverticillate penicilli, ampulliform phialides, slimy texture with sparse mycelial funicles and absent conidiogenesis on MEA. T. lentulus is featured by vivid yellow mycelium on Cz and MEA, absent conidiogenesis on CYA, and globose smooth-walled conidia. T. mae presents sparse conidia on CYA and YES, funiculous and floccose texture on MEA, and ovoid smooth-walled conidia. Both morphological and molecular characters show that T. dimorphus is unique and has no close relatives. Although T. lentulus and T. mae resembles T. adpressus and T. pinophilus very much, phylogenetic analyses of CaM, BenA, ITS and Rpb2 sequences all support their status as novel species.