Canker disease of willow and poplar caused by Cryptosphaeria pullmanensis recorded in China

Abstract

Summary A new canker disease of Salix alba and Populus alba has been observed in Xinjiang, China. Black circular spots on dead branches and stems are the symptoms of the disease. Sixty‐seven isolates recovered from Salix matsudana, S. alba and Populus alba were identified as Cryptosphaeria pullmanensis based on morphological features and multigene phylogeny. Pathogenicity tests were performed on S. alba and P. alba stems using the C. pullmanensis isolates. Cankers on and Cryptosphaeria pullmanensis of C. pullmanensis from the stems fulfilled Koch's postulates and confirmed C. pullmanensis as the causal agent of the canker disease. C. pullmanensis is characterized by its yellow stromatic tissue surrounded by a black conceptacle with regularly arranged multiple locules sharing common walls and hyaline, allantoid, aseptate conidia (mean size 7.42 × 1.72 μm). This is the first report of C. pullmanensis causing Cryptosphaeria canker in China, and S. alba and P. alba are new host records for C. pullmanensis.

Cryptosphaeria Canker of Populus nigra Caused by Cryptosphaeria pullmanensis, a New Threat to Poplar Industry in Iran

“…This species was recently reported on different hosts including Populus fremontii from United states, Salix alba and P. alba from China (Ma et al. ) and Juglans regia from Iran (Raoufi et al. ).…”

“…; Ma et al. ). In phylogenetic analysis using Baysian inference in this study, our isolates well separated and gathered with other Cr.…”

“…pullmanensis , although it exhibits some differences such the absence of the unusual thickenings at the ends of the ascospores, well‐developed, pulvinate stromata and longer conidia (Glawe and Rogers ; Ma et al. ). The morphological description of the asexual stage of our isolates in this study was in full agreement with previous descriptions noted by Glawe ().…”

“…Due to their economic importance and versatility in response to different environmental conditions, they are widely grown in many countries beyond the centre of origin (Ma et al. ). In recent years, increasing attention has been drawn to poplars trees ( Populus spp.)…”

“…Members of the genus Cryptosphaeria are well‐known wood pathogens, causing canker and dieback diseases on different species in the family Salicaceae (Ma et al. ). Cryptosphaeria was originally described with Cr.…”