The identification of barnyardgrass leaf spot caused by Exserohilum monoceras
稗草叶枯病病原尖角突脐孢菌的鉴定

Three fungal isolates, KF-1, HN-14 and K-12, from barnyardgrass leaf blight, which were collected from Hunan and Beijing, were studied morphologically and molecularly. The results showed that there were differences between the three isolates and the two Exserohilum monoceras strains G-9 and X-27 which were accurately identified and deposited in culture collections of China Agricultural University in colonial morphology, sporulation and spore morphology especially septa of spore. G-9, KF-1, X-27 and HN-14 grow quickly and produce abundant spores on PDA plate, but K-12 grows slowly and produced less spores. To further identify the relationship of 5 isolates, 5.8S-ITS sequence were compared. Results indicated that the similarity of ITS sequence of five isolates were over 98% and the phylogenetic tree based on ITS1 and ITS2 sequence also revealed that G-9, KF-1, K-12, X-27, and HN-14 were all clustered into one group and distinct from the other outgroup and suboutgroup. Based on the above data, these three isolates were proved to be E. monoceras.