Identification, biological characteristics and fungicide sensitivity of Colletotrichum species that cause anthracnose on Anemarrhena asphodeloides in China

Zhi mu (Anemarrhena asphodeloides Bunge.) is an important medicinal plant in China, and its growth is greatly threatened by the fungal disease anthracnose, which can be caused by a number of species of Colletotrichum. Studying the phytopathogen and its sensitivities to fungicides will help to control anthracnose on zhi mu. Ten isolates of Colletotrichum were collected from zhi mu in Hebei, Anhui and Shanxi Provinces in China for this study. The isolates were identified as C. gloeosporioides, C. liriopes and C. spaethianum based on multi‐locus phylogenetic analyses, including ACT, CHS‐1, GADPH, HIS3 and ITS, micromorphological characteristics and the characteristics of colonies. Koch's postulates were confirmed by inoculating the leaves of zhi mu in vitro. The levels of virulence of 10 isolates varied significantly. Isolate YC‐1 was the most virulent, while BZ‐2 was the least virulent. The sensitivity of isolates YC‐1, BY‐1 and BY‐2 (C. spaethianum, C. gloeosporioides and C. liriopes respectively) to fungicides were examined. The EC50 values of BY‐1, BY‐2, and YC‐1 to tebuconazole, difenoconazole, prochloraz, fludioxonil, pyraclostrobin, carbendazim and azoxystrobin confirm that all of the isolates were markedly sensitive to the seven fungicides tested, strongly suggesting that these fungicides could be used to control anthracnose on zhi mu in the field.