Spp. Associated with Leaf Blight of Maize in Heilongjiang Province, China

Maize ( L.) is a major economic crop worldwide. Maize can be infected by species causing leaf blight that can result in significant economic losses. In this study, 168 isolates recovered from symptomatic maize leaves were identified based on morphological characteristics, pathogenicity, and multilocus sequence analyses of the genes glyceraldehyde-3-phosphate dehydrogenase (), the internal transcribed spacer of ribosomal DNA (rDNA ITS), the RNA polymerase II second largest subunit (), and histone3 (). Maize isolates grouped to four species including , . , . , and sp. Notably, . (71.4%) was the most prevalent of the four isolated species, followed by . (21.5%), sp. (4.1%), and . (3.0%). Pathogenicity tests showed that all four species could produce elliptic to nearly round, or strip, lesions on leaves of maize, gray-white to dry white in the lesion centers and reddish-brown at the edges. The average disease incidence (58.47%) and average disease index (63.55) of maize leaves inoculated with . were significantly higher than levels resulting from . (55.28% and 58.49), sp. (55.34% and 58.75), and . (56% and 55). Haplotype analyses indicated that there were 14 haplotypes of . and five haplotypes of . in Heilongjiang Province and suggested the occurrence of a population expansion. Results of the study showed that species associated with maize leaf blight in Heilongjiang Province are more diverse than those that have been previously reported. This is the first report globally of . , . , and an unclassified species as causal agents of leaf blight on maize.