<i>Epicoccum</i> spp. Causing Maize Leaf Spot in Heilongjiang Province, China

Abstract

Maize leaf spot occurs worldwide and affects maize production. Maize can be infected by several pathogens causing leaf spot, such as <i>Bipolaris zeicola</i>, <i>Bipolaris maydis</i>, <i>Curvularia</i> species, <i>Alternaria</i> species, etc. In the current study, 30 <i>Epicoccum</i> isolates recovered from symptomatic maize leaves were identified based on morphological characteristics, pathogenicity, and multilocus sequence analyses of nuLSU, ITS, <i>tub2</i>, and <i>rpb2</i>. These maize isolates were grouped into five <i>Epicoccum</i> species, including <i>E. nigrum</i>, <i>E. layuense</i>, <i>E. sorghinum</i>, <i>E. latusicollum</i>, and <i>E. pneumoniae</i>. Pathogenicity tests showed that all five <i>Epicoccum</i> species could produce small ellipse- and spindle-shaped spots on maize leaves. The lesion center was grayish yellow to dark gray and surrounded by a chlorotic area. Furthermore, the <i>Epicoccum</i> isolates exhibited high pathogenicity to 20 main maize varieties of Heilongjiang Province but showed different sensitivities to the commonly used fungicides carbendazim and tebuconazole. In addition, these <i>Epicoccum</i> isolates showed different production capacity of pectinase, cellulase, protease, amylase, laccase, and gelatinase, but all showed high lipase activity. This is the first report globally of <i>E. layuense</i>, <i>E. latusicollum</i>, and <i>E. pneumoniae</i> as causal agents of maize leaf spot. <i>E. pneumoniae</i> was first reported as a plant pathogen.