Curvularia malina causes a foliar disease on hybrid Bermuda grass in China

Abstract

Hybrid Bermuda grass (Cynodon dactylon × C. transvaalensis) was observed with an unknown foliar disease during a survey conducted in the golf courses of Hainan Province in southern China (during April 2011 to April 2015). Leaves on affected plants initially had small, dark brown, circular or oblong spots. Frequently, the spots would coalesce into large lesions with dark brownish-black margins. Leaf blight may occur under high disease pressure, resulting in black patches 2–15 cm in diameter on close mown turf such as golf course putting greens and fairways. Symptomatic leaf samples were collected from infected plants and cultured on potato dextrose agar. A sterile, filamentous fungus was isolated in pure culture. On the basis of colony morphology and combined sequences of the internal transcribed spacer regions and intervening 5.8S nrDNA (ITS), partial glyceraldehyde-3-phosphate dehydrogenase gene (GAPDH) and partial translation elongation factor 1-alpha gene (TEF-1α), the fungus was identified as Curvularia malina. Pathogenicity testing showed C. malina isolates were pathogenic to healthy hybrid Bermuda grass and Koch’s postulates were fulfilled by re-isolating the pathogen.