First report of Colletotrichum higginsianum causing anthracnose of Arugula (Eruca sativa) in Florida.
Arugula (Eruca sativa) is grown in Florida (USA) and is an important component in packaged salad products. During spring 2013, leaf lesions on arugula caused significant economic losses in Miami-Dade County, Florida. Symptoms initially appeared as small water-soaked lesions that later became circular, sunken, and white in the centre with a dark brown to black halo, up to 4 mm in diameter. Acervuli were found under a dissecting microscope on infected leaf lesions with black spines or setae. Occasionally, small, circular, often longitudinal dark brown spots appeared on leaf branches. Based on cultural and morphological characteristics of the conidia, molecular investigations (sequence analysis of the rDNA internal transcribed spacer region, chitin synthase 1 and actin) and pathogenicity tests, the causal agent was identified as C. higginsianum. This is thought to be the first report of C. higginsianum causing anthracnose of arugula in Florida.