Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

First report of Corynespora leaf spot on sweet potato caused by Corynespora cassiicola in China.

Abstract

In August 2015, a leaf spot disease on sweet potato (cv. Xinnong IV) was observed in Meishan of Sichuan Province, China. The disease occurred from mid-August to early September and caused severe yield loss. Leaf symptoms appeared as small gray spots with brown margins at earlier stages, then expanded into suborbicular brown necrotic lesions surrounded by a yellow halo. Subsequently, lesions developed concentric rings with gray and brown bands, and leaves with multiple lesions senesced prematurely. Abundant conidiophores and conidia arose from lesions. Based on morphological characteristics, molecular data (sequence analysis of the internal transcribed spacers, β-tubulin, translation elongation factor and Cas2 genes) and a pathogenicity test, the causal agent was identified as C. cassiicola, which is consistent with previous report in Sri Lanka and Saipan. However, this is thought to be the first report of C. cassiicola on sweet potato in China.