Bremia lactucae causing Downy Mildew on Lactuca serriola in Korea

Jin A  Lee1   Bora  Kim1   Dong-Jae  Lee1   Young-Joon  Choi1,*   



Lactuca serriola L. (syn. L. scariola L.), commonly known as prickly lettuce, invaded Korea in the late 1970s. The plant has since become widely naturalized and disruptive to native plant communities. In May 2020, downy mildew infections were observed on L. serriola in Gimje-si, Korea. Molecular phylogenetic and morphological analyses identified the causal agent as Bremia lactucae. This is the first report of B. lactucae infection on L. serriola in Korea.

Figures & Tables

Fig. 1. Downy mildew disease caused by Bremia lactucae on Lactuca serriola in Korea. A and B, Vein-limited spots above (A) and below (B) an infected leaf. C, Close-up view of veinlimited downy mildew growth developing on the lower surface. D, Conidiophores emerging from stomata under a stereomicroscope. E and F, Conidiophore under a differential interference contrast microscope. G and H, Ultimate branchlets. I and J, Conidium. Scale bars: 50 μm for E and F, 10 μm for G-J.