Leaf spot on Rosa banksiae caused by Calonectriafujianensis in China

Rosabanksiae is a vine-like shrub rose that is endemic to China. In recent years, leaf spot disease hasbeen observed frequently in park in Nanjing City, Jiangsu Province, China. The initial symptoms were small yellow spots; as the disease progressed, the lesions became dark brown. Isolates NLXH2-1-1, NLXH2-2-3, and NLXH 2-4-3 were obtained. Koch's postulates were tested and confirmed that these isolates were pathogenic. Morpho-logically, macroconidia were cylindrical, rounded at both ends, straight, and (48-) 50-55 (-60) x (2.5-) 3.5-4.5 (-5) mu m in length (av. = 52.5 x 4 mu m), with 1-3-septate, and gathered conidia bundles. By morphological features and multigene phylogenetic analysis of the six genesITS, act, cmdA, his, LSU and tub2 region, the causal fungus is Calonectria fujianensis.This is the first report leaf spot by Ca. fujianensis on the R. banksiae, provide a theoretical basis for disease prevention and control.

Automated summary

Rosabanksiae, an endemic vine-like shrub rose in China, has been frequently affected by leaf spot disease in a park in Nanjing City, Jiangsu Province. The disease initially presents as small yellow spots, which progress into dark brown lesions. The causal fungus of this disease was identified as Calonectria fujianensis through morphological and multigene phylogenetic analysis. This is the first report of leaf spot caused by Ca. fujianensis on R. banksiae, providing a theoretical basis for disease prevention and control.