The blackleg disease of Ajuga multiflora and its pathogen
多花筋骨草黑胫病及其病原菌鉴定

Ajuga multiflora (Labiatae) is an ornamental plant widely growing in gardens in southern China. Blackleg symptoms were observed on A. multiflora in autumn of 2005 in Hangzhou, Zhejiang Province. It was caused by Phoma species. The disease was found throughout the year, and most severe during the flowering phase. Brown water-soaked spots initially appeared on the base of leaf petioles, the lesions rapidly became black-rot, then followed by wilting and drying of individual leaves. At last the disease resulted in plant death. The typical symptom of the disease was black stem rot. The six isolates of the causal agent were all identified as Phoma multirostrata based on their morphological characteristics, pathogenicity tests and rDNA ITS sequence analyses. It is the first report of P. multirostrata causing blackleg of A. multiflora in China.