Novel species of Calonectria isolated from soil near Eucalyptus plantations in southern China.

Calonectria species are soil-borne and widely distributed in tropical and subtropical regions around the world. The species in this genus include many important plant pathogens that cause serious diseases to economically important crops and forest trees. Previous research results indicated that the leaf blight and cutting rot caused by Calonectria species caused big losses to the Eucalyptus industry in southern China, and large number of Calonectria species identified in China have been collected from soil in Eucalyptus plantations. In this study, Calonectria samples were isolated from soils close to Eucalyptus plantations in Guangdong Province, southern China. These isolates were identified by DNA sequence analyses based on the calmodulin (cmdA), histone H3 (his3), translation elongation factor 1-alpha (tef1), and β-tubulin (tub2) gene regions, and combined with morphological characteristics. One novel species of Calonectria was identified and described, named Calonectria xianrensis, which resides in the Prolate Group. Results in this study suggest that more species of Calonectria may be distributed in soils in China.