Calonectria species isolated from Eucalyptus plantations and nurseries in South China.

Diseases caused by species of <i>Calonectria</i> (<i>Ca.</i>) represent a serious threat to the growth and sustainability of <i>Eucalyptus</i> plantations in China. Symptoms caused by these fungi mainly include leaf blight on trees in plantations and rotting of stems and leaves in nurseries. Extensive surveys have recently been conducted where <i>Calonectria</i> species were collected in <i>Eucalyptus</i> plantations and nurseries in the FuJian, GuangDong, GuangXi, and YunNan Provinces of South China. Additional isolates were baited from soil samples in the Hong Kong Region. The aim of this study was to identify the 115 <i>Calonectria</i> isolates obtained using comparisons of DNA sequence data for the β-tubulin (<i>tub2</i>), calmodulin (<i>cmdA</i>), histone H3 (<i>his3</i>) and partial translation elongation factor-1α (<i>tef1</i>) gene regions as well as their morphological features. Seven known species were identified, including <i>Calonectria arbusta</i>, <i>Ca. asiatica</i>, <i>Ca. chinensis</i>, <i>Ca. eucalypti</i>, <i>Ca. hongkongensis</i>, <i>Ca. mossambicensis</i> and <i>Ca. pentaseptata</i>. In addition, six novel taxa were collected and are described here as <i>Ca. aciculata</i>, <i>Ca. honghensis</i>, <i>Ca. lantauensis</i>, <i>Ca. pseudoturangicola</i>, <i>Ca. pseudoyunnanensis,</i> and <i>Ca. yunnanensis</i> spp. nov. Overall, the results reflect a high diversity of <i>Calonectria</i> species in China.