Cylindrocladium buxicola, a new species affecting Buxus spp., and its phylogenetic status

Abstract

A leaf and twig blight disease of Buxus spp. was found to be associated with a new species of Cylindrocladium. The novel species status was confirmed using morphological characters, sequencing of the ribosomal 5.8S RNA gene and the flanking internal transcribed spacers (ITS), the β-tubulin gene, and the high mobility group (HMG) of the MAT2 mating type gene. Cylindrocladium buxicola is proposed as a new name. Fifteen isolates from the UK and one isolate from New Zealand were paired in all combinations but no fertile perithecia were obtained suggesting that C. buxicola is heterothallic and all isolates belonged to one mating type. AFLP analysis showed that the isolates collected in the UK and New Zealand are genetically homogenous. Phylogenetic analyses indicated that this species falls within a new lineage.

• AFLP
• β-tubulin
• Buxus
• Calonectria
• Cylindrocladium
• ITS
• MAT2

We would like to thank Ms. Georgina Godwin-Keene (CABI Bioscience) for assistance with the electron microscopy, Dr. B. Spooner from Kew Gardens for his help with the drawings, the Forestry Commission at Alice Holt and CABI Bioscience for space in their laboratories, Andrew Peace for his help with the statistical analysis, Caroline Gorton for her technical assistance, and Prashant Mishra for unpublished DNA sequences of Fusarium culmorum.