Kabatiella bupleuri sp. nov. (Dothideales), a pleomorphic epiphyte and endophyte of the Mediterranean plant Bupleurum gibraltarium (Apiaceae)

Abstract

Bupleurum gibraltarium is an evergreen shrub endemic to southern Spain and northern Algeria and Morocco. We have collected and cultured an undescribed Kabatiella species that is consistently associated with the flower rachises and leaves of B. gibraltarium in the province of Granada. The fungus forms melanized acervuli on overwintered flower rachises. It also can be isolated from yeast-like conidial masses that emerge from senescing leaves and from surface-disinfected healthy leaves. Like other Kabatiella species, the fungus forms blastic falcate to lunate conidia simultaneously from the apex of conidiogenous cells in acervuli. In culture, melanized single-septate conidia form blastically from the vegetative hyphae that accumulate in yeast-like masses. These conidia germinate by budding to form secondary yeast-like cells or directly as hyphae. In culture, the fungus behaves like, and could be confused with, Aureobasidium and Hormonema species. We describe the growth of this species in agar media and its phylogenetic position based on the analyses of nuclear ribosomal RNA gene sequences. This new species is a sister species of the morphologically similar clover pathogen, K. caulivora.

• Aureobasidium
• black yeasts
• endophytic fungi
• meristematic fungi

Acknowledgments

Portions of this work were supported the Junta de Andalucía Project in Scientific Excellence RNM-7987 Sustainable use of plants and their fungal parasites from arid regions of Andalucía for new molecules useful for antifungals and neuroprotectors. Marc Stadler, Sybren de Hoog and an anonymous reviewer made helpful suggestions on text.