Unusual reticulated parenthosomes surround the dolipore of a hyphomycete with clamp connections, Ditangifibulae dikaryotae gen. et sp. nov.

Abstract

Ditangifibulae dikaryotae gen. et sp. nov. is described from culture and by electron microscopy. Median longitudinal sections through hyphal septa reveal a dolipore surrounded by an unusual parenthosome with a highly reticulated complex of interlocking membranes unlike previously described vesiculate parenthosomes. Other features of the dolipore are characteristic of the Tremellaceae and Filobasidiaceae. The hyphomycete is robust and unusual in the number of types of propagules formed. These include two size classes of blunt allantoid conidia, ovoid to pyriform conidia formed blastically, thallic terminal thickwalled chlamydospores often with stalks, and a dikaryotic yeast phase. Conidia and yeast cells germinate on agar media to form hyphae with complete clamp connections. The morphology of the hyphomycete is dependent on clamp connections because conidiophore branches and conidiogenous cells arise from clamps. Multibranched conidiophores with prominant clamp connections terminate with digitate conidiogenous cells. The digitate arrangement originates through the frequent anastomosis of clamps. Aerial hyphae are clamped whereas submerged or subhymenial hyphae lack clamps and are much broader (astatocoenocytic). Rudimentary conidiomata with an organized tissue form rarely and are sporodochium-like. Recognizable basidia and ballistospores are absent. The dikaryotic yeast phase is similar to Cryptococcus spp. Growth ceases above 36 C or with greater than 6 parts per million benzimidazole in culture medium.

Key Words:

• basidiomycete anamorph
• basidiomycetous yeasts
• Chamaecyparis noothatensis
• Craterocolla
• Cryptococcus
• Ditangium
• gasteroid auricularioid Heterobasidiomycetes
• septal pore
• Tremellaceae
• Tremelliineae