Two new genera isolated from marine habitats in Thailand:: Pseudolignincola and Thalespora (Halosphaeriales, Ascomycota)

Pseudolignincola siamensis and Thalespora appendiculata gen. et sp. nov. were isolated from plant substrata in Thai mangroves. Sequence analysis of the partial SSU rRNA gene places them in the Halosphaeriales, Ascomycota. Thalespora appendiculata is phylogenetically close to Okeanomyces, while P. siamensis does not show a strong affinity with any genus in the order (sequence analysis of the partial LSU rRNA gene). Pseudolignincola siamensis is characterised by having clavate asci with a truncate, thickened apex, a pore and plasmalemma retraction and cylindrical ascospores without appendages. A Humicola anamorph (H. siamensis sp. nov.) is associated with this species. Pseudolignincola siamensis is morphologically similar to Lignincola nypae but they differ in the dimensions of the ascomata, asci and ascospores, and ascospore septation. Also, no anamorph has been reported for L. nypae. Thalespora appendiculata has deliquescing asci and elongate-cylindrical ascospores which taper at one end, bearing a unipolar, tetra-radiate appendage, which develops when the ascospores are mounted in seawater. This species closely resembles Bathyascus tropicalis with its 1-septate ascospores, but the latter differs in ascospore shape and lack of ascospore appendages.