Castanediella monoseptata C.G. Lin & K.D. Hyde

Lin, Chuan-Gen, J. Bhat, Darbhe, Liu, Jian-Kui, D. Hyde, Kevin & Yong Wang,, 2019, The genus Castanediella, MycoKeys 51, pp. 1-14 : 5-8

Castanediella monoseptata C.G. Lin & K.D. Hyde sp. nov. Figure 3

Holotype.

THAILAND. Chiang Mai: on decaying leaves, 24 August 2016, Chuangen Lin, MRC 3-1 (MFLU 18-1696, holotype; HKAS 102199, isotype), ex-type living cultures KUMCC 18-0133.

GenBank number.

ITS: MH806360, LSU: MH806357

Etymology.

In reference to the 0-1-septate conidia

Saprobic on plant host. Asexual morph: Colonies on substrate effuse, white. Mycelium partly superficial, composed of septate, branched, hyaline to subhyaline, smooth hyphae. Conidiophores macronematous, mononematous, solitary, erect, unbranched, straight or flexuous, septate, hyaline, subcylindrical, smooth, 8-29 × 2-4 μm. Conidiogenous cells polyblastic, integrated, sympodial, subcylindrical, hyaline, with several scars. Conidia solitary, dry, acropleurogenous, smooth, fusiform, curved, 0-1-sepatate, hyaline, 15.4-25.8 × 1.5-2.3 μm (av. 23.03 × 1.98 μm, n = 45). Sexual morph: Undetermined.

Culture characteristics: Conidia germinating on PDA within 24 h. Colonies on PDA effuse, grayish white to dark from above and below, reaching a diam. of 5-7 cm in 30 days at 25 °C.

Notes.

A megablast search of the NCBI nucleotide database using the ITS sequence of the ex-type culture showed the highest similarities with uncultured Sordariales fungi (GenBank GQ268569; identities = 518/539(96%), gaps = 3/539(0%)) and Castanediella couratarii (GenBank KX960789; identities = 516/540(96%), gaps = 4/540(0%)).

Five Castanediella species, C. cagnizarii , C. diversispora , C. hyalopenicillata , C. malaysiana and C. ramosa , were reported to produce 1-septate conidia. Castanediella monoseptata can be distinguished from these species by its unbranched conidiophores and falcate and 15.4-25.8 × 1.5-2.3 μm conidia. Castanediella monoseptata is phylogeneti cally closely related to C. couratarii and C. ramosa , but differs from both species by its conidial morphology. Castanediella couratarii has shorter conidia (9.5-19 × 2-3 μm) are aseptate and C. ramosa has larger conidia (26-44 × 2-3 μm) that are 0-3-septate.