Volutellonectria asiana J. Luo, X.M. Zhang & W.Y. Zhuang, 2012

Luo, Jing & Zhuang, Wen-Ying, 2012, Volutellonectria (Ascomycota, Fungi), a new genus with Volutella anamorphs, Phytotaxa 44, pp. 1-10 : 5-6

Volutellonectria asiana J. Luo, X.M. Zhang & W.Y. Zhuang , sp. nov.

FIGS.2A− B , 3A− H

MycoBank MB561607

Etymology. The specific epithet refers to the locality of the fungus.

Ascomata on old sporodochia or thin basal stromata, perithecial, solitary or 2−5 in a group, superficial, obpyriform, 110−210 µm high, 85−190 µm diam, with a small and red papilla, not collapsing or laterally collapsing when dry, red-orange when fresh and orange to red-orange when dry, turning dark red in 3% KOH and orange-yellow in lactic acid, smooth. Ascomatal wall 7.5−12 µm thick, of two layers; outer layer 6−9.5 µm thick, cells angular, 4−7.5 × 2.5−5 µm, cell wall 0.5−1.5µm thick; inner layer 1.5−3.5 µm thick, cells flattened, 5−11 × 1−2 µm, cell wall 0.5−1 µm thick. Asci subcylindrical to clavate, 8-spored, with an apical ring, 35−47 × 4−6 µm (n = 50). Ascospores subfusoid, uniseptate, not constricted at the septum, hyaline, smooth, irregularly biseriate, 9.5−15 × 2−3 µm (n = 50).

Sporodochia solitary or gregarious on substrate, usually stipitate, with a small basal stroma, 75−145 µm diam. Seta arising from sporodochial base and surrounding the conidiophores, 175−325 µm long, 3−5.5 µm wide at base, tapering to a round apex, 1−4-septate, smooth, hyaline, walls 0.5−1.5 µm thick. Conidiophores branched, 2540 µm long, 2−3 µm wide at base, closely aggregated. Conidiogenous cells in whorls of 2−4, adpressed, straight, cylindrical, slightly tapering towards the tip, 6.5−13 µm long, 1.5−2.5 µm wide at base, 0.5−1.5 µm near aperture (n = 50). Conidia rod-shaped, distally rounded, with a median displaced hilum, straight, 1-celled, hyaline, smooth, 4−8.5 × 1.5−2.5 µm (n = 50).

Colonies on PDA 3 cm diam after 5 d in the dark at 24 C, pale pinkish cinnamon, surface velvety, aerial mycelium white to yellowish, reverse light pinkish cinnamon. Colonies on (CMD) reaching 2.5 cm diam after 5 d in the dark at 24 C, pale pinkish buff, surface felty, aerial mycelium absent to sparse, reverse light buff. Conidiophores simple, unbranched, erect, septate. Conidiogenous cells cylindrical, slightly tapering towards the tip, 15−52 µm long, 1−1.5 µm wide at base, 0.51 µm near aperture (n = 50). Conidia subellipsoid to subfusoid, distally rounded, with a median displaced hilum, straight, 1-celled, hyaline, smooth, 4−11.5 × 1.5− 2.5 µm (n = 50). Sporodochia not observed.

Holotype. CHINA. HAINAN, Bawanling , 1100 m, on leaves of a palm, 6 July 2000, Zhuang W. Y., Wu W. P. and Zhang X. M., H17 , HMAS 76861 , ex type culture HMAS 188475 .

Paratype. Thailand. Saraburi, Khao Yai National Park, Phaedeodai , 1100 m, on Pandanus sp. , 12 August 1997, Samuels G. J . and Chaverri P ., 8410, BPI 745740 .

Notes. Volutellonectria asiana is most similar to V. consors in having red-orange and obpyriform perithecia with a red papilla, subcylindrical to clavate asci with an apical ring, hyaline ascospores with a smooth surface, smooth-walled sporodochial setae, 1-celled conidia, and light-colored colonies. V. consors , however, differs in having larger perithecia 210−270 µm high and 150−220 µm diam, a hairy perithecial surface, thicker perithecial walls 15−25 µm thick, somewhat longer asci 40−55 µm long, wider ascospores 3− 4 µm wide, ellipsoid conidia, and red sclerotia formed in culture ( Samuels 1977).

Our molecular data also support the establishment of V. asiana as a new species ( FIG. 1 ). The two isolates are grouped together with high statistical support (1.00 BIPP; 100% BP) and separated from the morphologically similar species, V. consors .

Figures

FIGURE 1. The BI consensus tree inferred from combined ITS and 28S nrDNA datasets. BI posterior probability values/MP bootstrap support values ≥ 50% are shown at internodes.The dashes indicate the values <50%.

FIGURE 2. Ascomata (left) and sporodochia (right) on natural substrates. A−B. Volutellonectria asiana (HMAS 76861). C−D. Volutellonectria ciliata (GJS85.205). Bars = 200 µm.

FIGURE 3. A−H. Morphology of Volutellonectria asiana (HMAS 76861). A. Median section of an ascoma. B−C. Asci with ascospores. D. Sporodochium from natural substrate. E−F. Conidiophores bearing conidia from aerial mycelium in culture. G. Conidia from sporodochia on natural substrate. H. Conidia from conidiophores in culture.