Leptosillia cordylinea Senan., & KD Hyde, 2020

Senanayake, Indunil C., Jeewon, Rajesh, Hyde, Kevin D., Bhat, Jayarama D. & Cheewangkoon, Ratchadawan, 2020, Taxonomy and phylogeny of Leptosillia cordylinea sp. nov. from China, Phytotaxa 435 (3), pp. 213-226 : 217-219

Leptosillia cordylinea Senan., & KD Hyde sp. nov. FIGURE 2

Index Fungorum number: IF557082; Facesoffungi number: FoF07392

Etymology—Species epithet derived from the host genus where fungus collected.

Holotype — MFLU 20–0056

Saprobic on leaves of Cordyline fruticosa . Sexual morph Undetermined. Asexual morph Coelomyceteous. Conidiomata 120–150 × 110–140 μm (x̅ = 135 × 125 μm, n = 20), scattered on upper surface of leaves mostly along the margin, pycnidial, solitary to aggregated, scattered, superficial to slightly immersed on upper surface of leaves, small, globose, black, shiny, coriaceous, opening by an ostiole and exuding white masses of conidia. Peridium 12.4–13.4 μm (x̅ = 12.9 μm, n = 20), composed of few layers of thick-walled, dark brown cells of textura angularis. Conidiophores 6.7–13 × 1.9–2.4 μm (x̅ = 11.2 × 2 μm, n = 50), cylindrical, hyaline, smooth, thick-walled, branched up to 2 times, arising from the inner wall of the pycnidium. Conidiogenous cells 5.6–8.5 × 1.4–2.4 μm (x̅ = 6.58 × 1.95 μm, n = 50), holoblastic with sympodial proliferation, ampuliform, lageniform to cylindrical, hyaline, smooth, arranged in a palisade layer. Conidia 2.3–3.5 × 1–1.5 μm (x̅ = 3.3 × 1.3 μm, n = 50), allantoid to straight cylindrical, hyaline, thinwalled, smooth, 1-celled.

Culture characteristics:—Colony on PDA at 16 °C reaching 3 cm diam., after 2 weeks, white, circular, smooth, entire margin, with sparse, short to woolly aerial mycelium at the center, white from the upper, off-white from reverse; conidiomata not formed on culture.

Material examined:— CHINA, Guangdong, Shenzhen, Nanshan, Nanhai Avenue, Shenzhen University, saprobic on leaves of Cordyline fruticosa ( L.) A.Chev. ( Asparagaceae ) without any disease symptoms, 28 August 2018, I. C. Senanayake, SI 4, ( MFLU 20–0056; holotype), ex-holotype culture KUMCC 20–0033.

Habitat & host range:—Tropical, terrestrial, Cordyline fruticosa (this study)

Mode of life:—Saprobic (this study)

Distribution:— China (this study)

Notes:—There are no sequence data for Leptosillia fusariospora and L. pinicola and the asexual morph of these two species are so far undetermined. Therefore it is hard to determine that our strain is the asexual morph of Leptosillia fusariospora or L. pinicola . However, based on the ecological data, we conclude that our strain could not be the Leptosillia fusariospora or L. pinicola . Leptosillia cordylinea is the first species in this genus recorded in Asia, while others are reported from Europe and North America. In addition, Leptosillia cordylinea is the only epifoliar species while others are collected from living or dead branches of woody trees. The host Cordyline fruticosa is native to China, Taiwan, Myanmar, Indonesia, New Zealand, eastern and northern Australia ( Phoulivong et al. 2010).

Morphological comparison between Leptosillia species are listed in TABLE 3. Further we provided a phylogenymorphology-ecological character mapping of Leptosillia species ( FIGURE 3 ). According to the phylogenetic analysis of our study ( FIGURE 1 ), Leptosillia species group into three subclades (A-C) which is well-supported by morphological and ecological data ( FIGURE 3 ). Clade A represented by Leptosillia macrospora , L. slaptonensis and L. wienkampii , comprises endophytic fungi reported in Europe on host plant of Fabaceae , Fagaceae , Rosaceae , Salicaceae , and Ulmaceae . Species in this clade have pyriform, superficial to semi-immersed ascomata with falcate to lunate ascospores. Clade B representing by Leptosillia acerina and L. muelleri comprises endophytic species reported in Europe on living or dead branches of Acer species and are morphologically similar in having lunate to falcate, aseptate ascospores arranged in bi or triseriately. Clade C is represented by our new species Leptosillia cordylinea with L. pistaciae . Even though ecologically they are different, morphologically and phylogenetically these two species share similarities such as allantoid conidia with holoblastic conidiogenesis and sympodial proliferation in the asexual morph. However as discussed above, there are substantial DNA differences that justify that they are different species.

Figures

FIGURE 1. Phylogram generated from maximum likelihood analysis based on combined ITS, LSU, RPB2, β-tubulin and tef 1–α sequence data. Bootstrap support values for MP and ML greater than 50% and Bayesian posterior probabilities greater than 0.90 are given near nodes. The tree is rooted with Barrmaelia rhamnicola (CBS 142772, BR1) and Entosordaria perfidiosa (EPE, CBS 142772). Ex-type strains are in bold and the newly generated sequences are indicated in blue bold.

FIGURE 2. Leptosillia cordylinea. a. Appearance of host plant. b. Specimen. c. Conidiomata on substrate. d. Cross section of conidioma. e–h. Conidiophores, conidiogenous cells and conidia. i–r. Conidia. s. Upper surface of culture on PDA. t. Lower surface of culture on PDA. u. Close-up of colony from upper surface. Scale bars: d = 150 µm, e–h = 10 µm, i–r = 5 µm.

FIGURE 3. Mapping of ecological and morphological characters of Leptosillia species on phylogenetic tree topology obtained from maximum likelihood analysis.