Hymenochaete sharmae Hembrom, K. Das & A. Parihar, 2019

Wang, Xiang-Hua, Das, Kanad, Bera, Ishika, Chen, Yu-Hui, Bhatt, Rajendra Prasad, Ghosh, Aniket, Hembrom, Manoj Emanuel, Hofstetter, Valérie, Parihar, Arvind, Vizzini, Alfredo, Xu, Tai-Min & Zhao, Chang-Lin, 2019, Fungal Biodiversity Profiles 81 - 90, Cryptogamie, Mycologie 20 (5), pp. 57-95 : 58-65

81. Hymenochaete sharmae Hembrom, K. Das & A. Parihar , sp. nov.

( Figs 1-5 )

Distinct from other Hymenochaete species by the combination of resupinate, closely adnate, greyish white to purplish grey basidiomata with chalky white floccose margins when fresh, its cracked, separable hymenophore becoming rusty brown to charcoal black and papery thin when mature, ellipsoid basidiospores (5-6.26-7 × 3-3.68-5 Μm) and occurrence on bamboos.

TYPUS. — India. Jharkhand, Sahibganj district, Taljhari block, Sogorbhanga village, on the dead stump of bamboos, 40 m a.s.l., 24°59’07.3”N, 87°43’27.8”E, 13.XI.2016, M.E. Hembrom, MEH-70191 (holo-, CAL [ CAL 1535 ]!).

MYCOBANK. — MB 830163.

GENBANK. — KY929017 , MK588753 (nrITS,), KY929018 , MK588836 (nrLSU).Etymology. — Commemorating Dr. Jai Ram Sharma, the pioneer worker who revised Indian Hymenochaetaceae .

OTHER SPECIMENS EXAMINED. — India. Jharkhand: Sahibganj district, Mandro Block, Chaldi on the forest track to Chaldi from Solbandha, Sahibganj, 210 m a.s.l., 25°11’16.0”N, 87°36’52.7’E, on dead roots of Bamboos, 9.XI.2011, M.E. Hembrom, MEH-70173; Sahibganj district, Borio block, Simaljori from Kairasol Pir-Baba, 119 m a.s.l., 25°09’40.0”N, 87°41’15.1”E, on dead roots of bamboos, 30.IX.2017, M.E. Hembrom, MEH-70191; Borio block, Dalabari village, 122 m a.s.l., 25°02’38.2”N, 87°39’12.2”E, on standing dead bamboos, 26.VIII.2013, M.E. Hembrom, MEH-66088; Sahibganj district, Taljhari block, Gogi approach from Simaljori to Karanpurato, 228 m a.s.l., 25°09’00.1”N, 87°42’21.6”E, on dead bamboo stump, 30.IX.2017, M.E. Hembrom, MEH-70198; Taljhari block, Dhamdhamia village, 40 m a.s.l., 24°56’55.4”N, 87°45’32.7”E, on dead stump of bamboos, 28.IX.2015, M.E. Hembrom, MEH-69985; Sahibganj district, Pathna-Barharwa block, Chandragoda paharia hilly areas, 240 m a.s.l., 24°51’10.0”N, 87°38’18.4”E, on dead stump of bamboos, 7.IX.2013, M.E. Hembrom, MEH-66204; Rajmahal hills, Godda district, Boarijor block, Tatkunda from Boarijor-Lalmatia road, 225 m a.s.l., 25°01’19.3”N, 87°24’07.0”E, on dead stump of bamboos, 1.IX.2013, M.E. Hembrom, MEH-66168; Boarijor block, Amarpur Puriabadar, 398 m a.s.l., 25°00’03.0”N, 87°27’45.8”E, on dead stump of bamboos, 8.IX.2014, M.E. Hembrom, MEH-66450; Rajmahal hills, Pakur district, Litipara block, Charaknarapahar from Sathia-Narchi, 356 m a.s.l., 24°44’01.3”N, 87°34’30.3”E, on dead stump of bamboos, 18.VIII.2014, M.E. Hembrom, MEH-66912; Pakur district, Hiranpur block, Dangapara, 310 m a.s.l., 24°37’05.6”N, 87°28’30.2”E, on dead stump of bamboos, 28.VIII.2014, M.E. Hembrom, MEH-66258; Rajmahal hills, Dumka district, Ramgarh block, Kakni, Karbindha, 214 m a.s.l. 24°30’14.2”N, 87°16’06.9”E, on dead bamboos, 17.IX.2015, Samuel Murmu, SM-15-09; Dumka district, Gopikandar block, Gariapani to Dumurtola, 130 m a.s.l., 24°24’32.2”N, 87°29’49.6”E, on dead stump of bamboos, 20.X.2015, M.E. Hembrom, MEH-69927; Dumka district, Kathikund block, Kanhaideeh village, 140 m a.s.l., 24°19’42.0”N, 87°30’54.7”E, on dead stump of bamboos, 18.IX.2015, M.E. Hembrom, MEH-69912; Dumka district, Sikaripara block, Karakata forest area, 323 m a.s.l., 24°12’52.9”N, 87°30’15.3”E, on dead stump of bamboos, 23.X.2015, M.E. Hembrom, MEH-69957; Dumka district, Maslia block, Madhuban bichkhora hills, 160 m a.s.l., 24°14’31.9”N, 87°12’45.6”E, on dead stump of bamboos, 21.X.2015, Samuel Murmu, SM-15-16.

DESCRIPTION

Basidiomata

Annual, resupinate, widely effused up to 600 mm or more long in the longest direction, papery thin, 160-500 Μm thick in section, closely adnate, inseparable when fresh, initially appearing as small slightly grayish brown patches, then growing in irregular pattern in all directions on the host surface and finally becoming fused with adjacent basidiomata covering entire lower part of bamboo nodes, internodes and roots before fading to give appearance of a mark of grayish white ‘paint’.

Hymenophore

Smooth when fresh but gradually cracking into distinct various angular shapes and finally detaching off from host as brittle papery crust, irregularly and distantly papillate, azonate, grayish brown then violet white to pale violet to dark brown to pale blue, becoming greyish violet at maturity, finally chestnut brown to charcoal brown in old specimens.

Margin

1-5 mm wide, floccose, chalky white. Subiculum smooth, sandy, duplex, pale orange to greyish orange towards host surface while greyish white towards hymenophore.

Hyphal system

Monomitic, septate, hyphae swelling in KOH, IK-, CB-, older tissue more or less darkening towards substrata and mostly unchanging toward hymenium in KOH. Subiculum of repeatedly branched, compactly interwoven generative hyphae and setae; cortex absent. Generative hyphae 3-6 Μm wide, septate, much branched, moderate to distinctly thick-walled, pale yellow to hyaline. Setae evenly distributed throughout the context, 10-80 × 6-15 Μm, acuminate (mostly) to few with lateral swellings; tip acute (mostly) to more or less obtuse, few sheathed with hyaline crystalline contents, with or without lumen, hyaline to dark brown.

Hymenium

Generative hyphae 2-4 Μm wide, septate, branched, thinwalled, interwoven, hyaline.

Setae

25-80 × 9-15 Μm, randomly and sparsely distributed, subulate; tip acute to obtuse, sheathed (mostly) with crystalline hyaline contents, emergent up to 25 Μm, dark brown.

Cystidia

Absent.

Cystidioles

Present, 16.5-24 × 3-3.5 Μm, thin-walled, hyaline.

Hyphidia

Emergent, septate, sparsely branched, obtuse to ampullate, hyaline.

Basidia

12-16 × 4-6 Μm, clavate, 4-sterigmate, septate at base.

Basidioles

11-16 × 4-5 Μm, clavate, septate at base.

Basidiospores

5-6.26-7 × 3-3.68-5 Μm, Q = 1.4-1.66-1.96, ellipsoid, thin-walled, smooth, hyaline, inamyloid, acyanophilic.

NOTES

This species is one of the common wood-rotting corticoid fungi in Rajmahal Hills of Jharkhand, India ( Fig. 1 ). It can easily be recognized in the field by its exclusive occurrence on bamboos, on which it forms remarkably thin, membranous, closely adnate, smooth to slightly papillate (under 10×), purplish grey to grayish white basidiomata which gradually crack into easily separable dark brown crusts (partially lamellate when associated with other wood inhabiting lower fungi). Under the microscope, the combination of emergent setae and hyphoid elements coupled with the relatively large-sized, ellipsoid basidiospores are significant taxonomic features. Further diagnostic features include the chalky white, floccose margin with highly variable size of setae.

0.1

The above-mentioned combination of morphological features is very distinct from six additional bambusicolous species of Hymenochaete reported from South East Asia ( Nie et al. 2017). Hymenochaete bambusicola S.H. He is distinct microscopically due to the presence of unusual dimitic hyphal system while absence of any hyphal layer in H. innexa G. Cunn. is quite characteristic ( Nie et al. 2017). Absence of any hyphoid elements in the hymenium of H. muroiana I. Hino & Katum. , H. orientalis S.H. He , H. rhabarbarina (Berk.) Cooke , and H. tropica S.H. He & Y.C. Dai segregates them from our species ( Nie et al. 2017).

Our nrITS- and nrLSU-based phylogenies ( Figs 2 , 3), with 43 and 35 sequences respectively, fully resolved the genus Hymenochaete . Respective sequences ( KY929017 , MK588753 for MEH-70191 and MEH- 66088 in case of nrITS; KY929018 , MK588836 for MEH-70191 and MEH- 66088 in case of nrLSU) derived from present Indian species are found to be clustered amongst few Asian species of Hymenochaete in both of our phylogenetic estimations. However, H. sharmae Hembrom, K. Das & A. Parihar , sp. nov., is recovered with strong support as a distinct taxon in both these phylogenetic analyses, being sister to the clade leading to H. japonica Yasuda and H. duportii Pat.

Morphologically, the present species resembles Hydnochaete duportii because of the formation of resupinate, effused basidiomata, cracking at maturity. However, the latter species differs by its umber brown margin, relatively thick basidiomata, and cylindrical basidiospores 4-5 × 1.5-2 Μm ( Ryvarden 1982). Similarly, Hydnochaete japonica , originally reported from Japan, is phylogenetically close to the present species but its pileate to effused reflexed basidiomata (more than 2 mm thick), dark brown to black hymenophore and rusty brown margin ( Ryvarden 1982) allow to separate it.

Another resupinate, papery thin species, Hymenochaete murina Bres. (included in both of our phylogenetic analyses) is very distinct because of its concolorous margin and medium-sized setae measuring 45-50 × 7-10 Μm ( Léger 1998). H. peroxydata (Berk. ex Cooke) Baltazar et al. has relatively thick basidiomata exceeding 2 mm in thickness, cinnamon colored margin, cylindrical basidiospores measuring 3-4 × 1.5-2 Μm, and blunt, medium to long, 35-70 × 7-15 Μm setae ( Ryvarden 1982) and occurrs on dicotyledonous hosts. The resupinate H. sphaerospora J.C. Léger & Lanq. , which shares with our species the presence of hyphoid elements in the hymenium, differs in its 0.5-1 mm thick basidiomata and globose to subglobose basidiospores ( Léger 1998).

Figures

FIG. 1.— Distribution of Hymenochaete sharmae Hembrom, K. Das & A. Parihar, sp. nov., in Rajmahal hills, Jharkhand, India. Map was prepared with the help of ArcGIS installed in Central National Herbarium of Botanical Survey of India, Howrah, India.

FIG. 2. — Phylogram inferred from Maximum Likelihood analysis using raxmlGUI based on nrITS sequences. One thousand bootstrap replicates were analyzed to obtain the nodal support values. Bootstrap support values (>70%) obtained from ML analysis are shown above or below the branches at nodes. The novel species Hymenochaete sharmae Hembrom, K. Das & A. Parihar, sp. nov., (KY929018, MK588836) is shown in bold.

FIG. 3. — Phylogram inferred from maximum likelihood analysis using raxmlGUI based on nrLSU sequences. One thousand bootstrap replicates were analyzed to obtain the nodal support values. Bootstrap support values (>70%) obtained from ML analysis are shown above or below the branches at nodes. The novel species Hymenochaete sharmae Hembrom, K. Das & A. Parihar, sp. nov., (KY929017, MK588753), is shown in bold.

FIG. 4. — Hymenochaete sharmae Hembrom, K. Das & A. Parihar, sp. nov., (MEH-70191, holotype), morphological features: A-C, basidiomata in the field; D, margin; E-G, hyphidia; H, cystidioles; I-N, setae; O, basidiospores. Scale bars: C, 50 mm; D, 10 mm; E-O, 10 µm.

FIG. 5. — Hymenochaete sharmae Hembrom, K. Das & A. Parihar, sp. nov., (MEH-70191, holotype), microscopic features: A, transverse section through basidi- omata showing arrangement of hyphae, setae, basidia, basidioles, cystidioles and hyphidia; B, setae; C, basidiospores; D, hyphidia; E, basidia; F, cystidioles; G, basidioles. Scale bars: A-G, 10 µm.