Halojulella Suetrong K.D. Hyde & E.B.G. Jones, 2013

Ariyawansa, Hiran A., Jones, Evan B. G., Suetrong, Satinee, Alias, Siti A., Kang, Ji-Chuan & Hyde, Kevin D., 2013, Halojulellaceae a new family of the order Pleosporales, Phytotaxa 130 (1), pp. 14-24 : 18-20

Halojulella Suetrong K.D. Hyde & E.B.G. Jones , gen. nov.

MycoBank MB803342

Etymology: From the Greek hals = salt, in reference to the marine origin of the fungus.

Saprobic on young twigs and woody tissue of mangrove trees. Ascomata subglobose, pyriform or ellipsoidal, immersed becoming erumpent, short papillate, ostiolate, formed under a clypeus, coriaceous, brown to dark brown, solitary or gregarious Peridium one layered, wall composed of small, dark brown to black, heavily pigmented, thick-walled cells of textura angularis and fusing at the outside with the host. Hamathecium of septate cellular, hyphal-like, pseudoparaphyses. Asci 8-spored, bitunicate, fissitunicate, with a distinctive apical apparatus. clavate to cylindrical with moderately long pedicel with club-like base. Ascospores biseriate or partially uniseriate, ellipsoidal, muriform, 7-8 trans septate, 1-longiseptate, constricted at the septa, hyaline to golden brown at maturity, with a gelatinous sheath. Asexual state: Pycnidia in culture brown, thin-walled, ostiolate; Conidiophores filiform, septate, branched; Conidia hyaline, asepatate, thinwalled, guttulate, ellipsoidal.

Generic type: Halojulella avicenniae (Borse) Suetrong, K.D. Hyde & E.B.G. Jones , comb. nov. ( Fig. 2A–K ) MycoBank MB 803343

≡ Pleospora avicenniae Borse, Curr. Sci. 56(21): 1109. 1987.

≡ Julella avicenniae (Borse) K.D. Hyde, Mycol. Res. 96(11): 939. 1992.

Many collections of Julella avicenniae have been reported (Alias and Jones 2009) and the following account is based on collections made in Thailand.

Saprobic on woody mangrove material, or young twigs, widespread in the tropics. Ascomata 150–275 µm high, 200–350 µm diameter, globose or subglobose, immersed beneath a clypeus, membranous and ostiolate. Peridium two layered, thickened above with clypeal tissue, outer layer of small pseudoparenchymatous cells, brown, inner layer of hyaline cells. Hamathecium of cellular, hyphal-like, septate pseudoparaphyses. Asci 105–195 × 25–30 µm, 8-spored, bitunicate, fissitunicate, thick-walled, clavate, moderately long pedicel with club-like base, apically rounded, with an ocular chamber surrounded by distinct apical apparatus, not bluing in IKI (I-), developing from the base of the ascoma. Ascospores 25–30 × 12.5–15 µm, overlapping uniseriate, ellipsoidal, hyaline, with a central septum when young, becoming yellow to pale brown, or golden brown, with 6-7 transsepta when mature, constricted particularly at the central septum with up to 2-3 longisepta, and surrounded by a large spreading sheath. Asexual state coelomycetous, Phoma -like species, observed by Hyde (1992) in cultures and the following description is based on isolates derived from cultures made in Thailand.

Colonies on potato dextrose seawater agar (PDA/SW) cottony; cream to yellow brown. Colonies grow slowly on CMA/SW and PDA/SW reaching ca. 2-2.5 cm diameter in 30 d at room temperature (21–25ºC), mycelium 1.25–2.5 µm wide, superficial, immersed, hypha smooth-walled, septate.

Material examined. AUSTRALIA: Rye : on mangrove wood, 1 Mar 2005, E. B. G . Jones (BBH 23393, BCC 19246, 19247 , 19251 ) ; THAILAND: Trat Province: Mu Ko Chang National Park , on Avicennia wood, 19 Mar 2005, E. B. G . Jones (BBH 23394, BCC 18498, 19253 , 19254 ) ; THAILAND: Trat Province: Mu Ko Chang National Park, Laem Khai Ka , on Avicennia wood, 5 Oct 2005, S Suetrong , E. B. G . Jones , J Sakayaroj , R Choeyklin , U Pinruan, K-L Pang (BBH 23406, BCC 19606, 20052 , 20053 ) ; THAILAND: Chon Buri Province: Ban Ang Sila , on Avicennia wood, 27 Jun 2006, S Suetrong , J Sakayaroj , R Choeyklin (BBH 23414, BCC 22441, 22647 , 22648 ) ; MALAYSIA: Kuala Lumpur: Morib , on Avicennia wood, 25 Jun 2007, E. B. G . Jones (BBH 23430, BCC 28357, 28358 , 28359 ) ; THAILAND: Bangkok Province: Bang Khun Thian , on Avicennia officinalis , 20 Jun 2008, S Suetrong , R Choeyklin (BBH 23441 BCC 32312, 32313 , 32314 ) .

Notes. Halojulella avicenniae is a mangrove species, originally described from India as Pleospora avicenniae by Borse (1987). Subsequently it was collected on a submerged root of Avicenniae alba from north east coast of Queensland, and transferred to the genus Julella ( Hyde 1992) . Various strains of Halojulella avicenniae (BCC 18422, BCC 28357, GR 00584, JK 5326A and BCC 20173) have been isolated ( Suetrong et al. 2009) and five are included in this analysis ( FIGURE 1 ) with the data showing that H. avicenniae belongs in the Pleosporales , outside any of the known families, and thus a new family in the order is introduced. The significant characters that distinguish it from the genus Pleospora are ascomata in woody substrata, immersed beneath a clypeus, the peridium with a single layer of elongated cells and cellular, hyphal-like, pseudoparaphyses. Halojulella avicenniae is saprobic on intertidal twigs of the mangrove species Avicennia spp. , Ceriops tagal and Rhizophora mucronata and pneumatophores of Avicennia marina ( Alias and Jones 2000) . However it can colonize apical twigs of A. marina infected with the larva of an unidentified moth (Jones unpublished data).

Halojulella avicenniae differs from Julella buxi , in possessing 8-spored asci that are cylindrical-clavate with a prominent apical apparatus and a long furcate pedicel, and growing on young shoots of mangrove trees, never on bark and its marine habitat. Halojulella avicenniae forms a unique lineage in the Pleosporales .

A second maritime species ( Julella herbatilis Kohlm., Volkm. -Kohlm. & O.E. Erikss.) occurs on senescent leaves of Juncus roemerianus some 23-118 cm above the rhizome ( Kohlmeyer et al. 1997) and is regarded as facultative marine, but no cultures are currently available for a molecular analysis. Julella herbatilis differs from Halojulella avicenniae in having smaller ascomata, a peridium composed of cells of textura angularis, clavate to cylindrical asci with an indistinct ring, and ascospores that are elongate ellipsoidal with 5 transepta and one (-2) longiseptum, hyaline, shorter and narrow, and growing on the rush Juncus roemerianus in a salt marsh in the USA. Kohlmeyer et al. (1997) assigned this species to Julella with reservations, indicating it resembled Mycoglaena . Molecular data is needed to confirm the relationships of this species.

Figures

FIGURE 1. RAxML tree based on a combined dataset of SSU, LSU, RPB2 and TEF1, bootstrap support values for maximum likelihood (Black), maximum parsimony (Blue) greater than 50% and bayesian posterior probabilities greater than 0.90 (Red) below and above the nodes. Dothidea sambuci is the out group taxon. The original isolate numbers are noted after the species names.

FIGURE 2. Halojulella avicenniae (Material examined: BBH 23394); A: Surface view of ascomata on twigs of Avicennia wood. B: Close up of the ascomata. C: Section through mature ascoma. D. Close up of the peridium E. Cellular, septate pseudoparaphyses. F–G: 8-spored asci with an ocular chamber surrounded by distinct apical apparatus H: Apex of ascus, showing distinct apical apparatus. I– K. Pale brown matured ascospore. J–K Ascospores mounted in Cotton Blue to show mucilaginous sheath. Scale bars: A–B = 200 µm; C = 150 µm E–F = 40 µm; F–G = 80 µm, H = 30µm; I–L = 10 µm.