Barriopsis iraniana and Phaeobotryon cupressi: two new species of the Botryosphaeriaceae from trees in Iran.

Species in the Botryosphaeriaceae are well known as pathogens and saprobes of woody hosts, but little is known about the species that occur in Iran. In a recent survey of this family in Iran two fungi with diplodia-like anamorphs were isolated from various tree hosts. These two fungi were fully characterised in terms of morphology of the anamorphs in culture, and sequences of the ITS1/ITS2 regions of the ribosomal DNA operon and partial sequences of the translation elongation factor 1-alpha. Phylogenetic analyses placed them within a clade consisting of Barriopsis and Phaeobotryon species, but they were clearly distinct from known species in these genera. Therefore, they are described here as two new species, namely Barriopsis iraniana on Citrus, Mangifera and Olea, and Phaeobotryon cupressi on Cupressus sempervirens.

INTRODUCTION

Species of the Botryosphaeriaceae are cosmopolitan and occur on a wide range of plant hosts (von Arx & Müller 1954, Barr 1987). They can be primary pathogens, opportunists, endophytes or saprobes (Denman et al. 2000, Slippers & Wingfield 2007). While the family is well circumscribed, segregation of genera within the Botryosphaeriaceae has proven to be problematic. Von Arx & Müller (1954) made extensive synonymies under Botryosphaeria and included several genera known to have pigmented ascospores. In this way they effectively broadened the concept of Botryosphaeria to include species with hyaline ascospores, brown, aseptate ascospores, and brown, 1-septate ascospores. At least 18 anamorph genera have been associated with Botryosphaeria, including Diplodia, Lasiodiplodia, Fusicoccum and Sphaeropsis. Of these, only Fusicoccum and Diplodia were recognised by Denman et al. (2000), and this was supported by several studies (Jacobs & Rehner 1998, Zhou & Stanosz 2001, Alves et al. 2004). Pavlic et al. (2004) employed morphological and phylogenetic data to separate Lasiodiplodia from Diplodia. Later, Phillips et al. (2005) further broadened the concept by including Dothiorella within Botryosphaeria.

In a phylogenetic study based on 28S rDNA sequence data, Crous et al. (2006) recognised 10 lineages within Botryosphaeria corresponding to individual genera. A further lineage representing Aplosporella was subsequently added (Damm et al. 2007), and Phillips et al. (2008) recognised a further five genera bringing the total to 16.

The Botryosphaeriaceae has been the subject of numerous critical studies on the species associated with different hosts including grapevines (van Niekerk et al. 2004), Eucalyptus (Slippers et al. 2004), Olea (Lazzizera et al. 2008), Prunus (Slippers et al. 2007, Damm et al. 2007) and Protea (Denman et al. 2003, Marincowitz et al. 2008). Such studies have yielded several new species, thus revealing the diversity within this family. Furthermore, intensive sampling in different regions of the world has also revealed many new species (Pavlic et al. 2008, Taylor et al. 2009). Despite the importance attributed to the species in this family, there have been no studies on the Botryosphaeriaceae in Iran.

In the course of a survey of Botryosphaeriaceae in Iran during 2005–2007, besides some 14 known species, two new species with diplodia-like conidia were encountered. The aim of the present study was to characterise the species and to describe them based on DNA sequence data and morphology.

MATERIALS AND METHODS

Isolates and isolation

Infected branches, fruits and leaves with various disease symptoms, including dieback, canker, rot and necrosis, were collected from Cupressus sempervirens, Mangifera indica, Citrus sp. and Olea sp. in northern and southern provinces of Iran. Isolations were made by transferring conidia to potato-dextrose agar (PDA; Difco Laboratories). After incubating at 25 °C for 12 h, single germinating conidia were transferred to fresh PDA plates. Some isolates were obtained by plating pieces of tissue taken from the junction of the diseased and healthy areas of the samples, after surface sterilisation (1–4 min in 70 % ethanol), on PDA supplemented with 100 mg chloramphenicol. Representative isolates were deposited at the Iranian Research Institute of Plant Protection (IRAN, Tehran, Iran) and the Centraalbureau voor Schimmelcultures (CBS, Utrecht, The Netherlands).

Morphology

Sporulation was induced by culturing the isolates on 2 % tap water agar bearing pieces of double-autoclaved, halved poplar twigs or pine needles under near-ultraviolet light in a 12 h light-dark regime for 2–6 wk at 25 °C. Vertical sections through conidiomata were made with a Leica CM1100 cryostat microtome. The conidiogenous layer was dissected from conidiomata formed in culture. Structures were mounted in 100 % lactic acid and digital images were recorded with a Leica DFC320 camera on a Leica DMR HC microscope. Measurements were made with the Leica IM500 measurement module. For each isolate the mean, standard deviation and 95 % confidence interval were calculated from measurements of at least 50 conidia. Dimensions are presented as a range with extremes in parentheses. Dimensions of other fungal structures are given as the range of at least 20 measurements. Colony morphology, colour (Rayner 1970), and growth rates between 5 and 35 °C in 5 °C intervals, were determined on 2 % malt extract agar (MEA; Difco Laboratories) in the dark.

DNA extraction, PCR amplification and sequencing

Isolates were grown on 2 % malt extract broth (MEB) and incubated at room temperature for 4–7 d. Mycelium was collected by filtration. Mycelial mats were washed with sterile distilled water and freeze-dried with an Edward MicroModulyo 1.5K System (England) freeze drier. Genomic DNA was obtained by a modification of the method described by Reader & Broda (1985). The mycelium was ground in liquid nitrogen in 1.5 mL microtubes. Five hundred microlitres of extraction buffer (200 mM Tris-HCl pH 8.5, 250 mM NaCl, 25 mM EDTA pH 8.0, 1 % SDS) was added, the mixture thoroughly vortexed, and incubated at 65 °C for 1 h. Subsequently 500 μL of chloroform was added. The mixture was shaken gently and centrifuged at 13 000 rpm for 1 h at 4 °C. The supernatant was transferred to a new microtube and template DNA was precipitated overnight at −20 °C with 0.54 volume of ice-cold isopropanol and 3 M sodium acetate (0.1 volume). The DNA was pelleted at 13 000 rpm for 10 min at 4 °C. The resulting pellets were washed with 100 μL of cold 70 % ethanol and dried at room temperature. The dried pellets of template DNA were re-suspended in 100 μL of distilled water and incubated at 65 °C for 1 h. DNA concentrations were determined with a NanoDrop® ND-1000 spectrophotometer and DNA was stored at −80 °C.

The PCR reactions were carried out with Taq DNA polymerase, nucleotides and buffers supplied by MBI Fermentas (Vilnius, Lithuania), and PCR reaction mixtures were prepared according to Alves et al. (2004), with the addition of 5 % DMSO to improve the amplification of some difficult DNA templates. All primers used were synthesised by STAB Vida Lda. (Portugal). The ITS plus D1/D2 region of the LSU and the translation elongation factor 1-α (EF-1α) were amplified using the primer pairs ITS1 (White et al. 1990) /NL4 (O’Donnell 1993) and EF1-688F/EF1-1251R, respectively, as described by Alves et al. (2008). Nucleotide sequences of the ITS and EF-1α regions were determined using the primers ITS1/ITS4 (White et al. 1990) and EF1-688F/EF1-1251R (Alves et al. 2008). Both strands of the PCR products were sequenced by STAB Vida Lda (Portugal). Sequences of both DNA regions of additional isolates were retrieved from GenBank (Table 1). New sequences were deposited in GenBank (Table 1) and the alignment and trees in TreeBase (study accession number S2392, matrix accession number M4535).

Table 1

Isolates included in the phylogenetic study.

Species	Culture no.1	Substrate	Locality	Collector	GenBank2
					ITS	EF
Barriopsis fusca	CBS 174.26	Citrus sp	Cuba	N.E. Stevens	EU673330	EU673296
Barriopsis iraniana	IRAN1448C	Mangifera indica	Minab, Iran	J. Abdollahzadeh & A. Javadi	FJ919663	FJ919652
	IRAN1449C	Olea sp.	Rodan, Iran	J. Abdollahzadeh & A. Javadi	FJ919665	FJ919654
	IRAN1450C	Citrus sp.	Minab, Iran	J. Abdollahzadeh & A. Javadi	FJ919667	FJ919656
	IRAN1451C	Citrus sp.	Minab, Iran	J. Abdollahzadeh & A. Javadi	FJ919668	FJ919657
	IRAN1452C	Citrus sp.	Minab, Iran	J. Abdollahzadeh & A. Javadi	FJ919666	FJ919655
	IRAN1453C	Mangifera indica	Minab, Iran	J. Abdollahzadeh & A. Javadi	FJ919664	FJ919653
Botryosphaeria corticis	CBS119047	Vaccinium corymbosum	USA	P.V. Oudemans	DQ299245	EU017539
	ATCC22927	Vaccinium sp.	USA	R.D. Millholland	DQ299247	EU673291
Botryosphaeria dothidea	CBS 110302	Vitis vinifera	Portugal	A.J.L. Phillips	AY259092	AY573218
	CMW 8000	Prunus sp.	Switzerland	B. Slippers	AY236949	AY236898
Diplodia corticola	CBS 112549	Quercus suber	Portugal	A. Alves	AY259100	AY573227
	CBS 112546	Quercus ilex	Spain	M.E. Sánchez & A. Trapero	AY259090	EU673310
Diplodia mutila	CBS 112553	Vitis vinifera	Portugal	A.J.L. Phillips	AY259093	AY573219
	CBS 230.30	Phoenix dactylifera	USA	L.L. Huillier	DQ458886	DQ458869
Diplodia seriata	CBS 112555	Vitis vinifera	Portugal	A.J.L. Phillips	AY259094	AY573220
	CBS 119049	Vitis sp.	Italy	L. Mugnai	DQ458889	DQ458874
Dothiorella iberica	CBS 115041	Quercus ilex	Spain	J. Luque	AY573202	AY573222
	CBS 113188	Quercus suber	Spain	M.E. Sánchez & A. Trapero	AY573198	EU673278
Dothiorella sarmentorum	IMI 63581b	Ulmus sp.	UK	E.A. Ellis	AY573212	AY573235
	CBS 115038	Malus pumila	Netherlands	A.J.L. Phillips	AY573206	AY57322
Lasiodiplodia gonubiensis	CBS 115812	Syzygium cordatum	South Africa	D. Pavlic	DQ458892	DQ458877
Lasiodiplodia parva	CBS 494.78	Cassava-field soil	Colombia	O. Rangel	EF622084	EF622064
	CBS 456.78	Cassava-field soil	Colombia	O. Rangel	EF622083	EF622063
Lasiodiplodia pseudotheobromae	CBS 116459	Gmelina arborea	Costa Rica	J. Carranza-Velásquez	EF622077	EF622057
	CBS 374.54	Coffea sp.	Zaire	Unknown	EF622080	EF622059
Neodeightonia phoenicum	CBS 169.34	Phoenix dactylifera	USA	H.S. Fawcett	EU673338	EU673307
	CBS 122528	Phoenix dactylifera	Spain	F. Garcia	EU673340	EU673309
Neodeightonia subglobosa	CBS 448.91	keratomycosis in eye	UK	Unknown	EU673337	EU673306
Neofusicoccum luteum	CBS 110299	Vitis vinifera	Portugal	A.J.L. Phillips	AY259091	AY573217
	CBS 110497	Vitis vinifera	Portugal	A.J.L. Phillips	EU673311	EU673277
Neofusicoccum parvum	CMW 9081	Populus nigra	New Zealand	G.J. Samuels	AY236943	AY236888
	CBS 110301	Vitis vinifera	Portugal	A.J.L. Phillips	AY259098	AY573221
Phaeobotryon cupressi	IRAN1454C	Cupressus sempervirens	Gorgan, Iran	M.A. Aghajani	FJ919673	FJ919662
	IRAN1455C	Cupressus sempervirens	Gorgan, Iran	M.A. Aghajani	FJ919672	FJ919661
	IRAN1456C	Cupressus sempervirens	Gorgan, Iran	M.A. Aghajani	FJ919670	FJ919659
	IRAN1457C	Cupressus sempervirens	Gorgan, Iran	M.A. Aghajani	FJ919669	FJ919658
	IRAN1458C	Cupressus sempervirens	Gorgan, Iran	M.A. Aghajani	FJ919671	FJ919660
Phaeobotryon mamane	CPC 12440	Sophora chrysophylla	Hawaii	W. Gams	EU673332	EU673298
	CPC 12442	Sophora chrysophylla	Hawaii	W. Gams	EU673333	EU673299
Phaeobotryosphaeria citrigena	ICMP 16812	Citrus sinensis	New Zealand	S.R. Pennycook, P.R. Johnston & B.C. Paulus	EU673328	EU673294
	ICMP 16818	Citrus sinensis	New Zealand	S.R. Pennycook, P.R. Johnston & B.C. Paulus	EU673329	EU673295
Phaeobotryosphaeria porosa	CBS 110496	Vitis vinifera	South Africa	J.M. van Niekerk	AY343379	AY343340
Phaeobotryosphaeria visci	CBS 100163	Viscum album	Luxembourg	H.A. van der Aa	EU673324	EU673292
	CBS 186.97	Viscum album	Germany	T. Graefenhan	EU673325	EU673293
Spencermartinsia vitícola	CBS 117009	Vitis vinifera	Spain	J. Luque & S. Martos	AY905554	AY905559
	CBS 117006	Vitis vinifera	Spain	J. Luque & S. Martos	AY905555	AY905562

1 ATCC: American Type Culture Collection; CBS: Centraalbureau voor Schimmelcultures, The Netherlands; CMW: M.J. Wingfield, FABI, University of Pretoria, South Africa; CPC: Collection of Pedro Crous housed at CBS; ICMP: International Collection of Micro-organisms from Plants, Landcare Research, New Zealand; IMI: CABI Bioscience, Egham, UK; IRAN: Iranian Fungal Culture Collection, Iranian Research Institute of Plant Protection, Iran.

2 ITS: Internal transcribed spacers 1 and 2 together with 5.8S nrDNA; EF: Translation elongation factor 1-α partial sequence.

Phylogenetic analyses

The nucleotide sequences were aligned with ClustalX v1.83 (Thompson et al. 1997), using the following parameters: pairwise alignment parameters (gap opening = 10, gap extension = 0.1) and multiple alignment parameters (gap opening = 10, gap extension = 0.2, transition weight = 0.5, delay divergent sequences = 25 %). Alignments were checked and manual adjustments were made where necessary. Phylogenetic analyses were carried out using PAUP v4.0b10 (Swofford 2003) for maximum-parsimony (MP) analysis and MrBayes v 3.0b4 (Ronquist & Huelsenbeck 2003) for the Bayesian analysis. Trees were visualised with TreeView (Page 1996). Maximum-parsimony analysis was performed using the heuristic search option with 1 000 random taxon additions and tree bisection and reconnection (TBR) as the branch-swapping algorithm. All characters were unordered and of equal weight and gaps were treated as fifth character. Branches of zero length were collapsed and all multiple, equally parsimonious trees were saved. The robustness of the most parsimonious trees was evaluated by 1 000 bootstrap replications (Hillis & Bull 1993). Other measures used were consistency index (CI), retention index (RI) and homoplasy index (HI). A partition homogeneity test was done to determine the possibility of combining the ITS and EF1-α datasets (Farris et al. 1995, Huelsenbeck et al. 1996).

Bayesian analyses employing a Markov Chain Monte Carlo (MCMC) method were performed. The general time-reversible model of evolution (Rodriguez et al. 1990), including estimation of invariable sites and assuming a discrete gamma distribution with six rate categories (GTR+I+Γ) was used. Four MCMC chains were run simultaneously, starting from random trees, for 106 generations. Trees were sampled every 100th generation for a total of 104 trees. The first 103 trees were discarded as the burn-in phase of each analysis. Posterior probabilities (Rannala & Yang 1996) were determined from a majority-rule consensus tree generated from the remaining 9 000 trees. The analysis was repeated three times starting from different random trees to ensure trees from the same tree space were being sampled during each analysis.

RESULTS

DNA phylogeny

The ITS and EF1-α sequences for the 11 isolates studied were combined and aligned with 41 sequences of 22 taxa retrieved from GenBank, representing a selection of genera and species in the Botryosphaeriaceae. Incomplete portions at the ends of the sequences were excluded from the analyses. The combined dataset after alignment consisted of 941 characters including alignment gaps. A partition homogeneity test in PAUP was not significant (P = 0.52) indicating that the individual datasets were congruent and produced trees with the same topology. Therefore the two datasets were combined in a single analysis. Of the 941 characters, 446 were constant, while 10 were variable and parsimony-uninformative. Maximum parsimony analysis of the remaining 485 parsimony-informative characters resulted in a single tree of 1 340 steps (HI = 0.343). The overall topology of the 50 % majority rule consensus tree of 9 000 trees sampled in the Bayesian analysis had a similar topology as the MP tree (TreeBase S2392), which is presented in Fig. 1.

Fig. 1

Single most parsimonious tree resulting from maximum parsimony analysis of combined ITS and EF1-α sequence data. MP bootstrap values are given at the nodes. The tree was rooted to two isolates of Pseudofusicoccum stromaticum. The new species are in bold face.

Ten clades were identified, each corresponding to a separate genus. Isolates obtained in this study clustered in clades 1 and 2, corresponding to Phaeobotryon and Barriopsis. The five isolates from C. sempervirens clustered in a subclade of clade 1, separate from P. mamane. The remaining six isolates from this study formed a subclade within the Barriopsis clade (clade 2) separate from B. fusca. In both cases bootstrap support for the subclades was high.

All isolates studied here produced pycnidia on pine needles and Populus twigs on WA within 2–3 wk. No ascomata were seen either on the host or in culture. Based on morphology and phylogenetic positions, these isolates were separated into two species, one in Barriopsis and the other in Phaeobotryon. On account of their unique morphology and phylogeny they are described here as two new species.

Taxonomy

Abdollahzadeh, Zare & A.J.L. Phillips, sp. nov. — MycoBank MB513235; Fig. 2

Fig. 2

Barriopsis iraniana holotype. a. Conidiomata on pine needles in culture; b, c. conidia developing on conidiogenous cells between paraphyses; d. young conidium showing longitudinal striations while attached to a conidiogenous cell; e. hyaline, striate conidia; f–i. hyaline and brown, striate conidia, 1- and 3-septate conidia can be seen in f and g; j. catenulate chlamydospores. — Scale bars: a = 250 μm; b, c, e–i = 10 μm; d= 5 μm; j = 40 μm.

Teleomorph. Unknown.

Conidiomata brunnea vel nigra, uni- vel multilocularia, globosa. Cellulae conidiogenae hyalinae, cylindricae, conidio primo holoblastico, posteriora phialidica, proliferatione in eodem plano periclinaliter incrassatae. Conidia (22.7–)27–27.4(−37.7) × (12.8–)16.2–16.6(−21.5) μm, ovoidea, utrinque rotundata, primum hyalina, longitudinaliter striata, maturitate brunnea et 1–3 septa formantia.

Typus. IRAN 13939F.

Etymology. The name refers to Iran where the fungus was discovered.

Conidiomata stromatic, pycnidial, superficial, dark brown to black, covered with dense mycelium, on pine needles mainly unilocular and up to 600 μm diam; on Populus twigs mostly multilocular, individual or aggregated, thick-walled, ostiolate. Ostiole central, circular, non-papillate. Paraphyses arising from the conidiogenous layer, extending above the level of developing conidia, up to 70 μm long, 3.5 μm wide, thin-walled, hyaline, usually aseptate, sometimes becoming up to 2–3-septate, not constricted at the septa, tip rounded, occasionally branched. Conidiophores absent. Conidiogenous cells 7–12 × 3–5 μm, hyaline, thin-walled, smooth, cylindrical, holoblastic, proliferating at the same level, with visible periclinal thickening. Conidia thick-walled, initially hyaline, aseptate with longitudinal striations, striations visible on hyaline conidia even while attached to conidiogenous cells; oval, both ends broadly rounded, becoming brown, aseptate or 1–3-septate, with prominent longitudinal striations, wall smooth, (22.7–)24–30 × (12.8–)14–18(−21.5) μm, 95 % confidence limits = 27–27.4 × 16.2–16.6 μm (av. ± S.D. = 27.2 ± 1.8 × 16.4 ± 1.3 μm, l/w ratio = 1.7 ± 0.16). Chlamydospores catenate, intercalary, brown, smooth, thick-walled, formed within the agar medium.

Culture characteristics — Colonies with appressed mycelial mat and fluffy aerial mycelium in the middle, becoming dull green to olivaceous-black at the surface, and dull green to grey-olivaceous at the reverse after 2 wk in the dark at 25 °C. Colonies reaching 45–50 mm diam on MEA after 4 d in the dark at 25 °C. Cardinal temperatures for growth; min 5 °C, max > 35 °C, opt 25–30 °C.

Substrates — Endophytic in stems of Citrus sp., Mangifera indica, Olea sp.

Known distribution — Hormozgan Province, Iran.

Specimens examined. Iran. Hormozgan Province, Minab, Hajikhademi, on twigs of Mangifera indica, 27 Feb. 2007, J. Abdollahzadeh & A. Javadi, holotype IRAN 13939F, culture ex-type IRAN 1448C = CBS 124698. Other isolates are listed in Table 1.

Notes — Conidia of Barriopsis iraniana are significantly larger than those of B. fusca, the only other species known in this genus. The only available culture of B. fusca (CBS 174.26, ex-type) has lost its ability to sporulate. According to Stevens (1926) the anamorph is lasiodiplodia-like with hyaline conidia that become dark-brown and septate with irregular longitudinal striations. These characters of the anamorphs of Barriopsis are confirmed in the present study. Furthermore, we have shown that, in contrast to Lasiodiplodia, the conidia of Barriopsis are striate at a very early stage of development and the striations are clearly visible in young, hyaline conidia (Fig. 1d–i). This is an unusual character not found in any other genus of the Botryosphaeriaceae. We did not encounter the teleomorph of B. iraniana and it did not form in culture.

Abdollahzadeh, Zare & A.J.L. Phillips, sp. nov. — MycoBank MB513236; Fig. 3

Fig. 3

Phaeobotryon cupressi holotype. a. Conidiomata formed on pine needles in culture; b. sectioned conidioma; c. paraphyses and developing conidia; d, e. microconidiogenous cells; f. microconidia; g. conidia and conidiogenous cells; h. hyaline conidia; i, j. brown, aseptate conidia; k. germinating conidia; l. chlamydospores and a hyaline conidium. — Scale bars: a = 250 μm; b = 100 μm; c, h, i, k, l = 10 μm; d, e = 2.5 μm; f, g, j = 5 μm.

Teleomorph. Unknown

Conidiomata brunnea vel nigra, uni- vel multilocularia, globosa. Cellulae conidiogenae hyalinae, cylindricae, holoblasticae, conidio primo holoblastico, posteriora phialidica, proliferatione in eodem plano periclinaliter incrassatae. Conidia (19.8–)24.6–25(−30) × (10.2–)12.2–12.5(−17) μm, ovoidea, utrinque rotundata, hyalina, aseptata.

Typus. IRAN 13940F.

Etymology. Name refers to Cupressus, the host genus on which the fungus was discovered.

Conidiomata stromatic, pycnidial, superficial, dark-brown to black, mostly unilocular on pine needles and up to 650 μm diam, mostly multilocular on Populus twigs, individual or aggregated, thick-walled, ostiolate. Ostiole central, circular, non-papillate. Paraphyses hyaline, thin-walled, arising from the conidiogenous layer, extending above the level of developing conidia, up to 42 μm long, 4.8 μm wide, usually aseptate, sometimes becoming up to 2-septate, tip rounded, occasionally branched. Conidiophores absent. Conidiogenous cells hyaline, smooth, thin-walled, cylindrical, 7–14 × 2–5 μm, holoblastic, phialidic, proliferating internally with visible periclinal thickening. Conidia thick-walled, initially hyaline, oval, both ends broadly rounded, aseptate, (19.8–)21–28(−30) × (10.2–)11–15(−17) μm, 95 % confidence limits = 24.1–25 × 12.2–12.5 μm (χ̅ ± S.D. = 24.8 ± 1.9 × 12.4 ± 1.3 μm, l/w ratio = 2 ± 0.3), forming a single septum at germination, rarely becoming brown and 1-septate, internally verruculose when aged. Microconidiomata globose, dark-brown to black, superficial, occasionally immersed in pine needle or Populus tissue. Microconidiophores cylindrical, 7–13 × 1.5–2.5 μm, hyaline, aseptate becoming 1–2-septate, branched. Microconidiogenous cells hyaline, thin-walled, phialidic, proliferating internally, giving rise to periclinal thickening, 6–10 × 1–2 μm. Microconidia oval, thin-walled, hyaline, aseptate 2–4 × 1–2. Chlamydospores intercalary, brown, smooth, thick-walled, formed within the agar medium.

Cultural characteristics — Colonies with abundant aerial mycelium towards periphery, appressed in the centre, becoming grey-olivaceous to olivaceous-grey at the surface, and grey-olivaceous in reverse after 2 wk in the dark at 25 °C. Colonies on MEA reaching 46–53 mm diam after 4 d in the dark at 25 °C. Cardinal temperatures for growth; min 5 °C, max > 35 °C, opt 25 °C.

Substrate — Endophytic in stems of Cupressus sempervirens.

Known distribution — Golestan Province, Iran.

Specimens examined. Iran, Golestan Province, Gorgan, City Park, on twigs of Cupressus sempervirens, 15 Aug. 2006, M.A. Aghajani, holotype IRAN 13940F, culture ex-type IRAN 1455C = CBS 124700. Other isolates are listed in Table 1.

Notes — This species differs from P. quercicola and P. mamane in its smaller conidia, and has thus far only been collected from Cupressus species. The hyaline, aseptate conidia of P. cupressi are superficially similar to those of other Diplodia species with hyaline conidia. Furthermore, conidial dimensions of P. cupressi are similar to those of Diplodia cupressi (21.5–30.5 × 12–16) as reported by Alves et al. (2006). Microconidia have been reported for P. quercicola (Phillips et al. 2005), P. mamane (Phillips et al. 2008) and P. cupressi (this paper). They have also been reported in D. cupressi (Alves et al. 2006), but not in other Diplodia species (Alves et al. 2004, Damm et al. 2007, Phillips et al. 2007, Lazzizera et al. 2008). Thus it is possible that P. cupressi has been mistaken for D. cupressi in the past. Pycnidial paraphyses in Phaeobotryon clearly distinguish this genus from Diplodia.

DISCUSSION

This paper forms part of a larger study of the Botryosphaeriaceae from Iran, and is the first attempt to characterise the species present in this country. Two new species are described, one in Barriopsis and another in Phaeobotryon. These species could be distinguished based on their DNA sequence data and unique morphological characteristics. Only a few species are thus far known from these genera, and confirmed reports have been infrequent.

Barriopsis was introduced when Phillips et al. (2008) transferred Physalospora fusca to Barriopsis fusca. Stevens (1926) originally placed this species in Physalospora, but was obviously hesitant to do so on account of its brown ascospores. Petrak & Deighton (1952) then transferred it to Phaeobotryosphaeria as Phaeobotryosphaeria fusca. Although von Arx & Müller (1954) considered Phaeobotryosphaeria a synonym of Botryosphaeria, Phillips et al. (2008) showed that it is morphologically and phylogenetically distinct from other genera in the Botryosphaeriaceae. However, the fungus considered by Stevens (1926) and Petrak & Deighton (1952) does not have apiculi on its ascospores, and thus does not fall within the concept of Phaeobotryosphaeria, which has small, hyaline apiculi on the ascospores. It was for this reason that Phillips et al. (2008) introduced the genus Barriopsis. Barriopsis iraniana is only the second species to be described in this genus. The new data on morphology of the anamorph, as reported in this paper, reveal further distinctions from other genera in the Botryosphaeriaceae, namely the striations visible on conidia at an early stage of development.

Phaeobotryon was introduced by Theissen & Sydow (1915) to accommodate Dothidea cercidis. In the original description of D. cercidis the ascospores were reported to be hyaline. However, Theissen & Sydow (1914) observed them to become brown with age and subsequently (Theissen & Sydow 1915) introduced the genus Phaeobotryon. Von Arx & Müller (1954, 1975) placed Phaeobotryon in synonymy with Botryosphaeria in their broader concept of this genus. However, Phillips et al. (2008) considered Phaeobotryon as morphologically and phylogenetically distinct from other genera in the Botryosphaeriaceae and thus reinstated the name. The genus at present consists of four species (P. cercidis, P. cupressi, P. mamane and P. quercicola), while the status of P. disruptum and P. euganeum remains uncertain. Cultures are available for only two of these, P. mamane and P. cupressi, and therefore these were the only two for which DNA sequence data are available. Phillips et al. (2008) did not observe conidia of P. cercidis, but they reported the conidia of P. mamane as brown and 1–2-septate. Phillips et al. (2005) found hyaline, aseptate conidia associated with P. quercicola, and considered these to be the anamorph. Phaeobotryon cupressi has smaller conidia than both P. mamane and P. quercicola, and the three species can be distinguished easily on the basis of conidial dimensions. No information is available regarding conidial characters of the remaining Phaeobotryon species, namely P. cercidis, P. disruptum and P. euganeum, since they were described based on features of the teleomorphs only and no anamorphic characters were considered.

Barriopsis appears to be confined to regions with tropical or subtropical climates. The type species, B. fusca, was originally collected from Citrus and an unknown woody host in Cuba (Stevens 1926). A search of the Systematic Mycology and Microbiology Laboratory Fungal Database (April 2009; http://nt.ars-grin.gov/fungaldatabases revealed that the majority of reports of this species are from warmer climates. In the present study, B. iraniana was found only in the subtropical southern part of Iran. In contrast to Barriopsis, Phaeobotryon appears to have a wider distribution, and species have been reported from Germany, USA (Carolina and Hawaii) and the northern, temperate regions of Iran.

Both B. iraniana and P. cupressi were isolated from diseased plants. However, pathogenicity was not tested for either species and their role as causal agents of plant diseases is not known. Furthermore, as far as we are aware, pathogenicity of none of the other species in Barriopsis and Phaeobotryon is known.