New and noteworthy records of coprophilous species of Coniochaeta and Sordaria ( Sordariomycetes , Ascomycota ) from Ukraine

The article reports new data on the occurrence of five coprophilous species of the genera Coniochaeta and Sordaria in Ukraine. These fungi represent a large group of coprophilous Sordariomycetes. Unlike fimicolous discomycetes, this group of fungi is poorly studied in Ukraine. The dung samples were collected on Tendra Island in the Black Sea (Kherson Region), and in the north-east of the country (Sumy Region). All specimens were obtained by incubating of the dung samples in moist chambers. Three species, Coniochaeta leucoplaca, C. vagans, and Sordaria minima are newly reported in Ukraine; the latter is for the first time recorded in Eastern Europe. For other two species, Sordaria alcina and S. humana, these are the second records in the country. For all species, descriptions of the Ukrainian specimens on various types of dung are provided and compared to original descriptions. Based on the collected specimens, distinctive morphological characters of the species are described in detail. All species are illustrated by micrographs obtained using light and scanning electron microscopy. For each specimen, its locality, substrate, and collection date are indicated. In addition to morphological characters, ecological peculiarities and data on general distribution of these species are briefly discussed.


Introduction
Coprophilous fungi, an important component of herbivore dung, are actively involved in decomposition of organic matter in the remains of ingested vegetation.Although fungal communities on dung include representatives of various taxonomic groups, members of the class Sordariomycetes (Ascomycota) possess the highest diversity.In Ukraine, however, perithecioid fungi on dung, despite their ubiquity and dominance on these substrata, until recently remained relatively unexplored, in contrast to coprophilous discomycetes.Only a few species of this group were recorded more than a hundred years ago (Krupa, 1888;Bobjak, 1907;Namyslowski, 1910Namyslowski, , 1914)).The first list of coprophilous fungi in Ukraine (Milovtsova, 1937) comprised ten species of pyrenomycetes found on dung.In the 2000s, occasional finds of these fungi were made during mycological observations in several nature reserves and national nature parks of the country (Dudka et al., 2004(Dudka et al., , 2009a, b;, b;Hayova, 2005;Akulov et al., 2010).Recent special studies on coprophilous ascomycetes (Golubtsova, 2008;Golubtsova et al., 2010) added eight new records for Ukraine.
This article reports five species of coprophilous fungi of the genera Coniochaeta (Sacc.)Cooke and Sordaria Ces.& De Not., three previously unregistered in Ukraine species and two which are the second records for the country.
Coniochaeta (Coniochaetaceae, Coniochaetales) is a cosmopolitan genus including lignicolous, terricolous and coprophilous species.The genus is characterized by small non-stromatic perithecioid ascomata bearing dark stiff setae clustered around the neck, or sometimes also scattered on the venter.Coniochaeta species have non-amyloid, unitunicate, short-stalked, cylindric asci and dark brown, one-celled, discoid ascospores with a germination slit along the narrow side and evanescent hyaline sheath surrounding ascospores.According to a spit in the Black Sea, within the Black Sea Biosphere Reserve (Kherson Region), and in the north-east of the country (Sumy Region).All specimens were obtained by incubating of the dung samples in moist chambers at room temperature (18-20 °C) in natural light for 5 to 30 days, depending on fungal growth and development of ascomata.
Micromorphological characteristics were examined by light microscopy under a stereomicroscope MBS-10 (Russia) and dissecting microscope .Dimensions of microstructures were measured using Tsview7 modular software (Fuzhou, China).Photomicrographs were taken with 3.0mp Digital Microscope Camera (Fuzhou, China).Asci and ascospores mounted in tap water were examined at magnifications up to 600×.Spore statistics included length and width (for Coniochaeta spp., width in frontal and side view) on a minimum of 20 samples from each collection.The quotient between spore length and width (Q), as well as the average quotient (Q av ), was calculated.The amyloid apical apparatus and walls of the asci were determined by treating with Meltzer's reagent.Aqueous Сotton Blue was used for staining hyaline gelatinous sheaths.For scanning electron microscopy, samples were coated with an ultrathin coating of gold by ion beam sputtering unit JFC-1100.Images were obtained by a scanning electron microscope JEOL JSM-6060 LA (Japan).
The specimens are deposited at the Mycological Herbarium of the M.G.Kholodny Institute of Botany, National Academy of Sciences of Ukraine (KW-M).Taxonomic arrangement, species and authors names are provided according to Index Fungorum online database (http://www.indexfungorum.org/).

Results and discussion
Taxonomic descriptions of five species of Coniochaeta and Sordaria based on the Ukrainian collections are provided below.Their morphological characters are described in detail and illustrated by micrographs obtained using light and scanning electron microscopy.All examined specimens are listed following the description of each species.For each specimen, its substrate, locality, and collection date are indicated.Ecological peculiarities and data on general distribution of the species are briefly discussed.
Notes.This obligatory coprophilous species appears in literature under two synonymic names: C. discospora (Fakirova, 1969;Prokhorov, Armenskaya, 2001;Bell, 2005) and C. vagans (Doveri, 2004;Asgari et al., 2007;Heine, Welt, 2008).Moreover, some authors (Moravec, 1968;Hawksworth, Yip, 1981;Mahoney, LaFavre, 1981;Checa et al., 1988;Watling, Richardson, 2010) do not recognize C. vagans as a separate species and treat it rather as a synonym of C. ligniaria.In that case the latter, which is known to occur on woody substrates, is considered as a species able to colonize both decaying wood and herbivorous dung.In external appearance, as stated by Watling & Richardson (2010), "it is difficult to see any differences between the material on wood and that on dung".However, as already mentioned above, Doveri (2004) and, subsequently, Chang & Wang (2011) regarded morphology of ascospore germ slit as a reliable character to distinguish both coprophilous and noncoprophilous species of Coniochaeta.Thus, C. vagans is characterized by ascospores with a germ slit extending the full length (Doveri, 2004) while ascospores of C. ligniaria possess a laterally one-sided germ slit.Furthermore, C. vagans differs from C. ligniaria by ascospore width which does not overlap.In the former species, spore width in frontal view mostly does not exceed 11 μm, while in the latter one ascospores are usually wider than 11 μm (Asgari et al., 2007).
In our observations, ascospores have a germ slit extending over the entire length of the spore (Fig. 2, d) and do not exceed 11 μm in width in face view.
These morphological characters as well as ecological characteristics of our collections fit the diagnosis of C. vagans (Doveri, 2004;Bell, 2005;Asgari et al., 2007;Chang, Wang, 2011).Additionally, in our specimens asci are mostly eight-spored; however, occasionally we observed six-or even four-spored asci, with clearly visible two, or respectively, four degenerated ascospores (Fig. 2, k-p).The tips of the asci are truncate, with a distinct apical structure (Fig. 2, e, i).
Coniochaeta vagans is reported for the first time in Ukraine.A similar but independent lignicolous species, C. ligniaria, is known in the country from several morphological characters fit well the description of C. leucoplaca.
Sordaria alcina is an obligate coprophilous fungus, currently known to occur exclusively on dung.Lundqvist (1972) described this species as apparently confined to cervid dung.Since then, it has been reported in feces of various animals, both domestic (cow, horse) and wild (deer, elk, hare, mouse).In Ukraine, S. alcina was found by now on dung of cow, horse and hare.These are the second published records of the species in the country, with a description and illustrations of the reported collections.
Sordaria alcina can be easily confused with morphologically resembling and widespread in Ukraine species, S. fimicola.According to various data, these species have distinct but overlapping dimensions of asci General distribution.Europe: Austria, Bulgaria, Denmark, Estonia, Finland, France, Germany, Iceland, Italy, Latvia, Netherlands, Poland, Portugal, Russia, Spain, Sweden, Ukraine, UK.Africa: Kenya, Tanzania.Asia: Israel, Indonesia, Iraq, Uzbekistan, Japan.Australasia: Australia.North America: Canada, USA.South America: Argentina.
Notes.Sordaria humana is a cosmopolitan species growing on dung of omnivores (particularly man and dog), carnivores and herbivores, sometimes on seeds, soil, old paper and various decaying vegetable material.It is one of the most common fimicolous pyrenomycetes.
Morphologically S. humana is best characterized by its broadly obovoid to subglobose spores often lacking a gelatinous perisporium.However, it is unclear whether all known collections of this species lack gelatinous sheath.Some authors describe the spores devoid of perisporium (Minoura, 1969), while others report it to be present although variable in thickness (Boedijn, 1962;Liou, Chen, 1979;Khan, Krug, 1989) or ephemeral (Saccardo, 1882;Munk, 1957).Another point of view is that ascospores of S. humana lack gelatinous perisporium in collections only from carnivore dung (Lundqvist, 1972;Khan, Krug, 1989;Doveri, 2004).In this case, spores with or without a sheath may reflect substrate difference, since a sticky sheath would be ecologically determined for fungi on the dung of herbivores.
Von Arx et al. (1987) transferred S. humana and a few other species in a new genus, Asordaria, proposed for those species of Sordaria which possess ovoid or broadly ellipsoidal smooth ascospores surrounded by gelatinous sheath.However, these criteria were regarded not significant and thus separation of the taxa from Sordaria on that basis has been widely debated (Eriksson, Hawksworth, 1988;Khan, Krug, 1989).Thereafter, a multiple gene analyses conducted by Cai et al. (2006) provided evidence on the congeneric status of Asordaria and Sordaria.
We also regard this species within the genus Sordaria.Despite a wide distribution of S. humana, the examined materials represent the second published records of the species in Ukraine, with a description and illustrations of the reported collections.
In our specimens, perithecia are schizothecioid in structure (Fig. 4, a-d), with thin translucent walls composed of hyaline to smoky-hyaline cells (Fig. 4, e).Asci have no distinct apical structure; ascospores without a gelatinous sheath or appendages but with a germ pore at one end; ascospores mostly uniseriate, rarely obliquely uniseriate or overlapping in the middle part of the ascus (Fig. 4, f-k).In general, all features we observed fit those in descriptions of the collections from the UK (Massee, Salmon, 1901;Richardson, 1998), Denmark (Larsen, 1971), and Italy (Doveri, 2004), with one exception.Larsen (1971) reported 4-spored asci in some perithecia in her collections, and rarely both 8-spored and 4-spored asci in the same perithecia.We have not observed 4-spored asci in our specimens.
Regarding the ecological role of this fungus, it has been revealed that being a coprophile, S. minima shows the ability to act as a mycoparasite.Doveri (2004) following Lundquist's comment on the habitat of S. minima cited that "the fungus grows sometimes directly on dung, but its mycelium is then probably in contact with the discomycetes".He concluded that S. minima is obviously a parasite of Thelebolus sp.In one of our specimens, an apothecium of Thelebolus cf.stercoreus Tode (Fig. 4, l) was also found in immediate proximity to perithecia of S. minima.We regard it as evidence to confirm that S. minima has ability to parasitize a saprobic fungus on dung.