New records of Microbotryum species parasitizing Caryophyllaceae from Ukraine

of Microbotryum species parasitizing Caryophyllaceae from Ukraine. Acta Mycol. 45 (2): 163–167, 2010. Four records of smut fungi belonging to the genus Microbotryum Lév. are reported. Two species were found on new hosts, namely M. dianthorum on Dianthus borbasii and D. pseudoserotinus and M. superbum on D. stenocalyx . Microbotryum lagerheimii on Lychnis viscaria is a new species for Ukraine.

It is known that many species of the genus Microbotryum develop in the anthers of plants belonging to the Caryophyllaceae.They are the so-called "anthericolous smut fungi".These species easily produce hybrid forms which can subsequently become new species (Chlebicki, Suková 2005).Therefore, for each region the establishment of the host-plants ranges of these species thorough morphological and, when it is possible, molecular investigations are all important.
Ukraine is a region with a considerable diversity of vascular plants, including the Caryophyllaceae with the level of endemism at about 24% (Fedoronchuk 2009).So, during the studies on smut fungi both rare species belonging to the genus Microbotryum and new species of their host-plants may be found.This paper deals with such fungi which we have found on the Lychnis L. and Dianthus L. species in 2009.

MATERIALS AND METHODS
Sori and spores were studied using dried herbarium specimens.For light microscopy (LM), spores were dispersed in a droplet of lactophenol on a microscope slide, covered with a cover glass, gently heated to boiling point to rehydrate the spores and eliminate air bubbles, and examined at 400× and 1000× magnification.For scanning electron microscopy (SEM), spores were placed on double-sided adhesive tape, mounted on a specimen stub, sputter-coated with gold, ca.20 nm, and examined in SEM at 30 kV.The studied materials are stored in the National Herbarium of Ukraine of M.G.Kholodny Institute of Botany (KW).

RESULTS AND DISCUSSION
Smut fungi on Dianthus SpecieS.For a long time, the smut fungi which develop their sori in the anthers of different Dianthus species were included in Ustilago violacea Pers.: Pers., a combined cosmopolitan parasite of hosts belonging to the Caryophyllaceae.However, in 1924 Liro described two separate species, U. dianthorum Liro in the anthers of D. deltoides L. and U. superba Liro on D. superbus L. Much later, a new genus Microbotryum was offered for some anthericolous smut fungi, and U. violacea s. lat.was included in this genus as M. violaceum (Pers.)G. Deml et Oberw.(Deml, Oberwinkler 1982).Scholz and Scholz (1988) transferred smut fungi that  developed in anthers of many Dianthus species into M. dianthorum (Liro) H. Scholz et I. Scholz, but Liro's U. superba was left in M. violaceum.Denchev and Scharkova (1997), having investigated 229 specimens of smut fungi on 22 Dianthus species, concluded that all of them belong to the same species, namely M. violaceum s. lat.However, Vánky (2004) supposed that this species can be divided into smaller ones through the use of analyses of as many of type specimens as possible with employment of both traditional morphological and molecular-phylogenetic methods.Such studies have been made by Lutz et al. (2005Lutz et al. ( , 2008)), and their results confirmed the separation of M. dianthorum.However, within this species a great variability in the spore dimensions was found.In addition, the number of meshes per spore diameter also strongly varied.In spite of this, all specimens were clustered together by molecular data.Similar investigations regarding other fungi from M. violcaeum-complex parasitizing D. sylvestris Wulfen and D. cartusianorum L. showed insignificant morphological differences between both of these samples and from other specimens of this complex.However, they differed by molecular-biological data and features of microsatellite analyses.Thus, they were cryptic species (Denchev et al. 2009).The results of molecular-phylogenetic investigations also made it possible to restore a species status of smut fungus on D. superbus and regard it not any more as U. superba but as M. superbum (Denchev et al. 2009).
Only two species of smut fungi parasitizing Dianthus species were known in Ukraine, e.g., M. dianthorum (reported as U. dianthorum) on D. pseudoarmeria M. Bieb.from the forest-steppe zone and M. superbum (reported as U. superba) on D. superbus from Polissia region (Zerova et al. 1971).No specimens of these fungi were found in the National Herbarium of Ukraine of the M.G.Kholodny Institute of Botany (Fungi of Ukraine 1996).So far, the smut fungi on Dianthus have been considered to be rare in Ukraine.However, in summer 2009 we collected three specimens of the anthericolous smut fungi on D. borbasii Vandas, D. pseudoserotinus Błocki (D. arenarius p.p.) and D. stenocalyx Juz.(D. superbus p.p.).The first and the second of them were identified by us as M. dianthorum and the last as M. superbum.The characteristics of these fungi on new hosts are given below.
anthericolouS Smut funguS on lychniS.During field research in Cherkasy region (Ukraine) intense development of smut fungus in the anthers of Lychnis viscaria L. was recorded.Thus, about 20% of plants in the studied population were affected.The fungus was identified as Microbotryum lagerheimii.This species has been recently described (Denchev 2007) in the anthers of L. alpina L. and L. viscaria.It is closely related to M. silenes-inflatae (DC.ex Liro) G. Deml et Oberw.known on Lychnis alpina, Silene vulgaris subsp.glareosa (Jord.)Marsden-Jones et Turrill, S. vulgaris subsp.vulgaris (Moench) Garcke (Oberna behen (L.) Ikonn.), S. cucubalus Wibel, S. inflata Sm. and S. venosa Asch.) but differs in having far less (small or medium) intensity of spore mass coloration (Denchev, Minter 2008).Microbotryum lagerhemii is also known from Czech, Finland, Germany, Italy, Latvia, Norway, Poland, Russia, and Sweden (Denchev 2007).Thus, the fungus is a European endemic within a boreal-temperate area.In Ukraine it was found for the first time.