Elias Polemis

Macrofungi as ecosystem resources: Conservation versus exploitation

Fungi are organisms of significant importance not only for the crucial roles they undertake in nature but also for many human activities that are strictly dependent on them. Indeed, fungi possess fundamental positions in ecosystems functioning including nutrient cycles and wood decomposition. As concerns human-related activities, edible and non-edible mushrooms are also involved and/or exploited in forestry, pharmaceutical industry and food production; hence, nowadays they represent a major economic source worldwide. In order to maintain and improve their strategic importance, several conservation strategies, such as habitat preservation, are needed. This article reports several contributions inherent to the relationships between wood-decaying fungi, edible and non-edible mushrooms and their potential exploitation as non-timber forest products and genetic resources.

A reappraisal of the Pleurotus eryngii complex - new species and taxonomic combinations based on the application of a polyphasic approach, and an identification key to Pleurotus taxa associated with Apiaceae plants.

The Pleurotus eryngii species-complex comprises choice edible mushrooms growing on roots and lower stem residues of Apiaceae (umbellifers) plants. Material deriving from extensive sampling was studied by mating compatibility, morphological and ecological criteria, and through analysis of ITS1-5.8S-ITS2 and IGS1 rRNA sequences. Results revealed that P. eryngii sensu stricto forms a diverse and widely distributed aggregate composed of varieties elaeoselini, eryngii, ferulae, thapsiae, and tingitanus. Pleurotuseryngii subsp. tuoliensis comb. nov. is a phylogenetically sister group to the former growing only on various Ferula species in Asia. The existence of Pleurotusnebrodensis outside of Sicily (i.e., in Greece) is reported for the first time on the basis of molecular data, while P. nebrodensis subsp. fossulatus comb. nov. is a related Asiatic taxon associated with the same plant (Prangos ferulacea). Last, Pleurotusferulaginis sp. nov. grows on Ferulago campestris in northeast Italy, Slovenia and Hungary; it occupies a distinct phylogenetic position accompanied with significant differences in spore size and mating incompatibility versus other Pleurotus populations. Coevolution with umbellifers and host/substrate specificity seem to play key roles in speciation processes within this fungal group. An identification key to the nine Pleurotus taxa growing in association with Apiaceae plants is provided.

Annotated Checklist of Basidiomycota (Subclass Agaricomycetidae) from the Islands of Naxos and Amorgos (Cyclades, Greece)

Naxos and Amorgos are islands in the Aegean Sea with a typically arid to semiarid climate, the vegetation being dominated by thermo-Mediterranean shrubs. From the floristic point of view, both are among the most interesting islands of the Cyclades. However, no data were available on their fungal diversity. This work presents an annotated check-list of the basidiomycetes belonging to the subclass Agaricomycetidae (Agaricales and Boletales) from these two islands. A total of 142 species and subspecific taxa are recognized and assigned to 58 genera. The genus Simocybe as well as 21 taxa at the species or subspecies level constitute new records for Greece, while further 76 taxa represent first national reports for habitat, hosts and/or substrates. A brief description of key diagnostic characters — in conjunction with a discussion of pertinent literature — is provided for the most interesting findings.

Macrofungi in Mediterranean maquis along seashore and altitudinal transects

In semi-arid Mediterranean environments, fungal activity is fundamental for buffering biotic and abiotic stress to the plant and for sustaining a vegetation cover. Despite the important role that fungi play in habitats stability, mycological data from Mediterranean ecosystems are scarce and fragmentary. We investigated fungal diversity in several areas characterized by Mediterranean maquis, from continental Italy, Sicily, and Greece in order to contribute to the analysis of distribution, ecology, and diversity of macrofungi in evergreen sclerophyllous shrublands at different elevation and distance from the seashore across the Mediterranean Basin. Several fungal taxa that are remarkable due to their ecology, rarity, and limited geographical distribution were recovered. Among them, the ectomycorrhizal species Amanita dunensis and A. valens were recorded for the first time in Italy. The wood-inhabiting macrofungi, Aleurodiscus dextrinoideocerussatus, Peniophorella tsugae, Perenniporia meridionalis, Phanerochaete martelliana, Vararia ochroleuca, and six Peniophora species were reported for the first time in Greece. Some species, such as Gloeodontia columbiensis, Ceriporia aurantiocarnescens, Peniophora pithya, and P. tamaricicola were collected on new substrates. For the two rare basidiomycetes Amanita eliae and Battarrea phalloides, molecular identification and phylogenetic analysis gave valuable information on their relationship with similar taxa.

The family Hymenochaetaceae (Agaricomycetes, Basidiomycota) in the islands of the Aegean Archipelago (Greece)

In the frame of studying the diversity of wood-rotting macrofungi in Aegean islands, a notable Mediterranean biodiversity “hotspot”, the following hymenochaetoid species are reported for the first time in Greece: Fomitiporia erecta, Fomitiporia rosmarini, Hymenochaete fuliginosa, Inonotus cuticularis and Phylloporia ribis. The records of F. erecta and F. rosmarini are the first ever on Quercus coccifera in a worldwide context. Furthermore, they extend the known distribution of both species to the east Mediterranean region as well. The detected occurrence of P. ribis constitutes the first report of this genus for Greece; it was found on living trees and shrubs of Crataegus monogyna and Rhamnus alaternus in Andros and on Spartium junceum in Naxos. I. cuticularis was recorded on Acer sempervirens living tree trunk in Andros and on Quercus ithaburensis subsp. macrolepis in Agios Efstratios, while H. fuliginosa was detected in Ikaria on Quercus ilex. Detailed descriptions are provided for all five taxa, and the findings are critically discussed in conjunction with the relevant taxonomical literature. Furthermore, 10 additional hymenochaetoid taxa are reported together with information on their hosts and distribution in the Aegean islands.

Heterobasidiomycetous fungi from Aegean Islands (Greece): New annotated records for a neglected group

Abstract As part of an inventory of macrofungi in selected islands of the Aegean Archipelago (Greece), 18 species of heterobasidiomycetes (phylum Basidiomycota) belonging to the orders Auriculariales, Cantharellales, Dacrymycetales and Tremellales were collected and identified from the islands of Agios Efstratios, Amorgos, Andros, Crete, Ikaria, Naxos and Nisyros. Among the heterobasidiomycetous fungi collected, Ceratobasidium cornigerum, Dacrymyces lacrymalis, Exidiopsis effusa, E. galzinii, Thanatephorus amygdalisporus, Tremella aurantia, Tulasnella pallida and T. pruinosa constitute first national records, while the genera Ceratobasidium, Thanatephorus and Tulasnella are reported for the first time in Greece. All species are listed with information on their hosts/substrates and occurrence in the investigated islands, while the most interesting records are described, illustrated, and critically discussed in the light of existing taxonomic and distribution data.

Taxonomic Identity, Geographic Distribution, and Commercial Exploitation of the Culinary-Medicinal Mushroom Pleurotus nebrodensis (Basidiomycetes).

An updated overview of the outcome of studies conducted on the culinary-medicinal mushroom Pleurotus nebrodensis is presented by placing emphasis on the clarification of the taxonomic identity of P. nebrodensis and other related taxa possessing entirely white to cream basidiomes, which grow in association with different plants of the family Apiaceae. Cultivation techniques, quality of the product sold and sales price, as well as nutritional and medicinal aspects are discussed. Taking also into consideration the high economic importance of P. nebrodensis, it is essential to proceed with the verification of the commercial strains currently available in the international market under the name of P. nebrodensis since it is very probable that many (or most) of them do not represent the real P. nebrodensis. TO confirm this hypothesis, an in silico analysis was conducted on a large of number of ITS1-5.8S-ITS2 rRNA sequences deposited in the National Center for Biotechnology Information database under the name P. nebrodensis. Results demonstrated that all P nebrodensis material examined from China (plus several sequences of no reported origin) corresponded to P. eryngii subsp. tuoliensis, with only 2 exceptions, which were grouped within P. eryngii sensu stricto. The real P. nebrodensis biological material from Italy and Greece is certified and is available upon request by the authors at the University of Palermo and the Agricultural University of Athens.

Diversity of macrofungi and exploitation of edible mushroom resources in the National Park “Appennino Lucano, Val D'Agri, Lagonegrese” (Italy)

An investigation on the macrofungal diversity of the National Park “Appennino Lucano, Val DAgri, Lagonegrese” (Basilicata, southern Italy) was carried out, together with an evaluation of wild edible mushrooms in agro-forest ecosystems and their possible exploitation as a new source of food and revenue in rural and under-developed areas of this region. An unpublished list of 249 mushroom taxa (229 Basidiomycota and 20 Ascomycota), mostly belonging to the genera Tricholoma, Tuber, Russula, Amanita, Boletus, Lactarius, Mycena, Agaricus, Clitocybe and Hygrophorus, growing in this important natural area is provided together with ecological characterization of the recorded specimens. Inonotus obliquus is a new record for Basilicata, while Mycena bresadolana is reported for the first time from southern Italy. The presence of Amaurodon mustialaënsis, an extremely rare species of the northern hemisphere reported for the first time on white fir, is noteworthy. Among the previous findings, 116 species of edible mushrooms are presented and discussed in view of their relative abundance and edibility.

Taxonomic relationships among non-macrocystidiate taxa of Lactarius subg. Russularia from Europe with special reference to species from Greece

Members of the ectomycorrhizal genus Lactarius form symbiotic relationships with a wide range of plant species. For the purposes of this study, 29 specimens originally assigned to L. atlanticus, L. serifluus and L. subumbonatus were examined by including all pertinent available material from Greece. The detailed study of macroscopic and microscopic characteristics by using compound optical, differential interference contrast (DIC) and scanning electron microscopy in combination with molecular approaches (ITS1-5.8S-ITS2 rDNA sequencing) permitted a clear separation between L. atlanticus and L. subumbonatus, while their basidiospore shape and height of ornamentation were found to be of diagnostic value. Moreover, the morphological delimitation between the specimens identified as L. serifluus and L. subumbonatus is not clear, and these specimens were intermixed into the same phylogenetic cluster with high support. Thus, the latter name should be considered as a synonym of the former. As concerns other related taxa of L. subg. Russularia, the American L. rubidus and L. subserifluus demonstrated relatively high evolutionary affinity with European collections of L. serifluus/L. subumbonatus and L. atlanticus, respectively.

Diversity of saproxylic basidiomycetes in Quercus ilex woodlands of central and insular Greece

Abstract The sclerophyllous forests of Quercus ilex (holm oak) possess a unique position in earth’s biosphere, existing only in countries of the Mediterranean basin. However, very little information exists about mushrooms associated with holm oak in east Mediterranean, including Greece, where Q. ilex appears mostly in relict forests and fragmented stands. A pertinent long-term investigation was undertaken in selected Q. ilex dominated habitats of Crete, Andros, Naxos and Ikaria islands (Aegean Archipelago) as well as in mountains of Attica. Specimens of xylotrophic basidiomycetes were collected and identified. As a result, 74 species were recorded; among them Hemimycena cephalotricha, Hyphoderma cremeoalbum, Hyphodontia radula, Irpex litschaueri, Mycena algeriensis, Phanerochaete martelliana, Phloeomana alba and Phlebia unica constitute new records for the Greek mycobiota, while 68 species are reported for the first time on Q. ilex in Greece. Moreover, the presence of Fomitiporia mediterranea on this host was evidenced through ITS sequencing, and comments are made about its relationship to F. punctata and F. pseudopunctata. The importance of findings is discussed in conjunction with their environmental value; five species could be assigned in the “Species of Special Interest” categories, and other five polypores are proposed as suitable indicators for Q. ilex habitat assessment and conservation.