Italian Botanist 17: 55—68 (2024)

doi: 10.3897/italianbotanist. | 7.123048 LW Italian Botanist

Published by Societd Botanica Italiana

https://italianbotanist.pensoft.net

Pleurotus nebrodensis (Basidiomycota), a rare endemic
mushroom of Sicily: current and future issues

Maria Letizia Gargano', Giuseppe Venturella**, Gaetano Balenzano’,
Valeria Ferraro*, Fortunato Cirlincione', Giulia Mirabile??

| Department of Soil, Plant and Food Sciences, University of Bari “Aldo Moro”, Bari, Italy 2. Department of

Agricultural, Food and Forest Sciences, University of Palermo, Palermo, Italy 3 NBFC, National Biodiversity
Future Center, Palermo, Italy 4 Department of Pharmacy-Pharmaceutical Sciences, University of Bari “Aldo
Moro’, Bari, Italy

Corresponding author: Fortunato Cirlincione (fortunato.cirlincione@uniba.it)

Academic editor: Lorenzo Peruzzi | Received 14 March 2024 | Accepted 9 May 2024 | Published 20 June 2024

Citation: Gargano ML, Venturella G, Balenzano G, Ferraro V, Cirlincione FE, Mirabile G (2024) Pleurotus nebrodensis
(Basidiomycota), a rare endemic mushroom of Sicily: current and future issues. Italian Botanist 17: 55-68. https://doi.

org/10.3897/italianbotanist.17.123048

Abstract

This paper deals with the basidiomycete Pleurotus nebrodensis, one of the rare examples of endemic fungi
in Italy and Europe. After clarifying the taxonomy of this taxon, including a comparison with a species
from China misidentified as “Pleurotus nebrodensis’, we describe the characteristics of its natural habitat,
and provide a new morphological description and information on its pilot-scale cultivation, current con-
servation status according to [UCN criteria and conservation strategies. New ITS region sequences were
deposited in GenBank. Furthermore, the antibacterial and anti-cancer properties of P nebrodensis are
mentioned, making it a potential medicinal mushroom. Finally, a critical analysis, on a phylogenetic basis,

of the Italian production of substrates inoculated with “P nebrodensis” strains is also included.

Keywords

Basidiomycete, fungal diversity, medicinal mushroom, mediterranean area

Introduction

The term endemism refers to a species whose occurrence is indigenous and exclusive
to limited territories and lacking in the surrounding and distant ones. Endemic species
are generally extremely vulnerable to climate change because evolution has led them to

Copyright Maria Letizia Gargano et al. This is an open access article distributed under the terms of the Creative Commons Attribution License
(CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

56 Maria Letizia Gargano et al. / Italian Botanist 17: 55-68 (2024)

be formed exactly for that site (Veron et al. 2019). The application of the term endemic
for fungi is problematic, although some cases have been demonstrated over time. The
study of fungal endemism, especially on islands, is often hampered by insufficient data
making it difficult to apply the term endemic and evaluate case studies (Stallman et al.
2022). In the State of Biodiversity in Italy, published in 2005 (Blasi et al. 2005), 56
fungal species are reported as possible endemics.

The environmental characteristics of Sicily and its numerous ecosystems allow for
high levels of biodiversity to be found on the island in all groups of organisms. Plant
species endemic to Sicily amount to about 15% and include taxa with a punctiform dis-
tribution (Di Gristina et al. 2022) while only one fungal species, Pleurotus nebrodensis
(Inzenga) Quél. (Pleurotaceae), is currently reported as endemic (Ferraro et al. 2022).

Along with Alessioporus ichnusanus (Alessio, Galli & Littini) Gelardi, Vizzini &
Simonini (Angelini et al. 2021) and Poronia punctata (L.) Fr. (Ceci et al. 2021), P ne-
brodensis is one of the few Italian fungal species currently included on the International
Union for Conservation of Nature's (IUCN) Red List of Threatened Species and is in
the TOP 50 Mediterranean Island Plants (https://top50.iucn-mpsg.org/species/39).
This condition makes in situ and ex situ conservation strategies necessary.

Among the conservation strategies indicated by Courtecuisse (2001), that of natu-
ral habitat conservation appears to be the most effective. Based on International Union
for Conservation of Nature (IUCN) criteria, the Extent of Occurrence (EOO) of the
P. nebrodensis population is less than 100 km’. The population is severely fragmented
and there has been a progressive decline in the number of localities, now fewer than ten
(Pasta et al. 2017). The number of mature individuals is <150 with alternating pattern
in the fruiting years with an average of ca. 70 basidiomata/year. This is mainly due to
the increasing number of collectors (professional and amateur), motivated by the high
commercial price (50-60 euros per kg) and the remarkable organoleptic properties of
this mushroom, despite the absence of a real market for the product. Another negative
drawback of the increasing human pressure is the harvesting of young basidiomata, which
may seriously affect fruiting of this prized species in the near future (Gargano etal. 2011).

Article 5 of the Madonie Park’s Regulation on the Collection of Epigean Mush-
rooms, issued in 2017, the territory within which all the growth localities of the rare
endemic mushroom fall, states that the collection of P nebrodensis in zone A, a wild
zone under total protection, is prohibited, while in the other zones collection of basidi-
omata smaller than 3 cm in size is prohibited. P nebrodensis is also protected by the
park’s regulations as well as by Regional Law No. 3 (February 1, 2006).

Moreover, subpopulations of P nebrodensis fall within Natura 2000 sites, which
are all included in the territory of the Madonie Mountains and more specifically in the
following localities: [TA020004 “M. San Salvatore, M. Catarineci, Vallone Mandarini,
humid environments, “ITA020016 “Monte Quacella, Monte dei Cervi, Pizzo. Car-
bonara, Monte Ferro, Pizzo Otiero”, and ITA020020 “Evergreen oak forests of Geraci
Siculo and Castelbuono”.

One of the strategies for ex situ conservation, particularly for saprotrophic fun-
gi whose mycelium can be easily reproduced in the laboratory, is that of cultivation

P. nebrodensis, a rare endemic mushroom of Sicily (southern Italy) a7

outside its habitat. This has considerable relevance in the case of fungal species at risk
of extinction or closely confined to threatened habitats. In the Mediterranean region,
the cultivation of Pleurotus species is diffused and represents ca. 10-20% of total mush-
room production (Ferraro et al. 2022). The ex situ cultivation of P nebrodensis is part of
the project “PLEURON - Project for the cultivation of Plewrotus nebrodensis in a pro-
tected environment for food, medicinal and phytogenic purposes”, recently approved
(2023) by the Sicilian Administrative Region and aimed at cultivating the mushroom
on a pilot scale and in a protected environment. The partnership consists of Consortia
for Research, Universities and farms located in the Madonie territory. This ambitious
project is based on previous positive experiences in growing Pleurotus mushrooms in
Italy (Varese et al. 2011; Venturella et al. 2016). In particular, P nebrodensis can be
grown at different altitudes within semi-shaded tunnels. Moreover, cultivated P nebro-
densis basidiomata have the same organoleptic features as the wild basidiomata (Zer-
vakis and Venturella 2002). Thus, ex situ cultivation will provide additional income to
local farmers, with the possibility of selling the product at lower prices than those of
mushrooms collected in the wild. Finally, ex situ cultivation would ensure a gradual
reduction in pressure from the many seekers of the prized mushroom in nature.

In this survey we report the taxonomy, ecology, distribution, and potential appli-
cations of this important Sicilian endemic fungus. In addition, because the binomial
“Pleurotus nebrodensis’ is often misapplied, an attempt is made to help clarify the exact
taxonomic placement of the mycelium marketed by a leading company selling mush-
room-growing substrates under the name “Pleurotus nebrodensis’ .

Materials and methods

Collection, habitat details and morphological characters

Field research carried out in pastures of the Madonie mountains (N. Sicily, Italy) led
to the collection of a white-colored mushroom on dead roots of Prangos ferulacea (L.)
Lindl., a perennial herbaceous plant distributed in the Mediterranean Basin, the Bul-
garian Black Sea coast, and the Caucasus. In accordance with the Prodrome of Veg-
etation in Italy (Biondi and Blasi 2005), P ferulacea is part of the plant association
no. 62.2.1 Cerastio-Astragalion nebrodensis Pignatti & Nimis ex Brullo 1984 in which
xerophilous and basiphilous communities occurring on dolomitic substrates with more
or less pronounced slopes, mainly on consolidated rocks and sometimes on rocky ridg-
es, are present (Fig. 1). This plant association is distributed throughout the Madonie
mountains in the supramediterranean thermotype.

Field excursions were carried out in the years 2022 and 2023 during the fruiting
period of P nebrodensis extending from late April to early June. ‘The research localities
fall in the area of Monte dei Cervi (1794 m), a mountain falling within the territo-
ries of Scillato and Polizzi Generosa, 37°52'45"N, 13°58'14"E (DMS), and Vallone
Faguare a canyon located at 1,263 m a.s.l., 37°51'42"N, 14°03'54"E (DMS) in the

58 Maria Letizia Gargano et al. / Italian Botanist 17: 55-68 (2024)

Figure |. Pastures of Prangos ferulacea on the Madonie mountains of northern Sicily (Photo G. Venturella).

territory of Petralia Sottana (Madonie mountains). Based on the classification of Rivas-
Martinez (1995), the bioclimatic characters of the area can be overall referred to the
mesomediterranean (average temperature: 13-16 °C) and supramediterranean (aver-
age temperature: 8—13 °C) thermotypes, with ombrotype varying between subhumid
(average rainfall: 600-1000 mm) and humid (average rainfall: >1000 mm).

Six fresh basidiomata of P nebrodensis were collected and identified according to
macroscopic characters (cap, flesh, lamellae, stipe, type of occurrence, color of spore
prints, etc.). In addition, microscopic characters (basidiospores, basidia, cheilocystidia,
hyphal system, hyphal wall, hyphae, and pellis) were observed at 40X-1000X (Am-
Scope, Irvine, USA). The morphological examination was carried out according to
Venturella et al. (2015).

The specimens (Fig. 2A) were dried at 40 °C in a 475 W stainless steel dryer (Mau-
ro Valla, Borgotaro, Italy) and deposited in the Herbarium SAF of the Department of
Agricultural, Food and Forest Sciences (SAAF 503) of the University of Palermo. The
nomenclature of fungi follows Index Fungorum while the binomial of plants is referred
to Euro + Med PlantBase (www.emplantbase.org).

Establishment of pure cultures

A piece of tissue from fresh basidiomata was placed on potato dextrose agar (PDA)
in Petri dishes under aseptic conditions under a laminar flow hood. The Petri dishes
were sealed with Parafilm and incubated at 25 + 2 °C. The pure culture is kept in the
Mycotheca of the Herbarium SAF (SAF 40) (Fig. 2B).

P. nebrodensis, a rare endemic mushroom of Sicily (southern Italy) 59

Figure 2. Pleurotus nebrodensis samples a Exsiccata of P nebrodensis deposited in the Herbarium SAF of
Palermo University b Pure culture of P nebrodensis (Photo G. Mirabile).

Extraction of DNA, amplification, ITS sequencing and phylogenetic analysis

Twelve marketed cultivation bags (four strains, indicated as 1, G, 6, and 8, in three rep-
licates), inoculated with P nebrodensis mycelium, provided by Italmiko (Senise, Poten-
za), were analyzed in order to identify, by a molecular approach, the exact taxonomic
identity of basidiomata. DNA was extracted from fresh basidiomata using the Extract-
N-Amp™ kit (Sigma-Aldrich, St. Louis, USA) following the manufacturer’s instruc-
tions. DNA purity and concentration were measured at 260/280 nm and 260/230
nm using the NanoDrop ND-1000 spectrophotometer (Thermo Fisher Scientific,
Waltham, USA). The Internal Transcribed Spacer (ITS) region of rDNA was amplified
using ITS1F and ITS4 primers by polymerase chain reaction (PCR) in a total reac-
tion volume of 20 ul (4 ul of extracted DNA, 1 ul of each primer at 10 uM ,10 ul of
the Extract-N-Amp PCR reaction mix (Sigma-Aldrich, St. Louis, USA), and 4 ul of
sterilized distilled water. The amplification was performed in a MultiGene OptiMax
thermocycler (Labnet International Inc., Edison, USA) with the following parameters:
3 min of initial denaturation cycle at 94 °C; 35 cycles at 94 °C for 30 s; annealing stage
at 55 °C for 30 s; elongation for 45 s at 72 °C and 10 min of final extension at 72 °C.
PCR product was separated in 1.5% agarose gel by electrophoresis and detected under
UV light. PCR product was purified using Exo I-SAP protocol (Applied Biosystems,
Foster City, USA) and sent to BMR Genomics (Padova, Italy) for sequencing. In the
sequencing reaction, only primer ITS1F was used. The obtained sequence was manu-
ally adjusted and compared with those in GenBank using the BLASTn tool (https://
blast.ncbi.nlm.nih.gov).

The new sequences were deposited in GenBank. Sequences with 99—100% of simi-
larity, as well as P eryngii complex representative sequences from a previous ITS-phylo-
genetic study (Table 1, Zervakis et al. 2014) were obtained from GenBank and aligned
with the isolated sequence obtained in this study. Alignments were performed using
ClustalW software and manually adjusted, if necessary, using MEGA11. The Neigh-
bour-Joining algorithm was used to generate the phylogenetic tree and the evolution-
ary distances were calculated based on Maximum Composite Likelihood. Bootstrap
percentages were calculated from 1000 re-samplings.

60 Maria Letizia Gargano et al. / Italian Botanist 17: 55-68 (2024)

Table |. Strains of Pleurotus used for [TS-phylogenetic analysis. Those obtained in this study are in bold.

Taxon Host Geographic origin Accession number

P. eryngii vat. eryngii Eryngium sp. China HM998840
P. eryngii vat. eryngii Eryngium sp. Ukraine HM998820
P eryngii var. eryngii Eryngium sp. Italy KF743828
P. eryngii vat. eryngii Eryngium maritimum Greece HM998811
P eryngii Commercial China HM998841
P. eryngii Apiaceae Iran HM998833
P. eryngii Commercial Italy OR681547
P eryngii var. elaeoselini Laserpitium latifolium Italy HM998827
P eryngii var. elaeoselini Laserpitium siler Italy HM998825
P eryngii var. elaeoselini Elaeoselinum asclepium Italy HM998819
P eryngii var. elaeoselini Laserpitium latifolium Italy KF743824
P eryngii var. ferulae Ferula communis France HM998808
P eryngii var. ferulae Ferula communis Greece HM998813
P eryngii va. ferulae Ferula communis Greece HM998814
P eryngii var. thapsiae Thapsia garganica Italy HM998815
P. eryngii subsp. tuoliensis Ferula sp. Iran HM998836
P eryngii subsp. tuoliensis Ferula sinkiangensis China HM998839
P. eryngii subsp. tuoliensis Ferula sinkiangensis China HM998842
P. nebrodensis Prangos ferulacea Greece KF743821
P. nebrodensis Prangos ferulacea Italy HM998818
P. nebrodensis Prangos ferulacea Greece KF743820
P. nebrodensis Prangos ferulacea Greece HM998826
P. nebrodensis Prangos ferulacea Italy HM998816
P. nebrodensis Prangos ferulacea Italy HM998832
P. nebrodensis Prangos ferulacea Italy KF743830
P. nebrodensis Commercial Italy OR681545
P. nebrodensis Commercial Italy OR681546
P. nebrodensis Commercial Italy OR681548
P ferulaginis Apiaceae Iran KF743829
P ferulaginis Ferulago campestris Italy KF743833
P ferulaginis Ferulago campestris Italy KF743826
P ferulaginis Ferulago campestris Italy KF743827
Results

Taxonomy

Pleurotus nebrodensis (Inzenga) Quél. was described under the binomial Agaricus
nebrodensis by Giuseppe Inzenga (Inzenga 1863), one of the most eminent mycolo-
gists of the second half of the 19 century. Different binomials have been attrib-
uted to P nebrodensis many of them have subsequently fallen into synonymy with
P. nebrodensis. Saccardo (1915) considered P nebrodensis as a variety of Pleurotus
eryngii (DC.) Quel. while other authors report the binomials of Agaricus fossula-
tus Cooke (Aitchinson 1888) or Dendrosarcus fossulatus (Cooke) Kuntze (1898).
The study of herbarium material deposited at the Muséum National d'Histoire
Naturelle in Paris (Venturella 2000) revealed that the exsiccatum positioned in
the center of the herbarium sheet (Fig. 3A) corresponds to P nebrodensis and is

P. nebrodensis, a rare endemic mushroom of Sicily (southern Italy) 61

perfectly superimposable on the original drawing of Giuseppe Inzenga (Fig. 3B).
The subsequent elucidation by Venturella et al. (2016) confirmed Inzenga’s intui-
tion that P nebrodensis is a valid species and that the binomial A. fossulatus is to be
referred to P nebrodensis subsp. fossulatus (Cooke) Zervakis & Venturella, and is a
related Asiatic taxon growing on P ferulacea.

Morphological description

The basidiomata of P nebrodensis (Fig. 4) are fleshy with a pileus 3.0—15.0 cm wide,
applanate, uplifted, shallowly depressed, convex or conchate, light ivory to cream. The
margin of the pileus is plane, incurved, uplifted with a surface entire or eroded, smooth.
The cuticle is glossy or translucent, dry, smooth (glabrous) or becoming cracked. The
color of the flesh is cream, with consistency hard-tough to turgid, color unchanging
when cut, sulphur-yellow when dry, 1-2 mm thick at the margin and 1-4 cm thick at
the center. The taste is mildly farinaceous. Lamellae 4-8 mm width, 2.5—7.5 cm length,
annexed to decurrent, gill spacing sub-distant to close, moderately broad in thickness,
light ivory, margin of gills smooth to eroded, face of gills waxy, lamellulae present,
extending one-half to one-third the length of gills. Stipe 1.5—3 cm width, 2.5-4.5 cm
length, terete in cross section, slightly tapered to tapered at the base. Consistency fi-
brous, flesh solid to stuffed. Stipe eccentrically or lateral attached to pileus, inserted in
the root residues of P ferulacea, basal tomentum and veil absent. The stipe surface is
smooth, light ivory colored. The habit is solitary or connate. Basidiospore print light
ivory to cream. Basidiospores 12.5—15.1(—18) x 5.2—-6.1 um, cream, asymmetrical, cy-
lindrical to phaseoliform, smooth, hyaline, guttulate. Basidia 4-spored, with basidioles
40-50 x 10-11.5(—14) um, sterigmata 3—4.5 um. Cheilocystidia (leptocystidia) 50-60

x 6.2—7.5(—9) um, clavate, apex mucronate to capitulate. Hyphal system monomitic.

Hyphal wall thin. Hyphae septate with clamp connections. Specialized hyphae absent,
no pigmentation. Pellis in two layers, 5-10 um width.

Figure 3. Pleurotus nebrodensis a herbarium sheet deposited in PC showing a specimen of Sicilian prove-
nance of P nebrodensis (sub. Agaricus nebrodensis Inz.) in the center b the original drawing of the medium-
sized basidiome of P nebrodensis by Giuseppe Inzenga (1863).

62 Maria Letizia Gargano et al. / Italian Botanist 17: 55-68 (2024)

Figure 4. Basidiomata of Pleurotus nebrodensis a In situ (Photo G. Venturella) b microscopic features
(basidia and spores) (Photo G. Mirabile).

Analysis of mycelium contained in commercial cultivation bags

In a separate publication, the commercial strains on the international market under
the name “Pleurotus nebrodensis” were verified, and it was shown that the great part
of them do not correspond to P nebrodensis but should be referred to another tax-
on, i.e. Pleurotus subsp. tuoliensis (C.J. Mou) Zervakis & Venturella (Venturella et
al. 2016). Fresh mushrooms morphologically similar to P nebrodensis of uncertain
taxonomic identity are still cultivated and marketed in Italy. Based on the certified
source material belonging to true P nebrodensis, preserved in the Herbarium SAF of
the Department of Agricultural and Forestry Sciences (University of Palermo, Italy) we
investigated 12 cultivation bags, labelled by the provider and inoculated with myce-
lium of “P nebrodensis” and marketed by a leading company located in southern Italy
that applied for certification.

Molecular and phylogenetic analysis of the twelve marketed cultivation bags
(Fig. 5) showed that the mushrooms grown in bags labeled as 1 and 8 clustered with
P. nebrodensis. The mushrooms obtained in the bags labeled with the letter “G” falls in
the cluster P eryngii sensu stricto, shown in Fig. 6.

Regarding the three replication of cultivation bags labeled as 6, two of them be-
longs to P nebrodensis cluster (Fig. 6), while one replication, which presented a com-
pletely different mycelium morphology, resulted as /rpex latemarginatus (Durieu &
Mont.) C.C. Chen & Sheng H. Wu, probably a contaminant.

Discussion

Italy, located in the center of the Mediterranean basin, is considered one of 34 global
biodiversity hotspots (Mittermeier et al. 2011). Hotspots are key locations for bio-
diversity conservation because they have a high rate of endemic species. Sicily, due

P. nebrodensis, a rare endemic mushroom of Sicily (southern Italy) 63

Figure 5. Bag “G” producing Pleurotus eryngii mushrooms (left) and bag n. 1 producing the P. nebro-
densis (right) (Photos G. Mirabile).

to its insularity and the topography of the land, is home to a rich animal, plant and
fungal diversity. Pleurotus nebrodensis and its habitat are currently not protected by any
international conservation rules. Consequently, there is an urgent need to raise aware-
ness among policy makers and the scientific community to implement appropriate
conservation actions and sustainable use towards this important natural resource. The
regulation on mushroom picking by the Madonie Park Authority to limit the nega-
tive impact on P nebrodensis fructification is often ignored by gatherers given the poor
controls. Ex situ cultivation will reduce the pressure due to overharvesting in natural
habitats and at the same time lower the cost of this prized mushroom, which is current-
ly too high for the pockets of most consumers. Finally, given the environmental and
economic value of the P nebrodensis stand, it is desirable to encourage the involvement
of citizens and an increase in public awareness for the protection and enhancement of
P. nebrodensis. Citizen interest in this mushroom can also stimulated by the demon-
strated medical application potential of P nebrodensis. Different medicinal properties
are attributed to the genus Pleurotus (Fr.) P. Kumm (Lesa et al. 2022). In recent years,
data have been published on the antibacterial and antitumor properties of other Pleu-
rotus species fruiting in the Mediterranean Basin. As regards P nebrodensis from Sicily,
it contains biologically active compounds that act in modulating the immune system
and inhibiting the growth of cancer cells (Alam et al. 2011). Specifically, the water
extract of P nebrodensis is able to suppress proliferation of colon cancer cells without
significant effects on proliferation of normal cells. It also has a potential application
in contrasting the biofilm mode of growth of human pathogens. Cold water extracts
were tested on human colon cancer cells (Fontana et al. 2014) with positive effects on
antitumor activity and immunomodulation and increased natural killer cell activity.

64 Maria Letizia Gargano et al. / Italian Botanist 17: 55-68 (2024)

HM998840
HM998841
HM998820
HM998827
97 | KF 743828 Pleurotus eryngii sensu stricto
A OR681547
HM998833
| HM998808
HM998811
HM998836
99 — HM998839 Plewrotus eryngii var. tuoliensis
sa ' HM998842
KF743821
49 ,» HM998818
s: (| A ORGS1545
Si} | =) & OR681546
72' A OR6S1548
& KF 743820
—— HM998826
HM998816
HM998832
KF743830
KF 743829
KF 743833
- KF743826
81 KF 743827

Plewrotus nebrodensis

Pleurotus ferulaginis

0.01

Figure 6. Phylogenetic tree obtained from the analysis of ITS1-5.8S-ITS2 sequences obtained from this
study (labelled with black triangle) and additional sequences from NCBI.

The same extracts were also tested in vivo against medically relevant bacteria, such
as Pseudomonas aeruginosa, Staphylococcus epidermidis, S. aureus, and Escherichia coli.
These findings open interesting perspectives for the inclusion of P nebrodensis among
the most valuable mushroom-based products to be used in integrated medicine.
There is also a need to resolve the confusion that exists in the commercial exploita-
tion of material bearing the name “Pleurotus nebrodensis’ through accurate taxonomic
identification in order to ensure that products on the market are of safe origin and
genetic purity. This covers both the production of mushrooms for the food market
and the supply of dried powders for the production of mushroom-based products.
In the first case, there is a problem that can be traced to a practice long in use by
mushroom hunters in the Madonie mountains of mixing basidiomata of P nebrodensis
with another morphologically similar white fungus named P eryngii var. elaeoselini

P. nebrodensis, a rare endemic mushroom of Sicily (southern Italy) 65

Venturella, Zervakis & La Rocca (Fig. 7). However, this taxon is genetically separated
from P nebrodensis as it falls into the species complex of P eryngii (Zervakis et al. 2014).

It has been recently demonstrated that the Italian market for mushroom-based
products is characterized by products of dubious origin (Risoli et al. 2023). Thus, the
future use of dried powders of P nebrodensis in the production of mushroom-based
products, one of the main targets of the above-mentioned project recently funded by
the Sicilian Administrative Region, cannot disregard a careful review of all the genetic
material sold by the companies that produce substrates and mushrooms in order to
enable them to supply the market with the real “P nebrodensis”. In addition, based
on the results that will emerge from the PLEURON project, we suggest not to allow
the cultivation of species related to P. nebrodensis in the Madonie territory in order to
avoid the risk of genetic mixing between congeneric species.

Figure 7. Basidiomata of Pleurotus eryngii var. elaeoselini are almost impossible to distinguish macro-
scopically from those of P nebrodensis. (Photo G. Venturella).

Acknowledgements

This manuscript was carried out as part of the Sicily Rural Development Program
2014-2022, Submeasure 16.1 - “Support for the establishment and management of
EIP operational groups on agricultural productivity and sustainability”, D.D.G. No.
4052 of 09/29/2022, Project title: “PLEURON - Project for the cultivation of Pleurotus

nebrodensis in a protected environment for food, medicinal and phytogenic purposes”.

66 Maria Letizia Gargano et al. / Italian Botanist 17: 55-68 (2024)

The research was also funded by the National Recovery and Resilience Plan (NRRP),
Mission 4, Component 2, Investment 1.4-Call for tender No. 3138 of 16 December
2021, rectified by Decree n. 3175 of 18 December 2021 of Italian Ministry of Univer-
sity and Research funded by the European Union - NextGenerationEU Project Code
CN_00000033, Concession Decree No. 1034 of 17 June 2022 adopted by the Italian
Ministry of University and Research, CUP B73C22000790001, Project Title "National
Biodiversity Future Center-NBFC".

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