Suillus collinitus
Encyclopedia
Suillus collinitus is a pored mushroom
of the genus Suillus
in the Suillaceae
family. It is an edible mushroom
found in European pine forests. The mushroom has a reddish to chestnut-brown cap
that reaches up to 11 cm (4.3 in) in diameter, and a yellow stem measuring up to 7 cm (2.8 in) tall by 1 to 2 cm (0.393700787401575 to 0.78740157480315 in) thick. On the underside of the cap are small angular pores, initially bright yellow before turning greenish-brown with age. A characteristic feature that helps to distinguish it from similar Suillus species, like S. granulatus
, is the pinkish mycelia at the base of the stem.
Molecular analysis has shown the species to be related to other typical Mediterranean Suillus species such as S. bellinii
, S. luteus
, and S. mediterraneensis
. S. collinitus is a mycorrhizal species, and forms associations with several species of pine
, most notably the Aleppo pine
. This tree species is commonly used in reforestation
schemes and soil conservation
against erosion
in the Mediterranean region, and S. collinitus is often used as a beneficial inoculant to help the young trees better survive in typically harsh soil conditions.
as Boletus collinitus by Elias Magnus Fries
in 1838. Otto Kuntze
transferred it to the genus Suillus
in his 1898 Revisio Generum Plantarum. In 1969 Swiss mycologist H.S.C. Huijsman described the variety S. collinitus var. aureus (as S. fluryi var. aureus; S. fluryi is a synonym
of S. collinitus) based on a collection from Switzerland. The variety velatipes was described in 1998 by Giampaolo Simonini and colleagues from Italian collections.
A 1996 molecular analysis of 38 different Suillus species used the sequences of their internal transcribed spacer
s to infer phylogenetic relationships and clarify the taxonomy
of the genus. The results indicated that S. collinitus is most closely related to a specimen of S. granuatus collected from Nepal. According to the authors, this Nepalese isolate
probably represents a species distinct from North American and European isolates, based on morphology and host tree association. In 2006, a phylogenetic analysis of Suillus isolates collected from Spain showed that S. collinitus was closely related to other species "typical of the Mediterranean area", namely S. bellinii
, S. luteus
, and S. mediterraneensis
.
The specific epithet collinitus is derived from Latin
, and means "smeared" or "greased". The British botanist Mordecai Cubitt Cooke
called the mushroom the "ringless yellow boletus" in an 1873 publication.
of Suillus collinitus is a medium to large, fleshy bolete
. The cap
is initially rounded, becoming convex and finally flat, reaching up to 11 cm (4.3 in) in diameter. The cap is covered with a brown cuticle
of variable shade that is decorated with minuscule radial striations, which become more obvious in fully expanded specimens and especially in dry weather. The cap is often shaped irregularly and becomes viscid (sticky) when damp. The tubes
are short and their stem attachment is usually slightly decurrent to adnate. The small and angular pores are yellow but darken with age. Young, fresh specimens sometimes bear droplets of a clear fluid that collect on the pore surface.
The cylindrical stem
is often short and stubby, typically 4 – tall by 1 – thick, coloured yellowish and ornamented with sparse reddish-brown granules. There is no ring
. The base of the stem bears pink overtones and is attached to distinctively pink mycelial threads
, which are visible when the fruit body is uprooted. The flesh
is yellowish, thick and soft. In a colour reaction test
with ammonia
solution, the flesh turns reddish.
The spore
s are seen ochre
-brown in mass
, but pale yellow when viewed with a light microscope. They are fusiform (tapered at each end), sized 8–10.5 by 3–4.5 μm
. The basidia (spore-bearing cells of the hymenium
) are four-spored.
Especially characteristic for S. collinitus are the cap striations and pink mycelium. The fungus in many aspects resembles S. granulatus
– a common species in European pine forests. S. granulatus, however, has a homogenous brown cap without striations, and its mycelium is characteristically white.
(Pinus halepensis), is distinguished by a glutinous brown veil at the base of the stem, and a slender white felting at the cap margin.
, especially in the Mediterranean basin
. Some common species which occur throughout much of Europe and also associate with two-needled pines include S. luteus
and S. granulatus
.
with a sour odor and nondescript taste. It is advisable, as for all species of Suillus, to pick only young specimens and to peel the cuticle before preparation. The mushroom contains several tocopherols, a class of chemical compounds collectively known as vitamin E
, and which confer antioxidant
activity. They also contain several organic acid
s, most predominantly the pairs malic
and quinic
acids, and citric
and ketoglutaric acid, which respectively make up 42% and 30% of total organic acids. The composition and concentration of organic acids in mushrooms are major factors in influencing their flavour; some organic acids contribute to antioxidant activity.
relationships with several species of pine (Pinus). These include several two-needled European species of pine: Aleppo pine
(P. halepensis) European black pine
(P. nigra), stone pine
(P. pinea), and Scots pine
(P. sylvestris). The fungus favours limestone
soils. S. collinitus is thermophilic, commonly occurring in southern Europe. It is rarely seen in more northern regions, such as the British Isles and Poland. It is red-listed
in Denmark as near-threatened, and in Estonia as endangered. It has also been collected in Iran.
Suillus collinitus is the most frequent fungus associating with Aleppo pine – a hardy tree utilised for reforestation
schemes and soil conservation
against erosion
in the Mediterranean region. A study performed in the south of France discovered that S. collinitus and S. mediterraneensis
are multi-stage ectomycorrhizal fungi, associating with both young and mature stands of Aleppo pine. These two species may play a key role in the survival and adaptation of this species of pine on disturbed calcareous
sites. Roots mycorrhizal with S. collinitus were found capable of surviving successive disturbances by fire or ploughing. Moreover, the fungus retained its viability to propagate via its mycelial network which helped the recolonisation effort of newly introduced trees. The fungus has also been shown to improve the growth of Mediterranean pines grown in greenhouse
s and nurseries. Unlike other Suillus species that grow in wet climates, such as S. grevillei
and S. spraguei
, S. collinitus does not typically produce fruit bodies in young plantations. This fruiting behaviour may be attributed to the typically nutrient-poor xeric Mediterranean environment in combination with a lack of tree canopy. The absence of above-ground indicators of fungal presence makes analysis of underground populations difficult; molecular markers have been developed to assist in monitoring fungal growth and ectomycorrhizal formation and persistence in young plantations.
The ectomycorrizhae formed between several Suillus species and Aleppo pine has been studied under in vitro
conditions in the laboratory. Tree shoots inoculated with either S. collinitus, S. bellinii, and S. mediterraneensis tended to grow better and showed superior mycorrhizal development than other tested Suillus species, suggesting that the three have a "physiological specificity" for the tree. A 2010 publication reported that the fungal hyphae are covered in crystals of oxalic acid
, which, in addition to reducing soil pH
, reduces grazing
by the soil microarthropod
Folsomia candida.
Boletales
The Boletales are an order of Agaricomycetes, containing over 1300 species with a diverse array of fruiting body types. The boletes are the best known members of this group, and until recently, the Boletales were thought to only contain boletes...
of the genus Suillus
Suillus
Suillus is a genus of basidiomycete fungi in the family Suillaceae and order Boletales. Species in the genus are associated with coniferous trees, and are mostly distributed in northern temperate locations, although some species have been introduced to the Southern Hemisphere.-Taxonomy:The genus...
in the Suillaceae
Suillaceae
The Suillaceae are a family of fungi in the order Boletales , containing the boletus-like Suillus, the small truffle-like Truncocolumella, as well as the monotypic genus Psiloboletinus. As of 2008, there are 54 species in the family...
family. It is an edible mushroom
Edible mushroom
Edible mushrooms are the fleshy and edible fruiting bodies of several species of fungi. Mushrooms belong to the macrofungi, because their fruiting structures are large enough to be seen with the naked eye. They can appear either below ground or above ground where they may be picked by hand...
found in European pine forests. The mushroom has a reddish to chestnut-brown cap
Pileus (mycology)
The pileus is the technical name for the cap, or cap-like part, of a basidiocarp or ascocarp that supports a spore-bearing surface, the hymenium. The hymenium may consist of lamellae, tubes, or teeth, on the underside of the pileus...
that reaches up to 11 cm (4.3 in) in diameter, and a yellow stem measuring up to 7 cm (2.8 in) tall by 1 to 2 cm (0.393700787401575 to 0.78740157480315 in) thick. On the underside of the cap are small angular pores, initially bright yellow before turning greenish-brown with age. A characteristic feature that helps to distinguish it from similar Suillus species, like S. granulatus
Suillus granulatus
Suillus granulatus is a pored mushroom of the genus Suillus in the Suillaceae family. It is similar to the related S. luteus, but can be distinguished by its ringless stalk. Like S. luteus, it is an edible mushroom that often grows in a symbiosis with pine...
, is the pinkish mycelia at the base of the stem.
Molecular analysis has shown the species to be related to other typical Mediterranean Suillus species such as S. bellinii
Suillus bellinii
Suillus bellinii is a pored mushroom of the genus Suillus in the Suillaceae family. It is found in coastal pine forests of southern Europe.-Description:...
, S. luteus
Suillus luteus
Suillus luteus is a basidiomycete fungus, and the type species of the genus Suillus. It is a common fungus indigenous to coniferous forests of Eurasia and North America, and introduced to southern Australia and New Zealand...
, and S. mediterraneensis
Suillus mediterraneensis
Suillus mediterraneensis is a species of edible mushroom in the genus Suillus. Originally named Boletus mediterraneensis in 1969, it was transferred to Suillus in 1992....
. S. collinitus is a mycorrhizal species, and forms associations with several species of pine
Pine
Pines are trees in the genus Pinus ,in the family Pinaceae. They make up the monotypic subfamily Pinoideae. There are about 115 species of pine, although different authorities accept between 105 and 125 species.-Etymology:...
, most notably the Aleppo pine
Aleppo Pine
Pinus halepensis, commonly known as the Aleppo Pine, is a pine native to the Mediterranean region. Their range extends from Morocco and Spain north to southern France, Italy and Croatia, and east to Greece and northern Tunisia, and Libya, with an outlying population in Syria, Lebanon, southern...
. This tree species is commonly used in reforestation
Reforestation
Reforestation is the natural or intentional restocking of existing forests and woodlands that have been depleted, usually through deforestation....
schemes and soil conservation
Soil conservation
Soil conservation is a set of management strategies for prevention of soil being eroded from the Earth’s surface or becoming chemically altered by overuse, acidification, salinization or other chemical soil contamination...
against erosion
Erosion
Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...
in the Mediterranean region, and S. collinitus is often used as a beneficial inoculant to help the young trees better survive in typically harsh soil conditions.
Taxonomy, phylogeny, and naming
The species was first describedSpecies description
A species description or type description is a formal description of a newly discovered species, usually in the form of a scientific paper. Its purpose is to give a clear description of a new species of organism and explain how it differs from species which have been described previously, or are...
as Boletus collinitus by Elias Magnus Fries
Elias Magnus Fries
-External links:*, Authors of fungal names, Mushroom, the Journal of Wild Mushrooming.*...
in 1838. Otto Kuntze
Otto Kuntze
Otto Carl Ernst Kuntze was a German botanist.-Biography:Otto Kuntze was born in Leipzig.An apothecary in his early career, he published an essay entitled Pocket Fauna of Leipzig. Between 1863 and...
transferred it to the genus Suillus
Suillus
Suillus is a genus of basidiomycete fungi in the family Suillaceae and order Boletales. Species in the genus are associated with coniferous trees, and are mostly distributed in northern temperate locations, although some species have been introduced to the Southern Hemisphere.-Taxonomy:The genus...
in his 1898 Revisio Generum Plantarum. In 1969 Swiss mycologist H.S.C. Huijsman described the variety S. collinitus var. aureus (as S. fluryi var. aureus; S. fluryi is a synonym
Synonym (taxonomy)
In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...
of S. collinitus) based on a collection from Switzerland. The variety velatipes was described in 1998 by Giampaolo Simonini and colleagues from Italian collections.
A 1996 molecular analysis of 38 different Suillus species used the sequences of their internal transcribed spacer
Internal transcribed spacer
ITS refers to a piece of non-functional RNA situated between structural ribosomal RNAs on a common precursor transcript. Read from 5' to 3', this polycistronic rRNA precursor transcript contains the 5' external transcribed sequence , 18S rRNA, ITS1, 5.8S rRNA, ITS2, 28S rRNA and finally the 3'ETS...
s to infer phylogenetic relationships and clarify the taxonomy
Taxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...
of the genus. The results indicated that S. collinitus is most closely related to a specimen of S. granuatus collected from Nepal. According to the authors, this Nepalese isolate
Genetic isolate
A genetic isolate is population of organisms that has little genetic mixing with other organisms within the same species. This may result in speciation, but this is not necessarily the case...
probably represents a species distinct from North American and European isolates, based on morphology and host tree association. In 2006, a phylogenetic analysis of Suillus isolates collected from Spain showed that S. collinitus was closely related to other species "typical of the Mediterranean area", namely S. bellinii
Suillus bellinii
Suillus bellinii is a pored mushroom of the genus Suillus in the Suillaceae family. It is found in coastal pine forests of southern Europe.-Description:...
, S. luteus
Suillus luteus
Suillus luteus is a basidiomycete fungus, and the type species of the genus Suillus. It is a common fungus indigenous to coniferous forests of Eurasia and North America, and introduced to southern Australia and New Zealand...
, and S. mediterraneensis
Suillus mediterraneensis
Suillus mediterraneensis is a species of edible mushroom in the genus Suillus. Originally named Boletus mediterraneensis in 1969, it was transferred to Suillus in 1992....
.
The specific epithet collinitus is derived from Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
, and means "smeared" or "greased". The British botanist Mordecai Cubitt Cooke
Mordecai Cubitt Cooke
Mordecai Cubitt Cooke was an English botanist and mycologist.Cooke came from a mercantile family in Horning, Norfolk, and worked as an apprentice to a fabric merchant before becoming a clerk in a law firm, but his chief interest was in botany. He founded the Society of Amateur Botanists in 1862...
called the mushroom the "ringless yellow boletus" in an 1873 publication.
Description
The fruit bodyBasidiocarp
In fungi, a basidiocarp, basidiome or basidioma , is the sporocarp of a basidiomycete, the multicellular structure on which the spore-producing hymenium is borne. Basidiocarps are characteristic of the hymenomycetes; rusts and smuts do not produce such structures...
of Suillus collinitus is a medium to large, fleshy bolete
Bolete
A bolete is a type of fungal fruiting body characterized by the presence of a pileus that is clearly differentiated from the stipe, with a spongy surface of pores on the underside of the pileus...
. The cap
Pileus (mycology)
The pileus is the technical name for the cap, or cap-like part, of a basidiocarp or ascocarp that supports a spore-bearing surface, the hymenium. The hymenium may consist of lamellae, tubes, or teeth, on the underside of the pileus...
is initially rounded, becoming convex and finally flat, reaching up to 11 cm (4.3 in) in diameter. The cap is covered with a brown cuticle
Pileipellis
thumb|300px||right|The cuticle of some mushrooms, such as [[Russula mustelina]] shown here, can be peeled from the cap, and may be useful as an identification feature....
of variable shade that is decorated with minuscule radial striations, which become more obvious in fully expanded specimens and especially in dry weather. The cap is often shaped irregularly and becomes viscid (sticky) when damp. The tubes
Hymenium
The hymenium is the tissue layer on the hymenophore of a fungal fruiting body where the cells develop into basidia or asci, which produce spores. In some species all of the cells of the hymenium develop into basidia or asci, while in others some cells develop into sterile cells called cystidia or...
are short and their stem attachment is usually slightly decurrent to adnate. The small and angular pores are yellow but darken with age. Young, fresh specimens sometimes bear droplets of a clear fluid that collect on the pore surface.
The cylindrical stem
Stipe (mycology)
thumb|150px|right|Diagram of a [[basidiomycete]] stipe with an [[annulus |annulus]] and [[volva |volva]]In mycology a stipe refers to the stem or stalk-like feature supporting the cap of a mushroom. Like all tissues of the mushroom other than the hymenium, the stipe is composed of sterile hyphal...
is often short and stubby, typically 4 – tall by 1 – thick, coloured yellowish and ornamented with sparse reddish-brown granules. There is no ring
Annulus (mycology)
An annulus is the ring like structure sometimes found on the stipe of some species of mushrooms. The annulus represents the remaining part of the partial veil, after it has ruptured to expose the gills or other spore-producing surface. An annulus may be thick and membranous, or it may be cobweb-like...
. The base of the stem bears pink overtones and is attached to distinctively pink mycelial threads
Mycelium
thumb|right|Fungal myceliaMycelium is the vegetative part of a fungus, consisting of a mass of branching, thread-like hyphae. The mass of hyphae is sometimes called shiro, especially within the fairy ring fungi. Fungal colonies composed of mycelia are found in soil and on or within many other...
, which are visible when the fruit body is uprooted. The flesh
Trama (mycology)
In mycology trama is a term for the inner, fleshy portion of a mushroom's basidiocarp, or fruit body. It is distinct from the outer layer of tissue, known as the pileipellis or cuticle, and from the spore-bearing tissue layer known as the hymenium....
is yellowish, thick and soft. In a colour reaction test
Chemical tests in mushroom identification
Chemical tests in mushroom identification are methods that aid in determining the variety of some fungi. The most useful tests are Melzer's reagent and potassium hydroxide.- Ammonia :Household ammonia can be used. A couple of drops are placed on the flesh...
with ammonia
Ammonia
Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...
solution, the flesh turns reddish.
The spore
Spore
In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoa. According to scientist Dr...
s are seen ochre
Ochre
Ochre is the term for both a golden-yellow or light yellow brown color and for a form of earth pigment which produces the color. The pigment can also be used to create a reddish tint known as "red ochre". The more rarely used terms "purple ochre" and "brown ochre" also exist for variant hues...
-brown in mass
Spore print
thumb|300px|right|Making a spore print of the mushroom Volvariella volvacea shown in composite: mushroom cap laid on white and dark paper; cap removed after 24 hours showing pinkish-tan spore print...
, but pale yellow when viewed with a light microscope. They are fusiform (tapered at each end), sized 8–10.5 by 3–4.5 μm
Micrometre
A micrometer , is by definition 1×10-6 of a meter .In plain English, it means one-millionth of a meter . Its unit symbol in the International System of Units is μm...
. The basidia (spore-bearing cells of the hymenium
Hymenium
The hymenium is the tissue layer on the hymenophore of a fungal fruiting body where the cells develop into basidia or asci, which produce spores. In some species all of the cells of the hymenium develop into basidia or asci, while in others some cells develop into sterile cells called cystidia or...
) are four-spored.
Especially characteristic for S. collinitus are the cap striations and pink mycelium. The fungus in many aspects resembles S. granulatus
Suillus granulatus
Suillus granulatus is a pored mushroom of the genus Suillus in the Suillaceae family. It is similar to the related S. luteus, but can be distinguished by its ringless stalk. Like S. luteus, it is an edible mushroom that often grows in a symbiosis with pine...
– a common species in European pine forests. S. granulatus, however, has a homogenous brown cap without striations, and its mycelium is characteristically white.
Varieties
Two varieties of S. collinitus have been described. S. collinitus var. aureus has a golden-yellow cap. S. collinitus var. velatipes, originally found in Italy growing in poor acidic soil in association with Aleppo pineAleppo Pine
Pinus halepensis, commonly known as the Aleppo Pine, is a pine native to the Mediterranean region. Their range extends from Morocco and Spain north to southern France, Italy and Croatia, and east to Greece and northern Tunisia, and Libya, with an outlying population in Syria, Lebanon, southern...
(Pinus halepensis), is distinguished by a glutinous brown veil at the base of the stem, and a slender white felting at the cap margin.
Similar species
Suillus collinitus is often found in the same habitat with other thermophilic species, including S. mediterraneensis and S. belliniiSuillus bellinii
Suillus bellinii is a pored mushroom of the genus Suillus in the Suillaceae family. It is found in coastal pine forests of southern Europe.-Description:...
, especially in the Mediterranean basin
Mediterranean Basin
In biogeography, the Mediterranean Basin refers to the lands around the Mediterranean Sea that have a Mediterranean climate, with mild, rainy winters and hot, dry summers, which supports characteristic Mediterranean forests, woodlands, and scrub vegetation...
. Some common species which occur throughout much of Europe and also associate with two-needled pines include S. luteus
Suillus luteus
Suillus luteus is a basidiomycete fungus, and the type species of the genus Suillus. It is a common fungus indigenous to coniferous forests of Eurasia and North America, and introduced to southern Australia and New Zealand...
and S. granulatus
Suillus granulatus
Suillus granulatus is a pored mushroom of the genus Suillus in the Suillaceae family. It is similar to the related S. luteus, but can be distinguished by its ringless stalk. Like S. luteus, it is an edible mushroom that often grows in a symbiosis with pine...
.
Edibility
Various authors regard Suillus collinitus as edibleEdible mushroom
Edible mushrooms are the fleshy and edible fruiting bodies of several species of fungi. Mushrooms belong to the macrofungi, because their fruiting structures are large enough to be seen with the naked eye. They can appear either below ground or above ground where they may be picked by hand...
with a sour odor and nondescript taste. It is advisable, as for all species of Suillus, to pick only young specimens and to peel the cuticle before preparation. The mushroom contains several tocopherols, a class of chemical compounds collectively known as vitamin E
Vitamin E
Vitamin E is used to refer to a group of fat-soluble compounds that include both tocopherols and tocotrienols. There are many different forms of vitamin E, of which γ-tocopherol is the most common in the North American diet. γ-Tocopherol can be found in corn oil, soybean oil, margarine and dressings...
, and which confer antioxidant
Antioxidant
An antioxidant is a molecule capable of inhibiting the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons or hydrogen from a substance to an oxidizing agent. Oxidation reactions can produce free radicals. In turn, these radicals can start chain reactions. When...
activity. They also contain several organic acid
Organic acid
An organic acid is an organic compound with acidic properties. The most common organic acids are the carboxylic acids, whose acidity is associated with their carboxyl group –COOH. Sulfonic acids, containing the group –SO2OH, are relatively stronger acids. The relative stability of the conjugate...
s, most predominantly the pairs malic
Malic acid
Malic acid is an organic compound with the formula HO2CCH2CHOHCO2H. It is a dicarboxylic acid which is made by all living organisms, contributes to the pleasantly sour taste of fruits, and is used as a food additive. Malic acid has two stereoisomeric forms , though only the L-isomer exists...
and quinic
Quinic acid
Quinic acid is a cyclitol, a cyclic polyol. It is a crystalline acid obtained from cinchona bark, coffee beans, and other plant products and made synthetically by hydrolysis of chlorogenic acid. Quinic acid is also implicated in the perceived acidity of coffee...
acids, and citric
Citric acid
Citric acid is a weak organic acid. It is a natural preservative/conservative and is also used to add an acidic, or sour, taste to foods and soft drinks...
and ketoglutaric acid, which respectively make up 42% and 30% of total organic acids. The composition and concentration of organic acids in mushrooms are major factors in influencing their flavour; some organic acids contribute to antioxidant activity.
Distribution, habitat, and ecology
Suillus collinitus is found throughout Europe. It is an ectomycorrhizal fungus, forming mutually beneficial symbioticSymbiosis
Symbiosis is close and often long-term interaction between different biological species. In 1877 Bennett used the word symbiosis to describe the mutualistic relationship in lichens...
relationships with several species of pine (Pinus). These include several two-needled European species of pine: Aleppo pine
Aleppo Pine
Pinus halepensis, commonly known as the Aleppo Pine, is a pine native to the Mediterranean region. Their range extends from Morocco and Spain north to southern France, Italy and Croatia, and east to Greece and northern Tunisia, and Libya, with an outlying population in Syria, Lebanon, southern...
(P. halepensis) European black pine
European Black Pine
Pinus nigra, the European Black Pine, is a moderately variable species of pine, occurring across southern Mediterranean Europe from Spain to the Crimea, in Asia Minor and on Cyprus, and in the high mountains of the Maghreb in North Africa....
(P. nigra), stone pine
Stone Pine
The Stone Pine , is also called Italian Stone Pine, or Umbrella Pine , and Parasol Pine. It is in the pine family Pinaceae and occasionally listed under the invalid name Pinus sativa. The tree is native to the Mediterranean region...
(P. pinea), and Scots pine
Scots Pine
Pinus sylvestris, commonly known as the Scots Pine, is a species of pine native to Europe and Asia, ranging from Scotland, Ireland and Portugal in the west, east to eastern Siberia, south to the Caucasus Mountains, and as far north as well inside the Arctic Circle in Scandinavia...
(P. sylvestris). The fungus favours limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
soils. S. collinitus is thermophilic, commonly occurring in southern Europe. It is rarely seen in more northern regions, such as the British Isles and Poland. It is red-listed
Regional Red List
A Regional Red List is a report of the threatened status of species within a certain country or region. It is based on the IUCN Red List of Threatened Species, an inventory of the conservation status of species on a global scale...
in Denmark as near-threatened, and in Estonia as endangered. It has also been collected in Iran.
Suillus collinitus is the most frequent fungus associating with Aleppo pine – a hardy tree utilised for reforestation
Reforestation
Reforestation is the natural or intentional restocking of existing forests and woodlands that have been depleted, usually through deforestation....
schemes and soil conservation
Soil conservation
Soil conservation is a set of management strategies for prevention of soil being eroded from the Earth’s surface or becoming chemically altered by overuse, acidification, salinization or other chemical soil contamination...
against erosion
Erosion
Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...
in the Mediterranean region. A study performed in the south of France discovered that S. collinitus and S. mediterraneensis
Suillus mediterraneensis
Suillus mediterraneensis is a species of edible mushroom in the genus Suillus. Originally named Boletus mediterraneensis in 1969, it was transferred to Suillus in 1992....
are multi-stage ectomycorrhizal fungi, associating with both young and mature stands of Aleppo pine. These two species may play a key role in the survival and adaptation of this species of pine on disturbed calcareous
Calcareous
Calcareous is an adjective meaning mostly or partly composed of calcium carbonate, in other words, containing lime or being chalky. The term is used in a wide variety of scientific disciplines.-In zoology:...
sites. Roots mycorrhizal with S. collinitus were found capable of surviving successive disturbances by fire or ploughing. Moreover, the fungus retained its viability to propagate via its mycelial network which helped the recolonisation effort of newly introduced trees. The fungus has also been shown to improve the growth of Mediterranean pines grown in greenhouse
Greenhouse
A greenhouse is a building in which plants are grown. These structures range in size from small sheds to very large buildings...
s and nurseries. Unlike other Suillus species that grow in wet climates, such as S. grevillei
Suillus grevillei
Suillus grevillei is a mycorrhizal mushroom with a tight, brilliant and dry cap where the hymenium easily separates from the flesh of the cap, with a central stalk that is quite slender...
and S. spraguei
Suillus spraguei
Suillus spraguei is a species of fungus in the Suillaceae family. It is known by a variety of common names, including the painted slipperycap, the painted suillus or the red and yellow suillus. Suillus spraguei has had a complex taxonomical history, and is also frequently referred to Suillus pictus...
, S. collinitus does not typically produce fruit bodies in young plantations. This fruiting behaviour may be attributed to the typically nutrient-poor xeric Mediterranean environment in combination with a lack of tree canopy. The absence of above-ground indicators of fungal presence makes analysis of underground populations difficult; molecular markers have been developed to assist in monitoring fungal growth and ectomycorrhizal formation and persistence in young plantations.
The ectomycorrizhae formed between several Suillus species and Aleppo pine has been studied under in vitro
In vitro
In vitro refers to studies in experimental biology that are conducted using components of an organism that have been isolated from their usual biological context in order to permit a more detailed or more convenient analysis than can be done with whole organisms. Colloquially, these experiments...
conditions in the laboratory. Tree shoots inoculated with either S. collinitus, S. bellinii, and S. mediterraneensis tended to grow better and showed superior mycorrhizal development than other tested Suillus species, suggesting that the three have a "physiological specificity" for the tree. A 2010 publication reported that the fungal hyphae are covered in crystals of oxalic acid
Oxalic acid
Oxalic acid is an organic compound with the formula H2C2O4. This colourless solid is a dicarboxylic acid. In terms of acid strength, it is about 3,000 times stronger than acetic acid. Oxalic acid is a reducing agent and its conjugate base, known as oxalate , is a chelating agent for metal cations...
, which, in addition to reducing soil pH
Soil pH
The soil pH is a measure of the acidity or basicity in soils. pH is defined as the negative logarithm of the activity of hydrogen ions in solution. It ranges from 0 to 14, with 7 being neutral. A pH below 7 is acidic and above 7 is basic. Soil pH is considered a master variable in soils as it...
, reduces grazing
Grazing
Grazing generally describes a type of feeding, in which a herbivore feeds on plants , and also on other multicellular autotrophs...
by the soil microarthropod
Arthropod
An arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...
Folsomia candida.
External links
- YouTube Video describing features (in French)
- www.sentieriboschivi.ch Images of S. collinitus var. velatipes (in Italian)