Genus Lactarius Research Articles

Morpho-molecular analyses and scanning electron microscopy reveal two new species of genus Lactarius from the northwestern Himalaya, India.

One of the largest subgenera of the genus Lactarius, Lactarius subg. Russularia is abundant in the forests of the Himalayas. This article proposes Lactarius crassostipes sp. nov. and Lactarius flavocorpus sp. nov. under the L. subgenus Russularia. It includes comprehensive macro- and micro-morphological descriptions, scanning electron microscopy (SEM) micrographs, drawings, and comparisons with related species. The taxa's novelty is validated using phylogenetic analyses based on nrITS. RESEARCH HIGHLIGHTS: SEM and subsequent nrITS-based molecular phylogeny revealed two novel species (L. crassostipes and L. flavocorpus) of the genus Lactarius subg. Russularia. To further characterize the size, form, and ornamentation of these novel species' basidiospores, SEM analysis is an additional tool. In L. crassostipes "crasso" means thick and "stipes" indicates stipe. In contrast to L. flavocorpus, where "flavocorpus" refers to the golden yellow fruiting body, the name alludes to its unique thick stipe. L. crassostipes sp. nov. and L. flavocorpus sp. nov have been collected from the coniferous and broad-leaved forests of Union Territory of Jammu and Kashmir, India, respectively. The diagnostic characteristics, habit, habitat, and similarities to related species are given.

The Genus <I>Lactarius</I> in India

The genus Lactarius (family Russulaceae) is presently known by 56 species and 12 varieties from India. Based on a thorough survey of Himalayan forests and the reports by earlier workers, a detailed distribution, associated trees and the colour of the latex both before and after the exposure is presented for all the Indian taxa.

Two New Species of Genus Lactarius Pers. (Russulaceae) from Arunachal Pradesh, India

Two New Species of Genus Lactarius Pers. (Russulaceae) from Arunachal Pradesh, India

Lactarius badiosanguineus: A new record to Indian mycobiota from Jammu and Kashmir, India

AbstractThe genus Lactarius is cosmopolitan in distribution and forms an ectomycorrhizal association with varied host plants. In the present study, samples of Lactarius badiosanguineus were collected during a fungal survey from different regions of Jammu province, Jammu and Kashmir, India. Identification was carried out through combined morpho‐anatomical and nuclear ribosomal DNA internal transcribed spacer (ITS) sequence analysis that confirmed its position as Lactarius badiosanguineus. This taxon is reported here for the first record from India. Detailed morphological descriptions, color photographs, line drawings, and molecular phylogeny are provided.

A Spirobicyclo[3.1.0]Terpene from the Investigation of Sesquiterpene Synthases from Lactarius deliciosus.

Milk cap mushrooms in the genus Lactarius are known to produce a wide variety of terpene natural products. However, their repertoire of terpene biosynthetic enzymes has not been fully explored. In this study, several candidate sesquiterpene synthases were identified from the genome of the saffron milk cap mushroom L. deliciosus and expressed in a sesquiterpene-overproducing Escherichia coli strain. In addition to enzymes that produce several known terpenes, we identified an enzyme belonging to a previously unknown clade of sesquiterpene synthases that produces a terpene with a unique spiro-tricyclic scaffold. These findings add to the rich diversity of terpene scaffolds and mushroom terpene synthases and are valuable for biotechnological applications in producing these terpenoids.

Substances of Milky Juice of Genus Lactarius Fungi: Chemical and Toxicological Characteristics

Background: Fungi of the genus Lactarius Pers. before the maturation of spores are not damaged by microorganisms, insects, mollusks, and animals. Such resistance correlates with the period when the basidiomes of these fungi are filled with milky juice, which contains substances of various chemical nature that provide their protection. Objective: The aim of our work is to present the results of our recent and previously published studies on the identification and toxicological characteristics of substances available in the milky juice of fungi of the genus Lactarius Pers and used for protection against predator and parasite organisms. The possibility of using these substances to suppress tumor cells is also discussed. Methods: The biological effect of the juice of L. pergamenus, L. quietus, and L. volemus, as well as methylene chloride, extracts obtained from fresh, frozen and dried basidiomes of L. pergamenus was studied. Purification of individual fractions of hexane extract from the basidiomes was performed by chromatography on a silica gel column and their analysis by done by thin layer chromatography and gas chromatography mass spectrometry. Results: The sesquiterpene aldehydes were shown to be the main component of the chemical protection system of Lactarius. These agents are present in the milky juice of the Lactarius fungi, and they are easily oxidized by oxygen in the air. The milky juice of these mushrooms is also rich in higher fatty acids and phthalates. Phthalates possess an insecticidal effect, while higher fatty acids are capable of forming adducts with sesquiterpenes that provide emulsion stability. Water-soluble substances, in particular, the polyphenol oxidase enzyme, whose activity correlates with the content of milky juice in basidiomes, also play a protective role. Conclusion: Milky juice of mushrooms of Lactarius Pers. genus is a stable balanced emulsion containing a large number of substances. One part is responsible for the toxic effects on other organisms, while the other part determines the chemical stability of the emulsion. Altogether, they create an effective system of protection of fungi of the Lactarius genus against microorganisms, insects, mollusks, and animals.

Essential Mineral Content (Fe, Mg, P, Mn, K, Ca, and Na) in Five Wild Edible Species of Lactarius Mushrooms from Southern Spain and Northern Morocco: Reference to Daily Intake.

Mushroom consumption has increased in recent years due to their beneficial properties to the proper functioning of the body. Within this framework, the high potential of mushrooms as a source of essential elements has been reported. Therefore, the present study aims to determine the mineral content of seven essential metals, Fe, Mg, Mn, P, K, Ca, and Na, in twenty samples of mushrooms of the genus Lactarius collected from various locations in southern Spain and northern Morocco, by FAAS, UV-Vis spectroscopy, and ICP-OES after acid digestion. Statistics showed that K was the macronutrient found at the highest levels in all mushrooms studied. ANOVA showed that there were statistically significant differences among the species for K, P, and Na. The multivariate study suggested that there were differences between the accumulation of the elements according to the geographic location and species. Furthermore, the intake of 300 g of fresh mushrooms of each sample covers a high percentage of the RDI, but does not meet the recommended daily intake (RDI) for any of the metals studied, except for Fe. Even considering these benefits, the consumption of mushrooms should be moderated due to the presence of toxic metals, which may pose health risks.

Fungi of the Russulaceae family in the conditions of natural monuments of the Penza region and the influence of environmental factors on their distribution

The relevance of the study of fungi of the Russulaceae family is determined by the fact that they play an important role in the life of temperate forest ecosystems as mycorrhizal symbionts of the main forest-forming tree species. In addition, this group of fungi is of great practical importance, as they are edible fungi. Despite this, they are one of the little studied groups of Agaricomycetes. The information about the fungi of the studied family in the conditions of the Russian Federation is limited, and therefore the data on their ecology are contained mainly in foreign literature. The purpose of this work is to study the species composition of fungi of the Russulaceae family and to establish the influence of the main environmental factors on the distribution of this group of fungi on the territory of some forest natural monuments of regional significance (Burchikhinsky slopes, Zasursky blueberry forest, Kichkleysky pine forest with oak, Nikonovsky forest and Floodplain oak forest) in the conditions of the Penza region. The studies were carried out in 20162022 by methods of route and stationary studies. When determining fungi, the method of light microscopy was used. As a result, the species composition of fungi of the Russulaceae family of the studied natural monuments located in the Penza region was studied. Within the studied protected areas, 78 species of fungi of the Russulaceae family were identified. As a result of the taxonomic analysis of mycobiota, it was found that it included 24 species from the genus Lactarius, 3 from the genus Lactifluus, and 51 from the genus Russula. All of them belong to the ecological-trophic group of symbiotrophs. 19 species form mycorrhiza with various tree species, and 59 species have a narrow specialization in relation to partners in symbiosis (29 species are associated with Quercus robur, 15 with Betula pendula, 10 with Pinus sylvestris, 2 with Populus tremula, 1 with Tilia cordata, 1 with Alnus glutinosa and 1 with Corylus avellana). It has been established that the leading factors determining spatial distribution and productivity of fruiting bodies of fungi of the studied family are soil fertility and moisture. In megatrophic habitat conditions, acidity also has a significant effect on the distribution of fungi of the family under consideration. The species composition of fungi of the Russulaceae family for habitat types was determined in accordance with the edaphic grid. For different ecotopes, the composition of indicator species was revealed. An estimate of the yield of fruiting bodies of fungi of the Russulaceae family in various types of forests, depending on fertility and soil moisture, is given.

Russulaceae of the Pakaraima Mountains of Guyana. IV. New species forming a distinct lineage of Lactarius subg. Plinthogalus

ABSTRACT The Neotropics have recently emerged as an important region for studies of tropical ectomycorrhizal (ECM) fungi. Specific neotropical areas with high ECM host tree densities have ECM fungal diversities rivaling those of higher-latitude forests. Some forests of the Guiana Shield are dominated by endemic ECM trees of the Fabaceae, including species of Dicymbe (subfam. Detarioideae), Aldina (subfam. Papilionoideae), and Pakaraimaea (Cistaceae). One of the most species-rich ECM fungal families present in each of these systems is Russulaceae. Long-term sampling in forests in Guyana’s Pakaraima Mountains has revealed a number of species of the Russulaceae genera Lactarius, Lactifluus, and Russula. In this study, we document a previously unknown, distinct lineage of Lactarius subg. Plinthogalus containing eight species from the Guiana Shield. Here, we describe five of these species from Guyana as new to science: Lactarius humiphilus, Lactarius mycenoides, Lactarius guyanensis, Lactarius dicymbophilus, and Lactarius aurantiolamellatus. Morphological descriptions, habit, habitat, and known distribution are provided for each new species. Sequence data for the barcode internal transcribed spacer (ITS) locus are provided for types and most other collections of the new taxa, and a molecular phylogenetic analysis based on the ITS, 28S, and RPB2 (second-largest subunit of the RNA polymerase II) loci across the genus Lactarius corroborates their morphology-based infrageneric placement. The discovery of this lineage changes our insights into the biogeography and evolutionary history of Lactarius subg. Plinthogalus.

Selected fungi of the genus Lactarius - screening of antioxidant capacity, antimicrobial activity, and genotoxicity

ABSTRACT It is well-known that mushrooms of the genus Lactarius constitute a natural food resource providing health benefits as a nutritient. This genus contains 4 mushrooms identified as L. deliciosus, L. volemus, L. sanguifluus, L. semisanguifluus and L. piperatus which were collected in Serbia. The aim of this study aimed was to identify and characterize the content of phenolic compounds and examine the antioxidant potential of 5 wild edible mushrooms. L. sanguifluus contained the highest content of total phenol compounds (75.25 mg gallic acid equivalents (GAE) per g dry extract weight (GAE/g DE) and exhibited the greatest antioxidant activity through the ability to remove radicals as evidenced by ABTS assay (8.99 mg of trolox equivalents (TE) per g dry extract weight (mg TE/g DE); total reducing power (TRP) assay mg ascorbic acid equivalents per mg of dry extract weight (0.42 mg AAE/g DE) and CUPRAC (14.23 mg TE /g DE). L. deliciosus methanolic extract produced greatest scavenging of the DPPH radical (46%). The methanol mushroom extracts were screened for in vitro antimicrobial activity against a panel of pathogenic bacterial strains using the microdilution method. Of all the extracts tested, L. sanguifluus extract showed the best antibacterial properties. The cytokinesis block micronucleus assay results for the examined mushrooms demonstrated that extracts at a concentration of 3 μg/ml decreased the number of micronuclei (MN) in the range of 19–49% which is significant bearing in mind that radioprotectant amifostine reduced the frequency of MN by only 16.3%. Data thus demonstrate that the 5 wild edible mushrooms of genus Lactarius contain constituents that are beneficial not only as nutrients but also have the potential as antioxidants, antibacterial and antigenotoxic properties.

Lactarius indoevosmus and L. kanadii  (Russulaceae), two new species from the northwestern Himalayas, India, inferred from morphology and molecular data

Two new species of the genus Lactarius from India, Lactarius indoevosmus (L. subg. Lactarius) and L. kanadii (L. subg. Plinthogalus) are presented with detailed descriptions, line drawings, photomicrographs, and comparisons with related species. The novelty and placement of these taxa within the genus Lactarius are confirmed with an ITS-based phylogeny.

Taxonomic Revision of the Genus Lactifluus (Russulales, Basidiomycota) of South Korea

Lactifluus (Pers.) Roussel is an ectomycorrhizal genus that was recently recognized to be distinct from the genus Lactarius. To date, 226 Lactifluus species have been reported worldwide. Misidentification of Lactifluus species is common because of intraspecific morphological variation, cryptic diversity, and the limited number of taxonomic keys available. Molecular data are indispensable for species delimitation; a multilocus phylogenetic analysis showed that most Asian Lactifluus species are not conspecific with morphologically similar species present on other continents. In particular, Korea has misused European and North American Lactifluus names. In this study, we evaluated the taxonomy of Lactifluus in Korea using both morphological and multilocus molecular (ITS, nrLSU, rpb1, and rpb2) data. We examined 199 Lactifluus specimens collected between 1980 and 2016, and a total of 24 species across the four Lactifluus subgenera were identified. All Korean species are distinct and clearly separated from European and North American species. Five taxa corresponded to previously described species from Asia and the remaining 19 taxa are confirmed as new species. Herein, we provide keys to the Korean Lactifluus species within their subgenera, molecular phylogenies, a summary of diversity, and detailed description of the new species.

<p><strong>Two new species of genus <em>Lactarius </em>(<em>Russulaceae</em>) from North-western Himalaya, India</strong></p>

Two new species of genus Lactarius from India, Lactarius sarthalanus (L. subg. Plinthogalus) and L. drassinus (L. subg. Lactarius) are presented with detailed descriptions, line drawings and microphotographs. The novelty and placement of these taxa within the genus Lactarius are confirmed with ITS based phylogeny.

Metal concentrations in Lactarius mushroom species collected from Southern Spain and Northern Morocco: Evaluation of health risks and benefits

In this work, the concentration of five non-essential (Cr, As, Cd, Pb and Hg) and three essential elements (Cu, Zn and Se) in five different species from the genus Lactarius collected from Southern Spain and Northern Morocco were determined by ICP-MS after a block acid digestion. Zn was found to be the major element in all the studied samples, followed by Cu and Cr in almost all the cases. The data obtained from the Health Risk Index (HRI) assessment suggested that As content in L. semisanguifluus and L. deliciosus collected from different locations in Granada and Cadiz provinces (Spain) may pose a risk to human health. The comparison between the Daily Intake of Metals (DIM) and the Recommended Dietary Allowance (RDA) indicated that the consumption of the studied mushrooms only covers a small percentage of the daily requirements of Cu, Zn and Se.

Site fertility and soil water-table level affect fungal biomass production and community composition in boreal peatland forests.

A substantial amount of below-ground carbon (C) is suggested to be associated with fungi, which may significantly affect the soil C balance in forested ecosystems. Ergosterol from in-growth mesh bags and litterbags was used to estimate fungal biomass production and community composition in drained peatland forests with differing fertility. Extramatrical mycelia (EMM) biomass production was generally higher in the nutrient-poor site, increased with deeper water table level and decreased along the length of the recovery time. EMM biomass production was of the same magnitude as in mineral-soil forests. Saprotrophic fungal biomass production was higher in the nutrient-rich site. Both ectomycorrhizal (ECM) and saprotrophic fungal community composition changed according to site fertility and water table level. ECM fungal community composition with different exploration types may explain the differences in fungal biomass production between peatland forests. Melanin-rich Hyaloscypha may indicate decreased turnover of biomass in nutrient-rich young peatland forest. Genera Lactarius and Laccaria may be important in nutrient rich and Piloderma in the nutrient-poor conditions, respectively. Furthermore, Paxillus involutus and Cortinarius sp. may be important generalists in all sites and responsible for EMM biomass production during the first summer months. Saprotrophs showed a functionally more diverse fungal community in the nutrient-rich site.

Macromycetes of the “Baydarsky” Nature Reserve

The article is the first summary on the macromycetes of the “Baydarsky” State Natural Landscape Reserve. The annotated list of macromycetes of the reserve includes 201 species of macromycetes from 97 genera, 45 families, 13 orders. The species composition of families Boletaceae (26 species), Russulaceae (22), Tricholomataceae (19), Agaricaceae (15) and Amanitaceae (12), genera Lactarius (14), Amanita (11), Tricholoma (9), Russula (8), Cortinarius and Ramaria (6 species each), Agaricus and Hygrophorus (5 species each) is found out most fully completed; the number of Boletales mushrooms in the volume of Boletus s. l. is 26 species. For the registered in the reserve 9 species, this is the first find in the Crimean Peninsula, and for 45 species this is the same one in the Sevastopol region. In the Red Book of the Russian Federation included 7 species, the Red Book of the Republic of the Crimea - 14, and the Red Book of the city of Sevastopol - 16.

Biologically Active Aldehydes In Extracts Of Lactarius Pergamenus (Fr.) Fr Fresh Fruiting Bodies

The biologically active aldehydes in extracts of fungi of the genus Lactarius were identified. It’s established that these substances are unstable, they are found in fresh and frozen fungi, but are absent in dried mushrooms and interact with 1,4-phenylenediamine to form a colored compound. Methylene chloride is the best extragent for these substances. TLC on silufol plates showed that there were several substances in Lactarius pergamenus fruiting bodies and they had varying degrees of stability. For selection of these substances, methylene chloride extract was separated on a column of silica gel. Fraction, which gave the most expressive reaction with 1,4-phenylenediamine on thin-layer chromatograms were analyzed by GC-MS both in the absence and in the presence of 1,4-phenylenediamine. As a result, it was found that 1,4-phenylenediamine or other aromatic amines interacted with highly active aldehydes, that were present in fruiting bodies. Among them 2,2-dimethylocta- 3,4-dienal was the most stable and was present in the biggest quantity. This substance very rarely occurs in the vegetable kingdom and in fungi extracts of Lactarius genus wasn’t previously described. Its possible function in fungi is prevention of damage by parasites and eating by animals.

Seasonal Dynamics of Soil Fungal and Bacterial Communities in Cool-Temperate Montane Forests

Both fungal and bacterial communities in soils play key roles in driving forest ecosystem processes across multiple time scales, but how seasonal changes in environmental factors shape these microbial communities is not well understood. Here, we aimed to evaluate the importance of seasons, elevation, and soil depth in determining soil fungal and bacterial communities, given the influence of climate conditions, soil properties and plant traits. In this study, seasonal patterns of diversity and abundance did not synchronize between fungi and bacteria, where soil fertility explained the diversity and abundance of soil fungi but soil water content explained those of soil bacteria. Model-based clustering showed that seasonal changes in both abundant and rare taxonomic groups were different between soil fungi and bacteria. The cluster represented by ectomycorrhizal genus Lactarius was a dominant group across soil fungal communities and fluctuated seasonally. For soil bacteria, the clusters composed of dominant genera were seasonally stable but varied greatly depending on elevation and soil depth. Seasonally changing clusters of soil bacteria (e.g., Nitrospira and Pelosinus) were not dominant groups and were related to plant phenology. These findings suggest that the contribution of seasonal changes in climate conditions, soil fertility, and plant phenology to microbial communities might be equal to or greater than the effects of spatial heterogeneity of those factors. Our study identifies aboveground–belowground components as key factors explaining how microbial communities change during a year in forest soils at mid-to-high latitudes.

A phylogenetic and taxonomic revision of sequestrate Russulaceae in Mediterranean and temperate Europe.

A comprehensive morphological and genetic study of type material and new collections of sequestrate Russulales species formerly belonging to the genera Arcangeliella, Elasmomyces, Gymnomyces, Hydnangium, Hymenogaster, Macowanites, Martellia, Secotium and Zelleromyces is here undertaken, for the purpose of providing a complete taxonomical revision of sequestrate Russulaceae species in the Mediterranean and temperate regions of Europe. As a result, seven distinct taxa in the genus Lactarius and 18 in the genus Russula are identified. Six of them are new species: L. populicola, L. subgiennensis, R. bavarica, R. candidissima, R. hobartiae and R. mediterraneensis, and seven represent new combinations: L. josserandii (≡ Zelleromyces josserandii), L. soehneri (≡ Hydnangium soehneri), R. candida (≡ Hydnangium candidum), R. cerea (≡ Hydnangium cereum), R. messapica var. messapicoides (≡ Macowanites messapicoides), R. meridionalis (≡ Zelleromyces meridionalis) and R. neuhoffii (≡ Hydnangium neuhoffii). Twenty-two of the 25 taxa are illustrated, while descriptions, microscopy images, as well as extensive information on the ecology, chorology and phylogeny for all taxa are provided. A key is further included to facilitate their identification.

Taxonomic revision of the genus Lactarius (Russulales, Basidiomycota) in Korea

The genus Lactarius Pers. (Russulales) is a cosmopolitan group of Basidiomycota that forms ectomycorrhizal relationships primarily with both deciduous and coniferous trees. Although the genus has been well-studied in Europe and North America, only fragmentary researches have been carried out on Asian species. In particular, the distribution of Lactarius species in South Korea is poorly understood due to insufficient morphological descriptions and a lack of DNA sequence data. In addition, the misuse of European and North American names has added to confusion regarding the taxonomy of Asian Lactarius species. In this study, the diversity of Lactarius in South Korea was evaluated by employing both morphological and phylogenetic approaches. A multi-locus phylogenetic analysis of 729 Lactarius specimens collected between 1960 and 2017 was performed using the internal transcribed spacer (ITS) region, partial nuclear ribosomal large subunit (nrLSU), partial second largest subunit of RNA polymerase II (rpb2), and minichromosome maintenance complex component 7 (mcm7). 49 Lactarius species were identified in three Lactarius subgenera: L. subg. Russularia (17 spp.), L. subg. Lactarius (22 spp.), and L. subg. Plinthogalus (10 spp.). Among them, 28 Lactarius species were identified as new to science, while just 17 were previously described Lactarius species. Four of the taxa remain un-named due to paucity of materials. A key to Korean Lactarius species, molecular phylogenies, a summary of diversity, and detailed description are provided.