Cap Color Research Articles

Pan-genome analysis reveals genomic variations during enoki mushroom domestication, with emphasis on genetic signatures of cap color and stipe length

IntroductionThe domestication of edible mushrooms, including Flammulina filiformis, offers valuable insights into the genetic changes driven by artificial selection. Understanding these changes is crucial for uncovering the mechanisms behind genome evolution in domesticated mushrooms. ObjectivesThis study aims to investigate the population structure, genetic diversity, and domestication-related genomic changes in F. filiformis. By comparing the genome sequences of 199 wild and cultivated strains, we aim to elucidate the impact of domestication on F. filiformis. MethodsWe performed de novo genome assembly and gene-based pan-genome analysis on the 199 strains, which included both wild and cultivated strains. We also conducted genome-wide association studies (GWAS) using presence-absence variation (PAV) and SNP data, combined with RNA sequencing, to identify genes associated with domestication traits, such as cap color and stipe length. Gene functional confirmation was achieved through genetic transformation experiments. ResultsOur analysis grouped the strains into four distinct populations, which correlated with varying intensities of artificial selection. The three cultivated populations exhibited smaller genome sizes, fewer genes, lower genetic variation, reduced gene expression diversity, and lower heterozygosity compared to the wild population. The analysis revealed the loss of genes related to the beta-lactam antibiotic catabolic process and specific MAPK pathway genes during domestication, rendering domesticated strains more susceptible to diseases. Four genes closely associated with cap color and stipe length were identified, but genetic transformation experiments confirmed the functional relevance of only two (FfB and FfD) identified through PAV-based GWAS. ConclusionThis study uncovered significant genomic variations between cultivated and wild F. filiformis populations, including the loss of pathogen resistance genes during domestication. We also identified key genes linked to cap color and stipe length, demonstrating for the first time the important role of PAV variation in mushroom domestication. These insights provide a foundation for future mushroom breeding and evolutionary research.

Development of a Test Tube Automatic Sorting Storage Device After Completion of Inspection.

To develop an automatic test tube classification and storage device that sorts test tube boxes by detecting the box height and test tube cap color, improving laboratory efficiency and accuracy. An upper computer uses a No. 1 push rod to allocate test tube boxes to specific branch conveyor belts based on initial sorting criteria. Further sorting is done by the No. 2 push rod, which places boxes into adjustable slots within a seven-layer elevating storage system, categorizing them by day through height adjustment to match the conveyor belt. This invention automates test tube sorting and storage, aiding medical staff in quickly and accurately locating test tubes post-inspection.

What about generic glaucoma medications and the ocular surface?

There is an ongoing debate among healthcare providers about the safety and effectiveness of generic eye drops compared to branded eye drops. Although one would expect generic eye drops to be a true copy of the original eye drop, there are surprisingly few requirements for the introduction of a generic eye drop on the market. Thus, only the concentration of the active ingredients must be identical to that of the original product. As many other factors such as bottle material, bottle shape and size and cap colour, drop size, pH, viscosity and buffer capacity can influence the efficacy, there are doubts whether generic products are truly identical to their original variants. This presentation will provide an overview of current original/generic eye drops and the challenges that patients may face when using generic variants.

Development of Cleaved Amplified Polymorphic Sequence Marker for Cap Color Identification in Pleurotus cornucopiae

Cap color is one of the most crucial commercial traits for oyster mushrooms, and dark-colored varieties are highly favored by consumers, yet they are relatively scarce on the market. There is an urgent need for the selection and breeding of dark oyster mushrooms. Previous studies identified PcTYR, a key gene that controls the cap color of Pleurotus cornucopiae, and four SNPs were identified based on a genome-level sequence comparison of the black and white gene pools for extreme traits in the segregating populations. In this study, we verified whether these SNPs were color-specific sites via specific primer design, PCR amplification, and enzyme digestion of the entire isolated population strains and developed CAPS/dCAPS markers for the early visual identification of cap color to assist material screening in cap color breeding. One CAPS marker, TYR-CAPS-3-2, was developed for identifying the cap color of oyster mushrooms. After digestion with the restriction endonuclease Mse I, the marker generated polymorphic bands that accurately and visually distinguished dark-colored (non-white) and white strains from the cap color-segregating population. Consequently, the application of this marker during the early growth stage of oyster mushrooms can facilitate molecular-marker-assisted selection, expediting the breeding process for dark-colored varieties.

Population genetics provides insights into the important agronomic traits of Ganoderma cultivation varieties in China

This study aimed to investigate the species diversity and genetic differentiation of the genome of the main cultivated strains of Ganoderma in China. Population genomics analysis was conducted based on 150 cultivated strains of Ganoderma collected nationwide. The results indicated that the main species currently cultivated in China were Ganoderma sichuanense and Ganoderma lucidum, with a minor proportion of Ganoderma sessile, Ganoderma weberianum, Ganoderma sinense, Ganoderma gibbosum and Ganoderma australe. A total of 336,506 high-quality single nucleotide polymorphism (SNP) loci were obtained through population evolution analysis. The Fst values were calculated using a 5-kb sliding window, which ranged from 0.11 to 0.74. This suggests varying degrees of genetic differentiation between populations and genetic exchange among varieties. On this basis, the genes related to the stipe length, cap color and branch phenotypes of Ganoderma were excavated, and the region with the top 1% ZFst value region was used as a candidate region. A total of 137, 270 and 222 candidate genes were identified in the aforementioned 3 phenotypes, respectively. Gene annotation revealed that genes associated with stipe length were mainly related to cell division and differentiation, including proteins such as Nse4 protein and DIM1 protein. The genes related to Ganoderma red color were mainly related to the metabolism of tryptophan and flavonoids. The genes related to the branch were mainly related to cytokinin synthesis, ABC transporter and cytochrome P450. This study provided 150 valuable genome resequencing data in assessing the diversity and genetic differentiation of Ganoderma and laid a foundation for agronomic trait analysis and the development of new varieties of Ganoderma.

Transcriptome Analysis Revealed That Hydrogen Peroxide-Regulated Oxidative Phosphorylation Plays an Important Role in the Formation of Pleurotus ostreatus Cap Color.

Pleurotus ostreatus is widely cultivated in China. H2O2, as a signaling molecule, can regulate the formation of cap color, but its regulatory pathway is still unclear, severely inhibiting the breeding of dark-colored strains. In this study, 614 DEGs specifically regulated by H2O2 were identified by RNA-seq analysis. GO-enrichment analysis shows that DEGs can be significantly enriched in multiple pathways related to ATP synthesis, mainly including proton-transporting ATP synthesis complex, coupling factor F(o), ATP biosynthetic process, nucleoside triphosphate metabolic processes, ATP metabolic process, purine nucleoside triphosphate biosynthetic and metabolic processes, and purine ribonuclease triphosphate biosynthetic metabolic processes. Further KEGG analysis revealed that 23 DEGs were involved in cap color formation through the oxidative phosphorylation pathway. They were enriched in Complexes I, III, IV, and V in the respiratory chain. Further addition of exogenous uncoupling agents and ATP synthase inhibitors clarifies the important role of ATP synthesis in color formation. In summary, H2O2 may upregulate the expression of complex-encoding genes in the respiratory chain and promote ATP synthesis, thereby affecting the formation of cap color. The results of this study lay the foundation for the breeding of dark-colored strains of P. ostreatus and provide a basis for the color-formation mechanism of edible fungi.

In Silico Characterization of the Physicochemical and Biological Properties of the Pink (Pleurotus djamor var. salmoneostramineus) Oyster Mushroom Chromoprotein.

Cap color is an important commercial trait for oyster mushrooms. Various pigment constituents determine a diverse color. However, the pigments of oyster mushrooms are still ambiguous. The pink oyster mushroom (Pleurotus salmoneostramineus or Pleurotus djamor) chromoprotein is one of the few proteins belonging to this fungus that has a record of its sequence of amino acid residues. However, even though there are studies about this chromoprotein isolation, purification, and crystallization, the current information focused on its 3-dimensional model and the cofactor and prosthetic group (3H-indol-3-one) binding sites is unreliable and fragmented. Therefore, in this study, using free online servers such as Prot pi, GalaxyWEB, MIB, and CB-Dock2, a structural analysis and the prediction of its physicochemical and biological properties were conducted, to understand the possible function of this chromoprotein. The obtained results showed that this molecule is a protein with a molecular weight of 23 712.5 Da, an isoelectric point of 7.505, with oligomerization capacity in a dimer and glycation in the Ser6 residue. In addition, the participation of the residues Leu5, Leu8, Lys211, Ala214, and Gln215 in the binding of the prosthetic group to the protein was highlighted; as well as Ser6 and Pro7 are important residues for the interaction of the Mg2+ ion and eumelanin. Likewise, morphological changes based on different culture conditions (light/dark) showed that this protein is constitutive expressed and independent of blue light. The findings in this study demonstrate that pink chromoprotein is a melanosomal protein, and it possibly has a critical role in melanogenesis and the melanin polymerization. However, more experimental studies are needed to predict a possible mechanism of action and type of enzymatic activity.

Synthesis and structural characteristics analysis of melanin pigments induced by blue light in Morchella sextelata.

Morchella sextelata, a highly sought-after edible mushroom worldwide, is evaluated based on its cap color as an essential commercial property indicator. In the present study, the effects of blue light on cap pigmentation in M. sextelata, as well as the synthesis and structural characteristics of melanin pigments within the cap were examined. The results showed that an increase in the proportion of blue light within the lighting environment promoted melanin synthesis and melanization of the cap. Transmission and scanning electron microscopy revealed the localization of melanin within the mycelium and its ultrastructural characteristics. The UV-visible analysis demonstrated that melanin exhibited a maximum absorption peak at 220 nm and possessed high alkaline solubility as well as acid precipitability. The structural characteristics of melanin were analyzed using FTIR, NMR, HPLC, and elemental analysis, which confirmed the presence of eumelanin, pheomelanin, and allomelanin in both brown and black caps. Furthermore, blue light can stimulate the synthesis of both eumelanin and pheomelanin. The obtained results can serve as the foundation for comprehending the mechanism by which light regulates color formation in mushrooms.

Indigenous knowledge on wild mushrooms in communities bordering miombo woodlands of central Zimbabwe

ABSTRACT Apart from timber, fruits, honey, firewood and other benefits from forests, mushrooms are an important forest food resource whose gathering has largely relied on indigenous knowledge systems (IKS). We surveyed five miombo woodland rural communities in central Zimbabwe with respondents of at least 16 years old, focusing on wild mushroom identification criteria used, ethnomycological knowledge transmission mechanisms, known mushroom foragers, known woody species associated with gathered mushrooms, and indigenous mushroom nomenclature systems used. Mushroom cap colour (99.52 %) was of similar importance to use of cap texture (95.78%) but more important (p ≤ .05) than cap shape, or other attributes. Women (69.04%) were more important (p ≤ .05) knowledge transmitters than other family members. Millipedes (91.79%) and insects (83.55%) constituted higher (p ≤ .05) mushroom foraging mention than other invertebrates. Julbernardia globiflora (84.16%) was more favourably mentioned (p ≤ .05) to associate with most mushrooms than other woody species. Mushroom nomenclature largely derived from their morphological traits, texture and habitat. The study demonstrates prevalence of moderately strong IKS and mushroom links to vegetation. These findings will help in ethnomycological research on aspects of miombo mushrooms and any relevant forest policy to benefit rural communities.

Comparison of Fumigation and Immersion of Essential Oils on Quality and Physiology of Fresh Shiitake Mushrooms (Lentinus edodes)

The effects of different essential oils with fumigation or immersion on sensory and physiological quality of fresh shiitake mushrooms were evaluated during the storage. Shiitake mushrooms were treated with essential oils (grapefruit essential oil, rosemary essential oil, cinnamon essential oil) by fumigation and immersion respectively. The surface color, browning degree, sensory evaluation, hardness, soluble protein content, total phenolic content and DPPH· scavenging ability of shiitake mushrooms were measured during the storage. The results showed that hardness, sensory qualities and soluble protein decreased gradually with the extension of storage period in all the treatments and rosemary essential oil had better effect on maintaining cap color, sensory quality, total phenolic content and DPPH· scavenging ability compared with other treatments. In general, immersion treatment showed better effect on shiitake mushrooms preservation than fumigation treatment.

Visual design elements of product packaging: Implications for consumers' emotions, perceptions of quality, and price

AbstractThis study used three progressive experiments to isolate two dimensions of bottled water packaging: cap color and bottle shape. The objective of the first experiment was to test how the color of the bottle cap can change consumer preference. We evaluated four cylindrical bottles with different color caps (red, black, blue, and white). Results show that using a blue cap generates substantial positive changes in preference. The goal of the second experiment was to isolate the effect of bottle shape. Of the three bottle forms (cylindrical, squared, and anthropomorphic), the anthropomorphic was preferred. Results show that using a blue cap or an anthropomorphic shape improves preference and quality perceptions. A third experiment compared four price gaps (same price, 5%, 10%, and 20%) for the best versus worst shape and/color combination. In general, increasing the price of the bottle with the best color and shape decreases the choice preference. However, a 20% price increase improves the quality perception and inverts this trend. These results give product designers and marketing managers insights on how use color and shape to gain consumer preference.

Isolation and identification of pigments from oyster mushrooms with black, yellow and pink caps

The genus Pleurotus, namely oyster mushroom, is widely cultivated and consumed worldwide. Cap color is an important commercial trait for oyster mushroom. Diverse color is determined by various pigment constituents. However, the pigments of oyster mushrooms are still ambiguous. In this study, we extracted and identified pigments of oyster mushroom species with black, yellow and pink cap color. The extracted pigments appearing the three color types correspondingly to the cap color, which were all identified as melanin using a panel of spectroscopic and physical/imaging techniques. Nevertheless, HPLC and elemental analysis indicated that the melanin in oyster mushrooms was actually a mixture of eumelanin and phaeomelanin. Differences in the quantities and relative proportions of eumelanin and phaeomelanin resulted in the color variation in oyster mushroom caps. Electron microscopy studies showed that the melanin units are likely located in the cell wall, as reported in other fungi. The pigments in oyster mushrooms with three different cap color were extracted and identified for the first time in this study, which provided fundamental knowledge for future studies on the mechanism of color formation in mushrooms.

Genetic Linkage and Physical Mapping for an Oyster Mushroom (Pleurotus cornucopiae) and Quantitative Trait Locus Analysis for Cap Color.

Oyster mushrooms are grown commercially worldwide, especially in many developing countries, for their easy cultivation and high biological efficiency. Pleurotus cornucopiae is one of the main oyster mushroom species because of its gastronomic value and nutraceutical properties. Cap color is an important trait, since consumers prefer dark mushrooms, which are now represented by only a small portion of the commercial varieties. Breeding efforts are required to improve quality-related traits to satisfy various demands of consumers. Here, we present a saturated genetic linkage map of P. cornucopiae constructed by using a segregating population of 122 monokaryons and 3,449 single nucleotide polymorphism (SNP) markers generated by the 2b-RAD approach. The map contains 11 linkage groups covering 961.6 centimorgans (cM), with an average marker spacing of 0.27 cM. The genome of P. cornucopiae was de novo sequenced, resulting in 425 scaffolds (>1,000 bp) with a total genome size of 35.1 Mb. The scaffolds were assembled to the pseudochromosome level with the assistance of the genetic linkage map. A total of 97% SNP markers (3,357) were physically localized on 140 scaffolds that were assigned to 11 pseudochromosomes, with a total of 32.5 Mb, representing 92.5% of the whole genome. Six quantitative trait loci (QTL) controlling cap color of P. cornucopiae were detected, accounting for a total phenotypic variation of 65.6%, with the highest value for the QTL on pseudochromosome 5 (18%). The results of our study provide a solid base for marker-assisted breeding for agronomic traits and especially for studies on biological mechanisms controlling cap color in oyster mushrooms. IMPORTANCE Oyster mushrooms are produced and consumed all over the world. Pleurotus cornucopiae is one of the main oyster mushroom species. Dark-cap oyster mushrooms are becoming more and more popular with consumers, but dark varieties are rare on the market. Prerequisites for efficient breeding programs are the availability of high-quality whole genomes and genetic linkage maps. Genetic studies to fulfill some of these prerequisites have hardly been done for P. cornucopiae. In this study, we de novo sequenced the genome and constructed a saturated genetic linkage map for P. cornucopiae. The genetic linkage map was effectively used to assist the genome assembly and identify QTL that genetically control the trait cap color. As well, the genome characteristics of P. cornucopiae were compared to the closely related species Pleurotus ostreatus. The results provided a basis for understanding the genetic background and marker-assisted breeding of this economically important mushroom species.

The abundance and diversity of Basidiomycetes fungi in sago bark waste

This study was aimed to determine the abundance and diversity of Basidiomycetes fungi on sago bark waste. This research was conducted in January-February 2020 at Tondok Alla village, Telluwanua district, Palopo city (as location I) and Kalotok village, South Sabbang district, North Luwu regency (as location II). Climate data for the study period were obtained from the BMKG online website. The morphology of the fungi obtained from the sago bark waste was observed and identified morphologically for stalk color, cap structure and cap colour. The number of identified Basidiomycetes were analyzed to obtain relative abundance, species richness, evenness, Shannon Wiener diversity index, Simpson dominance index, and community similarity index. The climate observation results showed that, the average temperature was 27.74 (° C), 80.36% humidity, 12.37 mm of rainfall, and 4 hours / day of sun exposure. The fungi observation results showed that, several species of Basidiomycetes fungi was observed at both locations. Schizophyllum commune is the dominant species at both sites, and Ganoderma sp. the least. The species richness index, species evenness index, and diversity index at location I were higher than location II, while the Simpson dominance index was the highest in location II. Both locations have the same community structure based on the similarity index.

Mushroom Toxicity Recognition Based on Multigrained Cascade Forest

Due to the tastiness of mushroom, this edible fungus often appears in people’s daily meals. Nevertheless, there are still various mushroom species that have not been identified. Thus, the automatic identification of mushroom toxicity is of great value. A number of methods are commonly employed to recognize mushroom toxicity, such as folk experience, chemical testing, animal experiments, and fungal classification, all of which cannot produce quick, accurate results and have a complicated cycle. To solve these problems, in this paper, we proposed an automatic toxicity identification method based on visual features. The proposed method regards toxicity identification as a binary classification problem. First, intuitive and easily accessible appearance data, such as the cap shape and color of mushrooms, were taken as features. Second, the missing data in any of the features were handled in two ways. Finally, three pattern-recognition methods, including logistic regression, support vector machine, and multigrained cascade forest, were used to construct 3 different toxicity classifiers for mushrooms. Compared with the logistic regression and support vector machine classifiers, the multigrained cascade forest classifier had better performance with an accuracy of approximately 98%, enhancing the possibility of preventing food poisoning. These classifiers can recognize the toxicity of mushrooms—even that of some unknown species—according to their appearance features and important social and application value.

The Efficacy of the After-visit Summary in Medication Recall Among Glaucoma Patients.

The purpose of this study was to determine whether patients given the AVS have better or worse glaucoma medication recall. Observational clinical study. Adults on ≥1 glaucoma medications examined between June 30, 2017 and August 2, 2017. in-person questionnaire and retrospective chart review. Self-reported glaucoma medications compared with prescribed glaucoma medication regimen verified by electronic medical record. Medication recall assessed using 3-point scoring: 1 point each for; (1) name or color of bottle or cap; (2) treatment eye(s); and (3) dosing regimen. 2-sample Welch t test, 2-proportion z-test, analysis of variance, univariate, and multivariate regression. A total of 118 patients enrolled: age 69.7±12.9 years (mean±SD), 55.9% of patients had received an AVS at the previous visit. Of these, 33.3% reported receiving an AVS, 51.2% reported not receiving one (15.1% did not recall or respond). Patients who had received AVSs had lower medication recall scores than those who did not (2.4±1.0 vs. 2.7±0.6, P=0.04). Receipt of an AVS was associated with having Nisha Chadha as their provider (P=0.01), fewer days since prior visit (P=0.0001), and medication regimen change at prior visit (P<0.0001). Multivariate analysis revealed completion of associate's degree or higher and fewer prescribed medications to be independent predictors of higher recall score (P=0.0002 and 0.002). AVSs were conceived to enhance patient care. This study indicates this goal is not achieved consistently. Less education and more complex medication regimens were identified as barriers to medication recall. Additional investigations should explore if modifying this document and enhanced explanation of its use will impact medication recall and health outcomes.

Catatan Beberapa Jamur Makro di Hutan Kampus Institut Pertanian Bogor

Macroscopic fungi is cosmopolitan-heterotrophic organisms which have an important ecological role in ecocystem. The aim of this study was to explore the diversity of species and the potency of Fungi in the Campus Forest of IPB Unversity. Observation was carried out in March to April 2019 using exploration method. Identification used morphological characteristic such as fruit body shape, hygrophnous, cap color, diameter, edge, and margin, wetness level, himenophore type. Result showed that 11 species of macroscopic fungi were identified, divided into 7 families, 4 order, and 1 class. The Group fungi were identified as Termitomyces sp. 1, Termitomyces sp. 2, Marasmius sp. 1, Marasmius sp. 2, Psathyrella sp., Geastrum sp., Stereum sp., Microporus sp., Polyporus sp., Ganoderma sp. 1 and Ganoderma sp. 2. All identified fungi were Basidiomycota. Some fungi found to be potentially used as food source, medicine, and also played an important role as a decomposer in the IPB university campus forest.

The effect of the sex, age, and breed of farmed rabbits and the choice of management system on the extensity and intensity of Eimeria infection.

Background and Aim:The most common causes of loss and diarrhea in rabbit farming are nutritional errors and coccidiosis. The infection can spread rapidly throughout a breeding area, reducing the rabbit population, and causing heavy losses. The aim of the study was to determine the influence of the system of animal management on the extensity and intensity of infection by Eimeria of farmed rabbits, together with the effect of the sex, age, and breed of the rabbits themselves.Materials and Methods:The study included 91 rabbits (Flemish Giant, New Zealand White, French Lope, Vienna Blue, California White, and mixed breed) from eight domestic (small-scale) farms from Poland. The prevalence and intensity of coccidial infection were determined by the Willis-Schlaf and McMaster coprological methods. The species were determined based on oocyst morphology: Their shape, color, form index, the presence or absence of micropyle and cap, and the presence or absence of residual, polar, and Stiedé bodies.Results:Seven species of Eimeria were isolated from the tested rabbits: Eimeria magna, Eimeria media, Eimeria perforans, Eimeria stiedae, Eimeria coecicola, Eimeria exigua, and Eimeria irresidua. Most infections were found to be of relatively low intensity. No significant differences in the extensity of Eimeria protozoan infection were observed with regard to sex. However, rabbit age had a significant influence on the extensity of infection by E. magna and of Eimerian protozoans combined. The greatest extensity was observed in rabbits aged below 6 months. For all species of Eimeria, greater extensity was observed among rabbits kept in groups than individually. The system of rabbit management also had a significant influence on the intensity of infection. Those kept in groups demonstrated a significantly higher mean intensity of infection of E. magna and all Eimeria species combined than those kept individually.Conclusion:Our findings indicate that Eimeria protozoa are a common occurrence on small-scale rabbit farms. As coccidiosis treatment does not always give good results, prevention is very important in the fight against this disease. It is necessary to develop a new preventive paradigm that pays special attention to the factors that promote the spread and development of infection in domestic (small-scale) farms from Poland. For example, it would be recommended to use large, dry, bright rooms with access to the sun, as these are conducive to preventing the occurrence of coccidia infections.

Effect of glaucoma on identification of bottle cap color in ophthalmic medications.

A prospective, nonrandomized, observational trial of 60 glaucoma patients to correlate visual acuity and visual field with ability to distinguish bottle cap color of commonly used ophthalmic medications was conducted. A total of 103 eyes from 60 patients (30 women) were evaluated. The mean logMAR acuity was 0.34±0.54 (approximately 20/45 Snellen acuity), average Humphrey Visual Field (HVF) mean deviation was -8.58±8.69 dB, mean Ishihara plates (out of 14) were 11.78±4.15, and bottle cap color score (out of 10) was 8.56±2.51. Multiple linear regression analysis revealed an independent correlation of visual acuity (P=0.0137) and Ishihara score (P<0.001) with cap color score, but no significant effect with visual field mean deviation (P>0.05). Glaucoma patients with poor visual acuity, but not necessarily advanced visual field loss, are likely to have difficultly identifying the color of their bottle caps. Physicians should be cognizant of this potential issue when reviewing medications with patients.

Diversity within the Hygrophorus agathosmus group (Basidiomycota, Agaricales) in Northern Europe

The North European species of the Hygrophorus agathosmus group in subsection Tephroleuci were studied. Three new species are identified based on morphology, ecology and sequence data. Two species are associated with Pinus spp. One of these is described here as H. suaveolens, while the other one is only known from one locality in the Nordic countries and seems to have a more South European distribution range. A closely related sister species to H. agathosmus is identified based on ITS sequence data, H. cf. agathosmus. It is confirmed to have an intercontinental distribution range and to be associated with Picea spp. probably on more acidic to neutral soil, whereas H. agathosmus s.s. has a more limited North-East European distribution range and occurs in older and rich Picea abies forests. A neotype for H. agathosmus is here selected from South Sweden. Hygrophorus agathosmus f. albus and H. agathosmus f. aureofloccosus are confirmed as forms. No genetic differences in the ITS region between specimens with grey cap colour and the two forms were observed. A key to the species in Northern Europe is provided.