CRISPR/Cas9 ribonucleoprotein (RNP)-mediated gene editing has recently been applied to Ganoderma lucidum as a promising tool for functional genomics and strain improvement. However, the multinuclear nature of this basidiomycete can result in genetic mosaicism, raising concerns about the long-term stability of edited strains. In this study, we report the occurrence of revertant phenotypes in CRISPR/Cas9-edited transformants of G. lucidum. Although the edited colonies initially exhibited the expected phenotype, repeated subculturing led to the reappearance of wild-type phenotypes. PCR and sequencing analyses revealed the coexistence of edited and non-edited nuclei, and the progressive loss of edited genotypes over successive generations. These findings demonstrate that multinuclearity is a key factor contributing to the instability of CRISPR/Cas9-based edits in G. lucidum. This brief report provides the first direct documentation of revertant occurrence in edited G. lucidum strains and underscores the need for rigorous selection strategies and novel approaches to secure stable homokaryotic transformants in mushroom genetic engineering.

This study reports the development of a new pure white Flammulina velutipes variety, ‘Seoldan’. The breeding process involved a primary cross between a brown strain (KMCC02267) collected by the Rural Development Administration and a white cultivar ‘Baekwoon’ (KMCC05472). From this cross, a white line ‘Fv-23-553’ was selected and subsequently crossed with a superior pure white resource (KMCC05474), resulting in the novel cultivar Seoldan. Mycelial growth tests showed that both varieties grew best at 25°C; however, Seoldan exhibited faster mycelial growth than the control variety under four temperature conditions except at 20°C. In media tests, Seoldan also demonstrated superior growth on three media types, with the exception of YM medium. In sawdust bottle cultivation, The time from scratching to the first fruiting was 2 days shorter in Seoldan than in the control variety, contributing to an overall reduction in cultivation time. The most distinct morphological trait of Seoldan is its pure white cap color. The average yield was 218.8 ± 10.6 g per bottle, comparable to that of the control. Morphologically, Seoldan produced smaller pileus and thinner stipes than the control. Furthermore, somatic incompatibility tests confirmed that Seoldan is genetically distinct from the control variety. These results indicate that Seoldan is a promising pure white variety with stable productivity, improved cultivation efficiency, and clear genetic differentiation from existing varieties.

Sanghuang mushroom is highly valued for its medicinal potential, including anticancer, anti-inflammatory, and antioxidant activities, and has recently gained significant economic and pharmacological importance. Despite considerable taxonomic revisions within the genus Sanghuangporus, confusion persists in Korea due to the continued use of outdated names such as Phellinus linteus, P. baumii, and Inonotus baumii, as well as inconsistencies in common names. This study aimed to clarify the species diversity of Sanghuangporus in Korea through integrative approaches combining phylogenetic, morphological, and ecological analyses. Using four genetic markers (ITS, nLSU, RPB2, and TEF1), we analyzed 11 dried specimens preserved at the Seoul National University Fungus Collection and 74 fungal strains maintained by the Korean Agricultural Culture Collection. As a result, we identified eight Sanghuangporus species in Korea: S. baumii, S. mongolicus, S. quercicola, S. sanghuang, S. subbaumii, S. vaninii, S. weigelae, and a novel candidate species, Sanghuangporus sp. 1. Among these, S. mongolicus and S. quercicola were newly recorded species for Korea. By providing diagnostic traits and ITS barcode sequences, this study offers a reliable taxonomic framework for the accurate identification of Sanghuangporus species. It also supports future taxonomic studies, cultivar development, and applied research in pharmaceutical and functional bioactive materials.

Tricholoma matsutake, one of the most famous edible mushroom in Asia, has been cultivated in red pine forest. Because of its difficulty in artificial cultivation, T. matsutake cultivation has relied on foraging in the forest. Under certain environmental conditions, T. matsutake form the Shiro, the condensed mycelium, and develop into fruiting bodies. Among the certain environmental conditions, fungal communities play a major role in the mushroom development. Therefore, fungal community investigations for Bonghwa and Yangyang have been conducted on soil with fairy rings in the past, soil with existing fairy rings, and soil with presumptive fairy rings developing in the future. From the six soil samples, total 163 genera of fungi were detected and species diversity and species abundance of each sample were also analyzed. In result, the species diversity and species abundance of the fairy rings in Yangyang were lower than those in Bonghwa. In comparison with the fairy rings in Yangyang and Bonghwa, the dominance of the genus Tricholoma was higher and that of the genus Motilella was lower in Yangyang. Through the continuous study, establishment of optimal environmental conditions to promote the T. matsutake cultivation is highly expected.

Despite their historical use, studies on the genetic functions of mushrooms and varietal improvement via biomolecular techniques are limited compared to other organisms. Recent advancements in CRISPR/Cas9 have enabled precise genetic modifications in mushrooms, with RNP-based systems offering high editing efficiency without foreign gene insertion. In this study, we optimized gene-editing conditions for Ganoderma lucidum (Yongji 2) by utilizing RNP/nanoparticle complexes to enhance efficiency. The optimal conditions included a 0.2 M sorbitol buffer (pH 7.0) and a protoplast-to-complex ratio of 10:1. Among eight gRNAs designed for the catA gene, three were identified with high activity, and PEG-mediated transformation resulted in successful gene edits, primarily involving 1 bp deletions. The editing efficiency reached 7–8%, demonstrating that nanoparticle-supported RNP systems are effective for marker-free gene editing in mushrooms. These findings highlight a promising approach for advancing genetic research and varietal improvement in G. lucidum and other mushroom species.

In order to develop a stable production and delicious unique cultivar of beech mushrooms, we generated hybrids using wild resources collected domestically, and we developed excellent strains by identifying the mycelial cultivability of the hybrid strains. The developed strains were cultivated according to the type of spawn and incubation time, and strains with excellent yield and shape were first selected, and second strains with less bitterness and excellent taste were selected through quantitative descriptive analysis. This was verified in farms, and ‘HM6-6’, which had a good reputation in the field, was directly developed cultivars as ‘Maruking’. In addition, the yield was high overall in the 90-day culture of the growth substrate inoculated with solid spawn, and the ‘Maruking’ cultivar, was also best in the 90-day culture. The yield was high overall in the 75-day culture of the liquid spawn, but ‘Maruking’ showed excellent yield when cultured for 70 days.

The Grifola frondosa cultivar KMCC03118 was used to isolate monokaryotic strains via spore separation, resulting in the successful crossbreeding of strains KMCC03118-11 and KMCC03118-23, which produced F1 hybrids. These F1 hybrids were then further crossed with various monokaryotic strains to generate F2 progeny. In evaluating the effects of different medium compositions on fruit body development, it was found that a substrate consisting of wheat bran and dried sawdust, with a carbon-to-nitrogen (C/N) ratio of 66-68, provided the most favorable conditions for mycelial growth. Among the strains tested, KMCC03137 and GF-18-50 demonstrated superior characteristics, including a larger fruit body diameter, thicker pileus, and greater stipe thickness, with the highest productivity observed at 143.6 ± 13.3 g and 144.7 ± 15.2 g, respectively. Furthermore, the color of the caps (L: 29.7 ± 7.1, a: 2.6 ± 0.7, b: 8.2 ± 1.8) remained consistent, indicating stable high-quality production. Based on these results, the optimal substrate composition for enhancing both the quality and productivity of the fruit bodies was determined to be 42% Quercus sp. sawdust, 42% Quercus sp. fermented sawdust, 6% wheat bran, and 10% dried tofu residue. This study provides a crucial foundation for the commercial cultivation and breeding improvement of Grifola frondosa, offering valuable insights into its genetic enhancement, and providing essential data for future research aimed at increasing the species' genetic diversity and productivity.

Oyster mushroom is one of the most widely cultivated and consumed mushrooms in Korea, and mechanization and automation of cultivation systems have enabled mass production. Many cultivars have been developed to replace the old ones such as ‘Suhan‘ and ‘Chunchuneutari 2 ho,‘ which have been cultivated for over 20 years. Among these, ‘Soltari‘ was developed in 2015. Although it has excellent quality, its cultivation is challenging and the productivity is somewhat lower. To address these issues, the Mushroom Division at the National Institute of Horticultural and Herbal Science selected the genetic resource KMCC05165 and attempted hybridization between monokaryons from KMCC05165 and ‘Soltari(KMCC04940)’. Through repeated cultivation tests and evaluation of fruiting body characteristics, the superior strain ‘Po-2019-smj22’ was selected and finally named ‘Otari‘. The optimal mycelial growth temperature of ‘Otari’ was between 25 and 30°C and optimal fruiting body growth temperature was between 13 and 18°C. Mycelial growth on PDA medium was best at 25°C, and at the same temperature, mycelial growth was similar across four media: PDA, MEA, MCM, and YM. In 1,100 mL bottle cultivation, the yield was approximately 174 g, which is about 5% higher than the control cultivar ‘Soltari‘, and the number of valid individuals was also higher at about 25. The diameter and height of the pileus were 29.8 mm and 17.6 mm, respectively, slightly smaller than ‘Soltari‘, and the stipe was thin and long with a thickness of 12.2 mm. Additionally, the pileus’ lightness index (L index) was 30.7, indicating a darker brown color compared to 'Soltari.' With excellent mycelial growth, ease of cultivation, and high yield, the new cultivar ‘Otari‘ is expected to be widely adopted by domestic oyster mushroom farms.

Owing to its excellent nutritional value, eggs are among the most important components of the human diet. Gender and environmental factors, such as feed composition, may alter the nutritional profile and quality of eggs. Feed additives have recently been used to enhance the health and productivity of hens, which has resulted in the production of higher-quality eggs. The fungus Cordyceps militaris, a well-established source of traditional medicines, contains potential bioactive metabolites, which prompted us to examine the effects of C. militaris-supplemented diets on the quality of hens’ eggs. The hens of two species (Gallus gallus domesticus and Araucana) were fed with one of three different diets: a control diet and diets supplemented with 2% or 5% of C. militaris. Egg quality was determined by measuring the Haugh Unit, yolk color, and shell thickness. In addition, egg and shell densities together with the ratio of yolk to albumen were calculated. Eggshell thickness and yolk color were both enhanced by the addition of C. militaris, whereas Haugh Unit values were somewhat reduced. Egg size, eggshell weight, and yolk and albumen production were all enhanced by C. militaris supplementation. Notably, in hens fed the 2% C. militaris-supplemented diet, enhancement was more evident in the yolk than in the albumen. The overall quality of the egg yolk was enhanced when 2% C. militaris was added to the hens' diet, which led to increases in both yolk color and quantity. Eggshell thickness and weight were also higher among eggs laid by hens fed the supplemented diets. Although these effects differed depending on the chicken species, we established that, in general, C. militaris contributes to improving egg quality.

Microsatellite SSR markers were developed and utilized to reveal the genetic diversity of 32 strains of Flammulina velutipes collected in Korea, China, and Japan. From the SSR-enriched library, 490 white colonies were randomly selected and sequenced. Among the 490 sequenced clones, 85 (17.35%) were redundant. Among the remaining 405 unique clones, 201 (49.6%) contained microsatellite sequences. We used 12 primer pairs that produced reproducible polymorphic bands for four diverse strains, and these selected markers were further characterized in 32 Flammulina velutipes strains. A total of 34 alleles were detected using the 12 markers, with an average of 3.42 alleles, and the number of alleles ranged from two to seven per locus. The major allele frequency ranged from 0.42 (GB-FV-127) to 0.98 (GB-FV-166), and values for observed (HO) and expected (HE) heterozygosity ranged from 0.00 to 0.94 (mean = 0.18) and from 0.03 to 0.67 (mean = 0.32), respectively. SSR loci amplified with GB-FV-127 markers gave the highest polymorphism information content (PIC) of 0.61 and mean allele number of five, whereas for loci amplified with GB-FV-166 markers these values were the lowest, namely 0.03 and two. The mean PIC value (0.29) observed in the present study with average number of alleles (3.42). The genetic relationships among the 32 Flammulina velutipes strains on the basis of SSR data were investigated by UPGMA cluster analysis. In conclusion, we succeeded in developing 12 polymorphic SSRs markers from an SSR-enriched library of Flammulina velutipes. These SSRs are presently being used for phylogenetic analysis and evaluation of genetic variations. In future, these SSR markers will be used in clarifying taxonomic relationships among the Flammulina velutipes.

Microsatellite SSR markers were developed and utilized to reveal the genetic diversity of 32 strains of Flammulina velutipes collected in Korea, China, and Japan. From SSR-enriched library, 490 white colonies were randomly selected and sequenced. In the 490 sequenced clones, 85 clones (17.35%) were redundant. Among the remaining 405 unique clones, 201 clones (49.6%) contained microsatellite sequences. As a result, 12 primer pairs produced reproducible polymorphic bands within diverse 4 strains and these selected markers were further characterized in 32 Flammulina velutipes strains. A total of 34 alleles were detected using the 12 markers, with an average of 3.42 alleles and the number of alleles ranged from two to seven per locus. The major allele frequency ranged from 0.42 (GB-FV-127) to 0.98 (GB-FV-166), and values for observed (HO) and expected (HE) heterozygosity ranged from 0.00 to 0.94 (mean = 0.18) and from 0.03 to 0.67 (mean = 0.32), respectively. SSR loci amplified with GB-FV-127 markers gave the highest polymorphism information content (PIC) of 0.61 and mean allele number of five, while for loci amplified with GB-FV-166 markers these values were the lowest, namely 0.03 and two. The mean PIC value (0.29) observed in the present study with average number of alleles (3.42). The genetic relationships among 32 Flammulina velutipes strains based on SSR data were generated by UPGMA cluster analysis. In conclusion, we succeeded in developing 12 polymorphic SSRs markers from SSR-enriched library of Flammulina velutipes. These SSRs are presently being used for phylogenic analysis and evaluation of genetic variations. In future, these SSR markers will be used in clarifying taxonomic relationships among the Flammulina velutipes.

‘Baekseung’, a new variety of Flammulina velutipes, was bred by mating two monokaryotic strains isolated from KMCC 4210 and KMCC 4216 in Mushroom Research Division, Baekseung ARES in 2016. Baekseung showed fast mycelial growth and high mycelial density on MEA (Malt Extract Agar) media for 7days of incubation. Spawn running period on the sawdust substrate required 30days at 25°C. The cultivation period and optimum temperature were 11±1 days at 14°C for primordia formation and 14±1 days at 7°C for fruiting body development. The length of pilei and stipes in Baekseung harvested in optimal stage exhibited 11.3±0.4㎜ and 89.2±7.1㎜ and Megumi harvested in optimal stage showed 8.2±1.0㎜ and 95.9±5.0㎜ respectively. Yield of Baekseung and Megumi strain grown of sawdust substrate was 153.7±12.5g and 150.5±29.7g per 850ml in bottle cultivation. The inferred tree exhibited the difference of phylogenetic relationship between the Korean white fruiting body strains such as Baekseung, Uri1ho, Fv-14-a-38, and Fv-14-a-51 and the Japanese white fruiting body strain Megumi.

‘Baekseung’, a new variety of Flammulina velutipes, was bred by mating two monokaryotic strains isolated from KMCC 4210 and KMCC 4216 in the Mushroom Research Division, Baekseung ARES in 2016. The Baekseung and Uri1ho strains showed fast mycelial growth and mycelial density on malt extract agar media after 7 days of incubation. The spawn running period on the sawdust substrate required a cultivation period and temperature of 30 days and 25oC, respectively, for primordia formation where in fruiting body development occurred from 11±1 days at 14oC and 14±1 days at 7oC. The length of the pilei and stipes of the Baekseung harvested in optimal stag were 11.3±0.4 and 89.2±7.1 mm, respectively, whereas the values for Uri1ho were 10.7±1.0 and 91.3±20.8 mm, respectively. The yield of the Baekseung and Uri1ho strain grown on the sawdust substrate was 153.7±12.5 and 139.8±17.8 g, respectively, per 850 ml in bottle cultivation. The inferred tree exhibited a phylogenetic relationship between the Korean white fruiting body strains of Baekseung, Uri1ho and Fv-14-a-38, Fv-14-a-51, and the Japanese white fruiting body-forming strains of KMCC 4226, and these were confirmed to be genetically related.

Oyster mushrooms are widely cultivated and consumed in Korea. P. ostreatus 'Suhan(ASI 2504)' is an ideal cultivar for mushroom farmers due to its dark pileus and thick stipe; however, as it is very sensitive to environmental conditions, an alternative cultivar is required. To develop a new cultivar, parental strains 'Suhan(ASI 2504)' and ‘ASI 0665 (Heuktari)’ were selected from various collected strains according to morphological characteristics. P. ostreatus ‘Soltari’ was developed by Di- Mon crossing between the dikaryotic strain ‘Suhan’ and the monokaryotic strain derived from ‘Heuktari’. Thirty-eight of the 100 crossed strains were selected following analysis of mitochondrial genetic characteristics, and 'Soltari' was ultimately selected by continuous cultivation tests. The mitochondrial DNA profile of ‘Soltari’ was found to be the same as that of ‘Heuktari, and a nuclear DNA profile of ‘Soltari’ was similar as those of the parental strains, ‘Suhan’ and ‘Heuktari.’ 'Soltari' mycelium grows adequately in moderate to high temperatures of 12–20oC, although its optimum temperature was found to be 30oC. Fruiting body production per 1.1-L cultivation bottle was approximately 158.8 g. Its stipe length and thickness were comparable to those of diameter and thickness were somewhat lower (42.72 vs. 51.33 mm and 18.18 vs. 22.46 mm, respectively). ‘Soltari’ was found to be more resistant to high CO2 atmosphere than 'Suhan', and the color of the pileus of 'Soltari' was dark gray at high temperature. Therefore, it is suggested that this new cultivar ‘Soltari’ is a good alternative cultivar and will contribute to energy saving in oyster mushroom farms.

The production scale of mushrooms in Korea is approximately 600 billion won, which is 1.6% of Korea’s gross agricultural output. In Korea, ca. 190,000 tons of mushrooms are harvested annually. Although the numbers of mushroom farms and cultivators are constantly decreasing, total mushroom yields are increasing owing to large-scale cultivation facilities and automation. The recent expansion of the well-being trend has caused an increase in mushroom consumption in Korea: the annual per capita mushroom was 3.9 kg (’13), whichis a little higher than that in Europe. Thus, mushroom export, mainly Flammulina velutipes and Pleurotus ostreatus, has increased since the mid-2000s. Recently, however, it is slightly reduced. Nevertheless, Vietnam, Hong Kong, the United States, and the Netherlands continue to export mushrooms, and Korea has increased its export to Australia, Canada, Southeast Asia, etc. Canned Agaricus bisporus, the first export of the Korean mushroom industry, reached it speak sales in 1977-1978. When Korea initiated trade with China in 1980, the international prices of mushrooms fell sharply, leading to shrinkage of the domestic markets. Spurred by the high demand to develop substitute goods for A. bisporus, the oyster mushroom (P. ostreatus) gained attention since it seemed to suit the taste of Korean consumers. Although the log cultivation technique for oyster mushroom was developed in the early 1970s, it required a great deal of labor. Thus, we developed the shelf cultivation technique, which is easier to manage and allows for mass production. In this technique, the growing shelf is made mafrom fermented rice straw, whichis the only P. ostreatus medium in the world and isused only in South Korea. After then, the use of cotton wastes as an additional material of medium, the productivity. Currently, we are developing a standard cultivation technique and environmental control system that can stably produce mushrooms throughout the year. The increase of oyster mushroom production may boostthe domestic market and contribute to industrial development. In addition, oyster mushroom production technology played a role in forming the basis for the development of bottle cultivation, which made mass production . In particular, bottle cultivation using liquid spawn could allow for the export of F. velutipes and Pleurotus eryngii. In addition, the white varieties of F. velutipes were second developed in the world after Japan. We also developed the new A. bisporus cultivar ‘Saeah’, which is easy to grow in Korea. In hopes to advance the mushroom industry, we will continue to develop cultivars with international competitive power and to improve cultivation techniques.