With the continuous standardization of cultivation patterns, the genetic diversity researches of commercial cultivated edible fungi in China is gradually focused on the main derived varieties of a few excellent cultivars. In the face of the situation that nuclear source cannot be easily replaced, the nuclear-cytoplasmic hybridization method simply replacing cytoplasmic source will be a good way to improve commercial cultivars. In this study, the research progress and genetic mechanism of nuclear-cytoplasmic hybrids in edible fungi were reviewed in hope of providing theoretical support for promotion and application of nuclear-cytoplasmic hybrid technology for edible fungi in China. The concept and characteristics of nuclear-cytoplasmic hybridization method for edible fungi were expounded. The advantages of definition of intraspecific nuclear-cytoplasmic hybrids with different genotypes, stabilizing fruiting capacity, clearing nuclear and cytoplasm sources and changing reproduction rate were also expounded. The genetic mechanism of nuclear-cytoplasmic hybrids in edible fungi was concerned in two aspects: coordination between two parental nuclei and between nucleus and mitochondria. Two parental nuclei regulate vegetative growth and reproduction of the heterokaryotic mycelia with competitive coordination, in which one parental nucleus is dominant in total gene expression and is named as dominated nucleus. Mitochondrial structure assembled correctly and functioned normally are the key to the successful coordination of nuclei and mitochondria in the nuclear-cytoplasmic hybrid, especially the complex co-encoded by nuclear and mitochondrial genomes in the oxidative phosphorylation system.
A systematic research of strains of the genera Harzia and Diversimediispora isolated from human nails revealed a new species, Harzia unguicola, and a newly recorded species in China, Diversimediispora humicola. Their morphological descriptions and illustrations are provided. Multigene phylogenetic analyses of Harzia by ITS and LSU, and of Diversimediispora by ITS, LSU, TUB2 and TEF1-α, provided supporting evidence for morphological identification results.
Oxneriaria applanata and Oxneriaria densa from China are described as new to science. Detailed descriptions and morphological illustrations are provided. Species are classified by morph-anatomical, chemical and phylogenetic analysis of rDNA-ITS sequences. Oxneriaria applanata is characterized by the flat, peripherally lobate thallus, aspicilioid apothecia, disc covered by hyperplastic hyphal cluster, hymenium 220-260 µm, hypothecium 150-220 µm, 6(-8)-spored asci, ellipsoid ascospores (30-42×12-26 µm), and the presence of stictic acid and two unknown terpenoids. Oxneriaria densa is characterized by thallus with warty reticulation, lecanorine apothecia sessile, urceolate and dense, hymenium 140-175 µm thick, hypothecium 75-110 µm thick, (6-)8-spored asci, ellipsoid ascospores (21-32×14-24 µm), and the presence of stictic acid and two unknown terpenoids.
Based on morphological, anatomical, chemical and molecular systematic methods, a new species, Leiorreuma polycrystallinum, was discovered in the investigation of lichen resources from China. It is characterized by the following characters: thallus crustose; apothecia lirelliform; thalline margin completely covering the proper excipulum, with abundant crystals; labia entire; disc black, opened, with white pruina; exciple completely carbonized, with well developed basal exciple; asci 2-8-spored; ascospores brown, transversely septate, 5-10-septate, (36-)41.5-47× 7-9.5 μm. A phylogenetic tree, morphological descriptions, and pictures of the new species were provided. The similarities and differences between the new species and similar species were discussed. A key to the known Leiorreuma species from China was also provided.
The Yanshan area lies at the temperate and boreal part of North China Plain. This area is rich in macrofungal species resources. Comprehensive investigations for funga in this region were conducted from 2021 to 2023. More than 1 230 specimens were collected in this area. Identifications of these samples were carried out based on morphology and molecular phylogeny. In total, 529 species, 173 genera, 77 families, 20 orders 5 classes and 2 phyla were identified, including 19 species, 14 genera, 13 families, 7 orders, and 3 classes of Ascomycota, as well as 510 species, 159 genera, 64 families, 13 orders, and 2 classes of Basidiomycota. The 15 dominant families included Russulaceae, Agaricaceae, Inocybaceae, etc. The 26 dominant genera contained Russula, Inocybe, Agaricus, etc. The results showed high macrofungal diversity in Yanshan area. Among the known species, 38 were edible, 27 simultaneously edible and medicinal, 42 medicinal, and 30 poisonous. The majority of species are cosmopolitan (52.60%) and north-temperate (40.46%). This study provides basic data for the protection and utilization of macrofungal resources in this area.
Danxia geomorphic area in Chishui of Guizhou Province is a typical plateau canyon danxia landform in southwest China. Due to the uniqueness of the primitive natural conditions, hydrological characteristic and vegetation structure, this area possesses high conservation value and it is significantly important to investigate its natural heritage and adaptation ecology. In this study, in-depth investigations on the diversity of cordycipitoid fungi in this area were conducted. Identification of species was carried out on the basis of morphological characteristics and ITS sequencing. In total, 261 cordycipitoid fungus specimens were collected from Xishui Danxia valley scenic area, Chishui Alsophila National Nature Reserve, waterfall scenic area, Sidonggou scenic area, and Yanziyan scenic area. In total, 30 species belonging to 12 genera within 4 families, were identified. The dominant genera were Cordyceps and Beauveria (Cordycipitaceae), which contained 13 species, accounting for 43.33% of the total. The widespread species Cordyceps tenuipes and Beauveria bassiana were dominant. There were some rare and endemic species, such as Ophiocordyceps karstii, Ophiocordyceps gryllotalpae, Yosiokobayasia kusanagiensis and Cordyceps chishuiensis. Prediction based on species distribution modeling method showed that the highly suitable area (with a suitability index of > 0.75) for cordycipitoid fungi was about 2 100 km2, and the Danxia geomorphic area in Chishui (Guizhou Province) and Luzhou (Sichuan Province) occupied approximately 90% (1 880 km2) of the total area, indicating the strong ecological specificity of cordycipitoid resources in the area. The monthly average temperature range (contributing 41.1%) and soil saturation (21.3%) were the primary environmental factors influencing the distribution of cordycipitoid fungi. Our survey provides firsthand data on the diversity of cordycipitoid fungi in the area, enriching the connotation of the World Natural Heritage for this unique geographical environment.
The hybrid strain 126-15 was obtained by crossing the monoploid strains of early-maturing strain GiC and high-yielding strain GiD of Gloeostereum incarnatum with complementary advantages. The backcross population was constructed by backcrossing the monoploid strain of 126-15 with the monoploid strains of GiC and GiD. The genetic diversity of the G. incarnatum backcross population was analyzed by SSR molecular markers combined with agronomic traits. SSR primer polymorphism analysis showed that 269 allele loci were detected from 29 pairs of SSR molecular markers, and the polymorphism information content (PIC) was 0.802 5±0.090 7, indicating relatively rich polymorphism. Cluster analysis of SSR molecular markers divided 67 strains into 7 groups at a similarity coefficient of 0.965 6. Among them, group Ⅰ only contained two recurrent parents GiC and GiD, and their hybrid strain 126-15. GroupsⅡ, Ⅲ, and Ⅴcontained 21 backcross strains with GiC as the recurrent parent, and groups Ⅳ and Ⅵ contained 25 backcross strains with GiD as the recurrent parent. The remaining strains were clustered into group Ⅶ. Cluster analysis based on agronomic traits divided 67 strains into 7 categories, of which only 7 backcross strains in group Ⅱ had the shortest growth period, and only 5 backcross strains in group Ⅵ were early-maturing and high-yielding strains. Both clustering results indicated that the backcross population had certain genetic diversity. The variation range of 7 agronomic traits was between 7.9% and 20.5%, and the coefficient of variation of yield was the largest. When the recurrent parent was GiC, 34.3% of the backcross strains showed over-parent heterosis in yield. When the recurrent parent was GiD, the backcross strains showed over-parent heterosis in growth period. The correlation coefficients between 6 agronomic traits reached significant or extremely significant levels. The research results provide references for the utilization of G. incarnatum germplasm resource diversity, variety identification, and backcross breeding.
Yunnan-Guizhou-Sichuan area is a common occurrence area of wheat stripe rust in China. It is greatly significant to clarify the genetic structure and inoculum source exchange relationship of Puccinia striiformis f. sp. tritici (Pst) in this endemic area. In this study, 203 samples of the pathogen collected from this area in 2022 were used as experimental materials, and 25 pairs of KASP-SNP primers were used to complete the genotype analysis. The results of genetic cluster analysis using KASP-SNP molecular data showed that the distribution of western Guizhou population of the pathogen was more similar to that of central Yunnan population, and the genetic distance was closer. Structure analysis showed that except for Sichuan basin population, the genetic structure of other populations was similar. DAPC analysis further showed that the Sichuan basin population was relatively independent and had less interchange with other population, while all populations except Sichuan basin population frequently exchanged genetically each other. The analysis of population genetic differentiation showed that the FST of Sichuan basin population and northeastern Yunnan-Liangshanzhou population was the largest (FST= 0.043), and the genetic difference between them was the largest. The genetic differentiation degree of western Guizhou population and that of central Yunnan population was the lowest (FST= 0.003). The gene flow among populations was > 4, indicating that there were frequent gene exchanges among populations. Genetic diversity level of Sichuan basin population and that of western Guizhou population was relatively high, with Shannon information index of 0.527 and 0.487 respectively. It was proved that there were frequent inoculum source exchanges of wheat stripe rust pathogen in Yunnan-Guizhou-Sichuan area, but there was exceptional independent area relatively lacking gene exchange. It was speculated that the pathogen in Yunnan and Guizhou may act as a large population in the transmission of wheat stripe rust in China.
Ganoderma lingzhi is a famous traditional Chinese medicine. Understanding the genetic diversity and population structure of the germplasm resources of G. lingzhi is crucial for the effective conservation, development and utilization of the fungus. In this study, the genetic diversity and population characteristics of 62 G. lingzhi germplasms from wild and different cultivated types were analyzed by whole-genome resequencing. In total, 1 388 506 SNP loci, 172 341 InDel loci, 2 003 high-quality polymorphic SNP loci, and polymorphism index PIC 0.031-0.755 were obtained. The genetic diversity and population characteristics of G. lingzhi germplasm resources showed that the genetic distance was 0.011 1-0.594 0. The genetic distance and NJ phylogenetic tree showed that the natural cultivated strains, factory cultivated strains and a part of wild strains were mixed into one clade. The greenhouse-cultivated and factory-cultivated strains clustered into one clade respectively, and the result was consistent with that under observation of artificial domestication and selective breeding of G. lingzhi. Nature-imitative cultivated strains (cultivation imitating woodland environment) and some greenhouse cultivated strains were clustered into one clade, and the genetic differentiation is nearly undetected. Population analysis showed that the germplasm resources of G. lingzhi could be divided into five subgroups. Except for the wild-type subgroup, the genetic background of other subgroups was simple relatively, showing genetic homogenization of cultivated G. lingzhi germplasm. Principal component analysis (PCA) showed that the location and distance of each strain were consistent with genetic distance, phylogenetic tree and population characteristics. This paper provides valuable genome resequencing data for evaluating the diversity and population differentiation characteristics of wild and different cultivated types of G. lingzhi germplasm, being helpful to the analysis of agronomic traits of G. lingzhi and breeding of new varieties.
Brown rot is an important fungal fruit disease that significantly damages the stone and pome fruit industries, causing pre- and post-harvest fruit rots. In China, multiple Monilinia species can cause brown rot diseases, among which M. yunnanensis is one of the most dominant species in terms of host range and geographic distribution. So far, however, genome resource for M. yunnanensis is still not publicly available. In this study, the generation of a high-quality genome of an apple-derived M. yunnanensis strain is assembled based on the third generation PacBio HiFi sequencing technology. The M. yunnanensis assembly was 43.27 Mb in size, made up of 16 scaffolds, with a N50 value of 2.61 Mb. Among the 16 scaffolds, six contained telomere-characteristic repeats at both ends and nine contained repeats at one end, supporting the near-chromosome level of the assembly. A streamed gene annotation pipeline predicted 9 569 protein-coding genes, among which 68.7% could be annotated by the PFAM database. Comparison of CAZYs (carbohydrate-active enzyme contents) among M. yunnanensis and other Ascomycota fungi revealed that several CAZY families related to hemicellulose (xylan) degradation showed characteristics of contracted evolution in Sclerotiniaceae. In the meanwhile, bidirectional evolution pattern was observed for PLs (pectin lyases) and GH28 (polygalacturonases) in Sclerotiniaceae, with the former showing contraction pattern and the latter showing expansion pattern. Such bidirectional evolution pattern is in line with elevated capacity of pectin utilization of Sclerotiniaceae fungi. Gene composition of mating type locus supports that M. yunnanensis is a heterothallic fungus and its genome encodes a secondary metabolite biosynthesis gene cluster related to neosartorin, which is presumed to function in ecological niche competition during pathogenesis or stroma survival. In sum, a near-chromosome level genomic map of Monilinia yunnanensis is first constructed and annotated, providing a foundation for further studies related to its biological and pathogenic characteristics, and population genetic diversity.
The agronomic traits, yield and nutritional quality of the morel Morchella sextelata were investigated under cultivation condition employing bagged exogenous nutrient containing 45% (high dose) and 20% (low dose) wheat grain as supplementary substrate, respectively. Four treatments of different quantities of nutrient bags (wet weight 1.0 kg per bag) ranging from 13 to 16 per plot were set up. The bags are made of heat-resistant polypropylene material. Before placing them on the morel mycelia colonized soil surface, 3-5 slits approximately 10 cm in length were created on one side of the nutrient bag. Following this, the side with the slits was affixed to the soil surface to encourage the entry of mushroom mycelium into the nutrient bag. The results showed that there were no significant differences in agronomic traits such as pileus length, pileus diameter, and single mushroom weight among the treatments. The yield of the high-dose groups significantly increased with the increase of the number of nutrient bags, reaching a maximum yield of 1 028.52 kg/667 m2. There was no significant difference in the yield of the low-dose groups, and the lowest yield was 576.10 kg/667 m2. The content of crude protein, total amino acids, essential amino acids, non-essential amino acids, sweet amino acids, bitter amino acids, umami amino acids and tasteless amino acids in the fruiting bodies of the high-dose groups was significantly lower than that in the low-dose groups, and the content decreased with the increase of the number of nutrient bags in the high-dose groups. The taste activity value (TAV) of each amino acid was greater than 1, indicating that they all contributed to the taste presentation of the fruiting bodies. The glutamic acid (Glu) content and TAV value of each treatment were the highest, making a notable contribution to the special flavor of the fruiting bodies. Although the wheat grain in the bagged nutrient is crucial for ensuring the high yield of morel mushrooms, it can also reduce the crude protein content in the fruiting bodies, thereby affecting the product quality.
The formula of culture substrate compounded by agricultural waste for cultivating Stropharia rugosoannulata was optimized by orthogonal experimental design, and the orthogonal test results were varified by variance analysis (ANOVA) and artificial neural network (ANN). The results showed that the optimal substrate formula optimized by ANOVA was sawdust 5 g/L, tea stalk 5 g/L, rape straw 30 g/L and wheat straw 30 g/L and that optimized by ANN was sawdust 5 g/L, tea stem 5 g/L, rape straw 29.99 g/L and wheat straw 15.36 g/L. ANOVA and ANN results are basically the same in the optimal formulas. The correlation coefficient (R), root mean square error (RMSE) and mean absolute error (MAE) of ANN fitting model are 0.928 96, 0.041 463 and 0.004 18 respectively. ANN has higher fitting ability and accuracy, and the fitting effect is also better, so it is more suitable for optimizing the formula of S. rugosoannulata culture substrate compounded by agricultural wastes.
Fifteen wild isoletes were screened from 30 wild collections of Hericium coralloides on the basis of antagonistic reaction determination and maternal performance examination. Through small and medium-scale trials under facility condition and variety comparison test, a stable, high-yield and high-quality Hericium coralloides strain ‘ZLsh-1’ was finally obtained. The mycelia are white, thick and dense; the fruiting bodies are white, fleshy and weeping-willow like, and measure 15-32 cm wide and 12-20 cm high. The single fruiting body weighs more than 450 g. Cultivation period from bag-casing to first harvest was about 10-15 days. Under bag cultivation condition, inoculation is performed from March to April, and fruiting begins in May, and the harvest time is from June to October. The strain ‘Zlsh-1’ with excellent appearance, steady traits, and strong adaptability is suitable for artificial cultivation.
