Medicinal Value, Genetic Diversity, and Genetic Relationship Analysis of Auricularia cornea (Agaricomycetes) Based on ITS, ISSR, and SRAP Markers.

Wild resources of Auricularia cornea (A. polytricha) are abundant in China, and genetic diversity and genetic relationships analysis of A. cornea can provide basis for germplasm resource utilization and innovation and molecular marker-assisted breeding. In this study, 22 Auricularia strains collected were identified as A. cornea based on ITS sequence analysis, and its genetic diversity was examined by ISSR and SRAP markers. The results showed that a total of 415 bands were amplified by 11 selected ISSR primers, with an average amplification of 37.73 bands per primer, and the mean values of Ne, I, and H were 1.302, 0.368, and 0.219, respectively. A total of 450 bands were amplified by 10 SRAP primers, with an average of 45 bands per primer, and the average of Ne, I, and H were 1.263, 0.302, and 0.183, respectively. The unweighted pair-group method with arithmetic means analysis based on ISSR-SRAP marker data revealed that the genetic similarity coefficient between the tested strains was 0.73-0.97, and the strains could be divided into five groups at 0.742, which had a certain correlation with regional distribution. The results of PCOA and population structure analysis based on ISSR-SRAP data also produced similar results. These results demonstrate the genetic diversity and distinctness among wild A. cornea and provide a theoretical reference for the classification, breeding, germplasm innovation, utilization, and variety protection of A. cornea resources.

Medicinal Value, Biological Characteristics, and Domestication of the Wild Mushroom Pholiota adiposa (Agaricomycetes).

Pholiota adiposa is an important edible and medicinal mushroom with high nutritional and medicinal effects. The fruiting body of wild fungi collected from Mudanjiang City, Heilongjiang Province, was identified by morphological description and molecular identification, the biological characteristics and domestication of the fungus was determined by single factor and orthogonal tests. The wild strain isolated was determined to be Ph. adiposa based on morphological characteristics, sequence alignment between ITS and nLSU, and phylogenetic relationship analysis. The single factor results revealed that the optimal carbon source, nitrogen source, culture temperature, and pH for the mycelia growth of Ph. adiposa were glucose, yeast paste, 25°C, and pH 6.5-7.0, respectively. Orthogonal test showed that the optimal formula for mycelia culture was fructose 20 g/L, yeast extract 6 g/L, KH2PO4 1 g/L and MgSO4 2.5 g/L. The highest single bag yield of the fruiting body of Ph. adiposa was 24.96 g in the culture medium formula of sawdust (20%), wheat bran (10%), soybean powder (1%), and quicklime powder (1%). The results will provide basic information for the protection, utilization and domestication of the resources of Ph. adiposa.

Atomic Diffusion and Crystal Structure Evolution at the Fe-Ti Interface: Molecular Dynamics Simulations.

The diffusion bonding method is one of the most essential manufacturing technologies for Ti-steel composite plates. In this paper, the atomic diffusion behavior at the Fe-Ti interface during the bonding process of Ti-steel composite plates is studied using classical diffusion theory and molecular dynamics (MD) simulation. Henceforth, the diffusion mechanism of Fe and Ti atoms at the bonding interface is obtained at the atomic scale. The results show that Fe and Ti atoms diffused deeply into each other during the diffusion process. This behavior consequently increased the thickness of the diffusion layer. Moreover, the diffusion quantity of Fe atoms to the Ti side was much greater than that of Ti atoms to the Fe side. Large plastic deformation and shear strain occurred at the diffusion interface during diffusion. The crystal structure of the diffusion zone was damaged and defects were generated, which was beneficial to the diffusion behavior of the interface atoms. As the diffusion time and temperature increased, the shear strain of the atoms at the interface also increased. Furthermore, there is a relationship between the mutual diffusion coefficient and the temperature. Subsequently, after the diffusion temperature was raised, the mutual diffusion coefficient and atomic disorder (Fe atom and Ti atom) increased accordingly.

Uncovering the genetic diversity of yams (Dioscorea spp.) in China by combining phenotypic trait and molecular marker analyses.

Yam is an important edible tuber and root plant worldwide; China as one of the native places of yams has many diverse local resources. The goal of this study was to clarify the genetic diversity of the commonly cultivated yam landraces and the genetic relationship between the main yam species in China. In this study, 26 phenotypic traits of 112 yam accessions from 21 provinces in China were evaluated, and 24 simple sequence repeat (SSR) and 29 sequence-related amplified polymorphism (SRAP) markers were used for the genetic diversity analysis. Phenotypic traits revealed that Dioscorea opposita had the highest genetic diversity, followed by D. alata, D. persimilis, D. fordii, and D. esculenta. Among the 26 phenotypic traits, the Shannon diversity indexes of leaf shape, petiole color, and stem color were high, and the range in the variation of tuber-related traits in the underground part was higher than that in the aboveground part. All accessions were divided into six groups by phenotypic trait clustering, which was also supported by principal component analysis (PCA). Molecular marker analysis showed that SSR and SRAP markers had good amplification effects and could effectively and accurately evaluate the genetic variation of yam. The unweighted pair-group method with arithmetic means analysis based on SSR-SRAP marker data showed that the 112 accessions were also divided into six groups, similar to the phenotypic trait results. The results of PCA and population structure analysis based on SSR-SRAP data also produced similar results. In addition, the analysis of the origin and genetic relationship of yam indicated that the species D. opposita may have originated from China. These results demonstrate the genetic diversity and distinctness among the widely cultivated species of Chinese yam and provide a theoretical reference for the classification, breeding, germplasm innovation, utilization, and variety protection of Chinese yam resources.

Two new species of Hymenochaetaceae on Dracaena cambodiana from tropical China.

Two new wood-rotting fungi in the family Hymenochaetaceae, Fulvifomes dracaenicola sp. nov. and Hymenochaete dracaenicola sp. nov., are described and illustrated from tropical China based on morphological characteristics and molecular data. It is worth to mention that both of them grow on Dracaena cambodiana which is a kind of angiosperm tree distributed in tropical regions. F. dracaenicola is characterised by perennial, pileate, triquetrous basidioma with yellowish brown fresh pores which becoming honey yellow with silk sheening upon drying, a dimitic hyphal system in trama and monomitic in context, and subglobose basidiospores measuring 4.8-5 × 4-4.1 µm. H. dracaenicola is characterised by annual, resupinate basidioma with a clay buff hymenophore, a dimitic hyphal system, absence of tomentum and cortex, presence of subulate setae, absence of cystidia, presence of cystidioles and simple hyphidia, and oblong ellipsoid basidiospores measuring 5.2-5.8 × 2.5-2.8 µm. The phylogenetic analyses based on ITS + nLSU rDNA sequences confirm the placement of two new species respectively in Fulvifomes and Hymenochaete. Phylogenetically closely related species to the two new species are discussed.

The complete chloroplast genome sequence of the Dioscorea persimilis Prain et Burkill (Dioscoreaceae).

Dioscorea persimilis belongs to Dioscorea genus, which is considered as one of the most popular food and traditional folk medicine in China. The complete chloroplast genome of D. persimilis was determined in this study. The total genome size was 153,219 bp in length, containing a pair of inverted repeats (IRs) of 25,477 bp, which were separated by large single copy (LSC) and small single copy (SSC) of 83,448 bp and 18,817 bp, respectively. The GC content is 37.01%. A total of 129 genes were predicted including 84 protein-coding genes, eight rRNA genes and 37 tRNA genes. Phylogenetic tree analysis of 24 species in the genus Dioscorea indicated that D. persimilis was closer to Chinese yam, but has remote phylogenetic relationship with Guinea yam.

The complete chloroplast genome sequence of the Pueraria lobata (Willd.) Ohwi (Leguminosae).

Pueraria lobata (Willd.) Ohwi is an essential traditional oriental medicine with therapeutic effects. In this study, we assembled the complete chloroplast genome of P. lobata. The total genome size was 153,442 bp in length, containing a large single-copy (LSC) region of 84,162 bp, a small single-copy (SSC) of 17,998 bp, and a pair of inverted repeats (IRs) of 25,641 bp, and possessing 35.41% GC content. In addition, the whole chloroplast genome encodes a total of 129 genes, including 84 protein-coding genes, 37 tRNA genes, and eight rRNA genes. Phylogenetic tree analysis of 48 species in the family Papilionoideae of Leguminosae indicated that P. lobata was belong to Papilionoideae and closely related to the genus, Pachyrhizus, Vigna and Phaseolus.

Cultivation and Medicinal Value of the Red Belt Conk Mushroom Fomitopsis pinicola (Agaricomycetes).

This study examined biological characteristics, liquid fermentation, and cultivation of Fomitopsis pinicola. A single-factor test concluded that the optimal carbon and nitrogen sources for mycelial growth were soluble starch and yeast paste; the optimal culture temperature was 31°C, and the optimal pH was 6.0. The orthogonal experiment indicated that the optimal formula for mycelial culture was 25 g soluble starch, 2 g yeast extract, 1 g KH2PO4, and 1.5 g MgSO4 added to 1 L water. The optimal conditions for liquid fermentation culture consisted of the following: a loading volume 90 mL, inoculation volume 30 mL, and rotation speed 160 rpm. The optimal substrate formula for domestic culture was 20% corn cob, 30% sawdust, 20% wheat bran, 25% cotton seed shell, 3% corn meal, 1% gypsum, and 1% lime, which produced the highest yield of fruiting bodies. The results provided basic data for deep liquid fermentation culture and recommendations for the further development and utilization of F. pinicola.

The complete chloroplast genome sequence of the Siraitia Grosvenorii (Cucurbitaceae).

Siraitia grosvenorii is a famous Chinese plant used in traditional food and medicine with pharmacological effects. The complete chloroplast genome sequence of S. grosvenorii has been determined in this study. The total genome size is 158,834 bp in length and contains a pair of inverted repeats (IRs) of 26,288 bp, which were separated by large single-copy (LSC) and small single-copy (SSC) of 87,702 bp and 18,556 bp length, respectively. A total of 131 genes were predicted including 86 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. Phylogenetic analysis showed that S. grosvenorii belongs to the family Cucurbitaceae. The complete chloroplast genome of S. grosvenorii would play a significant role in the development of molecular markers in plant phylogenetic and population genetic studies.

Genetic Diversity and Relationships of 24 Strains of Genus Auricularia (Agaricomycetes) Assessed Using SRAP Markers.

Auricularia species are well known for their traditional edible and medicinal importance. In this study, sequence-related amplified polymorphism (SRAP) markers were used to evaluate the genetic diversity and relationships of 24 Auricularia strains obtained from different ecological regions of China. A total of 402 polymorphic loci were detected using 11 SRAP primer combinations with 100% polymorphic loci. The similarity coefficient ranged from 0.662 to 0.903, with an average of 0.73. Cluster analysis using the pair-group method using arithmetic average, based on the data from SRAP loci amplified by 11 primer pairs, showed that 24 Auricularia strains were distinguished into 4 groups with 73% similarity. The results of principal coordinate analysis were in accordance with pair-group method using arithmetic average clustering, and the first, most informative coordinate accounted for 74.38% of all the variations, which indicated a high level of genetic diversity among Auricularia strains. In general, SRAP markers provide a powerful tool to discriminate Auricularia strains and to evaluate their genetic relationships.