Sheath rot is a new disease of hulless barley and oats, emerging in the highlands of Gansu Province and the neighboring region in recent years. The disease affects the boot of the flag leaf as well as the young spikes, causing symptoms of sheath rot and spike blight. A new genus, Dactylobotrys and a new species, Dactylobotrys graminicola are established and described to accommodate previously unknown pathogen of the disease. This new genus differs from Botrytis and other Botrytis-like fungi in having dactylate conidiogenous cells and complicated conidiophores. The new species produces abundant conidiophores and conidia. The conidiophores are scattered, dendroid, erect or repent, and branched alternately, dichotomously, cymosely or fastigiately, while the conidiogenous cells are digitiform or palmate, with several denticles bearing holoblastic-botryose conidia at the top. The conidia are hyaline, unicellular, very rarely 1-septate, spherical, ovoid, obpyriform, fusoid, lageniform, or irregularly shaped, with reticular ridges or verrucae on the surface. Conidia in mass are white, and gradually change into yellowish in old cultures. The type specimen has deposited in Herbarium Mycologicum Academiae Sinicae, Beijing (HMAS 245110, holotype) and Herbarium of Plant Protection Institute, Gansu Academy of Agricultural Sciences, Lanzhou (GAPP 1131, isotype).
Two taxa of Puccinia on Asteraceae collected from China are reported. Puccinia sonidensis on Scorzonera divaricata is described as new species. Puccinia hieracii var. hypochaeridis on Hypochaeris ciliata is firstly recorded in China. Morphological descriptions and illustrations are provided based on Chinese collections. The collections are deposited in the Mycological Herbarium of Chifeng University, Chifeng, Inner Mongolia, China (CFSZ), and the Herbarium Mycologicum Academiae Sinicae, Beijing, China (HMAS).
Taifanglania parvispora sp. nov. was isolated from the river mud of Sanya, Hainan Province, China. This new species was distinguished from other related taxa by its inflated hyphal bodies, short phialides, small, and pyriform to obovate conidia. The phylogenic tree was constructed based on the ITS1-5.8S-ITS2 rDNA sequences of some species of Taifanglania, Humicola, Phialemonium and Phialophora and the results showed that the new species was clustered with Taifanglania spp. in a clade, and became a separated subclade in the Taifanglania clade. Morphological and molecular analysis indicated that it was reasonable that T. parvispora was proposed as a new taxon in the genus Taifanglania.
A new disease, cobweb disease, was recently found in a Hypsizygus marmoreus growing factory in Fujian Province. A fungal isolate was generated from the diseased fruiting body. Pathogenicity test, morphological observation and rDNA-ITS sequence analysis have proved that the fungus was Hypomyces aurantius, the pathogen of the disease. It is the first report of the pathogen responsible for cobweb disease on Hypsizygus marmoreus in China. The biological test showed that the optimum culture conditions for the pathogen were 20°C, pH5.5, glucose as carbon source and peptone as nitrogen source. Light showed slight inhibition to the pathogen growth. It is indicated that the practices such as strictly controlling temperature, enhancing ventilation and keeping clean sanitation could efficiently prevent the occurrence of this disease in edible mushroom production.
The community structure and species diversity of the dead wood dwelling lichens in forest ecosystem of Altay Two River Sources National Natural Reserve were studied using two-way indicator species analysis and detrended correspondence analysis methods. The relation between the lichen species distribution pattern and environmental factors were analyzed according to canonical correspondence analysis results. Forty-three dead wood dwelling lichens species belonging to 20 genera and 14 families of 5 orders were found in this ecosystem. According to the quantitative analysis results, the lichen communities were divided into the following four types: community Ⅰ: Physcia dimidiate+Ph. semipinnata+Phaeophyscia erythrocardia; community Ⅱ: Cladonia subulata+Cl. fimbriata+Cl. humilis; community Ⅲ: Caloplaca cerina+Calicium abietinum+Chaenotheca stemonia; community Ⅳ: Parmeliopsis ambigua+Candelaria concolor+Lecidea elabens. The similarity index of community Ⅰ and Ⅱ was the highest (0.723), and that of communityⅠand Ⅲ (0.609) ranked second; the lowest similarity occurred between community Ⅲ and Ⅳ(0.262). The community Ⅲ holds the highest rank in species diversity (1.954), then community Ⅱ (1.742) and communityⅠ(1.685), while community Ⅳ ranks lowest (0.543). It was found that, the dead wood dwelling lichen species composition and distribution were mainly affected by the factors such as altitude, dead wood decayed degree, canopy density and dead wood volume.
nrDNA ITS sequences were used to analyze the genetic structure and genetic diversity of Colletotrichum fructicola populations consisting of 145 strains isolated from 10 sites. A total of 13 ITS haplotypes were identified among which the dominant haplotype (haplotype 5) included 127 specimens from the 10 sites. The genetic differentiation index, FST, revealed significant genetic differentiation between Suizhou populations and the others. AMOVA test showed that 13% of genetic differentiation occurred among population and 87% within population. The Mantel test showed no linear-correlation between genetic distance and geographical distance. Mismatch distribution analysis suggested there was population expansion for Colletotrichum fructicola and gene flow was detected between populations.
Ammopiptanthus nanus is an excellent sand-fixation and endangered plant that can not only well stand up to desert environment, but also maintain the balance and stability of desert ecosystem. To elucidate the community composition and genetic diversity of AM fungi in the rhizosphere of A. nanus by PCR-DGGE and DNA cloning and sequencing, samples from four different sites in Wuqia, Xinjiang were collected in June 2012. Soil samples were taken at depth intervals of 10-20cm, 20-30cm and 30-40cm. The results showed that the fingerprint characteristics of DGGE, richness, dominance and diversity index of AM fungi varied with sampling sites and soil depth. Richness and diversity index of AM fungi were the highest at 30-40cm soil layer in Shang Artux, reaching 20 and 3.48 respectively. 20 AM fungal sequences coincide with 14 species in two genera, Glomus and Rhizophagus. G. indicum and Rh. intraradices were not recognized by morphological definition.
Different stages of life cycle of Flammulina velutipes were observed using fluorescence microscopy. Mycelia formed from a single germinating basidiospore was monokaryotic and had no clamp connections. Parts of single-basidiospore isolates could form homokaryotic haplont fruiting bodies. Probasidia of homokaryotic fruiting bodies in the beginning contained one haploid nucleus that underwent once mitosis producing two incompatible nuclei and the development of the basidium became stagnant. Thus, the homokaryotic fruiting bodies were sterile. A pair of monokaryotic mycelia with compatible mating types formed heterokaryotic mycelium via plasmogamy. Heterokaryotic mycelia with two nuclei could produce clamp connections, and formed heterokaryotic fruiting bodies. Probasidia of heterokaryotic fruiting bodies had two compatible haploid nuclei which fused and formed a diploid nucleus subsequently. The diploid nucleus underwent meiosis and produced four haploid nuclei and each of them migrated into four basidiospores respectively through sterigmata. Each basidiosporic nucleus underwent mitosis producing two haploid nuclei. Thus, mature basidiospores of the heterokaryon were dikaryotic but homogeneous. Both homokaryotic mycelia and heterokaryotic mycelia can produce uninuclear iodia.
Arbuscular mycorrhizal fungi (AMF) necessarily rely on taking up carbohydrate from host plant roots to fulfill their entire life cycle due to their inability of photosynthesis. Adding exogenous materials is considered as a feasible way to regulate symbiotic associations between plant roots and AMF. A pot experiment was conducted to assess the effects of applying different kinds of sugars on Glomus mosseae colonization, spore density and subsequently the growth of Lycopersicon esculentum. The results showed the shoot dry weight and the amount of phosphorus (P) and potassium (K) in shoot were increased by applying glucose and sucrose, but no effect was found by applying maltose and starch. No significant effects were detected on the amount of nitrogen (N) in shoot after adding different sugars. The amount of alkali-hydrolyzale nitrogen in soil was decreased with adding of different sugars. Olsen-P and available K in the soil decreased with the increase of uptake amount of P and K in ground part of plant. No significant effect as found on soil organic matter for all treatments. The root colonization of AMF was increased by adding different sugars, and had increased by 27% in treatment of sucrose. The application of different kind of sugars had no significant effect on sporulation capacity of AMF.
The purpose of this study was to observe arbuscular mycorrhizal fungi (AMF) and dark septate endophytic fungi (DSE) colonization structures, so as to make clear their development features and to provide a basis for further exploring interactions between AMF and DSE. Roots and root zone samples of cucumber plants grown in commercial greenhouse in different continuous cropping years, growth stages, and soil layers were collected from the sampling sites in Laiyang of Yantai, Shouguang of Weifang, and Laixi of Qingdao. Typical vesicles, Arum (A) arbuscules, and Paris (P) arbuscules of AMF, hyphae and microsclerotia of DSE were observed on the cucumber roots. The highest colonization percentages of AMF and DSE showed in roots of cucumber plant in the mid-term of full productive stage, were 57% and 28% respectively, while the lowest percentages were 18% and 8% respectively in the seedling stage. P arbuscules were observed in roots of cucumber in initial flowering stage, while A arbuscules +P arbuscules in seedling and in the mid-term of full productive stage, A arbuscules +P arbuscules in <7 year and 7-10 year continuous cropping, and A arbuscules in>10 year continuous cropping. AMF and DSE colonization percentages were significantly greater in <7 year and 7-10 year continuous cropping than in >10 year continuous cropping. The highest colonization (29%) of AMF occurred on roots in 0-15cm soil layer, and only P arbuscule was observed; while the lowest colonization (12%) occurred in >30cm soil layer, and only A arbuscule was observed. As for A+P, they were generally observed in 15-30cm soil layer. P arbuscule colonization rate, P/A ratio, and DSE colonization are correlated with the development level of root knot nematode disease on cucumber. The present investigation showed that there was a positive correlation between cucumber root colonization percentage of AMF and that of DSE.
The method of random amplified polymorphic DNA (RAPD) was used for population analysis of 96 strains of Phytophthora melonis sampled from Guangdong Province and Guangxi Autonomous Region. Among the 180 tested primers, 12 ones were found to produce consistent polymorphic bands, and they were applied for RAPD analysis. At last 135 RAPD marker bands were generated, of which 124 ones showed polymorphism, accounting for 91.9% of the total bands. Based on genetic distance, a dendrogram was constructed with the software NTSYSpc Version 2.1, and the 96 tested strains were divided into 12 RAPD groups at 0.81 genetic similarity coefficient. Among the majority of these strains, their genetic similarity coefficients were low, and their genetic variations were clearly evident. It is concluded that considerable genetic variation exists among the strains of P. melonis in South China. Its genetic differentiation varied with geographic locations. The strains isolated from cucumber plants showed more evident genetic variation than those isolated from wax gourd plants. No correlation was found between the RAPD clades and geographic origin, host, virulence, mating type, or metalaxyl resistance.
Physarida is the biggest order in the class Myxogastria. The phylogenetic relationships in Physarida have been generally based on morphological characteristics. In order to study the phylogenetic relationships in Physarida and even in Myxogastria at the molecular level, the universal primers were used to amplify and sequence the rDNA ITS sequences from eight species representing five genera of the order Physarida. The obtained sequences were combined with known sequences in GenBank to construct a phylogenetic tree using both maximum likelihood (ML) and bayesian inference (BI) methods. The varieties for the rDNA ITS of different Physarida species were observed both on the base composition and length. The range of length are 777- 1 445bp, and G+C mol% are between 53.4% and 61.9%. Physarida and Stemonitida are clustered into two distinct branches. On the branch of Physarida, Physaraceae and Didymiaceae were divided into two separate branches. The results supported taxonomic viewpoint making a distinction between the two families, based on capillitium with or without calcareous granules. Didymium squamulosum samples from different geographic regions are composed of three branches, confirming that this morphospecies is consist of a biological species complex with different geographical origins, reproductive incompatibility and genetic variation.
A novel lipase gene, lm, was cloned from the thermophilic fungus Chaetomium thermophilum. DNA sequencing revealed that the genomic DNA of lm had an open reading frame of 870bp, encoded 289 amino acid residues, and contained four introns without any potential signal sequences. The obtained nucleotide sequence of lm was deposited in GenBank under Accession No. GU338248. A recombinant C. thermophilum lipase was expressed in the methylotrophic yeast Pichia pastoris. The highest lipase activity (19.77U/mg) and protein expression level (0.428mg/mL) were detected in the yeast culture after methanol induction for 6 days. SDS-PAGE analysis demonstrated that the recombinant lipase had a molecular mass of 35kDa. Optimal temperature for activity of the recombinant lipase was 60°C. The recombinant lipase was thermostable at 40-80°C and retained 65% relative activity after incubation at 80°C for 60min. The optimum pH for activity of the recombinant lipase was 10.0 and the lipase was stable from pH 9.0 to 12.0. The results indicated that the novel C. thermophilum lipase had high thermostability and alkaline tolerance, thus was of great value for industrial applications.
Dictyostelium discoideum is widely used as a model organism in slime mold. Its predation process is closely related to actins polymerization. To investigate the characteristics of actins from D. discoideum, the protein-protein interaction (PPI) and conserved motifs of 32 actins from D. discoideum were analyzed by bioinformatics analysis. The results indicated that there is a set of complex interactions and five groups of simple interactions within the 32 actins and other proteins. By using MEME SUITE analysis method, conserved motifs of 32 actin sequences and those of 21 actin sequences of other organisms, optimally matching with actin17 were analysed. As a result, six conserved motifs motif1, motif2, motif3, Motif1, Motif2, and Motif3 were obtained. Of which three motifs, motif1, Motif1 and Motif3, were newly found in this study, which were located on the crystal structure of profiling-actin-VASP202-244. All these results suggested that actin3, actin10, actin14, actin15, actin17, actin31 may be important actin for D. discoideum, and motif1, Motif1 and Motif3 may play important role in the evolution of conserved motifs.
An extracellular laccase from the culture broth of Pleurotus eryngii var. tuoliensis 00485 mycelia was isolated and its characterization was determined. The purification procedure was involved in exchange chromatography on DEAE-cellulose, CM-cellulose, and SP-Sepharose, and gel filtration on Superdex 75. The laccase was designed as PnLac. SDS-PAGE detection showed PnLac was a monmeric protein of 65kDa. Three amino acid sequences were obtained after tryptic digestion of PnLac, and they exhibited some similarity to those of laccases from the mushrooms Pleurotus ostreatus, Lentinus sajur-caju and Pleurotus eryngii by NBCI-BLAST. Its optimum pH and temperature were 3.0 and 50°C for ABTS [2,2´-azinzo-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt], respectively. The laccase activity was inhibited by Ca2+ and Hg2+ while increased by Cu2+ and Mn2+. The Km and Vmax values of PnLac was 0.17mmol/L and 1.76OD/min/U, respectively.
The antioxidant activities of methanolic extract (ME), alcoholic extract (EE), acetonic extract (AE), n-butyl alcohol extract (BAE) and ethyl acetate extract (EAE) from the fruiting bodies of Tuber liyuanum were evaluated using five analytical methods (DPPH radical-scavenging ability, hydroxyl radical-scavenging ability, superoxide radical-scavenging ability, ferrous ions-chelating ability and reducing power). The results showed that ME possessed the most potent capacity for scavenging of DPPH radical, superoxide radical and reducing power, with the EC50 values reaching 23.37mg/mL, 11.65mg/mL and 24.47mg/mL, respectively. EE showed the maximum capacity for scavenging of hydroxyl radical and chelating of ferrous ions, with the EC50 values reaching 7.24mg/mL and less than 0.5mg/mL, respectively. The total phenolic content of ME and EE were higher than that of the other three extracts, which were 3.08mg GAE/g extract and 1.34mg GAE/g extract, respectively, and positive correlations were found between total phenolic content and antioxidant activities of extracts.
The degradation ability of white-rot fungi to chlorothalonil and the degradation mechanism of chlorothalonil were investigated. By using agar plate culture method, the degradation capacities to chlorothalonil of 70 strains of white-rot fungi were verified, of which Cerrena unicolor Y4941 was studied emphatically using shake and liquid culture. Laccase activity assay was also employed in this study. The result proved that the tested white-rot fungi were not inhibited or eliminated by chlorothalonil. Among these strains, Trametes versicolor W4614, Funalia trogii W4289, Lenzites betulina Y4962, Rigidoporus crocatus D10146, Schizophyllum commune D9466 and Cerrena unicolor Y4941 showed strong capacities to degrade chlorothalonil. The degradation capability of strain Cerrena unicolor Y4941 decrease in order of living culture (LC) >crude enzyme liquor (CEL) >devitalized mycelia (DM). The lowest chlorothalonil residue of 1.92% was detected in 3 days of degradation. Enzyme assay showed the laccase activity reached 2 195.55U/L in liquid culture media. Cerrena unicolor Y4941 showed the highest degradation capability. The result suggests that white-rot fungi have potential application value in biodegradation of fungicides.
The fruiting bodies of Fomitopsis officinalis were extracted, using different polarity solvents. Petroleum ether extract, chloroform extract, ethyl acetate extract and methanol extract were obtained. The constituents of petroleum ether extracts were investigated by GC-MS, and the biological activities of extracts in different phase were measured. Forty-six kinds of constituents were identified from the petroleum ether extract. The extracts obtained by using the four solvents showed anti-tumor activity at 100μg/mL. The petroleum ether extract components at 50μg/mL displayed strong growth-inhibitory effects on NCI-H460 and SGC-7901 tumor cells with 99.03% and 82.57% of inhibition rate, respectively. The free radical scavenging rate of methanol extracts at 8mg/mL was 93.35%.
The purification technique of cordycepin from the fermentation broth of Cordyceps militaris was investigated. Cordycepin was adsorbed and desorbed by using macroporous resin AB-8 column chromatography and purification of cordycepin was carried out by reversed-phase chromatography. When pH value was 6.0 and concentration of cordycepin was 0.4mg/mL, the AB-8 column had a good adsorption capacity for sample loading amount of 5BV at 1.0BV/h loading flow rate. Using 20% ethanol as desorption solution, elution flow rate of 4BV/h and elution amount of 15BV were optimal for AB-8column desorption. The elution sample obtained was then loaded onto reversed-phase chromatography with octadecyl bonded silica (ODS) as stationary phase and ethanol (95%, pH6.0)-acetic acid solution (pH6.0) as mobile phase. Gradient elution with 5% to 95% ethanol was carried out in 40min at a flow rate of 1.0mL/min. The elution solution containing cordycepin was then crystallized and recrystallized. Under these three processes, the purity of cordycepin obtained could reach 40%, 90% and 99%, respectively.
The Changbai Mountains are rich in species diversity of the genus Mycena. Three species collected from the region, M. mirata, M. renati and M. roseocandida, are new records to China. The pileipellis hyphae of these three species have different extent of verrucous protuberance. Their macromophology and microscopic characteristics are described in detail. Morphological distinction between the species and their allies are recounted. Illustrations of the species are given. The studied materials are deposited at the Herbarium of Mycology of Jilin Agricultural University (HMJAU).
Varietal resistance of Agaricus bisporus against Mycogone perniciosa was investigated. Four kinds of defensive enzymes, phenylalanine ammonia-lyase, peroxidase, catalase and polyphenol oxidase might induce A. bisporus to produce resistance against the pathogen. After inoculation the activity of four enzymes changed significantly. Among the strains of A. bisporus studied, W192 contained the highest amount of the four enzymes, then As2796 and As258 followed.
