云南野生春兰根系内生微生物多样性的分析

春兰(Cymbidium goeringii)是一种具有较高经济和观赏价值的地生兰。由于栖息地的严重破坏,大多数地生兰处于濒危状态,根系与微生物的共生关系伴随着兰科植物从种子萌发到开花结果,因此根系内生微生物在地生兰生活史中具有重要作用。【目的】分析野生春兰根系内生菌群落组成与潜在功能,为春兰的人工保育提供理论依据。【方法】采集云南省昆明市、保山市和大理州的野生春兰的根系,利用宏基因组测序,并进行物种注释及功能注释。【结果】保山的春兰根内微生物丰度及多样性大于大理及昆明的春兰样品,春兰根系内生真菌的优势门为担子菌门(Basidiomycota)、子囊菌门(Ascomycota)和球囊霉门(Glomeromycota),优势科为球囊霉科(Glomeraceae)、多孔菌科(Polyporaceae)和角担菌科(Ceratobasidiaceae),其中角担菌科是春兰主要的兰科菌根真菌(orchid mycorrhizal fungi, OMF);内生细菌的优势门为厚壁菌门(Firmicutes)、变形菌门(Proteobacteria)和拟杆菌门(Bacteroidetes),优势科为韦...     

Occurrence of thermophilic actinomycetes in natural substrates in Nigeria

Thermophilic actinomycetes were isolated from 163 (48.95%) of 333 samples of vegetable substrates and soil from different sites in Anambra and Enugu States in Nigeria.Thermoactinomyces (Tha.) vulgaris was the most common, occurring in 32.4% of samples whileTha. thalpophilus was isolated from 20.1%.Tha. sacchari, Saccharomonospora (Sam.) viridis andSaccharopolyspora (Sap.) rectivirgula were isolated from 3–10.5% of the samples examined.Streptomyces (Stm.) thermovulgaris occurred in 2.7% andThermomonospora spp. in 0.6% of samples. Except forStm. thermovulgaris and, perhaps,Thermomonospora spp., all the species isolated are known to be allergenic in man. The five known allergenic species were abundant in hay and maize silage.T. vulgaris andT. thalpophilus were also frequently isolated from rice straw.Tha. vulgaris, Tha. thalpophilus andSap. rectivirgula were all most numerous in hay whileTha. sacchari was most numerous in maize silage. The widespread occurrence of thermophilic actinomycetes in Nigeria emphasizes the need for investigation of their role in allergic respiratory disorders.     

Fungi in the indoor environment of flour mill in Lucknow

Forty species of fungi were recovered from the indoor air of flour mills by exposing petri plates containing potato dextrose, czapek-dox, and sabouraud agar media for 5 minutes. A rotorod sampler was used. The fungal flora of the nearby outdoor environment was also studied for comparison. Species of genus Aspergillus dominated in the mills, being represented by 16 species including one ascosporic species. Other species were of genera Cladosporium and Fusarium. Variations in the fungal population in different months of the survey year were also observed.

Identifiable fungal spores recovered using the rotorod sampler were Alternaria (17% occurrence), Curvularia lunata (10.6%), C. letramera (10%), Cladosporium (19%), Drechslera sp. (9%), Epicoccum sp. (5%), Pithomyces sp. (3%), Nigrospora sp. (10.5%), Stemphylium sp. (4.5%) and Torula sp. (4.5%). Mycelial fragments and unidentifiable spores were also seen in abundance.

Varying allergic responses of patients tested intradermally for the antigens of six Aspergilli, viz., Aspergillus flavus, A. fumigatus, A. melleus, A. niger, A. niveus, and A. terreus were also recorded.     

Distribution of breeding and control of the filariasis vector Aedes samoanus in leaf axils of Pandanus in Samoa

Water in leaf axils of the screwpine Pandanus was sampled for mosquito immature stages at seventy villages in Upolu, fifty-five in Savai'i and three in Manono, the main islands of Samoa. Ten plants in every patch of Pandanus plantation were sampled at each village. Among 23,049 mosquito larvae collected from Upolu, 77% were the filariasis vector Aedes (Finlaya) samoanus, 17.7% were Ae.(Fin.)oceanicus and 5.3% were Ae.(Fin.)tutuilae. Out of 6981 larvae taken in Savai'i, 23.2% were Ae.samoanus, 67.6%Ae.oceanicus and 9.2%Ae.tutuilae. When larval counts per plant were analysed for each district, Ae.samoanus was found to predominate in Pandanus in Upolu and Ae.oceanicus in Savai'i. However, the adult density of Ae.samoanus was higher in Savai'i and this was attributed to the large areas of forests with Freycinetia for Ae.samoanus breeding. In Pandanus in Savai'i the number of Ae.samoanus was negligible. In Upolu, with more urbanization and larger plantations, there was greater breeding of Ae.samoanus in Pandanus. Two control trials were conducted against Ae.samoanus larvae in Pandanus, one using a sand culture of the parasitic nematode Romanomermis culicivorax and the other with temephos, an organophosphate insecticide. While R.culicivorax did not adapt to the leaf axil habitat, all plants were without larvae for 5 weeks after treatment with temephos.     

Flavonoids in the leaves of twenty-eight polygonaceous plants

Flavonoids in the leaves of twenty-eight species belonging to the Polygonaceae were studied. Thirty-three kinds of flavonoids were isolated, and eighteen kinds were obtained as crystals. Quercetin glycosides were commonly found in the family. In the quercetin glycosides, 3-O-rhamnoside was most frequently found: 3-O-glucuronide is also distributed widely. Myricetin glycosides were rare. Methylated flavonols were found in some species of the sectionsEchinocaulon andPersicaria. Eleven kinds ofC-glycosylflavones were found in the present survey, andC-glycosylflavones were distributed in all species of the genusRheum and in almost all species of the section Tiniaria.Rumex Acetosella andPolygonum suffultum are exceptional, the former contains flavone glycoside and the latterC-glycosylflavones only, as main components.     

Application of desmid diversity in assessing the water quality of 12 freshwater resources in Thailand

Desmids from 12 freshwater resources in the northern part of Thailand were investigated during 2002 to 2003. A total of 91 taxa were found. They belonged to 17 genera: Actinotaenium, Spirotaenia, Netrium, Gonatozygon, Pleurotaenium, Closterium, Euastrum, Micrasterias, Cosmarium, Cosmocladium, Stuarastrum, Staurodesmus, Xanthidium, Teilingia, Spondylosium, Hyalotheca and Desmidium. The water qualities in all the water resources were classified as oligotrophic to meso-eutrophic by trophic status. The taxa that could possibly be used as bioindicators of trophic state were Staurastrum gutwinskii, Spondylosium pandurifoemae, Cosmarium capitulum, C. mediosrobiculatum var. egranutum, S. tortum, Closterium gracile var. elongatum, C. kuetzingii and Closterium dianae var. dianae. The most frequently found taxa were Staurastrum limneticum var. burmense, S. tetracerum var. tetraerum, Pleurotaenium trabecula, Closterium ehrenbergii var. ehrenbergii and C. kuetzingii. The rare taxa in this study were Actinotaenium sp. Spirotaenia condensata, Pleurotaenium burmense var. dacchense and Micrasterias apiculata. Forty-one taxa of desmids were identified as new records for Thailand. Presented at the 6th Meeting of the Asian Pacific Society of Applied Phycology, Manila, Philippines.     

A comparison of in vitro with in vivo flowering in Gentian

Young nodal explants of Gentiana triflora Pall. var. axillariflora were cultured in a woody plant medium (WPM) supplemented with B5 vitamins, sucrose (3%) and kinetin (2.0 μM). A novel observation was made in that in vitro flowering occurred following development of the axillary bud of the cultures. A comparison was made between in vitro and in vivo flowers. Although smaller in size, the in vitro flowers were morphologically comparable to the in vivo ones. Flowers from both sources were semi-opened or not opened. The colour of the in vitro flowers was paler than those in vivo. Stigma development was generally poor in both in vitro and in vivo flowers. Pollen viability was over 90% in both types of flowers. About 11% and 34% of pollen from in vitro and in vivo flowers, respectively, germinated on WPM containing 100 g l⁻¹ sucrose solidified with 10 g l⁻¹ agar. Hand pollination of stigma could raise viable seed production in in vivo-flowering plants from 0.3 o/o (i.e. without aided pollination) to 3% but none in in vitro-flowering plants where only seed-like structures, probably unfertilised ovules, were found. This revised version was published online in August 2006 with corrections to the Cover Date.     

Occurrence of toxigenic strains of Fusarium in maize and barley in Germany

Summary A survey was made of maize and barley in Germany for the occurrence of toxigenic strains of Fusarium and of the mycotoxins produced in culture by these strains.The following 6 species of Fusarium were found: F. avenaceum, F. culmorum, F. equiseti, F.oxysporum, F. poae, and F. tricinctum. The species most commonly isolated from bird-damaged maize ears was F. avenaceum while F. culmorum was consistently isolated from maize stem rot. The predominant species in barley grain was F. poae while F. avenaceum, F. culmorum, and F. tricinctum were also isolated frequently.Cultures on autoclaved maize of all the Fusarium strains were assayed for toxicity by feeding to 1-day-old chickens for 14 days. Some strains of F. avenaceum, F. culmorum, F. equiseti, and F. oxysporum proved to be acutely toxic to chickens and caused mortality as well as marked reductions in weight gain and feed consumption. All the strains of F. poae and F. tricinctum had a low degree of toxicity.Culture material of all the strains were analyzed for the presence of 11 known Fusarium mycotoxins. The following 4 mycotoxins were detected in the strains examined: moniliformin in 9 out of 9 F. avenaceum strains (2 to 760 ppm) and in the single strain of F. oxysporum (1150 ppm); zearalenone in 4 out of 5 F. culmorum strains (320 to 1400 ppm); deoxynivalenol in 3 out of 5 F. culmorum strains.(1 to 15 ppm); and acetyldeoxynivalenol (1 to 2 ppm) in 3 out of 5 F. culmorum strains. This is the first report of moniliformin production by F. avenaceum and F. oxysporum and also the first report of the occurrence of moniliformin-producing Fusarium strains in Europe.     

Incidence and diversity of viruses in cowpeas and weeds in the unmanaged farming systems of savanna zones in Nigeria

Fields surveys were conducted to assess the incidence of commonly known legume viruses on cowpeas and weed hosts within and around the cowpeas farms in nine locations across the three agro-ecological zones of Nigeria. Of 315 cowpea leaf samples collected and tested for eight viruses, 69.5% were found to be infected. Bean common mosaic virus-blackeye mosaic (BCMV-BlCM), genus Potyvirus had the highest incidence (70%) and was also the most prevalent (78%). Cowpea aphid-borne mosaic virus (CABMV, genus Potyvirus) had 64% as incidence, incidence of Southern bean mosaic virus (SBMV, genus Sobemovirus) was 21%. Bean pod mosaic virus (BPMV, genus Comovirus) was detected in 1% of the samples tested. Cowpea mosaic virus (CPMV, genus Comovirus) was undetected. Other viruses tested included Cowpea mottle virus (CPMoV, genus Carmovirus), Cucumber mosaic virus (CMV, genus Cucumovirus), and Cowpea mild mottle virus (CPMMV, genus Carlavirus). Multiple virus infections were detected in 68.0% of the infected cowpea leaf samples. The combination of BCMV-BlCM and CABMV was the most common, occurring in 76.4% of all samples. Virus incidence in weeds around the cowpea plots was 2.5% (9 out of 356) whereas 1.5% (5 out of 332) of the weeds collected within the cowpea plots were infected. Some of the weeds infected were Chromoleana odorata, Centrosema sp., Thithonia diversifolia and Talinum triangulare.     

Natural levels of fungal infections in grasshoppers in Northern Benin

The infection of grasshoppers by naturally occurring, entomopathogenic fungi was monitored at two sites in Malanville, northern Benin, Africa. Grasshoppers were collected and recorded from the sites between June and December 1992 and all of them, barring the first instars, were incubated in ventilated cages. At the first site, 1343 individuals of 35 grasshopper species were incubated, and at the second site, 857 individuals of 36 grasshopper species were incubated. Three hyphomycete fungi (Deuteromycotina: Hyphomycetes), Metarhizium flavoviride Gams and Rozsypal, Beauveria bassiana (Bals.) Vuillemin and Sorosporella sp. were found infecting grasshoppers. The average incidence of M. flavoviride infection was 2.9% and 1.8% at the two sites for all host species. M. flavoviride sporulated on most grasshopper cadavers within 10 days of collection. B. bassiana and Sorosporella sp. were only collected from one and five grasshopper individuals respectively. A significant difference was noted in the time to death of small grasshopper species infected with M. flavoviride compared to larger species. At one site, M. flavoviride infection was positively correlated with rainfall during the 10‐day period in which samples were taken.     

Survey of flea infestation in cats in Spain

Fleas are a common cause of feline skin disorders as well as vectors of zoonotic diseases. This study evaluated the flea species infesting domestic cats in Spain and assessed factors influencing their distribution. Fleas from 217 cats from 57 localities in Spain were identified and associations between abundance, and host‐dependent, host habitat and environmental factors were examined. Variations in infracommunity and component community structure were also explored. Three species were present, of which Ctenocephalides felis (Bouché) (Siphonaptera: Pulicidae) was the most abundant (98.4%), followed by Ctenocephalides canis (Curtis) (1.1%) and Pulex irritans (L.) (Siphonaptera: Pulicidae) (0.5%). Overall abundance and abundances of both C. felis and C. canis were higher on farms than in apartments, but overall flea abundance and abundances of both C. felis and C. canis were lower in rural than urban environments. Overall abundance and C. felis abundance were lower during the warmest months, and mean annual rainfall was positively correlated with overall, C. felis and C. canis abundances. No relationship between the number of species per cat and any host, habitat or physiographical variable was found. Species richness was not correlated with mean annual temperature or rainfall. Flea abundance was mainly associated with host habitat and environmental factors.     

不同季节冬水田紫色土细菌群落的垂直分布规律

【背景】土壤细菌对环境变化非常敏感,是土壤环境质量检测的重要指标。【目的】为研究不同季节冬水田紫色土细菌的垂直分布规律,揭示土壤细菌群落结构和物种多样性与土壤环境因子的相互关系。【方法】以冬水田紫色土为研究对象,分别于2020年8月(夏季)和2021年 1月(冬季)采集不同深度土壤样品,对土壤细菌16S rRNA基因进行Illumina MiSeq高通量测序,分析在不同季节细菌群落组成和多样性的垂直分布规律。【结果】冬水田紫色土细菌ACE指数、Chao1指数和Shannon指数均呈现出夏季高于冬季,并且随土层深度增加呈现降低的趋势。冬水田紫色土优势菌门为变形菌门(Proteobacteria)、绿弯菌门(Chloroflexi)、酸杆菌门(Acidobacteria)、硝化螺旋菌门(Nitrospirae)、放线菌门(Actinobacteria)和浮霉菌门(Planctomycetes),优势菌属为Desulfobacca、Haliangium、Anaeromyxobacter、Candidatus_Omnitrophus和Defluviicoccus。Chloroflexi和Actinobacteria在夏季相对丰度较高,Proteobacteria和Nitrospirae在冬季相对丰度较高;Anaeromyxobacter和Candidatus_Omnitrophus在夏季相对丰度较高,Desulfobacca、Haliangium和Defluviicoccus在冬季相对丰度较高。冗余分析(redundancy analysis,RDA)和环境因子热图分析结果均表明,总氮(total nitrogen,TN)、土壤有机质(soil organic matter,SOM)和土壤氧化还原电位(soil redox potential,Eh)是显著影响紫色水稻土细菌群落的主要因子。【结论】本研究丰富了对冬水田紫色水稻土细菌群落组成和多样性的认识,证实了不同季节冬水田紫色土细菌群落组成和多样性存在差异。     

Survey of Campylobacter jejuni in stray cats in southern Italy

Aim: To evaluate the presence of thermotolerant Campylobacter spp. in stray cats in southern Italy. Methods and Results: One hundred and thirteen animals were trapped in two different environments (urban area, harbour area) of the city of Naples. From each cat, rectal swabs were collected. The samples were processed in order to detect thermotolerant Campylobacter spp. by culture methods. The positive samples were then confirmed by multiplex polymerase chain reaction. Campylobacter jejuni was isolated from 19/113 (16·8%) stray cats, whereas Campylobacter coli was not isolated. The cat data (age, environment and sex) were analysed by two statistical analyses using the C. jejuni status (positive/negative) as a dependent variable. As regards statistical regression model results, age and environment were risk factors for C. jejuni positivity. In particular, cats older than 1 year had a significantly higher risk of being positive for C. jejuni than cats aged up to 1 year (OR = 10·440; P = 0·000). Moreover, cats living in the harbour area had a significantly higher risk to be a carrier of C. jejuni than cats living in urban area (OR = 17·911; P = 0·008). Conclusion: The findings of the present survey confirm stray cats as potential carriers of C. jejuni. Significance and Impact of the Study: This is the first study on the prevalence of C. jejuni in stray cats in Europe.     

Prevalence of coccidia and gastrointestinal nematode infections in cross bred goats in the dry areas of Sri Lanka

The prevalence and intensity of oocysts of coccidia, particularly Eimeria species, and eggs of gastrointestinal nematodes in kids (2–4 months), young goats (5–12 months) and adult goats (>1 year) were determined in five large herds managed extensively in five villages in the dry zone. Of the representative samples examined, oocysts were found in 88% of kids, 91% of young goats and 83% of adults. Seven species of Eimeria were identified in faecal samples by salt flotation. Eimeria ninakohlyakimovae (31%), E. alijevi (29%) and E. arloingi (21%) were the most common species in all age categories. Other species encountered were E. christenseni (7%), E. jolchijevi (6%), E. hirchi (3%) and E. aspheronica (1%). Gastrointestinal nematode eggs were found in 89% of the kids, 94% of the young goats and 84% of the adult goats. Identification of gastrointestinal nematodes revealed Haemonchus contortus (90%) followed by Oesophogostomum spp. (8.5%) and Trichostrongylus spp. (1%) in all three age categories examined. Both Eimeria and gastrointestinal nematodes were found in 77% of the kids, 86% of the young goats and 71% of adult goats. The mean oocyst counts per gram of faeces in kids, young goats and adult goats were 9728, 1946, and 2667, respectively. The oocyst counts were not different significantly between age groups (P>0.05). The mean egg counts per gram of faeces in kids, young goats and adult goats were 1217, 1641 and 1092, respectively. The egg counts in kids were significantly lower than that in young goats (P<0.05). The intensity of Eimeria and gastrointestinal nematode infections between herds were significantly different (P<0.01).     

Metabolism of Aromatic Amino Acids in Microorganisms

It was found that when Rhodotorula rubra IFO 0911 was grown in a phenylalanine medium, benzoic acid and p-hydroxybenzoic acid besides cinnamic acid were formed in the cultured both. The conversions of cinnamic acid into benzoic acid and of benzoic acid into p-hydroxybenzoic acid, and the degradation of p-hydroxybenzoic acid were demonstrated in intact cells of Rhodotorula rubra. These activities were observed in the cells grown on various media, including the medium containing no phenylalanine, and were found to be distributed widely in Rhodotorula. The cells of Rhodotorula rubra were also able to degrade p-coumaric acid, 3,4-dihydroxybenzoic acid (protocatechuic acid), p-hydroxyphenyl-acetic acid, 3-methoxy-4-hydroxycinnamic acid (ferulic acid) and 3-methoxy-4-hydroxybenzoic acid (vanillic acid). From these results, the metabolic pathways for phenylalanine and tyrosine in Rhodotorula were discussed.     

Biochemical characterisation of Pythium spp. involved in cavity spot of carrots in France

The pathogenicity and growth rate in vivo were assessed on 27 isolates of Pythium spp. recovered from cavity spot lesions on carrots grown in various parts of northwest France. Polyacrylamide gel electrophoresis of isoesterases was used to identify the Pythium spp. involved. Slow-growing isolates were more aggressive than fast-growing ones when inoculated on carrot tap roots. Isoesterase patterns identified the slow-growing isolates as P. violae and P. sulcatum; P. ultimum and P. intermedium were identified among the less aggressive fast-growing isolate group, in which some isolates were also classed as P. sylvaticum or P. irregulare, which have similar electrophoretic profiles. The incidence of Pythium spp. associated with the disease in France is discussed in regard to cavity spot in other countries.     

Distribution of keratinophilic fungi in animal folds in Kuwait

Soil samples from seventeen animal herds (camels, goats, sheep, cows) were surveyed for the occurrence of keratinophilic fungi. Twenty four species related to eleven genera were recovered on defated wool baits. Eleven Chrysosporium species were reported in the following order of dominance: C. keratinophilum, C. tropicum, C. indicum, C. queenslandicum, C. pannicola, C. carmichaelii, C. state of Arthroderma curreyi, C. zonatum, C. state of A. cuniculi and Chrysosporium state of Renispora flavissima. The Aphanoascus teleomorph of C. keratinophilum, C. indicum and C. tropicum were frequently reported in soils from cow and sheep folds. Scopulariopsis, Cephaliophora and Sepedonium, although not keratinolytic, were also recorded on wool baits of soils from cow herds which are slightly acidic. The frequency and distribution of these fungi are discussed in relation to animal species and the general ecological conditions of desert soils.     

Occurrence of yeasts in psittacines droppings from captive birds in Italy

Three-hundred twenty five droppings from parrots raised in the premises of 4 breeders and in several private households were cultured for yeasts. One-hundred sixty droppings (49.2%) resulted positive. From these specimens 212 isolates belonging to 27 different species were obtained. Mainly Candida species such as C. albicans, C. catenulata, C. curvata, C. famata, C. glabrata, C. guilliermondi, C. holmii, C. intermedia, C. krusei, C. lambica, C. lusitaniae, C. membranaefaciens, C. parapsilosis, C. pelliculosa, C. sake and C. valida were isolated. Debaryomyces marama, D. polymorphus, Geotrichum sp., Pichia etchelsii, P. ohmeri, Rhodotorula glutinis, R. rubra, Rhodotorula sp., Saccharomyces cerevisiae, S. kluyiveri and Zygosaccharomyces sp. were also obtained. Dark colonies on Staib medium were never observed. The psittacine birds apparently serve as carriers for several Candida species or their perfect states and to a lesser extent for other opportunistic yeasts such as Rhodotorula, Trichosporon and Saccharomyces spp., which are considered part of the transient microbiota of the gastrointestinal tract. The most striking finding was the absence of Cryptococcus spp. among the isolates. The present survey confirms the role of pet birds in carrying potential zoonotic yeasts. This revised version was published online in June 2006 with corrections to the Cover Date.     

Restorative Morphogenesis in vitro in the Annual Medic in the Presence of Benzylaminopurine

Four annual medic species (Medicago orbicularis (L.) All., M. rigidula (L.) Desr., M. scutellata (L.) Miller, and M. rugosa Desr.) were used as model objects for studying the spectrum of morphogenetic reactions in vitro. The seeds were incubated on nutrient media with benzylaminopurine at different concentrations until germination and, thereafter, the explants of seedlings were cultivated in order to obtain primary calluses and morphogenetic structures. Normal and abnormal (with reduced root and/or apex) seedlings were cultivated in the presence of benzylaminopurine. Further cultivation of explants from the seedlings of both types showed a considerable intra- and interspecific polymorphism by the capacity for callusogenesis, frequency of primary restorative reactions, and pattern of microreproduction in vitro. In the control (the seeds were incubated on a hormone-free medium), no cases of microreproduction by way of organogenesis or somatic embryogenesis were observed. In all experimental variants, the restorative reactions preceded microreproduction in vitro.