林下参内生球毛壳菌FS-01对人参病原真菌的抑制作用

为探究林下参内生真菌球毛壳菌(Chaetomium globosum)FS-01菌株对人参病原菌的抑菌作用,该研究在实验室条件下,测定了FS-01菌株菌丝、发酵液和孢子悬浮液对人参黑斑病菌(Alternaria panax)、人参菌核病菌(Sclerotinia schinseng)、人参灰霉病菌(Botrytis cinerea)、人参立枯病菌(Rhizoctonia solani)、人参根腐病菌(Fusarium solani)5种人参病原菌的抑制作用。结果表明:内生真菌球毛壳菌FS-01对5种病原菌均有抑制作用,其中,对人参黑斑病菌的抑制作用最高,为30.80%,其次是人参立枯病菌、人参菌核病菌、人参根腐病菌和人参灰霉病菌; 发酵液抑菌实验结果表明,在加入内生真菌球毛壳菌FS-01菌株发酵液的PDA培养基上,对人参灰霉病菌的抑制作用最高,为82.09%,其次是人参菌核病菌、人参黑斑病菌、人参立枯病菌和人参根腐病菌; 孢子抑菌实验结果表明,在加入内生真菌球毛壳菌FS-01菌株孢子悬浮液的PDA培养基上,对人参黑斑病菌的抑制作用最高,为83.72%,其次是人参灰霉病菌、人参立枯病菌、人参菌核病菌和人参根腐病菌。综上结果认为,内生真菌球毛壳菌FS-01菌株对人参病原菌均有很高的抑菌作用,可作为人参病原菌的生防菌株资源。     

Viability of Heterodera glycines Exposed to Fungal Filtrates

Filtrates from nematode-parasitic fungi have been reported to be toxic to plant-parasitic nematodes. Our objective was to determine the effects of fungal filtrates on second-stage juveniles and eggs of Heterodera glycines. Eleven fungal species that were isolated from cysts extracted from a soybean field in Florida were tested on J2, and five species were tested on eggs in vitro. Each fungal species was grown in Czapek-Dox broth and malt extract broth. No toxic activity was observed for fungi grown in Czapek-Dox broth. Filtrates from Paecilomyces lilacinus, Stagonospora heteroderae, Neocosmospora vasinfecta, and Fusarium solani grown in malt extract broth were toxic to J2, whereas filtrates from Exophiala pisciphila, Fusarium oxysporum, Gliocladium catenulatum, Pyrenochaeta terrestris, Verticillium chlamydosporium, and sterile fungi 1 and 2 were not toxic to J2. Filtrates of P. lilacinus, S. heteroderae, and N. vasinfecta grown in malt extract broth reduced egg viability, whereas F. oxysporum and P. terrestris filtrates had no effect on egg viability.     

Endophytic fungi from the root tubers of medicinal plant Stephania dielsiana and their antimicrobial activity

The adverse effects of chemical synthetic fungicides on agricultural fields and the environment are driving a need to search for safer and less environmentally harmful plant protectants to move toward more sustainable development of agriculture. The endophytic fungal community associated with the medicinal plant Stephania dielsiana, and its potential for providing antimicrobial secondary metabolites were investigated. A total of 26 isolates of endophytic fungi were obtained, and 21 isolates were identified and classified into eight different genera, including Briansuttonomyces, Glomerella, Pleosporales, Diaporthe, Phoma, Penicillium, Periconia and Colletotrichum, and the most frequent endophytic species obtained were Diaporthe phaseolorum, Penicillium sp., Periconia igniari and Colletotrichum sp. The ethyl acetate (EtOAc) extract of the endophytic fungus Diaporthe phaseolorum Stdif6 displayed the most significant antifungal activity against all tested phytopathogens, with EC₅₀ values ranging from 0.0138 to 0.3103 mg/mL. While the EtOAc extract of the endophytic fungus Penicillium sp. Stdif9 exhibited greater potential for antibacterial activity, with the minimum inhibitory concentration (MIC) values against seven bacteria ranging from 1.25 to 6 mg/mL. The remarkable antimicrobial activity of fungal endophytes suggests that fungal endophytes harbored inside the root tubers of S. dielsiana hold great promise as biocontrol agents against a broad spectrum of economically significant pathogens.     

Diversity and antimicrobial activity of endophytic fungi isolated from Nyctanthes arbor-tristis, a well-known medicinal plant of India

Endophytic fungi from Nyctanthes arbor-tristis were isolated and evaluated for their antimicrobial activity. A total of 19 endophytic fungi were isolated from 400 segments of healthy leaf and stem tissues of N. arbor-tristis. Eighteen endophytic fungi were obtained from leaf, while only ten from stem. Alternaria alternata had the highest colonization frequency (15.0%) in leaf, whereas Cladosporium cladosporioides ranked first in stem with a colonization frequency of 12%. The diversity and species richness were found higher in leaf tissues than in stem. The similarity indices between leaf and stem were 0.473 for Jaccard’s and 0.642 for the Sorenson index, respectively. Of 16, 12 (75%) endophytic fungal extracts showed antibacterial activity against either one or more pathogenic bacteria. The endophytic Nigrospora oryzae showed maximum inhibition against Shigella sp. and Pseudomonas aeruginosa. The leaf endophytes Colletotrichum dematium and Chaetomium globosum exhibited a broad range of anibacterial activity and were active against Shigella flexnii, Shigella boydii, Salmonella enteritidis, Salmonella paratyphi, and P. aeruginosa. Nine out of 16 (56.25%) endophytic fungi exhibited antifungal activity to one or more fungal pathogens. Colletotrichum dematium inhibited 55.87% of the radial growth of the phytopathogen Curvularia lunata. The antimicrobial activity of these endophytic microorganisms could be exploited in the biotechnological, medicinal, and agricultural industries.     

Molecular profiling of marine endophytic fungi from green algae: Assessment of antibacterial and anticancer activities

Bioactive natural metabolites, especially from the marine endophytic fungi, are largely unexplored. Endophytic fungi are being increasingly recognized as a group of organisms that produce novel metabolites of industrial importance. This study investigated the anticancer and antibacterial potential of the marine algal endophyte, Penicillium chrysogenum. The different organic solvent extracts of the endophytic fungi grown on different growth medium were analyzed for anticancer and antibacterial activities. The highest inhibitory activity was observed for the ethyl acetate (EA) extract of the culture filtrate grown in potato dextrose broth (PDB) for 21 days, against the tested human breast cancer cell (MCF-7) line. Similarly, the PDB-EA extract showed an appreciable activity against the human pathogens. The biochemical analysis of the Cha EA metabolites revealed terpenoids, steroids, phenolics and flavones. Gas Chromatography (GCMS) data revealed several bioactive compounds such as anthraquinone and cinnamic acid. The Cha EA extract induced membrane damage and thus, apoptosis in MCF-7cells. The secondary metabolites produced by these marine endophytic fungi have contributed to considerable anticancer and antimicrobial activities and hence, this study is an evidence of potential sources of antimicrobial and anticancer compounds from Penicillium chrysogenum.     

Endophytic Fungi Isolated from Oil-Seed Crop Jatropha curcas Produces Oil and Exhibit Antifungal Activity

Jatropha curcas L., a perennial plant grown in tropics and subtropics is popularly known for its potential as biofuel. The plant is reported to survive under varying environmental conditions having tolerance to stress and an ability to manage pest and diseases. The plant was explored for its endophytic fungi for use in crop protection. Endophytic fungi were isolated from leaf of Jatropha curcas, collected from New Delhi, India. Four isolates were identified as Colletotrichum truncatum, and other isolates were identified as Nigrospora oryzae, Fusarium proliferatum, Guignardia cammillae, Alternaria destruens, and Chaetomium sp. Dual plate culture bioassays and bioactivity assays of solvent extracts of fungal mycelia showed that isolates of Colletotrichum truncatum were effective against plant pathogenic fungi Fusarium oxysporum and Sclerotinia sclerotiorum. Isolate EF13 had highest activity against S. sclerotiorum. Extracts of active endophytic fungi were prepared and tested against S. sclerotiorum. Ethyl acetate and methanol extract of C. truncatum EF10 showed 71.7% and 70% growth inhibition, respectively. Hexane extracts of C. truncatum isolates EF9, EF10, and EF13 yielded oil and the oil from EF10 was similar to oil of the host plant, i.e., J. curcas.     

Phylogeny,antimicrobial, antioxidant and enzyme-producing potential of fungal endophytes found in <Emphasis Type="Italic">Viola odorata</Emphasis>

Viola odorata, a medicinal plant, is traditionally used to treat common cold, congestion and cough. Given its medicinal properties and occurrence in the northwestern Himalayas, we isolated and characterized endophytic fungi from this plant morphologically, microscopically and by internal transcribed spacer-based rDNA sequencing. In total, we isolated 27 morphotypes of endophytes belonging to phyla Ascomycota and Basidiomycota. The roots showed the highest diversity of endophyte as well as fungal dominance, followed by leaves and leaf nodes. The fungal extract of VOR16 (Fusarium oxysporum) displayed potent antimicrobial activity against Salmonella typhimurium, Klebsiella pneumoniae and Escherichia coli, with a minimum inhibitory concentration of 0.78, 0.78 and 1.56 μg/mL, respectively, while fungal extract VOLF4 (Aspergillus sp.) exhibited promising antioxidant activity (IC₅₀ of 17.4 μg/mL). To identify the components responsible for various bioactivities, we analyzed the content of penicillin G in the extract of bioactive endophytes. The results suggested that the expression of penicillin G under the fermentation conditions applied was too low to display antimicrobial effects. Thus, the activity may be contributed by a different, novel secondary metabolite. The antioxidant activity of VOLF4 may be attributed to its high content of flavonoids. Of the endophytic fungi assessed, 27% were found to be enzyme producers. The highest zone of clearance was observed in VOLN5 (Colletotrichum siamense) for protease production. Only VOR5 (Fusarium nematophilum) was found to be a producer of cellulase, glutenase, amylase and protease. In summary, this is the first report of the isolation of endophytes, namely Fusarium nematophilum, Colletotrichum trifolii, C. destructivum, C. siamense and Peniophora sp., from V. odorata and their bioactive and enzyme-producing potential.     

黄花倒水莲内生真菌生物活性评价及HNLF-44菌株鉴定

为充分开发黄花倒水莲(Polygala fallax)的内生真菌资源，获得具有抗植物病原真菌、抗氧化活性的内生真菌，该文以黄花倒水莲内生真菌为研究对象，使用平板对峙法检测内生真菌对6种植物病原真菌的抑菌活性，测定内生真菌发酵液的DPPH清除自由基能力和总还原能力，评价内生真菌的抗氧化活性，并对具有强抑菌活性和抗氧化活性的菌株进行形态和ITS鉴定。结果表明：(1)黄花倒水莲内生真菌中有2株内生真菌对香蕉专化尖孢镰刀菌、柑橘树脂病菌、叶点霉菌、香蕉具条叶斑病菌、茄病镰刀菌、三七根腐病菌具有明显的抑菌活性，抑菌率在50.3%～91.4%之间，其中HNLF-5对柑橘树脂病菌的抑菌率为73.2%,HNLF-44对香蕉专化尖孢镰刀菌抑菌率为91.4%。(2)内生真菌发酵液具有良好的抗氧化活性，DPPH清除率均在80%以上，总还原能力吸光值范围为0.279 2～0.748 8。(3)HNLF-44菌株为链格孢属真菌。该研究表明，药用植物黄花倒水莲内生真菌具有较好的生物活性，为后续从黄花倒水莲内生真菌中挖掘潜在新型抑菌活性和抗氧化活性物质奠定了基础。     

剑叶龙血树内生真菌的分离及体外抑菌活性筛选

为研究剑叶龙血树内生真菌资源多样性,初步探讨和筛选具有抑菌活性的特异性菌株以及进一步开发剑叶龙血树内生真菌的抗菌活性化合物。该文采用植物组织分离法从剑叶龙血树茎和叶中分离内生真菌,对内生真菌进行液体发酵7 d,经乙酸乙酯萃取后制得粗提物,并采用牛津杯扩散法,以10种常见病原菌和5种临床耐药菌为靶标检测其发酵粗提物的抑菌活性,对有较好抑菌活性的内生真菌进行分子鉴定。结果表明:(1)从剑叶龙血树茎、叶中共分离得到345株内生真菌,294株对一种以上指示菌有抑制活性;(2)其中84株内生真菌对5株临床耐药菌均有不同程度的抑制活性,占所分离菌株总数的24.35%,75%的内生真菌对金黄色葡萄球菌有抑制活性。这说明剑叶龙血树中存在多种有抑菌活性的内生真菌,为剑叶龙血树内生菌抗菌活性成分挖掘及新型抗菌药物筛选奠定了基础。     

Isolation and identification of endophytic bacteria from root tissues of Salvia miltiorrhiza Bge. and determination of their bioactivities

Endophytic bacteria are microorganisms that live in host plants, but do not cause diseases to the hosts. This study examined the occurrence, distribution, growth-promoting and antifungal activities of endophytes in the root of Salvia miltiorrhiza Bge. Six endophytic bacterial strains, which belong to genera of Pseudomonas, Rhizobium, Bacillus and Novosphingobium, were isolated from the root of healthy S. miltiorrhiza. Cell suspension (approx. 10⁹ cell?·?ml^?1) of two isolates and cell-free fermentation filtrate of four isolates substantially promoted the growth of hypocotyl and radicle of muskmelon seeds. The cell-free fermentation filtrate of six isolates had no inhibiting effect on tested pathogenic fungi, namely Fusarium solani, F. oxysporum f. sp. vasinfectum and F. oxysporum. Six compounds were isolated from one of the six endophytic bacteria, namely, Bacillus aryabhattai, and two of these compounds displayed certain antifungal activity against three tested S. miltiorrhiza pathogens. Our work indicates that endophytic bacteria occur in the root of S. miltiorrhiza, and that associated bacterial isolates have growth-promoting effect on muskmelon seeds and are expected to be a potential source for bioactive metabolites.     

Microbial conversion and in vitro and in vivo antifungal assessment of bioconverted docosahexaenoic acid (bDHA) used against agricultural plant pathogenic fungi

Microbial modification of polyunsaturated fatty acids can often lead to special changes in their structure and in biological potential. Therefore, the aim of this study was to develop potential antifungal agents through the microbial conversion of docosahexaenoic acid (DHA). Bioconverted oil extract of docosahexaenoic acid (bDHA), obtained from the microbial conversion of docosahexaenoic acid (DHA) by Pseudomonas aeruginosa PR3, was assessed for its in vitro and in vivo antifungal potential. Mycelial growth inhibition of test plant pathogens, such as Botrytis cinerea, Colletotrichum capsici, Fusarium oxysporum, Fusarium solani, Phytophthora capsici, Rhizoctonia solani and Sclerotinia sclerotiorum, was measured in vitro. bDHA (5 μl disc⁻¹) inhibited 55.30–65.90% fungal mycelium radial growth of all the tested plant pathogens. Minimum inhibitory concentrations (MICs) of bDHA against the tested plant pathogens were found in the range of 125–500 μg ml⁻¹. Also, bDHA had a strong detrimental effect on spore germination for all the tested plant pathogens. Further, three plant pathogenic fungi, namely C. capsici, F. oxysporum and P. capsici, were subjected to an in vivo antifungal screening. bDHA at higher concentrations revealed a promising antifungal effect in vivo as compared to the positive control oligochitosan. Furthermore, elaborative study of GC-MS analysis was conducted on bioconverted oil extract of DHA to identify the transformation products present in bDHA. The results of this study indicate that the oil extract of bDHA has potential value of industrial significance to control plant pathogenic fungi.     

Mycoparasitism studies of Trichoderma species against three phytopathogenic fungi: evaluation of antagonism and hydrolytic enzyme production

Trichoderma spp. are used for biocontrol of several plant pathogens. However, their efficient interaction with the host needs to be accompanied by production of secondary metabolites and cell wall-degrading enzymes. Three parameters were evaluated after interaction between four Trichoderma species and plant-pathogenic fungi: Fusarium solani, Rhizoctonia solani and Sclerotinia sclerotiorum. Trichoderma harzianum and T. asperellum were the most effective antagonists against the pathogens. Most of the Trichoderma species produced toxic volatile metabolites, having significant effects on growth and development of the plant pathogens. When these species were grown in liquid cultures with cell walls from these plant pathogens, they produced and secreted β-1,3-glucanase, NAGAse, chitinase, acid phosphatase, acid proteases and alginate lyase.     

Antimycotic activities of Cinnamon-derived compounds against <Emphasis Type="Italic">Rhizoctonia solani</Emphasis> in vitro

In this study, the effects of medicinal plant extracts on the development of mycelium in the following phytopathogenic fungi were evaluated: Phytophthora capsici, Rhizoctonia solani, Fusarium solani, Colletotrichum gloeosprorioides, and Botrytis cinera. Of the 26 medicinal plants tested, six plant extracts showed antifungal activity against phytopathogenic fungi. The highest antifungal activity was exerted against R. solani by the n-hexane fraction of a Cinnamon (Cinnamomum cassia Blume) solvent extract. Therefore, the antifungal compound fractions I and II were purified from the n-hexane fraction by TLC on silica gel plates. When treated with solutions containing compound fractions I or II at a concentration of 2%, the mycelia growth rate of R. solani was reduced to 0.19 and 0.18, respectively. In addition, microscopic observation of the hyphal morphology of R. solani following treatment with compound fraction I revealed the presence of severely damaged hyphae. Specifically, the hyphal tips became swollen, collapsed or were completely destroyed in response to treatment with solution containing compound fraction I at concentration of 1%.     

Bioactive sesquiterpene,plasticizer, and phenols from the fungal endophytes of <Emphasis Type="Italic">Polygonum chinense</Emphasis> L.

There is a constant need for novel antibiotic and antioxidant sources due to the ever-increasing resilience of pathogens and the occurrence of chronic diseases. The natural sources of these agents have advantages due to lower production cost, structural variation, and uses of active compounds for pharmaceutical uses. The microbes living in planta termed “endophytes” are alternative sources of host bioactive compounds. In this study, ten endophytic fungi were isolated from Polygonum chinense L. and identified by sequencing of the internal transcribed spacer regions. The fungal strains were fermented and the ethyl acetate extracts were evaluated for antimicrobial and antioxidant capacities. Almost 80% of the endophytes showed antibacterial potency against one or more pathogenic bacteria. Among all strains, Penicillium canescens showed broad-spectrum antimicrobial activity against gram-positive and gram-negative pathogens as well as significant antioxidative and DNA protective capacities. The strain Fusarium chlamydosporum displayed significant anti-radical (126.8?±?6.7 μg/ml) and ferric reducing (84.7?±?2.1 mg AA/g dry extract) capacities. The bio-autography, chromatography, and mass spectroscopy analyses of P. canescens extract revealed the presence of sesquiterpene (germacrene), plasticizer (phthalic acid ester) along with phenolic acids, flavonoid (quercetin), and short chain hydrocarbons. The secondary metabolites of F. chlamydosporum were identified with phenolic acids as bioactive compounds by chromatography and mass spectroscopy. This study indicates P. chinense endophytes as potential sources of antimicrobial and antioxidant compounds for novel drug discovery.     

Exploring the biocontrol potential of fungal endophytes from an Andean Colombian Paramo ecosystem

We studied the diversity and biocontrol potential of 100 fungal endophytes isolated from Espeletia spp., endemic plant species from the Paramo in the Andean mountain range. Our sample was genotypically highly diverse at all ITS similarity levels. The antagonistic properties of these isolates were tested against common crop pathogens in Colombia, including Pectobacterium carotovorum, Ralstonia solanacearum, Pseudomonas syringae, Xanthomonas campestris, Rhizoctonia solani, Botrytis cinerea, Fusarium oxysporum, and Phytophthora infestans. All endophytic isolates were able to significantly inhibit the growth of at least one of the plant pathogens tested (P?<?0.05). Three main types of endophyte/pathogen interactions were observed. However, only those endophytes that produced an evident inhibition halo were further studied using their crude extracts to confirm that the inhibitory effect was due to the production of endophytic bioactive metabolites. From these experiments, nine promising isolates were selected for co-inoculation tests with R. solani in tomato plants. The isolates identified as Aureobasidium pullulans and Paraconiothyrium sporulosum not only protected the plants against this pathogen but also allowed them to exhibit similar growth and development as the uninoculated control. This work explores new alternatives for disease management without the application of chemical pesticides.     

Fungal Parasitism of Heterodera glycines Eggs as Influenced by Egg Age and Pre-colonization of Cysts by Other Fungi

The objective of this study was to determine the effect of egg age and pre-colonization of cysts by a saprophytic or parasitic fungus on parasitism of Heterodera glycines eggs by other parasitic fungi. In agar and in soil tests, fungi generally parasitized more eggs in early developmental stages than eggs containing a juvenile. The effect of pre-colonization of cysts by a fungus on parasitism of eggs by other fungi depended on the fungi involved. In most cases, pre-colonization of cysts by an unidentified, saprophytic fungal isolate (A-1-24) did not affect parasitism of eggs in the cysts subsequently treated with other fungi. However, pre-colonization of cysts by A-1-24 reduced fungal parasitism of eggs in cysts subsequently treated with Cylindrocarpon destructans isolate 3. In agar tests, pre-colonization of cysts by Chaetomium cochliodes, a saprophytic or weakly parasitic fungus, reduced parasitism of eggs in cysts subsequently treated with Verticillium chlamydosporium Florida isolate, Fusarium oxysporum, Fusarium solani, ARF18, and another sterile fungus. However, in soil tests, pre-colonization of cysts by C. cochliodes had no effect on parasitism of eggs by subsequent fungal parasites. In another test, parasitism of eggs by V. chlamydosporium in cysts was not affected by pre-colonizing fungi C. destructans, F. oxysporum, and F. solani but was reduced by Mortierella sp., Pyrenochaeta terrestris, and C. cochliodes. Parasitism of eggs in cysts by ARF18 was reduced by pre-colonizing fungi C. destructans, F. oxysporum, F. solani, P. terrestris, and C. cochliodes but not Mortierella sp.     

Clavatol and patulin formation as the antagonistic principle of <Emphasis Type="Italic">Aspergillus clavatonanicus</Emphasis>, an endophytic fungus of <Emphasis Type="Italic">Taxus mairei</Emphasis>

Many endophytic fungi are known to protect plants from plant pathogens, but the antagonistic mechanism has rarely been revealed. In this study, we wished to learn whether an endophytic Aspergillus sp., isolated from Taxus mairei, would indeed produce bioactive components, and if so whether (a) they would antagonize plant pathogenic fungi; and (b) whether this Aspergillus sp. would produce the compound also under conditions of confrontation with these fungi. The endophytic fungal strain from T. mairei was identified as Aspergillus clavatonanicus by analysis of morphological characteristics and the sequence of the internal transcribed spacers (ITS rDNA) of rDNA. When grown in surface culture, the fungus produced clavatol (2′,4′-dihydroxy-3′,5′-dimethylacetophenone) and patulin (2-hydroxy-3,7-dioxabicyclo [4.3.0]nona-5,9-dien-8-one), as shown by shown by NMR, MS, X-ray, and EI-MS analysis. Both exhibited inhibitory activity in vitro against several plant pathogenic fungi, i.e., Botrytis cinerea, Didymella bryoniae, Fusarium oxysporum f. sp. cucumerinum, Rhizoctonia solani, and Pythium ultimum. During confrontation with P. ultimum, A. clavatonanicus antagonized its growth of P. ultimum, and both clavatol as well as patulin were formed as the only bioactive components, albeit with different kinetics. We conclude that A. clavatonanicus produces clavatol and patulin, and that these two polyketides may be involved in the protection of T. mairei against attack by plant pathogens by this Aspergillus sp.     

Antifungal properties of essential oil and crude extracts of Hypericum linarioides Bosse

The chemical composition of the essential oil isolated from the aerial parts of Hypericum linarioides Bosse by hydrodistillation was analysed by GC–MS. It was determined that 74 compounds, which represent 84.1% of total oil, were present in the oil. The oil contains mainly δ-cadinene (6.9%), (Z)-β-farnesene (5.2%), γ-muurolene (5.5%), spathulenol (4.8%), hexahydrofarnesyl acetone (4.5%) and α-selinene (4.0%). The oil was also characterized by high content of sesquiterpenes (64.2% of total oil). The oil was tested for antifungal activity using mycelial growth inhibition assays (in vitro) against 11 agricultural pathogenic fungi, which consisted of six Fusarium species (Fusarium acuminatum, Fusarium culmorum, Fusarium equiseti, Fusarium oxysporum, Fusarium sambucinum and Fusarium solani) and three anastomosis groups of Rhizoctonia solani (AG-5, AG-9 and AG-11), Alternaria solani and Verticillium albo-atrum. The oil of H. linarioides showed antifungal activity against AG-9 and V. albo-atrum. In addition, petroleum ether, chloroform, acetone and methanol extracts of H. linarioides were tested against species of 11 fungi. The extracts showed moderate inhibition effects on the growth of A. solani, F. culmorum, F. equiseti and all anastomosis groups of R. solani.     

Diversity and antifungal activity of endophytic bacteria associated with <Emphasis Type="Italic">Panax ginseng</Emphasis> seedlings

Ginseng (Panax ginseng C.A. Meyer) is a medicinal crop that requires a long culture time before it is ready to harvest, thus generating high economic and environmental costs. Symbiotic bacteria that live within the plant provide the host plant with many advantages in terms of metabolism and disease resistance. Here, we isolated endophytic bacteria from various tissues of P. ginseng seedlings using a culture-dependent method and we compared their tissue distribution. In addition, their antimicrobial activity against two fungal pathogens was investigated. Based on 16S rRNA sequencing, we identified 21 bacterial strains from ginseng seedlings. Leaves and rhizomes showed higher bacterial species diversity than root bodies and tails. While Bacillus strains were detected in all tissues, Xanthomonas and Micrococcaceae strains were specifically isolated from rhizome and leaf tissues, respectively. Fourteen bacterial strains showed antimicrobial activities against Cylindrocarpon destructans and/or Botrytis cinerea, with different activities. Among them, two strains (PgKB29 and PgKB35) showed strong antimicrobial activities against both fungi. Taken together, these results provide a better understanding of endophytic bacteria in P. ginseng seedlings and suggest the possibility of biological control of fungal pathogens using endophytic bacteria.     

In Vitro Evaluation of Antagonism of Endophytic Colletotrichum gloeosporioides Against Potent Fungal Pathogens of Camellia sinensis

An endophytic fungus isolated from Camellia sinensis, Assam, Northeastern India was identified as Colletotrichum gloeosporioides on the basis of morphological characteristics and rDNA ITS analysis. This endophytic fungus was evaluated for growth inhibition against tea pathogens Pestalotiopsis theae and Colletotrichum camelliae. One isolate of C. gloeosporioides showed strong antagonistic activity against Pestalotiopsis theae (64 %) and moderate activity against C. camelliae (37 %). Fifty percent cell-free culture filtrate from 5-day-old cultures showed highest antagonistic activity against both the pathogens although the inhibition percent was less as compared to dual culture. In the experiment of volatile compounds none of the isolates of C. gloeosporioides strains showed visible inhibition against P. theae and C. camelliae. The activity of extracellular hydrolytic enzymes chitinase and protease was also high in this culture fluid and measured 10 and 4.3 IU/μl, respectively.