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991.
    从除虫菊叶中分离到1株内生真菌,经形态学和生长特性等研究初步鉴定其为半知菌类拟盘多毛孢(Pestalotiopsis sp.).该菌发酵液的10倍稀释液对苹果炭疽病菌(Glomerella cingulata)、番茄灰霉病菌(Botrytis cirerea)、玉米大斑病菌(Exserohilum turcicum)等6种病原真菌的抑制作用均达到85%以上,其5倍稀释液对番茄灰霉病菌、玉米大斑病菌、苹果炭疽病菌的孢子萌发抑制率均达80%以上.盆栽试验中对小麦白粉病(Blumeriagraminis)、番茄灰霉病、黄瓜霜霉病(Lycopersicon esculentum)的防治效果达60%以上.环境和营养因子对该菌的生长繁殖和抑菌活性影响较大:①在10~35℃时,菌丝能生长并形成孢子,最适生长繁殖温度为30℃,孢子的致死温度为65℃;②在pH 6.5~8.0时,菌丝生长、孢子形成和萌发均良好,最适pH值为7.5;③能直接利用玉米粉和糊精;④氮源以有机态氮为佳,硝态氮对其生长繁殖有抑制作用;⑤分别以D-木糖、山梨糖、甘露醇为碳源,以硝酸钠、甘氨酸、硫酸铵、牛肉膏、蛋白胨为氮源培养时,该菌株发酵液抑菌活性较高.  相似文献   
992.
宁夏沙坡头人工植被区土壤真菌种群的动态研究(英文)   总被引:5,自引:0,他引:5  
[Objective] The changes of fungi in different soil layers and sand dunes of artificial vegetation areas in Ningxia Shapotou during different times were studied. [Method]The number of soil fungi in different soil layers at same plot and in same soil layer at different plots were changed significantly.The quantitative distribution of fungi was the most in Cuiliugou but the fewest in quicksand among all soil types.[Result] The quantity of soil fungi in grasslands was varied in different soil layers at the same sample and in the same soil layer at different sample plots. The quantity of fungi from different soil types distributed mostly in Cuiliugou, a natural desert steppe, but little in quicksand. The species and quantity of fungi in CuiLiugou was the most in different types of sand-fixing lands. [Conclusion] The quantity of soil fungi in artificial vegetation areas raises with the increase of sand-fixing ages, The enhancement of vegetation construction and artificial management measures in inland is helpful for improving present situation of desertification.  相似文献   
993.
Current interest in biological-based management of weed seed banks in agriculture furthers the need to understand how microorganisms affect seed fate in soil. Many annual weeds produce seeds in high abundance; their dispersal presenting ready opportunity for interactions with soil-borne microorganisms. In this study, we investigated seeds of four common broadleaf weeds, velvetleaf (Abutilon theophrasti), woolly cupgrass (Eriochloa villosa), Pennsylvania smartweed (Polygonum pensylvanicum), and giant ragweed (Ambrosia trifida), for potential as sources of carbon nutrition for soil fungi. Seeds, as the major source of carbon in an agar matrix, were exposed to microbial populations derived from four different soils for 2 months. Most seeds were heavily colonized, and the predominant 18S rRNA gene sequences cloned from these assemblages were primarily affiliated with Ascomycota. Further, certain fungi corresponded to weed species, regardless of soil population. Relatives of Chaetomium globosum (98–99% sequence identity) and Cordyceps sinensis (99%) were found to be associated with seeds of woolly cupgrass and Pennsylvania smartweed, respectively. More diverse fungi were associated with velvetleaf seeds, which were highly susceptible to decay. The velvetleaf seed associations were dominated by relatives of Cephaliophora tropica (98–99%). In contrast to the other species, only few giant ragweed seeds were heavily colonized, but those that were colonized resulted in seed decay. The results showed that seeds could provide significant nutritional resources for saprophytic microbes, given the extant populations can overcome intrinsic seed defenses against microbial antagonism. Further, weed species-specific associations may occur with certain fungi, with nutritional benefits conferred to microorganisms that may not always result in seed biodeterioration.  相似文献   
994.
Pure-culture isolation from roots was compared with transformation of total DNA from roots followed by sequence analysis of ITS 1/2 rDNA of representative clones as methods for determining the abundance and composition of microbiota in roots of Betula pendula, Fagus sylvatica, Larix decidua, Prunus serotina and Quercus petraea. The results from the two methods differed greatly, with no overlap between the taxa identified. Pure-culture isolation revealed greater species diversity (47 taxa), the most frequent fungi being Ascomycota, including Penicillium spp., Phialocephala fortinii, Pochonia bulbillosa, Sesquicillium candelabrum and Trichoderma spp. Transformation of total DNA and sequencing revealed less diversity (22 taxa), the most frequent taxa being Basidiomycota, including Coprinus fissolanatus and Mycena spp., and Ascomycota, including PodosporaSchizothecium spp., Helgardia anguioides and Microdochium sp. Communities characterized by either method showed slightly greater fungal diversity and less species dominance on F. sylvatica than on roots of other trees, whilst DNA sequencing showed least diversity and greatest species dominance on Q. petraea.  相似文献   
995.
为进一步了解重庆地区玉米叶内生细菌的组成以及这些内生细菌与入侵重庆地区草地贪夜蛾肠道微生态的相互关系,以采集自巫山地区被草地贪夜蛾入侵的玉米地里的玉米嫩叶为材料,运用传统微生物培养方法尝试对其内生细菌进行初步的分离培养,并通过16S rDNA测序开展了优势菌的属水平鉴定.此次共分离获得了22个细菌分离株,经16S rDNA序列同源性分析,将它们归类到11个分类单元,分属克雷伯氏菌属(Klebsiella)、不动杆菌属(Acinetobacter)、寡养单胞菌属(Stenotrophomonas)、芽孢杆菌属(Bacillus)、肠球菌属(Enterococcus)、微杆菌属(Microbacterium)、鞘氨醇杆菌属(Sphingobacterium)、金黄杆菌属(Chryseobacterium)、无色杆菌属(Achromobacter)和丛毛单胞菌属(Comamonas).与前期研究得到的该地区草地贪夜蛾肠道微生物菌群数据比较可以发现,玉米内生细菌中包括克雷伯氏菌属(Klebsiella)、不动杆菌属(Acinetobacter)、肠球菌属(Enterococcus)、鞘氨醇杆菌属(Sphingobacterium)和金黄杆菌属(Chryseobacterium)在内的5个属可以在草地贪夜蛾肠道中分离到,表明草地贪夜蛾肠道微生物多数可能源自其食物,但是草地贪夜蛾肠道微生物中常见的假单胞菌属(Pseudomonas)、肠杆菌属(Enterobacter)、类芽孢杆菌属(Paenibacillus)、短波单胞菌属(Brevundimonas)和气单胞菌属(Aeromonas)并未在玉米嫩叶中分离到,说明它们可能是主要存在于草地贪夜蛾肠道中的微生物.该研究对草地贪夜蛾所取食的玉米叶中内生细菌的种类进行了初步分析,为后续研究玉米叶内生细菌和草地贪夜蛾肠道微生物的相互关系奠定了基础.  相似文献   
996.
木麻黄内生真菌次生代谢产物及生物活性   总被引:2,自引:1,他引:1  
【目的】分离和鉴定木麻黄Casuarina equisetifolia枝条和果实中的内生真菌,筛选具有抗菌和抗氧化活性的内生真菌。【方法】采用组织块分离法分离木麻黄枝条和果实中的内生真菌,通过菌落观察和分子生物学相结合的方法对分离到的内生真菌进行鉴定;采用薄层层析-生物自显影法测定木麻黄内生真菌次生代谢产物对细菌的抑制活性,采用多孔板-DPPH显色法测定抗氧化活性。【结果】从木麻黄枝条和果实中共分离鉴定得到12株内生真菌,枝条和果实内生真菌存在明显的差异,相同的菌株只有2株,分别为Cef-1(Pseudofusicoccum sp.)和Cef-7(Pestalotiopsis sp.);12株内生真菌分属于9个不同的属中,分别为Pseudofusicoccum、葡萄座腔菌属Botryosphaeria、拟盘多毛孢属Pestalotiopsis、木霉属Trichoderma、曲霉属Aspergillus、裂菌属Rhytidhysteron、拟茎点霉属Phomopsis、镰刀菌属Fusarium和炭疽菌属Colletotrichum。其中,葡萄座腔菌属种类最多,为木麻黄内生真菌的优势种群,其次是拟盘多毛孢属真菌。抗细菌活性的结果表明,Cef-2(Botryosphaeria sp.)表现出最强的抑制活性,对所有供试细菌的抑菌斑直径均大于10 mm,强于阳性对照硫酸链霉素,Cef-1和Cef-9(Fusarium sp.)对青枯病菌Ralstonia solanacearum也表现出较好的抑制活性。内生真菌Cef-2表现出最好的抗氧化活性,IC50为0.80mg/mL。【结论】木麻黄枝条和果实中均存在内生真菌且均以葡萄座腔菌属为优势种群,2个部位真菌的种类存在明显差异。内生真菌Cef-2表现出最强的抗细菌和抗氧化活性,可作为候选菌株进一步分离和鉴定其活性成分。  相似文献   
997.
The aim of this research was to evaluate the amount of woody debris (m3/ha) on the forest floor and the associated wood-colonizing fungi. The study was performed in the Taborz region, known for its Scots pine provenance experiments, against the background of a recently launched Polish legislation to protect the biodiversity on the forest floor in managed (harvested) stands. We investigated a managed stand (136-years-old) and the reserve stand ‘Sosna Taborska’(261-years-old). In the reserve stand, the mean volume of woody debris was six times higher than in the managed forests, i.e. 65 versus 11 m3/ha. In addition, in the reserve stand, the number of fungi taxa colonizing the dead wood was larger than in the managed stands, with a higher number of fruitbodies. Total fungal richness was higher in the reserve than in the managed stand, i.e. 28 versus 12 species. The dominant taxa at both sites were Fomitopsis pinicola and Fomes The aim of this research was to evaluate the amount of woody debris (m^3/ha) on the forest floor and the associated wood-colonizing fungi. The study was performed in the Taborz region, known for its Scots pine provenance experiments, against the background of a recently launched Polish legislation to protect the biodiversity on the forest floor in managed (harvested) stands. We investigated a managed stand (136-years-old) and the reserve stand ‘Sosna Taborska’(261-years-old). In the reserve stand, the mean volume of woody debris was six times higher than in the managed forests, i.e. 65 versus 11 m^3/ha. In addition, in the reserve stand, the number of fungi taxa colonizing the dead wood was larger than in the managed stands, with a higher number of fruitbodies. Total fungal richness was higher in the reserve than in the managed stand, i.e. 28 versus 12 species. The dominant taxa at both sites were Fomitopsis pinicola and Fomes fomentarius, although some taxa were only found in the reserve (e.g., Stereum hirsutum). The volume of woody debris as well as the diversity of fungi in the managed stand were lower than in the reserve, albeit greater than in other Scots pine stands in Poland. These results testify to the gains in biodiversity yielded by the management conservation management approach at the reserve stand.  相似文献   
998.
以湖南省壶瓶山国家级自然保护区生长的9株(3组)不同树龄银杏为研究对象,应用IlluminaHiSeq高通量测序技术,分析银杏叶片组织内生真菌的多样性及群落结构。结果表明:银杏叶片内生真菌群落的多样性、群落结构与组成均存在显著性差异,且随着树龄的增加,叶片内生真菌群落结构差异增大;子囊菌门(Ascomycota)为绝对优势菌门;曲霉属(Aspergillus)、假丝酵母属(Candida)、球腔菌属(Mycosphaerella)等真菌为银杏叶内生真菌群落优势菌属;通过对银杏叶黄酮含量进行检测,发现不同树龄银杏叶的黄酮含量存在显著差异,且随着树龄的增加,3种黄酮醇苷(槲皮素、山奈酚和异鼠李素)含量均呈递减趋势;进一步分析表明,黄酮类化合物作为重要环境因子,可能通过影响优势菌门子囊菌中优势菌属的定殖与生长对内生真菌群落的形成与变化产生显著影响。  相似文献   
999.
在曲靖市食用菌发展现状的基础上,为积极谋划经济发展新常态下曲靖市食用菌产业的升级发展,以特色产业助力“十三五”脱贫攻坚和高原特色农产品开发,充分发挥气候资源、区位、交通优势,坚持市场导向,强化政府引导,突出科技支撑,壮大经营主体,优化区域布局,调整产业结构,健全产业体系,大力推进园区化、标准化、工厂化、品牌化生产,大力发展精深加工,推动一、二、三产业融合发展,努力将食用菌产业打造成为富民强市的绿色产业,我们提出了曲靖市食用菌产业未来发展的建议。  相似文献   
1000.
千年桐内生真菌的分离鉴定及溶磷能力测定   总被引:1,自引:0,他引:1  
【目的】对千年桐(Aleurites montana)内生真菌进行分离鉴定,初步筛选具有较高溶磷活性的 内生真菌。【方法】从福建省南平市建阳区的外墩采育场、湖桥工区和书坊林场的千年桐根、茎、叶中分离纯 化得到内生真菌。根据菌落在根、茎、叶中出现频率及其直径生长速度筛选优势菌株,进一步对优势菌进行溶 磷能力的定性测定。【结果】共分离出 155 株菌株,其中茎内生真菌 60 株(38.71%)、叶 50 株(32.26%)、 根 45 株(29.03%)。湖桥样地采集的内生真菌数量最多、外墩样地最少。选出 25 株优势菌株,经形态学和 18 SrDNA 分子鉴定分别为毛霉菌属(Mucor sp.)、青霉属(Penicillium sp.)、拟盘多毛孢属(Pestalotiopsis sp.)、生赤壳属(Bionectria sp.)、木霉属(Trichoderma sp.)、嗜热真菌属(Thermomyces sp.)、链格孢属(Alternaria sp.)、盾壳霉属(Coniothyrium sp.)和镰刀菌属(Fusarium sp.)。对优势菌株溶磷效果的试验表明,具有较强 溶磷活性的菌株分属青霉属(Penicillium sp.)和嗜热真菌属(Thermomyces sp.)。【结论】千年桐内生真菌数 量在不同地点和不同器官间分布各有不同,初步确定千年桐内生真菌菌属组成,得到具有较强溶磷活性的菌株 分属青霉属(Penicillium sp.)和嗜热真菌属(Thermomyces sp.)。  相似文献   
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