芸芥体细胞胚胎发生及植株再生体系的建立

以芸芥子叶为外植体,诱导芸芥体细胞胚胎发生并建立植株再生体系.结果表明:基因型及植物生长调节剂对芸芥体细胞胚胎发生均有一定的影响,其中以含有1.0mg·L-12,4-D的MS培养基诱导芸芥体细胞胚胎发生的效果最优.在MS 0.2mg·L-12,4-D培养基上,胚性愈伤组织可大量增殖.对芸芥体细胞胚胎成熟的研究表明,体胚在N6培养基上成熟最佳,且45.2%的成熟体胚可在1/2MS 0.1mg·L-1IBA培养基上萌发生长.     

芸芥自交亲和性变异的初步研究

为了判断芸芥(Eruca sativa)自交亲和性的变异情况, 采用套袋自交、剥蕾自交和开放授粉3种方法, 对来源于中国、伊朗和巴基斯坦的52份芸芥的自交亲和指数及相对亲和指数进行了统计分析。结果表明: (1) 芸芥为高度自交不亲和植物, 其不同品种(系)中存在自交亲和基因; (2) 芸芥不同品种间自交亲和性存在广泛的变异, 品种间自交亲和指数介于0-4.98之间, 品种内不同个体间自交亲和性也存在广泛的变异; (3) 参试材料分为4种类型, 即高自交亲和、自交亲和、自交不亲和(0<自交亲和指数<1.00)及高自交不亲和; (4) 芸芥自交亲和性因生态类型而异, 西南地区的材料自交亲和性最高, 西北地区次之, 华北地区最低。总之, 芸芥为一种高度自交不亲和植物, 其自交亲和性状存在广泛的变异, 共有4种变异类型。     

抗辣椒炭疽病菌盘长孢状刺盘孢的木霉菌的筛选

本试验通过对峙培养法筛选出28株具有强拮抗能力和15株中等拮抗能力的木霉菌。使用玻璃纸培养法进一步复筛出6株木霉菌(104、393、424、402、451和123T),其非挥发性次生代谢产物对盘长孢状刺盘孢的抑制率高达92%以上。通过平板对扣培养法发现木霉菌424(Trichoderma atroviride)以及123T (T. paratroviride)的挥发性次生代谢产物对盘长孢状刺盘孢也具有抑制作用,抑制率分别为57.12%和60.43%。试验还对9个辣椒品种进行了盘长孢状刺盘孢的果实致病性评价,发现红尖椒属于高度易感病品种。在对该品种进行针尖刺伤法处理后,喷施木霉菌424和123T的分生孢子悬浮液后可以提高其对病菌的抗性。此外,试验还发现上述2株木霉菌的孢子悬浮液对辣椒种子萌发及幼苗生长具有促进作用,其将辣椒种子的发芽率由38.9%提高至70.0%。同时,辣椒幼苗经木霉菌分生孢子处理后,株高、根长、茎粗、鲜重和干重分别增加了52.5%、96.0%、104.0%、372.0%和224.0%。综上所述,本试验筛选的木霉菌424和123T能够充分发挥其生防能力,为进一步开发辣椒炭...     

四种提取芸芥基因组DNA方法的比较

以芸芥为材料 ,分别用CTAB法、SDS法、尿素法、NaOH法四种方法对芸芥基因组DNA进行了提取 ;并用紫外光分光光度计法、琼脂糖电泳法和RAPD分析法对所提取的DNA进行检测 ,将它们在DNA的产量、质量和耗时、耗费等方面的优缺点进行比较 ,以便在实际工作中根据不同的试验条件选取最合适的提取方法。通过四种方法的比较 ,研究认为尿素法是芸芥基因组DNA的最佳提取方法。     

木霉菌T23胶毒素合成基因的生物信息学分析与克隆

胶毒素是生防木霉菌重要的次生代谢产物之一。本研究以生防木霉菌T23为供试材料,旨在通过生物信息学技术及表达分析,挖掘木霉菌T23中胶毒素合成候选基因,探索木霉菌胶毒素合成的分子调控机制,可为新型生物农药的开发及应用提供理论依据。研究表明,木霉菌T23中胶毒素合成候选基因簇全长28 kb,簇内包含了8个基因,分别与烟曲霉胶毒素合成基因簇内的gliP、gliC、gliN、gliK、gliI、gliG、gliF、gliM高度同源。提取培养2 d、3 d、4 d、5 d的木霉菌T23菌丝的RNA,通过半定量RT-PCR技术探索各候选基因在木霉菌T23不同生长时期的表达情况,显示各基因在不同生长时期均有表达,属于组成型表达基因。成功克隆得到木霉菌T23中的gliP-T23基因并完成基因结构分析,该基因全长6 339 bp,由4个外显子和3个内含子组成,为后续的基因功能验证提供基础。     

木霉菌对3种致病真菌的作用关系研究

采用室内生长速率法测定了木霉菌 (Trichodermaspp .)与 3种致病真菌的互作关系 ,结果表明 ,木霉菌与 3种致病真菌间均存在明显的互作关系 ,但其互作类型与作用强度各不相同 :木霉菌与立枯丝核菌 (Rhi zoctoniasolani)间存在拮抗作用 ,但抑制强度不大 ;木霉菌与腐霉菌 (Pythiumaphanidermatum)不仅存在拮抗作用 ,且对腐霉菌的抑制强度较大 ;木霉菌与镰刀菌 (Fuariumspp .)间存在明显的协生作用。经进一步多方面考察后 ,有可能将该木霉菌用于病害防治     

对峙培养条件下木霉拮抗植物病原真菌能力的评价(英文)

木霉属真菌因具有拮抗植物病原真菌的能力而广泛用于农业生物防治。为提高初步筛选的效率,在对峙培养条件下探讨了不同木霉菌株的拮抗能力,将其分为强、中等、弱和无拮抗能力4种类型。在对峙培养中,具有强拮抗能力的木霉菌株生长速度快于植病菌,产生大量缠绕菌丝缠绕在植病菌的菌丝上,12d内在植病菌的菌落上大量产孢。具中等拮抗能力的木霉菌株表现为(1)生长速度较快或与植病菌相似,缠绕菌丝丰富,30d内在植病菌的菌落上少量产孢;(2)生长速度快,但缠绕菌丝较少或几近缺乏,12d内在植病菌的菌落上产孢丰富。具有弱拮抗能力的木霉菌株生长速度与植病菌的大致相同,缠绕菌丝较少,30d后在植病菌的菌落上少量产孢或不产孢。无拮抗能力的木霉菌株生长速度慢,常受植病菌菌落的限制,甚至被植病菌的菌落覆盖。上述分型和评价方法综合考虑了竞争和寄生等拮抗机制,可用于实验室内对木霉拮抗能力的快速初筛。     

莜麦类甜蛋白Permatin抑制木霉菌活性的机制研究

类甜蛋白(thaumatin-like proteins,TLPs)是一个高度复杂的蛋白质家族,与植物、动物和真菌的宿主防御和发育过程有关。TLPs已在多种植物中被发现,具有广谱抗真菌活性。近年来,植物来源的抗真菌蛋白在植物抗病原菌中具有广泛的应用前景,然而关于莜麦来源的抗真菌蛋白研究比较少。本研究从莜麦中分离纯化得到莜麦类甜蛋白Permatin,通过带毒平板法测定了Permatin蛋白对木霉菌的半抑制浓度;然后利用Delta Vision显微镜观察了Permatin蛋白对木霉菌孢子萌发及菌丝生长的影响;进一步结合碘化丙啶(propidium Iodine,PI)染色研究Permatin蛋白对木霉菌菌丝及孢子细胞膜通透性的影响。结果显示,Permatin蛋白对木霉菌的半抑制浓度为0.73μmol/L,可以显著抑制木霉菌孢子的萌发及菌丝的生长,并且能够破坏真菌菌丝及孢子细胞膜的通透性。本研究为莜麦Permatin蛋白在农业领域的应用提供了理论基础。     

马铃薯晚疫病生防木霉菌的筛选及鉴定

采用马铃薯活体筛选法从268株木霉菌中筛选获得两株对致病疫霉有较强抑菌活性的木霉菌株R-5和T-15。这两株木霉菌代谢液可抑制病原菌生长及孢子囊萌发。温室防病试验发现,接种两株木霉菌可以减轻晚疫病的发生。田间试验进一步证明,两株木霉菌对晚疫病具有良好的田间防治效果,防效分别达到了72.4%和70.0%。经分子生物学方法鉴定,两株木霉菌分别为拟康氏木霉和棘孢木霉。实验构建的以活体筛选为基础的生防木霉菌筛选方法是一种可行高效的生防木霉菌筛选方式。     

木霉属中国新纪录种Trichoderma pleuroticola和T. pleurotum

【目的】对蔬菜大棚土壤中和阿魏菇腐烂的菌盖上分离的两株木霉菌进行分类鉴定。【方法】结合形态学分类特征和ITS序列分析的方法进行鉴定。【结果】从蔬菜大棚的土壤中和阿魏菇腐烂的菌盖上分离的两株木霉菌分别为Trichoderma pleuroticola和T.pleurotum。T.pleuroticola的形态特征与T.harzianum相似,但其分生孢子显著大于T.harzianum的分生孢子,且在PDA上产生黑褐色的色素以及黄色的结晶物。T.pleurotum典型特征是分生孢子梗单生,有时匍匐,分枝散生,初级分枝和分生孢子梗顶端聚生,类似粘帚霉。【结论】分离的两株木霉分别是T.pleuroticola和T.pleurotum,为木霉菌中国新纪录种。     

Fungal antagonists of the plant pathogen Rhizoctonia solani: selection, control efficacy and influence on the indigenous microbial community

A broad spectrum of fungal antagonists was evaluated as potential biocontrol agents (BCAs) against the soil-borne pathogen Rhizoctonia solani using a new combination of in vitro and in vivo assays. The in vitro characterisation of diverse parameters including the ability to parasitise mycelium and to inhibit the germination of Rhizoctonia sclerotia at different temperatures resulted in the selection of six potential fungal antagonists. These were genotypically characterised by their BOX-PCR fingerprints, and identified as Trichoderma reesei and T. viride by partial 18S rDNA sequencing. When potato sprouts were treated with Trichoderma, all isolates significantly reduced the incidence of Rhizoctonia symptoms. Evaluated under growth chamber conditions, the selected Trichoderma isolates either partly or completely controlled the dry mass loss of lettuce caused by R. solani. Furthermore, the antagonistic Trichoderma strains were active under field conditions. To analyse the effect of Trichoderma treatment on indigenous root-associated microbial communities, we performed a DNA-dependent SSCP (Single-Strand Conformation Polymorphism) analysis of 16S rDNA/ITS sequences. In this first assessment study for Trichoderma it was shown that the pathogen and the vegetation time had much more influence on the composition of the microbiota than the BCA treatment. After evaluation of all results, three Trichoderma strains originally isolated from Rhizoctonia sclerotia were selected as promising BCAs.     

木霉对盐渍逆境下枸杞根系氮素吸收和氮素利用效率的影响

本研究采集滨海盐渍土开展盆栽试验,分析施加有机肥、木霉菌剂及菌肥对枸杞氮素吸收、同化、积累和利用效率的影响,以揭示木霉对盐渍逆境下枸杞的促生机理。有机肥为木霉菌肥的灭菌物,不含木霉活菌,但两者氮、磷、钾等养分含量无显著差异。结果表明: 施加有机肥、木霉菌剂和菌肥处理较对照均显著提高了根系分生区NO₃^-、NH₄⁺内流速率和成熟区NO₃^-内流速率,且施加菌肥的提升幅度高于施加有机肥。与对照相比,盐渍土壤施加木霉菌剂及菌肥显著增加了根、茎、叶生物量和氮含量以及植株氮累积量,增强了枸杞根和叶中硝酸还原酶、亚硝酸还原酶和谷氨酰胺合成酶活性,提高了枸杞氮素吸收效率、光合速率、稳定碳同位素丰度值和光合氮素利用效率,而且施加菌肥的效果明显优于施加有机肥。综上,木霉能增强盐渍逆境下枸杞氮素吸收、同化和积累,提升光合固碳能力和氮素利用效率,最终促进植株生长。     

Trichoderma spp. as elicitors of wheat plant defense responses against Septoria tritici

Leaf blotch of wheat is a widespread and highly active disease that affects wheat production. In addition to the use of chemicals and proper cultivation methods, microbial antagonists are used to control plant pathogens. Trichoderma spp. stimulate a systemic induced response in plants. Therefore, the efficacy of Trichoderma spp. against wheat leaf blotch was evaluated under greenhouse conditions. The susceptible plants were sprayed with Septoria tritici conidiospores. In order to select an efficient method of pretreatment with Trichoderma spp., leaf spraying and seed coating with 14 isolates were tested in 2003 and 2004. The extent of leaf necrosis area and pycnidial coverage was estimated. Antagonism was assessed by the capacity of each Trichoderma spp. isolate to restrict the progress of leaf blotch, 21 days after inoculation. Of the two methods, seed coating was more efficacious against leaf blotch than leaf spraying. Amongst the 14 isolates tested, the isolate prepared from T. harzianum (Th5) produced the highest level of protection. None of the treatments caused changes in plant stem diameter or dry weight. Trichoderma spp. did not get into leaves while S. tritici was present, even in asymptomatic leaf extracts. In addition, the leaf apoplast antifungal proteolytic activity was measured in plants 7, 15, and 22 days after sowing. This antifungal action decreased in plants only inoculated with S. tritici, but increased in those grown from seeds coated with the T. harzianum (Th5) isolate. This increase conferred resistance to the susceptible wheat cultivar. The endogenous germin-like protease inhibitor coordinated the proteolytic action. These results suggest that T. harzianum stimulates a biochemical systemic induced response against leaf blotch.     

Dominant fungi in the rhizosphere of established tea bushes and their interaction with the dominant bacteria under in situ conditions.

Species of Penicillium and Trichoderma were found to dominate the rhizosphere of established tea bushes in a detailed study conducted from various tea growing locations in India. Penicillium erythromellis, P. janthinellum, P. raistrickii, Trichoderma pseudokoningii and T. koningii were found to be closely associated with tea roots. While seasonal fluctuation was observed in the case of Penicillium spp., the population of Trichoderma spp. showed less variation during the year. Both species were sensitive to low temperatures. In general, fungi associated with the tea rhizosphere were found to prefer a mesophillic temperature range (15 °C to 35 °C). The dominant species of Penicillium and Trichoderma also exhibited tolerance to lower temperatures, i.e., 5 to 10 °C on agar plates. Most fungi were able to grow in a wide range of pH (4 to 12). Lowering of soil pH in the rhizosphere of tea bushes was positively correlated with the age of the bush and may have affected the development of a specific microbial community in the rhizosphere.

The populations of Penicillium and Trichoderma species were inversely correlated with the populations of two most dominant rhizosphere bacteria, Bacillus subtilis and B. mycoides. Both Bacillus species have been shown to have antagonistic activity against these two fungi under in vitro conditions. The present study demonstrates the existence of a similar antagonism under in situ conditions in the rhizosphere of established tea bushes.     

木霉诱导下山新杨PodaPIN9基因的组织表达调控

PIN蛋白具有多个跨膜结构域,影响着高等植物生长素的外向运输和众多生长发育过程。木霉菌是能促进植物生长、提高其对多种病害防御作用的生防因子。研究木霉菌对木本植物山新杨生长素的极性分布的影响有重要意义。克隆了山新杨PodaPIN9基因,对其核酸和蛋白序列进行分析;同时,构建的进化树显示PodaPIN9与6个物种的9条PIN基因具有高度一致性（>80%）。qRT-PCR分析表明,PodaPIN9在山新杨茎尖、成熟叶和根中均有表达。在根中表达量极低;在茎尖和叶中的表达量极高,分别是根中的503和346倍。该基因受木霉影响在茎尖和叶中的表达量均显著下调;而根中的表达量显著上调,达到对照的32.01倍。并发现根际接种木霉48 h会使杨树茎尖、叶和根中生长素含量降低。说明木霉菌能影响杨树茎尖、叶和根中IAA水平及PodaPIN9的表达量。并且Pearson相关性分析表明在茎尖、叶和根中,PodaPIN9表达量与IAA水平具有不同的相关性。     

Cyanide catabolizing enzymes in Trichoderma spp.

An investigation was made into the occurrence and distribution of the enzymes involved in HCN catabolism in different strains of the fungus Trichoderma. Three enzymes, cyanide hydratase, rhodanese and β-cyanoalanine synthase were studied. All the strains showed a high capacity to degrade cyanide via both the cyanide hydratase and rhodanese pathways. β-Cyanoalanine synthase, however, was not observed in any of the strains. The enzyme activities were found in varying levels in each of the Trichoderma strains. Experiments conducted with cyanide addition to the medium to assess whether the enzymes were induced in the presence of cyanide failed to show any statistically significant increase. This suggests a constitutive nature of both the enzymes in all the selected strains of Trichoderma used in this study.     

昆虫肠道木霉及其对芒果炭疽病菌拮抗作用

为获得优良生防木霉菌株,本研究以昆虫肠道为样本,从中分离鉴定木霉菌株,并以芒果炭疽病菌盘长孢状刺盘孢为靶标菌,通过对峙培养、挥发性物质和非挥发性物质筛选拮抗效果最优的木霉菌株,测定其孢子悬浮液对芒果炭疽病的室内防效研究.结果 显示,从105份昆虫肠道中共分离获得10株木霉,通过形态学特征和Tef1-Rpb2双基因联合建...     

指定木霉属三个种的附加模式并报道中国新记录种

对来自我国南方的木霉属标本进行分类学研究,首次发现灵芝木霉T. ganodermatis、异味木霉T. ingratum 和特里克木霉T. trixiae的有性阶段,对它们进行描述并指定3个种的附加模式。报道了3个中国新记录种：新厚木霉Trichoderma neocrassum、垫状木霉T. pulvinatum和塞缪尔斯木霉T. samuelsii、提供了它们的形态描述和图示。基于RPB2和TEF1基因序列的系统发育分析确定了上述种的系统发育位置。建立一个新名称取代晚出同名Trichoderma crystalligenum W.T. Qin & W.Y. Zhuang。     

木霉病的研究现状

木霉在自然界广泛分布,绝大多数对人类无害,但有些种类能够感染人类造成木霉病,其引起的人类感染表现形式多样,容易误诊。本文对Medline和中文文献数据库中的相关文献进行了系统查阅和分析,综合归纳了木霉病的致病种、地域分布、危险因子、临床表现形式、药物敏感性及其诊疗方案等,该综述对全面了解木霉病的特征及其临床医师的诊断具有重要的意义。     

木霉对月季幼苗生长的影响

为了研制促进月季生长的木霉生防菌肥，采用本实验室分离鉴定的哈茨木霉T6施于月季盆栽土壤中，分析木霉菌对"十姐妹"月季硬枝扦插发芽、幼苗生长、防御酶活性和内源激素水平的影响。结果表明：施用哈茨木霉T6的月季硬枝出芽率和幼苗枝条长度分别是对照的1.4和1.82倍；并且枝条和叶的干重、枝条和叶的含水率均显著增加。此外显著提高了叶中3种防御酶SOD、POD、CAT的活性及6种内源激素IAA、GA₃、ZT、ABA、SA和JA的水平。说明木霉T6具有促进月季生长和提高其抗性的作用，研究结果为研制促进月季生长的生物菌肥提供理论依据。