哈茨木霉几丁质酶诱导及其对水稻纹枯病菌的拮抗作用

 在实验室条件下分别以几丁质和水稻纹枯病菌(Rhizoctonia solani)细胞壁作唯一碳源诱导哈茨木霉(Trichoderma harzianum)菌株NF9、TC3和P1产生几丁质酶,用硫酸铵沉淀法制备几丁质酶粗提液。上述木霉菌株内切几丁质酶活性(对胶体几丁质浑浊度的减少率)分别为79.8%、74.4%和76.0%,均显著高于非诱导的阳性对照。培养第5 d几丁质诱导的木霉菌株NF9和TC3内切几丁质酶活性显著高于由水稻纹枯病菌细胞壁诱导的酶活性。体外测定表明,通过诱导的木霉菌株TC3、NF9和P1几丁质酶粗提液对水稻纹枯病病菌的拮抗圈直径可达38、21和23 mm,与非诱导的阳性对照比较有显著性差异。对木霉几丁质酶拮抗作用的特点及生防应用进行了讨论。     

木霉菌M2的鉴定及其对小白菜促生效果研究

以一株分离自健康、高产辣椒根际土壤的木霉菌(Trichoderma spp.)M2为供试菌株,研究其对小白菜生长发育的影响并在形态学分类的基础上结合r DNA-ITS序列分析的手段,对木霉菌M2进行分类鉴定,以期为微生物肥料的开发提供优良菌种。将木霉菌M2进行固体发酵制得孢子粉,研究其在温室条件下是否对小白菜的生长具有促生能力。结果表明:菌株M2属于哈茨木霉(Trichoderma harzianum);在温室盆栽试验中,土壤接种M2孢子粉对小白菜具有不同程度的增产作用,且能够提高叶绿素含量、可食用叶片数,其中接种5.0×10~9cfu的M2孢子粉处理的鲜重、干重最高,比对照组分别增加30.26%、20.08%;接种5.0×10~8cfu的M2孢子粉处理鲜重、干重较对照组分别增加18.33%、12.46%。这说明哈茨木霉M2菌株对小白菜的增产效果明显,具有潜在的农业应用价值。     

Evaluation of Microbial Antagonists for Biological Control of Botrytis cinerea Stem Infection in Cucumber and Tomato

Of fifteen isolates of yeasts, filamentous fungi and bacteria and a commercial product, tested in a bioassay with stem segments, eleven isolates consistently reduced incidence of disease and sporulation of Botrytis cinerea Pers; Fr in tomato and seven isolates in cucumber. Several isolates reduced disease by more than 75% in all experiments. Six antagonists that performed well in the bioassays and that were fairly easy to produce in vitro, were selected for further testing in two glasshouse experiments with cucumbers. After application of spores of B. cinerea and the antagonists or the fungicide tolylfluanid to pruning wounds, disease incidence was reduced by 50–100% by all antagonists in both experiments and only in one experiment by tolylfluanid.For Trichoderma harzianum T39, Aureobasidium pullulans and Cryptococcus albidus, biological control efficacy in bioassays with cucumber stem segments was not strongly influenced by temperatures in the range between 18 and 30°C, but at 24°C the efficacy of the three antagonists strongly decreased at relative humidities of 90% and 80% (vapour pressure deficits 0.299 and 0.598kPa, respectively) compared to 100.     

哈茨木霉天冬氨酸蛋白酶基因SA76的3＇RACE扩增和序列分析

由EST获得全长cDNA对于结构基因组学和功能基因组学都是至关重要的,cDNA末端快速扩增技术RACE是该领域中的重要研究方法.利用BD SMART RACE技术扩增编码分泌天冬氨酸蛋白酶SA76基因的3＇末端,将其与哈茨木霉cDNA文库中的SA76基因的EST序列进行序列拼接,获得2019bp的全长cDNA序列,其开放读码框长1593bp,5＇非编码区266bp,3＇非编码区201bp,编码530个氨基酸,有信号肽.哈茨木霉天冬氨酸蛋白酶基因与玉蜀黍赤霉、粗糙脉孢菌、球毛壳菌天冬氨酸蛋白酶基因的同源性分别为53%, 37%, 36%.利用BD SMART RACE技术首次从哈茨木霉中克隆天冬氨酸蛋白酶基因,为验证SA76基因的功能奠定基础,为进一步研究蛋白酶的作用机制及生物防治功能提供依据.     

Vineyard Compost Supplemented with Trichoderma Harzianum T78 Improve Saline Soil Quality

Understanding soil degradation is especially important in the Mediterranean Region where desertification is a serious problem, and soil salinization is one of the causes. Salinity reduces soil quality, limits crop productivity and brings on long term soil degradation. Therefore the restoration of degraded soils is necessary to reduce land degradation, improve soil fertility and achieve a sustainable food production. The addition of compost supplemented with the beneficial microorganism Trichoderma harzianum isolate T78 to saline soils (NaCl) was studied to determine the impact on soil microbiology, which is the key to restore and rehabilitate degraded soils. The selected Trichoderma harzianum isolate T78 showed high salt tolerance despite the low osmotolerance of the genus Trichoderma . Increasing salt concentration reduced Trichoderma sp colony‐forming units (CFU) from natural soil and adversely affected soil microbial biomass C as well as dehydrogenase, β‐glucosidase, phosphatase and urease activities. Simultaneous amendment of the saline soil with compost and inoculation with T. harzianum T78 improved the soil microbiological quality; the number of T. harzianum T78 CFU did not decrease as NaCl increased. As T. harzianum strain T78 is salt tolerant, increasing the relative abundance of this specific strain would contribute to the rehabilitation of saline soils. Vineyard composts supplemented with T. harzianum T78 represent a promising approach for the treatment and improvement of saline soil properties. Copyright © 2016 John Wiley & Sons, Ltd.     

木霉菌对抑制梨轮纹菌的生理特性研究

梨轮纹病菌被木霉菌感染后,多酚氧化酶(PPO)、过氧化氢酶(CAT)、过氧化物酶(POD)和超氧化物歧化酶(SOD)的活性最终下降;丙二醛(MDA)含量和超氧阴离子(O2-)产生速率上升。初步确定,梨轮纹病菌被木霉感染后,活性氧清除系统等被破坏,膜脂过氧化作用加强,是最终导致菌体受害的原因之一。     

哈茨木霉对辣椒生长的影响

 在田间用哈茨木霉(Trichoderma harzianum)制剂处理土壤,栽培辣椒,结果表明:哈茨木霉不但对辣椒疫霉（Phytophthora capsici）和尖镰孢（Fusarium oxysporum）引起的根腐病具有一定的防病作用,而且能促进植株生长,提前开花、挂果,提高产量15％左右。     

Production of chitinases with Trichoderma harzianun isolates using solid substrate fermentation

Over forty Trichoderma harzianum isolates have been screened in solid substrate fermentation (SSF)for chitinase production. Strains were isolated from Asian soil and tree bark samples. Identification was performed in Canada and Austria by classical and molecular taxonomical methods.……     

生防菌哈茨木霉FJAT-9040的GFP标记及土壤定殖示踪

哈茨木霉Trichoderma harzianum FJAT-9040对茄科尖孢镰刀菌具有较强拮抗作用。为跟踪分析该菌株在土壤中的存活与定殖特性,利用PEG-CaCl2介导的原生质体转化体系,筛选获得1株荧光性状稳定的菌株FJAT-9295,该菌株在生长速率、产孢量、对酸碱度和温度的适应性及对尖孢镰刀菌的抑菌活性等方面与野生型菌株FJAT-9040无显著差异（P〉0.05）。同时,研究了菌株FJAT-9295在4种类型土壤中的定殖能力以及作物生长对该菌株在土壤中定殖的影响。结果表明：菌株在育苗土中定殖最好,其次为沙土及菜园土,黄泥土中定殖最差;种植茄子比未种植作物的土壤更有利于菌株的存活;菌株FJAT-9295在不同类型土壤中的菌落数随时间的延长均略有下降,16天后趋于稳定,维持在105 CFU/g,较初始接菌量下降了约1个数量级。