哈茨木霉发酵产物对玉米萌发及苗期生长的影响

哈茨木霉是自然界中普遍存在并具有重要经济意义的一种丝状真菌,研究其对植物的生长所起的作用具有重要的应用价值和实际意义.试验应用本实验室自行配制的PDA培养基,采用液体发酵得到的哈茨木霉发酵产物,并用所得发酵产物处理玉米种子,研究木霉发酵产物对玉米萌发和苗期生长所产生的影响.结果表明:在试验的各处理中,除经哈茨木霉发酵产物原液处理的玉米苗的长势低于清水对照外,其它各组经木霉发酵液的稀释液处理的玉米种子的发芽势、生长势及叶绿素含量均较对照组有所增加,其中尤以50倍稀释液效果最好.说明哈茨木霉发酵产物适量浓度对玉米的发芽势、苗期生长、叶绿素含量均有显著的促进效果,显示了木霉在促进植物生长方面的潜能.

二维液相色谱法在线检测哈茨木霉发酵液中2460A含量

建立了在线检测哈茨木霉发酵液中微量2460A的二维液相色谱方法。利用Ultimate 3000双三元液相色谱仪,采用阀切换二维色谱技术,组合3根色谱柱实现2460A的在线净化、富集和含量检测。净化柱采用资生堂MF C8柱（10 mm×mm,5.0μm）,富集柱采用资生堂MGC18柱（20 mm ×mm,5.0μm）,以水-甲醇为流动相,梯度洗脱,流速2.0 mL/min；二维分析柱采用ThermoHypersil GOLD C18柱（250 mm ×mm,5.0μm）,以水-甲醇为流动相,梯度洗脱,流速1.0 mL/min；进样量1.0 mL；柱温40℃；检测波长424 nm。方法验证结果显示,2460A的线性范围为0.0025～10.0 mg/L（r=0.9981, n=8）,检出限为1.2μg/L；定量限为2.5μg/L；方法回收率为88.0％～104.4％。

Evaluation of Selected Chemical,Biological Fungicides,and Induced Resistance to Control White Rot(Sclerotium rolfsii Sacc.)on Tomato

Tomato(Solanum lycopersicum)is one of the most widely grown and consumed as fresh vegetable in the world.Sclerotium rolfsii Sacc.is one of the most destructive diseases and affects more than 500 plant species.This study was conducted for“Evaluation of Selected Chemical,Biological Fungicides,and Induced Resistant to Control White Rot(Sclerotium rolfsii Sacc.)on Tomato”.The experiment was conducted at the Royal University of Agriculture and divided into two sections.The first section conducted under in vitro condition consists of four treatments T1 control treatment,T2 copper hydroxide,T3 azoxystrobin+difenoconazole,T4 metalaxyl+mancozeb in Nagoya Laboratory,and had been starting from 11st May to 15th May 2020.Section two was conducted in a pot in net-house which started from 1st January 2019 to 19th February 2019 and 1st January to 19th February 2020 and arranged in RCBD(Randomized Completely Block Design)with six replications and nine treatments.T0 negative control,T1 inoculate but not treatment,T2 metalaxyl+mancozeb,T3 azoxystrobin+difenoconazole,T4 copper hydroxide,T5 acibenzolar-S-methyl,T6 chicken dung+Trichoderma harzianum,T7 acibenzolar-S-methyl+chicken dung+Trichoderma harzianum,T8 acibenzolar-S-methyl+metalaxyl+mancozeb.Data were collected on colonizing diameter in vitro.For pot experiment collected on disease incidence,incubation period Based on the result under in vitro condition metalaxyl+mancozeb highly inhibited germination of Sclerotium rolfsii when compared with another treatment.However,the application of copper hydroxide seems less effective compared with control.For in pot experiment,when treated after symptom of southern blight appeared to seem less effective on the severity of southern blight.In contrast,when applied as a protectant and curative when symptoms appeared only systemic fungicide azoxystrobin+difenoconazole significantly reduced the severity of Sclerotium rolfsii and delayed incubation period while compared with other treatments(p<0.05)and was followed by metalaxyl+mancozeb,whereas,copper hydroxide,acibenzolar-S-methyl,chicken dung+Trichoderma harzianum,acibenzolar-S-methyl+chicken dung+Trichoderma harzianum,acibenzolar-S-methyl+metalaxyl+mancozeb were less effective(p>0.05).Based on the three experiments we can assume that fungicide is more effective in reducing the growth of the pathogen and delaying the incubation period of fungal colonization when compared with biological control and induced resistance.

哈茨木霉发酵产物对豇豆萌发及苗期生长的影响

应用改良后的GPF培养基,采用三级发酵和固液两相发酵相结合的培养方法培养得到的哈茨木霉发酵产物,在豇豆萌发和苗期生长中进行应用。结果表明,哈茨木霉发酵产物适量浓度对豇豆的发芽势、苗期生长、氮素利用能力、叶绿素含量均有显著的促进效果,显示了木霉在促进植物生长方面的潜能。

哈茨木霉在水稻体内的定殖及其对水稻纹枯病抗性的影响

以具有抗腈菌唑标记哈茨木霉TUV-13菌株的分生孢子悬浮液对水稻种子分别进行浸种、蘸根、叶面接种,栽培至2叶1芯期,从秧苗各组织分离回收菌株TUV-13。对经菌液处理的秧苗进行显微及超微观察结果表明,浸种处理能使TUV-13菌株在水稻秧苗的根、茎、叶中稳定定殖;而蘸根处理、叶面接种,TUV-13菌株只能在处理的局部区域定殖。TUV-13菌株定殖后,水稻秧苗与抗病相关的酶活性显著提高,对水稻纹枯病防效达82.9%。

真菌来源新活性化合物2460A的研究

采用自行构建的以重组白细胞介素6受体(IL-6R)为靶位,基于受体配基竞争结合为基础的高通量筛选模型,从微生物代谢产物中获得了新结构化合物2460A。本文通过对产生菌核糖体DNA转录间隔区(rDNA-ITS)序列测定结果,确定了该化合物产生菌为哈茨木霉;研究结果显示,2460A具有和白细胞介素6(IL-6)竞争结合白细胞介素6受体(IL-6R)的活性,因此是具有IL-6R配基活性的微生物产物;MTT法测定结果表明,2460A对CM126和HT-29肿瘤细胞具有抑制作用,IC50分别为2.17×10-5 mol·L-1和1.8×10-5 mol·L-1;对肿瘤细胞周期影响作用实验结果显示,2460A对HT-29细胞的S期略有阻滞作用。本化合物体内抗瘤活性等深入研究工作正在进行中。