用斑点杂交法比较小麦全蚀菌病毒与其它真菌病毒的同源性

以小麦全蚀菌病毒泰安株(Gaeumannomyces graminis virus Taian strain,GgV-Taian)的dsRNA为探针进行斑点杂交,比较低了5种dsRNA真菌病毒和7株小麦全蚀菌病毒分离物间的同源性。GgV-Taian dsRNA与米曲霉病毒、黑曲霉病毒、美味侧耳病毒的dsRNA有杂交反应;而与草菇病毒dsRNA无反应;与5株GgV分离物均有反应。与无血清学关系的黑曲霉病毒也有杂交反应。本文提供了寄主分类地位甚远的真菌病毒有同源序列的新证据。

河北省小麦根病发生现状及致病病原种类调查

通过对河北省 4个不同生态区冬小麦不同生育期进行调查 ,基本掌握了河北省小麦根病的发生现状 ,调查表明 ,根病的发生在不同品种和地区以及同一品种或同一地区不同生育期的表现存在明显差异 ;分离培养结果表明 :该省小麦根病是由多种病原侵染所致 ,主要致病病原有根腐蠕孢菌、丝核菌、全蚀菌、镰刀菌、链格孢菌等 5个属

来源不同V-C组不同的小麦全蚀病菌病毒的特性

从地理位置不同,V—C组不同的13株小麦全蚀病菌中分离到直径23—36纳米的病毒。聚丙烯酰胺凝脉电泳表明这些菌株中的病毒dsRNA的组分及分子量不同。泰安株病毒有分子量为3.45,2.95,1.60,1.52,1.30,1.25,1.15,1.00,【1.00×10~6的9个dsRNA,而浙江、湖北菌株仅有一个组分、分子量为3×10~6。多数病毒衣壳多肽的的分子量为66×10~3—73×10~3。泰安菌株与烟台菌株病毒抗血清除与张家口菌株、青海菌株无反应外与其它菌株病毒均有反应,但在免疫双扩散中抗血清的滴定度不同。

Control Efficacy and Antifungal Mechanism of Bacillus Cereus Strain JK14 against Wheat Take-all Disease

[Objective] Study on control efficacy and inhibitory effect of Bacillus cereus strain JK14^·against wheat take-all disease, investigating its antifungal mechanism. [Method] B. cereus JK14^· was isolated from soil in the rhizosphere of wheat, inhibitory effects of whose nutrient solution form against Gaeumannomyces graminis var tritici strains 9862 and 9812 were measured in laboratory and then for its antifungal mechanism. The strain JK14^· with rifampicin and wheat take-all disease resistance was screened by increasing concentration of the two substrates, and colonization of JK14^·was studied. [Result] In pot experiment, the control effects of JK14^·, against 9862 and 9812 are 63% and 59%, respectively, which are higher than that of chemical fungicides, with 55% and 51% , respectively. JK14^· could deform mycelium and causes degradation of cell wall. And there are also dynamic change of JK14^· in root system. JK14^· on seed could extend to root along with seed germination and rooting, but per unit tissue mycelium number decreased gradually. [Conclusion] The results indicate some control efficacy of B. cereus strain JK14^· against wheat take-all disease.

灰葡萄孢代谢产物对3种小麦病害的抑制作用

分别用皿内试验和盆栽试验方法测定灰葡萄孢代谢产物对3种小麦病原菌的抑制作用。皿内试验结果表明,灰葡萄孢代谢产物对小麦纹枯病菌菌丝生长抑制率可达到66.2%,对小麦根腐病菌菌丝生长抑制率达到61.6%,对小麦全蚀病菌菌丝生长抑制率为12.5%。盆栽试验结果表明,在发病前喷施灰葡萄孢代谢产物培养液,对小麦纹枯病的预防效果可达97.6%,以上对小麦根腐病的预防效果可达84.6%。将灰葡萄孢代谢产物培养液稀释20倍后喷施,对小麦纹枯病和小麦根腐病的预防效果也分别可达60.7%和42.3%。盆栽试验中灰葡萄孢代谢产物对小麦纹枯病和小麦全蚀病的治疗作用效果分别为48.3%和29.7%,对小麦根腐病的治疗效果不明显。