致病

A cross was made between two isolates of Magnaporthe grisea, CH63 and TH16. A total of 78 ascospore isolates were tested for pathogenicity on 36 rice varieties. The 71 pathotypes were clearly observed in the sexual progeny.

报导了两个稻瘟菌株CH63和TH16的杂交后代在36个水稻品种上的致病性分离、遗传分析以及无毒基因组成的分析结果。78个子囊孢子菌株中呈现显著的致病性分离，共出现71种致病类型，在不同品种上分别出现1：1、1：3、3：1、1：7、1：15和15：1等的无毒性／毒性分离，表明供试菌株对不同品种的无毒性／毒性是一个或多个基因控制的。

Preventing and controlling crown gall disease applied the early biological controls strain K84, itself did not have the pathogenicity, its plasmid may synthesize one kind of bacteriocin Agrocin84, may suppress many pathogenic strains, but did not have pathogenicity to non-pathogenic strain .

防治根癌病应用较早的生防菌株是K84，本身无致病性，它的质粒可以合成一种细菌素Agrocin84，可以抑制很多有致病性的菌株，而对非致病性的菌株则无影响。

Based on the analysis, the pathogenic rate of the rice Zhe 173 to hybrid medium indicia rice, medium japonica rice and hybrid medium japonica was higher than others.

根据白叶枯病菌不同致病型菌株对参试品种致病率的分布情况分析，浙173菌株对杂交中籼、常规中粳稻和杂交中粳稻的致病率较高。

Isolates from watermelon-growing areas were classified into 3 races like race 0, race 1 and race 2 which were 8 (17.4), 30 (65.2), and 8 (17.4%), respectively. Pathogenecity of race 0 isolates are weakest which only make Sugar Baby susceptible; isolates of race 1 are intermediately pathogenetic, they make Sugar Baby and Charleston susceptible Gray but Calhoun Gray resistant; isolates belonging to race 2 possess the strongest pathogenecity, which make 3 hosts susceptible. Isolates of race 0 mainly distribute over the central and southern Hebei province, whereas race 2 cover the middle and north of Hebei, isolates of race 1 exist in the whole watermelon-growing areas in Hebei province.

根据鉴别寄主对供试菌系的抗感反应，将46个西瓜枯萎病菌系划分为0号、1号和2号3个不同的生理小种，分别包括8，30和8个菌系，占供试菌系的17.4%、65.2%和17.4%；0号生理小种菌系致病性最弱，仅使品种Sugar Baby感病，以冀中和冀南居多；1号生理小种菌系致病力中等，使鉴别寄主Sugar Baby和Charleston Gray感病，而使Calhoun Gray抗病，分布在整个河北省西瓜种植区；2号生理小种的菌系致病力最强，使3个鉴别寄主均能感病，主要分布在冀中和冀北。

The new chimeric infectious DNA clone and its derived, a virulent chimeric virus are constructed from the nonpathogenic PCV1 in which the immunogenic ORF gene of the pathogenic PCV2 replaces a gene of the nonpathogenic PCV1, preferably in the same position.

所述新型嵌合的传染性DNA克隆及其衍生的有毒力的嵌合病毒是用非致病性PCV1构建的，其中，致病性PCV2的免疫原性ORF基因取代了非致病性PCV1的基因，优选是在相同的位置上取代。

The results revealed that there was nosignificant difference between the symptoms produced by the mutant and thewild type strain by directly injecting the bacteria into mature turnip leaves,however,the mutant was nonpathogenic by inoculations with leaf-clippingand-spraying methods.

应用不同的接种方法对胞外多糖突变体的致病性进行了分析，发现突变体通过注射接种仍能产生与野生型相同症状，但通过喷雾和剪叶接种却完全丧失了致病能力，说明甘蓝黑腐病菌产生的胞外多糖可能在致病过程的早期阶段起作用，但对症状的产生不是必须的。

Methods Real-time PCR, using the primer-probe specific for the yst gene, was applied to detect the pathogenic （7 serotypes） and nonpathogenic （ 5 serotypes） Yersinia enterocolitica, other species of Yersinia （8 types）, and other enteric bacteria （8 types）.

应用针对致病性小肠结肠炎耶尔森菌染色体上yst基因而设计的特异引物和探针进行实时定量聚合酶链反应，检测致病性（7种血清型）和非致病性（5种）小肠结肠炎耶尔森菌、耶尔森菌属内的其他菌种（8种）及其他肠道细菌（8种）。

However the three mentioned analysis methods has been so far assured only available to high pathogenic pathotype identification, which was probably associated with the high expression of gene related to high pathogenicity, on the other hand, pathogenicity differentiation of Cercospora zeae-maydis was probably controlled by some complex factors regulated by by polygenes.

相比较而言，只有强致病类型菌株利用三种方法进行鉴定有一定程度的相关性，这可能与强致病类型致病相关因子在蛋白质和DNA水平上的表达强度高有关，另一方面可能是有复合因子控制灰斑病菌的致病性分化，这恰好反映出该病菌的抗性遗传是由多基因控制的特点。

The major direction of the research within the first year will be outlined as following:( 1 )The background study, collection, analysis, and identification of the possible metabolites such as protease, hemolysin, hemagglutinin, cytotoxin, leukocidin, and lipopolysaccharide;( 2 )The collection of the pathogenic factor such as outer membrane protein of vibrio spp.;( 3 )The analysis of pathogenic factor through the application of SDS-PAGE technique; and ( 4 )The activity assay of outer membrane protein on substrate to characterize the possible function or study the reaction mechanism.

致病因子之收集：将利用生物化学之方法，以弧菌属细菌外膜蛋白质为目标，收集与溶血素相关之致病因子。3。致病因子之分析：将利用SDS-PAGE电泳，对所收集得到之致病因子进行分析，并估算其可能之分子量。4。致病因子之活性测试：将利用所纯化之外膜蛋白质进行对受质活性之测试，以确定其功能或可能之作用机制。

The results showed that 9 pathogen collections of Sporisorium reilianum were divided into 3 pathogenic types in which there were type A with high pathogenicity, type B with moderate pathogenicity and C with weak pathogenicity. Type A were originated in most important corn-grown areas including Changchun ,Jilin,Gongzuling and Changling where corn head smut usually occurs severely, type B were collected from Siping,Tonghua ,Songyuan,Yanbian, and type C were collected from Baicheng where corn head smut usually occurs very lightly.

致病类型A为强致病类型，来源于吉林、长春、公主岭和长岭，是玉米丝黑穗病发生最严重的地区；致病类型C为弱致病类型，分布于白城地区；致病类型B其致病性介于A、C类之间，主要分布于四平、通化、松原和延边地区。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。