稻褐飞虱生物型的最新研究进展

稻褐飞虱Ｎｉｌａｐａｒｖａｔａｌｕｇｅｎｓ（Ｓｔａｌ）广泛分布在东亚、东南亚、南亚次大陆、澳大利亚北部和南太平洋群岛,在东亚季风区表现随气流远距离季节性迁飞,是亚洲水稻的重要害虫。利用抗虫品种是防治褐飞虱的有效措施。但７０年代以来,由于褐飞虱新的生物型的出现,使抗虫品种丧失了原有的抗性,给稻作生产造成巨大损失。褐飞虱的生物型是指具有不同致害性的褐飞虱群体,当它们为害具有不同抗虫基因的水稻品种时,表现出不同的致害反应。本文根据至１９９６年的研究结果,按生物型的发生、生物型的鉴定方法、生物型的异质性…     

褐稻虱生物型变异动态监测及抗虫品种资源推荐

本文报道近十多年来广东省褐稻虱Nilaparvata lugens(Stal)生物型变异动态监测的研究结果,针对当前褐稻虱优势生物型及发展趋势,推荐优良的抗褐稻虱品种资源。监测结果表明;根据苗期抗性反应,分蘖期生存率测定,田间系统调查监测,广州褐稻虱田间种群对带有Bph1抗性基因的代表品种IR26的致害力不断增强,1992年以来抗性反应达生物型2的水平。1992～1994年在全省7个不同生态类型地区取样测定及验证试验结果表明,生物型 2已上升为广东褐稻虱田间主害代的优势种群。多年的抗性鉴定结果证实,外引品种IR56、IR50404同其对应亲本PTB33、Babawee一样,对褐稻虱的抗性稳定,已推荐用作进一步抗 性育种的优良抗源。粳籼89等23个品种能抗褐稻虱生物型1和2,可及时替代带即BPh1抗性 基因的品种。     

稻褐飞虱生物型的研究

在浙江,如温州地区虽然大面积推广抗褐飞虱的杂交稻汕优6号已经5年,但是田间种群仍以生物型1占优势。 我们把田间褐飞虱罩在具有Bphl抗虫基因的品种 Mudgo 上连续饲养 11代,即可育成褐飞虱生物型2,既可以适应 Mudgo,也可适应具有 bph2基因的品种 ASD7和 IR36。在台湾省用同样方法育成的生物型 2也可以适应ASD7,因此我们的生物型 2与台湾省的生物型 2相类似;但是后者不适应 CR94-13(IR36的亲本),故两者又有所不同。菲律宾的生物型2对 ASD7和IR36均不能适应,故与我们的不同。 把田间褐飞虱在抗虫品种ASD7上连续饲养,结果很容易育成褐飞虱生物型3。甚至在 ASD7上所饲养的第1代5龄若虫即能为害具有bph2抗虫基因的品种 ASD7,甚至 IR36。这表明本地田间种群由生物型1能很快向生物型3转变。 由于褐飞虱在浙江基本上不能越冬,并根据本地自然种群的生物型鉴定结果,推测本省南部的虫源可能由台湾和福建迁入,而中部和北部虫源可能主要来自两广以至中印半岛。故本地自然种群可能混杂有生物型1、2甚至3的个体。     

水稻品种形态特征对稻虱缨小蜂功能反应的影响

在室内研究了水稻品种形态特征对褐飞虱卵在稻株上的分布以及由此而对稻虱缨小蜂功能反应的影响.结果表明,在所有测试品种中,褐飞虱卵在稻株上的垂直分布型可归为3类,即上中部为主分布型、中下部为主分布型和均匀分布型.稻株上、中、下各部位的褐飞虱卵量多少与其相应部位叶鞘鞘脊的相对高度呈极显着正相关.稻虱缨小蜂对上中部为主分布型褐飞虱卵(在浙农大40上)的功能反应明显地强于对中下部为主分布型的褐飞虱卵(在浙852上).     

水稻品种形态特征对稻虱缨小蜂功能反应的影响

在室内研究了水稻品种形态特征对褐飞虱卵在稻株上的分布以及由此而对稻虱缨小蜂功能反应的影响．结果表明,在所有测试品种中,褐飞虱卵在稻株上的垂直分布型可归为３类,即上中部为主分布型、中下部为主分布型和均匀分布型．稻株上、中、下各部位的褐飞虱卵量多少与其相应部位叶鞘鞘脊的相对高度呈极显著正相关．稻虱缨小蜂对上中部为主分布型褐飞虱卵（在浙农大４０上）的功能反应明显地强于对中下部为主分布型的褐飞虱卵（在浙８５２上）．     

水稻品种抗褐飞虱不同生物型的稳定性

采用Tai氏方法分析估测12个水稻品种抗褐飞虱不同生物型的稳定性,以期为选育抗虫稳定性好的水稻品种提供较为有效的分析和监测方法.结果表明：光照强度、苗龄、施氮量对不同水稻品种对褐飞虱不同生物型的抗性表现及抗性稳定性有明显影响.抗褐飞虱生物型Ⅱ的品种中,RHT、RP1976-18-6-4-2、Ptb33的抗性较稳定,IR56的抗性不稳定,IR36、ASD7的抗性极不稳定;感褐飞虱生物型Ⅱ的品种中,TN1的感虫性稳定,桂华占、佛山油占、IR26的感虫性较稳定,国粳4号、Mudgo的感虫性不稳定.抗褐飞虱孟加拉型的品种中,RP1976-18-6-4-2、RHT、Ptb33的抗性不稳定,IR56的抗性极不稳定;感褐飞虱孟加拉型的品种中,桂华占、佛山油占、IR26的感虫性稳定;TN1、IR36的感虫性不稳定;国粳4号、Mudgo、ASD7的感虫性极不稳定.     

稻飞虱酵母类胞内共生菌的组织学研究进展

褐飞虱Nilaparvata lugens体内酵母类共生菌在褐飞虱生长发育和繁殖中起着重要作用,并影响着褐飞虱对寄主植物的致害性变异。该文系统总结了国内外已有的研究成果,讨论了褐飞虱共生菌的分类地位、形态特征、在寄主发育中的功能、侵染途径等,提出了开展褐飞虱生物型形成过程中体内共生菌变异的研究建议,以便利用共生菌来监测田间不同生物型褐飞虱的发生情况,最终实现控菌防虫和对不同生物型的准确预测。     

褐飞虱泌露量测定方法的研究

<正> 褐飞虱Nilaparvata lugens Stal排泄的蜜露作为定量测定其相对取食量的指标已多次被实验所证实。一般的固定式(滤纸固定不动)蜜露测定法(图1b)由于简单易行,已广泛应用于褐飞虱生物型监测和水稻抗虫性鉴定。然而,由于褐飞虱雌成虫具有固定取食的特点,飞虱排泄的蜜滴往往重复滴落在滤纸的同一点而影响蜜露量的正确估算。綦立正等和王希     

褐飞虱生物型特异性蛋白质研究

褐飞虱生物型特异性蛋白质研究方继朝,杜正文,夏礼如,孙建中（江苏省农业科学院植物保护研究所南京２１００１４）褐飞虱是我国及东南业水稻重人害虫。利用抗虱基因、培育推广抗虫品种是综合治理褐飞虱的优先策略,在水稻牛产上发挥了重要作用［１］。但褐飞虱的牛物型...     

水稻抗褐飞虱基因研究和利用现状

稻褐飞虱（Nilaparvata lugens Stal）是一种单食性水稻害虫,根据其对水稻品种的危害,可分为生物型1、2、3、4等类型。它对亚洲各国水稻生产造成极大危害。实践证明,利用抗虫品种是防治稻褐飞虱最经济有效的方法。本文综述了稻褐飞虱的生物学特征和分布、生物类型,着重介绍抗稻褐飞虱基因的研究和利用现状,并对今后开展抗稻褐飞虱基因研究提出几点建议。     

Antigenic analysis of iron-regulated proteins in Pasteurella haemolytica A and T biotypes by immunoblotting reveals biotype-specific epitopes.

The antigenic relationships of the iron-regulated proteins (IRPs) in Pasteurella haemolytica A and T biotype strains were examined by SDS-PAGE and immunoblotting. P. haemolytica cells of the A biotype, grown under conditions of iron-limitation, expressed two IRPs, of 35 and 70 kDa. All T biotype strains expressed IRPs with slightly different molecular masses of 37 and 78 kDa. Immunoblotting of all 16 P. haemolytica serotypes was carried out using a panel of polyclonal and monoclonal antibodies raised against serotype A2 antigens. Polyclonal antibodies revealed inter-serotype cross-reactivity towards the 35 and 70 kDa IRPs within the A biotype but no cross-reactivity against a T biotype protein in the 78 kDa region. Monoclonal antibody against the 35 kDa antigen reacted only with the A biotype 35 kDa IRP. Identical profiles were obtained for 10 field isolates of serotype A2, further emphasizing the antigen conservation within the A biotype. These findings reinforce the view that the A and T biotypes of P. haemolytica should be considered as separate species and suggest that IRPs from single A and T biotype strains incorporated into a vaccine might provide cross-protection against all P. haemolytica serotypable strains. Similar studies on the IRPs of 10 untypable strains revealed some of these to have different antigenic reactivities from those observed within the A and T biotypes.     

Utility of MtCOI polymerase chain reaction-restriction fragment length polymorphism in differentiating between Q and B whitefly Bemisia tabaci biotypes

The invasive, insecticide-resistant, Q whitefly biotype, has gradually spread to other countries including the US via human-mediated movement of plant materials. We assessed the utility of the VspI -based mtCOI (mitochondrion cytochrome oxidase I) polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique as a rapid, cost-effective, and reliable alternative for differentiating the Q from the dominant B biotype in Arizona. Using the standard mtCOI gene sequencing and mtCOI PCR-RFLP techniques, we biotyped eight whitefly strains of five individuals each collected from poinsettia and cotton at different locations in Arizona. Complete concordance was observed between the two methods, with three strains being identified as the Q biotype and five samples as the B biotype. We also scanned the mtCOI gene sequences for VspI polymorphisms in the B and Q biotype whiteflies currently available in the GenBank database. This global screening revealed the existence of three and four VspI polymorphic types for the Q and B biotypes, respectively. Nevertheless, all three VspI polymorphic Q biotype whiteflies shared a common and unique VspI site that can be used to differentiate Q biotype from the four VspI polymorphic B biotype whiteflies identified. These results demonstrate that the VspI -based mtCOI gene PCR-RFLP provides a reliable diagnostic tool for differentiating the Q and B biotype whiteflies in the US and elsewhere.     

Isolation and characterization of the mutans streptococci from the dental plaques in Koreans

Mutans streptococci have been implicated as cariogenic bacteria in dental caries because they can produce high levels of dental caries-causing lactic acid and extracellular polysaccharide. The aim of this study was to isolate and characterize the mutans streptococci from the dental plaque obtained from Koreans. The dental plaque samples were collected from the anterior and molar teeth of both jaws in 155 subjects (aged 2 to 33.2 years, average age 13.7+/-4.7 years). The samples were diluted by 100-fold in 1x PBS and plated on mitis-salivarius bacitracin (MSB) agar plates. The mutans streptococci grown on MSB plates were screened by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) targeting dextranase gene (dex). The mutans streptococci were identified at the species level using a 16S rDNA sequencing comparison method. The biochemical tests were carried out to biotype the mutans streptococci. Ninety-five strains of the mutans streptococci out of 358 colonies, which were derived from 141 subjects, were isolated. Of them, 77 strains and 18 strains were Streptococcus mutans and Streptococcus sobrinus, respectively. The biotyping data showed that 62, 1, 20, 10, and 2 strains were biotypes I, II, IV, V and variant, respectively. Of the two strains of variant biotype, one strains was similar to biotype IV except that it was positive to the arginine hydrolysis test. We considered this one strain a new biotype, and classified it as biotype VII. In conclusion, S. mutans and its biotype I was most frequently isolated in Korean dental plaque. The mutans streptococci strains isolated in this study might be useful for the study of the pathogenesis and the prevention of dental caries.     

Geographical race typing of the causative agent of tularemia using antibiotics]

Reaction of the strains of the tularemia causative agent to erythromycin (100 gamma/ml) or oleandomycin (400 gamma/ml) is one of the taxonomic tests. The study of 82 strains of the holarctic race and 63 strains of the Central Asiatic race according to this test showed that the strains of the holarctic race were divided with respect to these macrolides into sensitive (biotype I) and resistant (biotype II). The strains of the both races were isolated at the territory of the Kazakh SSR. Such a reaction of the strains of the holarctic race is a stable feature and is not connected with virulence, the isolation source and the biochemical properties of the strains. Division of the holarctic race into the biotypes (I and II) with respect to erythromycin and oleandomycin may be of definite significance in epidemiological and epizootological examination for tularemia with a purpose of determining the source of the infection, as well as in defining the borders of the infection focus area with circulation of this or that biotype of the holarctic race of the tularemia causative agent.     

A rapid and efficient new assay for determination of the three biotypes of Agrobacterium tumefaciens

We describe a new method for determining the biotype of Agrobacterium tumefaciens strains, based on differential motility in a medium adjusted to different pH levels. Motility of biotype I increases with increasing pH. That of biotype II slightly decreases, but the cells remain motile; the motility of biotype III decreases and the cells become non-motile. The assay is able to distinguish between strains of all three biotypes within 2 d, and can be applied to relatively large numbers of isolates. Thus it is more rapid and efficient than the frequently used biochemical biotype tests.     

日本樱花根癌病病原菌的鉴定及其防治

从浙江省的慈溪、奉化、嵊州等地的日本樱花苗圃内,采集到具有典型症状的日本樱花根癌病植株。经分离纯化及在指示植物番茄、向日葵幼苗的致病性测定,共分离到致病性病原菌株１１株,经形态学、生理生化学特征鉴定及菌体可溶性蛋白ＳＤＳ－聚丙烯酰胺凝胶电泳,确定引起日本樱花根癌病的病原细菌为根癌土壤杆菌（Ａｇｒｏｂａｃｔｅｒｉｕｍｔｕｍｅｆａｃｉｅｎｓ）生物型１,经平皿拮抗和盆栽试验表明,生防菌Ｋ８４能够明显抑制致病菌株的致癌能力。     

流感嗜血杆菌的分型研究

目的分析同济医院分离的流感嗜血杆菌的生物学分型及荚膜基因分型,了解本地区分离的流感嗜血杆菌的主要流行株。方法2012年1月1日至2012年12月31日从华中科技大学同济医学院附属同济医院分离流感嗜血杆菌100株。根据脲酶、吲哚和鸟氨酸脱羧酶试验对流感嗜血杆菌进行传统的生物学分型,分为Ⅰ～Ⅷ八个生物型。回顾患者病史资料,分析生物学分型和流感嗜血杆菌所引起的疾病之间的关系。用流感嗜血杆菌荚膜编码基因（bexA）和a—f型特异性荚膜基因设计引物,采用PCR技术对流感嗜血杆菌进行荚膜基因检测。通过生物学分型和荚膜基因分型结果的比对,探讨两者之间的关联。结果分离的100株流感嗜血杆菌生物学分型结果如下：Ⅲ型6株,Ⅳ型28株,Ⅴ型1株,Ⅵ型54株,Ⅶ型11株。未分离到Ⅰ型、Ⅱ型和Ⅷ型。分析患者的临床诊断,发现主要流行株Ⅵ型流感嗜血杆菌主要引起患者肺炎（包括支气管肺炎和新生儿肺炎）和支气管炎（包括毛细支气管炎和喘息性支气管炎）。荚膜基因分型结果显示,未分离到b型和b-型流感嗜血杆菌。共分离到1株f型,其余99株均为无荚膜抗原的不可分型流感嗜血杆菌。生物学分型和荚膜分型之间无明显的相关性。结论该院分离的流感嗜血杆菌主要为生物型Ⅵ型。回顾患者病史,发现Ⅵ型主要引起肺炎和支气管炎。荚膜基因分型显示,本地区分离的流感嗜血杆菌主要为不可分型流感嗜血杆菌。生物学分型和荚膜基因分型之间无明显相关性。     

Identification of enterotoxigenic staphylococci from sheep and sheep cheese

The total of 127 Staphylococcus aureus strains obtained from sheep and sheep cheese were examined for their biochemical activities, biotypes, phage patterns, and ability to produce enterotoxins. Of the 83 staphylococcal strains isolated from animals 77 (93%) were classified as the C biotype. Of this group of sheep-adapted strains, 61 (79%) were sensitive to phage 78, and 46 (60%) produced enterotoxin C exclusively. The three isolated belonging to the A biotype produced enterotoxin D, and two of the three unclassifiable strains produced enterotoxin A. Of the 44 staphylococcal strains isolated from sheep cheese, there were 37 (84%) identified as the C biotype. From this series, 31 (84%) strains were lysed with phage 78, 6 (16%) strains produced enterotoxin C, and 1 strain produced enterotoxin A. One of the six strains determined as the A biotype produced enterotoxin D. C biotype strains, especially of ovine origin, are an exception among animal staphylococci, because a large number of them are enterotoixgenic. The C antigenic type is the most usual of the known enterotoxins in staphylococci of animal provenance.     

Vibrio vulnificus produces quorum sensing signals of the AHL-class

Vibrio vulnificus is an aquatic pathogenic bacterium that can cause vibriosis in humans and fish. The species is subdivided into three biotypes with the fish-virulent strains belonging to biotype 2. The quorum sensing (QS) phenomenon mediated by furanosyl borate diester or autoinducer 2 (AI-2) has been described in human strains of biotype 1, and here we show that the luxS gene which encodes AI-2 is present in all strains of V. vulnificus regardless of origin, biotype or serovar. In this study, we also demonstrate that V. vulnificus produces QS signals of the acylated homoserine lactone (AHL) class (AI-1). AHLs were detected in strains of biotype 1 and 2 from water, fish and human wound infections but not in strains isolated from human septicaemic cases. The AHL compound was identified as N -butanoyl-homoserine-lactone (C₄-HL) by both reporter strains and by HPLC-high-resolution MS. C₄-HL was detected when AHL-positive strains were grown in low-nutrient medium [modified sea water yeast extract (MSWYE)] but not in rich media (tryptic soy broth or brain–heart infusion) and its production was enhanced when blood factors were added to MSWYE. C₄-HL was detected in vivo , in eels infected with AHL-positive biotype 2 strains. No known AHL-related gene was detected by PCR or Southern blot suggesting that AHL-related genes in V. vulnificus are different from those found in other Gram-negative bacteria.     

中华鳖肠道益生菌的筛选、鉴定与生长特性研究

通过点种法初筛和牛津杯法复筛, 从中华鳖肠道筛选到1株对嗜水气单胞菌(Aeromonas hydrophila)、温和气单胞菌(A. sobria)以及豚鼠气单胞菌(A. caviae)具有拮抗作用的益生菌株Dec-43。对该菌株进行形态、生理生化特征分析, 结果与《常见细菌系统鉴定手册》中屎肠球菌(Enterococcus faecium)的生理生化特征一致。提取细菌基因组DNA, 通过16S rRNA基因通用引物进行PCR扩增, 从该菌株的16S rRNA基因中克隆到了一个长度1448 bp的片段, 经测序和序列比对, 该片段与Genbank中屎肠球菌的序列相似性达99%, 因此, 该菌株确定为屎肠球菌。通过单因素试验确定了该菌株的最佳生长温度、盐度、初始pH、接种量等参数分别为: 36℃、盐度0.6%、培养基初始pH 7、接种量10%; 通过正交试验, 确定了该菌株培养基中碳源(葡萄糖)、氮源(蛋白胨)最适含量分别为15和10 g/L。研究发现了一株中华鳖肠道潜在益生菌, 并研究了其生长特性, 为中华鳖养殖行业益生菌的应用提供了基础。