安徽省水稻品种对水稻白叶枯病的抗性及白叶枯病小种鉴定

为明确安徽省白叶枯病菌小种组成及常用、备用品种对该病的抗性,用白叶枯病强毒性小种FuJ和YN24、中等致病力的安徽省优势小种AH以及弱致病小种YN7对安徽省常用及备用水稻品种进行人工接种鉴定;用鉴别品种IRBB5、IRBB13、IRBB3、IRBB14、IRBB2、R24对安徽的白叶枯病菌株进行鉴定.结果表明,有3.5％的品种抗FuJ,15.4％的品种抗YN24,29.8％的品种抗AH;安徽省白叶枯病菌小种有R2、R5和R8,其中R5为优势小种.抗AH的品种可以用于安徽的水稻生产;生产中应防止FuJ和YN24等毒性强的菌株传入.     

水稻白叶枯病菌北方菌株的分子鉴别和致病型分析

为了阐明水稻白叶枯病菌(Xanthomonas oryzaepv.oryzae,Xoo)北方菌株的毒性组成,对2008年和2009年从辽宁、吉林、河北、山东稻区采集的103个菌株进行了PCR分子鉴定,并利用一套水稻抗白叶枯病近等基因系作为鉴别品种,进行了致病性测定。结果表明,用3种不同引物对测定菌株基因组进行PCR扩增,均可以鉴别出与Xoo代表菌株完全一致、而与水稻条斑病菌明显不同的特异性扩增片段带型。6个水稻鉴别品种对测定菌株的感病反应明显不同,抗病性强弱依次为IRBB5IRBB13IRBB3IRBB14IRBB2IRBB24。103个菌株对6个水稻鉴别品种表现出毒力多样性,92个菌株(89.32%)表现与9个标准小种(R1~R9)代表菌株相同的致病型,其中36个R5和R8菌株为优势菌株,9个菌株为对6个水稻品种都致病的R9强毒力菌株;此外,新发现了其余11个菌株(10.68%)具有7种新的致病型(R10~R16)。     

华南水稻白叶枯病菌致病性分化检测与分析

为了解华南稻区水稻白叶枯病菌的致病性分化和变异动态,采集华南地区水稻白叶枯病病叶标样分离病原菌,应用中国鉴别寄主IR26、南粳15、爪哇14、特特普、金刚30和国际水稻已知抗病基因的近等基因系IRBB5、IRBB13、IRBB3、IRBB14、IRBB2、IR24两套鉴别寄主,在水稻孕穗期采用剪叶法接种,依据寄主和菌株的互作反应检测病菌的致病性分化。结果显示,参试菌株可划分为Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ、Ⅸ六个致病型和R1、R2、R3、R4、R5、R8、R10七个致病小种。Ⅴ、Ⅳ致病型和R8、R5小种出现频率分别为27.40%、19.30%和44.67%、15.34%,为华南稻区优势种群。Ⅸ、Ⅴ、Ⅳ致病型和R8、R5小种对500份华南稻区品种资源的致病率依次为96.40%、95.00%、50.40%、62.00%和42.60%;Ⅸ致病型毒性最强且发展很快;强致病菌系Ⅴ型已替代Ⅳ型发展为华南优势致病菌系。     

IRBB21(Xa21)对广东稻白叶枯病菌5个小种的抗性反应

测定携有Xa21抗性基因品种IRBB21对广东省稻白叶枯病菌Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ5个小种的抗性反应。结果表明,IRBB21抗Ⅰ、Ⅱ、Ⅲ,不抗Ⅳ和Ⅴ;以IR24为遗传背景育成的分别含Xa1、Xa2、Xa3、Xa4、xa5、Xa7、xa8、Xa10、Xa11、xa13、Xa14等单基因的近等基因系对我省稻白叶枯病菌优势小种Ⅳ和强致病力小种Ⅴ的抗性反应表明,只有IRBB5和IRBB7抗病,IRBB1、IRBB2、IRBB3、IRBB4、IRBB8、IRBB10、IRBB11、IRBB13、IRBB14均感染。     

江苏省水稻品种对水稻细菌性条斑病抗性鉴定及评价

为明确江苏省水稻条斑病菌致病力分化状况和不同类型水稻品种对条斑病抗感特性,在孕穗期采用针刺接种法对徐淮稻区2007—2009年采集分离获得的45株条斑病菌进行致病力测定,根据病原菌在6个水稻鉴别品种IRBB4、IRBB5、IRBB14、IRBB21、IR24和金刚30上的抗感反应划分致病型,从中选择具有代表性的3种不同致病型条斑病菌,并鉴定了240个不同类型的水稻品种对条斑病的抗感性。根据菌株在鉴别品种上的抗感反应将供试菌株划分为8个致病型,其中优势致病型为C3致病型,所占比例为35.5%;大多数菌株与鉴别品种间表现出弱互作关系,少数菌株表现出强互作关系。粳稻品种对条斑病的抗性明显高于籼稻,但常规粳稻和杂交粳稻对强致病力菌抗性比例仅为59.8%和37.5%。表明水稻细菌性条斑病流行仍具有潜在的威胁。     

用生物间遗传学研究水稻品种和稻瘟病菌之间的相互关系

在温室中,将供试的13个水稻品种和7个鉴别品种的幼苗用稻瘟病菌的11个菌株分别进行接种,以同等条件下鉴别品种对菌株的反应所确定的小种,作为供试品种对该小种的反应,然后应用生物间遗传学的原理和方法来推导品种和菌株的基因型。结果表明:供试的水稻品种和稻瘟病菌株(或小种)间存在17个限定性相应基因对,不同品种所含的抗病性基因数有所不同,其作用是在相应的无毒性菌株(或小种)存在情况下而表现出品种的抗病性基因愈多,可能表现的抗病力愈强。本研究结果为水稻抗稻瘟病育种选择抗原亲本以及生产上选用具有较多抗病基因的品种进行合理布局,提供了有重要参考价值的遗传学信息和依据。     

云南省水稻细菌性条斑病菌的致病型划分和水稻抗性资源的鉴定

 为明确云南省水稻细菌性条斑病菌(Xanthomonas oryzae pv. oryzicola, Xoc)的致病力分化以及不同类型水稻品种对Xoc的抗感特性,通过针刺接种法将云南省8个稻区采集的86株Xoc菌株,接种于6个携带不同抗性基因的水稻鉴别品种(IRBB4、IRBB5、IRBB14、IRBB18、IRBB21和IR24)。根据这些菌株在鉴别品种上的毒力差异进行了UPGMA聚类分析,将其划分为9个致病型(Ⅰ型 ~ Ⅸ 型)。其中,Ⅰ型为优势菌群,分布频率为50.5%。对不同稻区的优势菌群进行分析,发现云南省各稻区Xoc的致病型呈多样性分布,以强毒力的Ⅰ型为高频率致病型。选用 Ⅰ 型、Ⅱ 型和 Ⅵ 型代表菌株对云南省的80个主栽和区试水稻品种进行抗性评价,对3个致病型表现抗性的材料比例分别为30.0%、35.0%和57.5%。筛选出9个对3种致病型都表现为抗性的品种,其中“Deyou16”和“Changgui2”表现为高抗。研究结果可为云南省防治水稻细菌性条斑病的水稻区域性布局和抗性品种的利用提供理论依据。     

黑龙江省不同来源稻瘟病菌致病性分析

将从黑龙江‘龙粳17’、‘吉特639’和‘垦稻10’病田中分离的9、8、8个稻瘟病菌菌株喷雾接种到4套鉴别寄主上,结果表明,中国稻瘟病菌生理小种鉴别寄主将这3个来源的菌株分别划分成8、7和4个生理小种,日本清泽鉴别品种则将其分别划分成9、8和8个生理小种,以黑龙江本地水稻品种作为鉴别品种,则可将其分别划分成8、7和5个致病型,以24个水稻抗稻瘟病单基因系为鉴别品种,则将上述菌株分别划分为9、7和8个致病型。     

侵染优质稻美香占2号的稻瘟病菌生理小种鉴定及无毒基因分析

为明确优质稻种美香占2号的抗瘟性,并为其合理布局以及与不同品种的轮换种植提供科学依据,利用7个中国鉴别品种和11个抗稻瘟病单基因系,对2013—2017年自广东省美香占2号品种上分离获得的50株稻瘟病菌Magnaporthe oryzae菌株进行生理小种鉴定和无毒基因型分析。结果显示,50株稻瘟病菌菌株被鉴定为11个生理小种,其中优势小种分别为C13、B13、B01、B05和C05;50株稻瘟病菌菌株对IRBLkh-K3(仅含Pik-h基因)、NIL-e1(仅含Pi50基因)、IRBL9-W(仅含Pi9基因)和IRBLzt-T(仅含Piz-t基因)4个抗稻瘟病单基因系表现出极低的毒性,频率分别为4%、6%、6%和8%;对IRBLz-Fu(仅含Piz基因)、IRBLkp-K60(仅含Pik-p基因)和IRBLi-F5(仅含Pii基因)3个抗稻瘟病单基因系表现出相对较高的毒性,频率分别为88%、86%和80%;自美香占2号以及其它4个主栽品种上获得的70株稻瘟病菌菌株被聚为不同类群;2003—2007年供试菌株中无毒基因AvrPi9、AvrPiz-t、AvrPi50和AvrPik-h的出现频率较高,无毒基因AvrPi1、AvrPita2、AvrPi2和AvrPish的出现频率中等,无毒基因AvrPii、AvrPik-p和AvrPiz的出现频率较低。     

江西省细菌性条斑病菌的致病型划分和水稻抗性资源的鉴定

为探明江西省水稻细菌性条斑病菌(Xanthomonas oryzae pv.oryzicola,Xoc)的致病力分化水平和品种资源的抗病性,本研究利用IRBB5、IRBB14、IR24、IRBB4、IRBB21和金刚30等6个鉴别品种,将分离自江西6个稻区的129株Xoc菌株划分为C1~C9 9个致病型;发现仅C5对鉴别品种IRBB4、C7对鉴别品种IRBB21表现为强互作关系;不同稻区的Xoc优势种群呈现多样性。孕穗期抗性测定结果显示:124个籼稻品种中,对C2型菌株5-16表现为中抗的品种仅占8.06%,对C6型菌株08-3-2表现为抗的品种占14.5%;252个东乡野生稻单株中,1株单株(东113)对C2型菌株表现高抗,14个单株表现抗性。东乡野生稻苗期注射接种结果显示,苗期抗病性与孕穗期抗性呈显著相关性,但苗期抗病性普遍低于孕穗期抗性,仅东113表现为中抗。但东乡野生稻对于Xoc的抗病性明显强于栽培稻,从野生稻中寻找抗性资源将是培育抗病品种的理想途径之一。     

Antagonistic Interactions Between Strains of Xanthomonas oryzae pv. oryzae

ABSTRACT The ability of some phytopathogenic bacterial strains to inhibit the growth of others in mixed infections has been well documented. Here we report that such antagonistic interactions occur between several wild-type strains of the rice bacterial blight pathogen Xanthomonas oryzae pv. oryzae. In mixed inoculations, a wild-type Philippine strain was found to inhibit the growth of a wild-type Korean strain. Furthermore, a nonpathogenic mutant of the Philippine strain maintained these antagonistic properties. Growth curve analysis indicated that both the wild-type Philippine strain and its nonpathogenic mutant inhibited the growth of the Korean strain 2 days after infection and prior to the onset of disease symptoms. When mixed with the nonpathogenic mutant, 10 out of 18 diverse wild-type X. oryzae pv. oryzae strains did not cause disease. Conversely, three of the strains that were not affected by the nonpathogenic mutant were found to inhibit the growth of both the wild-type and mutant Philippine strains, indicating that antagonism is widespread and strain specific. The observed growth inhibition occurred only in planta and did not correlate with bacteriocin activity in vitro. Antagonistic interactions also were found to affect resistance (R) gene-mediated resistance. The R gene Xa21 was capable of protecting rice plants coinoculated with nonantagonistic virulent and avirulent strains; however, when avirulent strains were coinoculated with virulent antagonistic strains, disease ensued. Taken together, these results indicate that X. oryzae pv. oryzae has evolved strategies to compete with rival strains in a fashion that allows virulent strains to evade R gene-mediated protection even when avirulent strains are present in the inoculum.     

水稻与白叶枯病菌互作的功能基因组学研究

水稻白叶枯病是水稻生产上重要的细菌病害之一。随着水稻和白叶枯病菌(Xanthomonas oryzaepv.oryzae,Xoo)全基因组序列的完成,该病害己成为植物-病原物互作研究的模式。水稻-Xoo互作涉及到寄主与病原菌因子的时空表达和严密调控。因此,阐明互作基因的表达调控机理,对于全面解析水稻-Xoo互作机制具有重要的科学意义。本文介绍了近年相关工作的研究进展。1Xoo基因鉴别和功能分析1.1Xoo侵染的基因表达谱和分子量化根据Xoo基因组序列信息,自主研制了载有调控基因、致病基因、特有基因以及保守基因特异片段的基因芯片,成功地用于在离体培养、…     

中生菌素对水稻白叶枯病的防治机制

对不同白叶枯病抗性水稻品种用200μg/ml中生菌素55℃温汤药液浸种，自然降温，秧田3—4叶期和移栽前5d各用30μg/ml中生菌素处理后，于成株期剪叶接种白叶枯病菌。结果表明中生菌素前期处理，于成株期接种白叶枯病菌时，高抗、中等抗性和感病品种中过氧化物酶、苯丙氨酸解氨酶和多酚氧化酶3种酶活性都有不同程度的提高，且以中等抗性品种酶活提高最多，接种24和48h，3种酶活性较清水对照分别增加26．92％、26．74％、24．06％和7．09％、1．31％、1．60％。盆栽试验表明，中生菌素对中抗品种的防治效果最好，达58．4％。说明中生菌素对水稻防御酶活性的诱激作用是其防治白叶枯病的机制之一。     

水稻白叶枯病菌单细胞系毒力分化研究

 以稀释倒平板法从0型菌086和IV型菌967-4和9620中分离到59个单细胞系;在12个近等基因系品种上,086和其单细胞系表现为弱毒力,2个IV型菌及其单细胞系能克服抗病基因Xa-1、2、3、8、10、11、14的抗性,不能克服Xa-21、4、5、7、13的抗性;带主效抗病基因的品种Asominori、XM5、M41、XM6和丰锦能把3个母株的59个单细胞系区分为12种数量差异或质量差异的不同致病型;将此5品种与近等基因系配合,适合作为病菌致病基因变异频度监测的寄主;采用"段叶沙培,切口取菌胶"法分离病菌,在中国致病型鉴定品种上划分的致病型,是田间病菌群体毒力结构的表型反应。     

利用多重PCR诊断水稻白叶枯病和细菌性条斑病的复合发生

为准确检测水稻白叶枯病菌、细菌性条斑病菌及这两种病菌的复合发生,利用软件DNAStar分析比较这两种菌的部分核酸序列,设计了检测这两种病菌的特异性引物。引物Xoo F-Xoo R能特异性扩增出水稻白叶枯病菌中一条大小162 bp的条带;引物Xooc F1-Xooc R1和Xooc F2-Xooc R2能够分别特异性扩增出水稻细菌性条斑病菌中690 bp和945 bp的条带。通过优化PCR反应条件,成功建立了多重PCR技术,可以对不同国家的水稻白叶枯病菌和细菌性条斑病菌进行准确检测,对由这两种病菌引起的复合侵染实现了准确诊断。     

Genotypic and Pathotypic Diversity in Xanthomonas oryzae pv. oryzae in Nepal

ABSTRACT Among the 171 strains of Xanthomonas oryzae pv. oryzae (the bacterial blight pathogen of rice) collected from eight rice-producing zones in Nepal, 31 molecular haplotypes were distinguished using two polymerase chain reaction-based assays. Six common haplotypes represented nearly 63% of the strains, and some haplotypes were geographically dispersed. Multiple correspondence analysis divided the collection into five putative genetic lineages. Lineages 1, 2, and 4 were the most frequently detected and occurred in diverse geographic populations. Twenty-six pathotypes (virulence phenotypes) of X. oryzae pv. oryzae were identified using 11 near-iso-genic rice lines, each containing a single gene for resistance. The 26 pathotypes grouped into five clusters, and cluster 1 contained wide virulence spectrum strains from all geographic populations. Although molecular variation was greatest between strains of different virulence phenotypes, some variation was observed among strains with identical virulence. There was a weak correlation (r = 0.52) between molecular haplotypes and virulence phenotypes. There are two major groups of X. oryzae pv. oryzae in Nepal. One group consists of strains with high molecular polymorphism and many pathotypes that are either virulent to the 11 major resistance genes or avirulent only to Xa21. Strains in the second group have low molecular polymorphism and are avirulent to Xa4, xa5, Xa7, and Xa21.     

化州市稻瘿蚊监测与综合防治技术规程

根据稻瘿蚊发生为害规律和测报防治实践,研究稻瘿蚊防治技术规程的适用范围、防治原则、防治指标、防治适期、虫情监测、预测方法及综合防治技术,阐明监测与综合防治技术规程的具体细则和技术指标,为稻瘿蚊防治规范化、标准化和绿色防控提供科学依据。     

水稻白叶枯病菌和细菌性条斑病菌的分子标记筛选及检测

 水稻白叶枯病菌（Xanthomonas oryzae pv. oryzae）和细菌性条斑病菌(Xanthomonas oryzae pv. oryzicola)是水稻种子产地检疫中最重要的两种检疫对象,且同属于水稻黄单胞杆菌。本研究基于生物信息学技术构建比较基因组学算法对两种病原的全基因组序列比对分析,得到一系列能够区分两种病原的特异性PCR引物。结合简单的PCR技术及全自动DNA分析系统,我们选取了12对引物分别对23株水稻白叶枯病菌和5株水稻细菌性条斑病菌及其它相关菌株进行验证。结果获得了2对显性标记(Xoo-Hpa1和Xoc-ORF2)以及3对共显性分子标记(M568、M897和M1575)可以达到理想的区分检测两种病原的效果。分子标记的检测灵敏度从5×10⁴到5 × 10⁷cfu·mL^-1不等,且从水稻种子浸提液中也能成功地检测水稻白叶枯病菌和细菌性条斑病菌。本研究丰富了检测标记的靶位点,并有效的结合了高通量检测的手段对多位点联合分析,增强了检测的可靠性,有望在今后的植物检疫及病原鉴定中发挥着重要的作用。     

Genetic Diversity of Xanthomonas oryzae pv. oryzae Strains from Sri Lanka

ABSTRACT Sixty strains of Xanthomonas oryzae pv. oryzae, collected from 29 locations in Sri Lanka in 1995, were analyzed by restriction fragment length polymorphism using either polymerase chain reaction-amplified 16S and 23S rDNA or the repetitive DNA element IS1112 from X. oryzae pv. oryzae as hybridization probes. Two different ribogroups were observed in the Sri Lankan strains using rDNA probes, whereas five clusters were identified by the IS1112 probe. Bootstrap analysis revealed that the five clusters defined by IS1112 were relatively robust. Our results suggest that the Sri Lankan strains are phylogenetically composed of five different groups. Each cluster was partially associated with climatic conditions (intermediate zone and wet zone) and was related to groups based on ribotyping. Based on virulence analysis using 12 rice cultivars, each containing a single resistance gene, 14 pathotypes were identified among the Sri Lankan strains. All strains were virulent to resistance genes Xa1, Xa2, Xa4, Xa10, Xa11, and Xa14. Only one strain (pathotype 1) was virulent to all major resistance genes including Xa21, while strains of the other pathotypes were all avirulent to Xa21. A partial relationship was found between the determined phylogenetic groups using the IS1112 probe and pathotypes for all but two clusters. The results of this study will facilitate the further understanding of the population structure of X. oryzae pv. oryzae in Sri Lanka.