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1.
来源于疣粒野生稻的白叶枯病新抗源的鉴定   总被引:1,自引:0,他引:1  
疣粒野生稻对白叶枯病高抗甚至免疫。粳稻品种8411与疣粒野生稻体细胞杂交获得了2个高抗所有栽培稻白叶枯病抗性基因均不能抵御的国际广致病菌系P6的新种质SH5和SH76,遗传分析鉴定出新种质含有1个抗P6小种的显性基因。本研究以高感白叶枯病水稻品种IR24及携带不同抗性基因的16个材料为参照,对分蘖期、孕穗期的SH5和SH76分别接种11个白叶枯病小种,抗性分析表明SH5和SH76的抗谱广,与IRBB21(Xa21)抗谱一致,与IRBB5(xa5)、IRBB7(Xa7)和Asominori(Xa17)的较相近。用Xa21的分子标记pTA248和XA21检测,确定SH5和SH76不携带Xa21基因,前期研究结果证实新种质中不含xa5和Xa7;与Asominori的杂交试验表明其抗性基因与Xa17基因不等位。这些结果表明SH5和SH76中存在1个抗P6小种的新基因。  相似文献   

2.
分子标记辅助选择聚合Xa23,Pi9和Bt基因   总被引:3,自引:0,他引:3  
利用分子标记辅助选择将高抗水稻白叶枯病的Xa23基因、广谱高抗稻瘟病的Pi9基因、抗水稻螟虫和稻纵卷叶螟的Bt基因聚合到同一株系中,获得了三基因聚合的纯合株系。病、虫抗性鉴定结果显示:聚合了Xa23、Pi9和Bt基因的株系HB1471、HB1473能同时抗白叶枯病、稻瘟病和稻纵卷叶螟;与Xa23、Pi9基因的供体材料L10相比,对白叶枯病和稻瘟病的抗谱相同、抗性水平相当;对稻纵卷叶螟抗性与Bt基因的供体亲本MH63-Bt水平相当。Xa23、Pi9和Bt三基因纯合株系可以作为水稻育种的多抗供体材料。  相似文献   

3.
无选择标记和载体骨干序列的Xa21转基因水稻的获得   总被引:6,自引:0,他引:6  
利用双右边界T-DNA载体通过根癌农杆菌介导法将水稻白叶枯病广谱抗性基因Xa21导入杂交稻重要恢复系C418中。T0代共获得27个独立转基因株系,通过田间抗性鉴定与PCR分析,有17个株系的Xa21基因分子鉴定为阳性,且对白叶枯病原菌P6生理小种具有抗性。通过对17个株系的后代植株进行田间抗性鉴定,分子标记辅助选择及Southern杂交分析,结果显示4个株系的T1代植株中能分离出无潮霉素标记基因的Xa21转基因植株。无选择标记Xa21转基因株系的获得率为15%。PCR检测还表明,这些无选择标记的Xa21转基因植株不带有载体骨架序列。通过对转基因后代进一步的抗性鉴定与PCR辅助选择,获得了无选择标记和载体骨架序列的转基因Xa21纯合的抗白叶枯病水稻。  相似文献   

4.
水稻白叶枯病是水稻生产上的主要细菌病害之一。从野生稻中发掘优异的水稻白叶枯病抗性材料,可以拓宽栽培稻抗白叶枯病遗传基础。经过温室接菌鉴定和PCR标记分析,对云南野生稻进行Xa21基因的检测鉴定。温室接菌鉴定表明,云南野生稻对广谱致病小种PX099及云南强致病菌Y8具有较好的抗性能力,特别是疣粒野生稻对致病菌株达到免疫程度;PCR标记分析表明,云南野生稻不含有Xa21基因,但含有与Xa21基因某些区域同源的片段。本研究结果为寻找新的抗源材料及快速发掘利用云南野生稻中的抗白叶枯病基因提供理论依据。  相似文献   

5.
由黄单胞杆菌水稻致病变种Xanthomonas oryzae pv.oryzae(Xoo)引起的白叶枯病是水稻重要细菌性病害之一。迄今,已有7个水稻白叶枯病抗性基因被克隆。Xa21是第一个被克隆的白叶枯病抗性基因,因具有广谱抗性而受到广泛的关注。对Xa21的发现、定位及克隆、表达特征、编码产物XA21的生化特性、作用与调控以及XA21介导的免疫反应模式等方面的研究结果进行综述,并对今后的研究方向进行展望。  相似文献   

6.
利用农杆菌介导的高效遗传转化系统,将白叶枯病抗性基因Xa21转入黄淮稻区主栽品种豫粳6号的胚性愈伤组织,获得转基因植株,GUS染色和PCR分析证明Xa21基因已整合到水稻基因组中,其自交T1代植株经GUS染色和白叶枯病接种鉴定呈现3:1分离,研究为培育抗白叶枯病水稻品种奠定了基础。  相似文献   

7.
转Xa21基因水稻中T-DNA整合的遗传定位   总被引:3,自引:0,他引:3  
利用转抗白叶枯病基因Xa21的水稻材料,通过TAIL-PCR方法扩增T-DNA整合的侧翼序列。从中筛选属于水稻基因组DNA的T-DNA整合的侧翼序列作为探针,将外源基因整合位点定位到窄叶青/京系17DH群体构建的水稻分子连锁图谱上。共获得属于水稻基因组DNA的T-DNA侧翼序列22个,其中的19个序列在定位群体的两个亲本之间显示RFLP多态性,分别定位在水稻基因组的第3,4,5,7,9,10,11和12染色体上。带有转基因Xa21的T-DNA整合的定位为研究外源基因在不同染色体位点的位置效应和稳定遗传打下基础。  相似文献   

8.
为了改良水稻‘红血糯’品种对条纹叶枯病的抗性,将‘秦稻2号’、‘香糯Q33’、‘青香糯’作为抗性的供体亲本配制杂交组合;同时选取了ST10、H21和STS11-43等3对显性分子标记用于亲本和F2群体田间抗病性的分子标记辅助检测。结果显示:(1)不同分子标记在亲本中的多态性不同,标记H21和STS11-43只有在‘红血糯’和‘香糯Q33’之间具有多态性,标记ST10在‘红血糯’与‘秦稻2号’、‘香糯Q33’、‘青香糯’之间都有多态性。(2)各个分子标记在不同杂交组合F2群体的室内分子检测显示,部分F2单株携带抗性基因条带,也有个别单株含有杂合抗病基因条带。(3)田间发病抗性检测显示,含有抗性基因的植株基本不发病,携带抗性基因的单株与田间发病情况调查结果基本相符,但对含有杂合抗病基因条带的抗病单株,其还需2~3代田间观察,纯化抗病基因。研究表明,分子检测结果与田间抗病性检测结果相符,3种分子标记可以用于‘红血糯’杂交后代的分子标记辅助检测,为改良‘红血糯’的条纹叶枯病抗性育种提供了可行的方法。  相似文献   

9.
Xa21是已经分离克隆的一个具有广谱抗性的水稻白叶枯病抗性基因,根据已克隆的白叶枯病抗性基因Xa21外显子Ⅱ序列设计特异性引物对云南3种野生稻及其他稻种进行PCR扩增.结果表明,只有普通野生稻(景洪普通野生稻和元江普通野生稻)及长雄野生稻中扩增到了长400bp的目的片段,而疣粒野生稻和药用野生稻及栽培稻中均没有扩增到目的片段.通过序列比较发现所克隆的序列同长雄野生稻的氨基酸序列变化是随机的.  相似文献   

10.
云南野生稻中Xa21基因外显子II的分离及序列分析   总被引:1,自引:0,他引:1  
Xa21是已经分离克隆的一个具有广谱抗性的水稻白叶枯病抗性基因,根据已克隆的白叶枯病抗性基因Xa21外显子II序列设计特异性引物对云南三种野生稻及其它稻种进行PCR扩增。结果表明只有普通野生稻(景洪普通野生稻和元江普通野生稻)及长雄野生稻中扩增到了长400 bp的目的片段,而疣粒野生稻和药用野生稻及栽培稻中均没有扩增到目的片段。通过序列比较发现所克隆的序列同长雄野生稻的氨基酸序列变化是随机的。  相似文献   

11.
Bacterial Blight (BB) caused by Xanthomonas oryzae pv. oryzae is a major disease of rice in tropical Asia. Since all the Basmati varieties are highly susceptible and the disease is prevalent in the entire Basmati growing region of India, BB is a severe constraint in Basmati rice production. The present study was undertaken with the objective of combining the important Basmati quality traits with resistance to BB by a combination of phenotypic and molecular marker-assisted selection (MAS). Screening of 13 near-isogenic lines of rice against four isolates of the pathogen from Basmati growing regions identified the Xa4, xa8, xa13 and Xa21 effective against all the isolates tested. Two or more of these genes in combination imparted enhanced resistance as expressed by reduced average lesion length in comparison to individual genes. The two-gene pyramid line IRBB55 carrying xa13 and Xa21 was found equally effective as three/four gene pyramid lines. The two BB resistance genes present in IRBB55 were combined with the Basmati quality traits of Pusa Basmati-1 (PB-1), the most popular high yielding Basmati rice variety used as recurrent parent. Phenotypic selection for disease resistance, agronomic and Basmati quality characteristics and marker-assisted selection for the two resistance genes were carried out in BC1F1, BC1F2 and BC1F3 generations. Background analysis using 252 polymorphic amplified fragment length polymorphism (AFLP) markers detected 80.4 to 86.7% recurrent parent alleles in BC1F3 selections. Recombinants having enhanced resistance to BB, Basmati quality and desirable agronomic traits were identified, which can either be directly developed into commercial varieties or used as immediate donors of BB resistance in Basmati breeding programs.  相似文献   

12.
Xa4 is a dominantly inherited rice gene that confers resistance to Philippine race 1 of the bacterial blight pathogen Xanthomonas oryzae pv. oryzae in rice. In order to isolate the gene by positional cloning, a bacterial artificial chromosome (BAC) library was constructed from genomic DNA isolated from an Xa4-harboring accession, IRBB56. The library contains 55,296 clones with an average insert size of 132 kb, providing 14 rice genome equivalents. Three DNA markers closely linked to Xa4 were used to screen the library. The marker RS13, a resistance gene analogue that co-segregates with Xa4, identified 18 clones, of which four and six, respectively, were simultaneously detected by the other two markers, G181 and L1044. Fingerprinting and Southern analysis indicated that these clones overlapped and define an interval spanning 420 kb. In an F2 population derived from an indica variety, IR24, and its Xa4-containing near isogenic line (NIL), IRBB4, the susceptible plants were screened in order to map the Xa4 gene genetically and physically. Out of 24 insert ends isolated from the BACs in the contig, three revealed polymorphisms between IR24 and IRBB4. Two insert ends, 56M22F and 26D24R, flanked Xa4 on each side. Based on the overlap of the BACs, six overlapping clones were considered to include the Xa4 allele, one of which, 106P13, was chosen for further investigation.  相似文献   

13.
Field performance of Xa21 transgenic indica rice (Oryza sativa L.), IR72   总被引:6,自引:0,他引:6  
Based on the characterization of the resistance phenotype and molecular analysis, several homozygous lines carrying Xa21 against the bacterial blight (BB) pathogen were obtained from previously transformed indica rice, IR72. The homozygous line, T103-10, with the best phenotype and seed-setting, was repeatedly tested under normal field conditions to evaluate its levels of resistance to the BB pathogen in Wuhan, China, in 1998 and 1999. The isolates of Xanthomonas oryzae pv oryzae (Xoo) used in this experiments were PXO61, PXO79, PXO99 and PXO112 isolated from the Philippines, T2 isolated from Japan, and Zhe173 isolated from China. The results demonstrated that the transgenic homozygous line expressed the same resistance spectrum, but with a shorter lesion length to each inoculated isolates as the lesion length of the Xa21 donor line IRBB21. The non-transformed control IR72 carrying Xa4 was resistant to PXO61, PXO112, Zhe173 and T2, but susceptible to PXO99 and PXO79. The negative control variety IR24 was susceptible to all isolates under field conditions. The results demonstrated clearly that the Xa21 transgene led to an excellent field performance of the introduced bacterial blight resistance trait on the recipient plants. The yield performance of this transgenic homozygous line, T103-10, is comparable with that of the control under field conditions. Received: 2 August 1999 / Accepted: 3 November 1999  相似文献   

14.
用PCR技术诊断水稻的白叶枯病抗性   总被引:23,自引:1,他引:22  
陆朝福  章琦 《遗传学报》1996,23(2):110-116
植物育种中应用分子标记辅助选择要求分子标记与目的基因紧密连锁,而且分析手段经济简便、重复性好。Xa21是最近发现的一个具有广谱抗性的水稻白叶枯病抗性基因,利用一个含Xa21基因的品系IRBB21分别与2个感病品种杂交获得2个F_2群体。用4对引物分别对3个亲本进行PCR分析,其中一对引物(PB78)的PCR产物在抗、感病品种间可揭示多态性。对2个F_2群体进一步的遗传分析表明,PCR标记和Xa21的白叶枯病抗性紧密连锁,其重组率仅为2.48%。根据该标记选择基因型纯合的抗性植株,其准确率可达100%。本文还就植物育种中分子标记的检测途径进行了评价。  相似文献   

15.
通过农杆菌介导的转化系统,将业已克隆的水稻抗白叶枯病基因Xa21导入重要的粳型杂交稻恢复系“C418”。PCR和抗性分析表明单拷贝整合的Xa21在T1代的分离比为3:1。在T2代通过PCR和抗性分析选择了Xa21纯合的转基因株系“C418-Xa21”。将选择的转基因纯合系“C418-Xa21”与常用的雄性不育系“屉锦A”杂交,产生了带有转基因Xa21的杂交稻“屉优418-Xa21”(简称转基因杂交稻)。分子分析表明转基因Xa21在杂交稻“屉优418-Xa21”中能稳定遗传,抗性分析表明转基因恢复系“C418-Xa21”和转基因杂交稻“屉优418-Xa21”对白叶枯病具有高度的广谱抗性,并保持了受体对照的优良农艺性状。另外我们还转基因杂交稻“屉优418-Xa21”对白叶枯病的抗性水平高于转基因恢复系“C418-Xa21”,这可能是遗传背景的差异所致,抗白叶枯病转基因粳型恢复系数 杂交稻的育成将有益于杂交稻在我国北方稻区的推广。  相似文献   

16.
To incorporate durable resistance against bacterial blight, a major disease rice, three resistance genes, xa 5, xa13 and Xa21, from IRBB 60 were transferred through marker-assisted backcrossing using RG 556, RG 136 and pTA248 markers linked to the three genes to supplement the Xa4 gene present in Lalat, a popular rice cultivar. Effective selection enabled the transfer in three back-crosses and a generation of selfing and background selection employing morphological and grain quality traits and molecular markers, led to >90 % recovery of the recurrent parental genome. The gene pyramids exhibited high levels of resistance against the pathogen in multi-location evaluation trials conducted over several locations of bacterial blight in India. IL-2 (CRMAS2621-7-1), a gene pyramid, was identified as being promising for several endemic regions of bacterial blight and was released as Improved Lalat in one of the identified regions. The success of the study demonstrates the vast potential of marker-assisted selection for gene stacking and recovery of the parental genome with high precision.  相似文献   

17.
水稻抗白叶枯病基因Xa21的研究进展   总被引:6,自引:0,他引:6  
白辉  李莉云  刘国振 《遗传》2006,28(6):745-753
Xa21是最早克隆的水稻抗病基因,作为类受体激酶类广谱抗病基因它受到广泛的关注。转基因Xa21材料,很可能成为世界上第一个被批准进行大田释放的水稻转基因材料。本文在简要回顾Xa21的发现、定位和克隆过程之后,总结了目前Xa21基因的抗病作用机理和育种应用研究现状,包括XA21蛋白质激酶的生化特性、AvrXa21的鉴别、Xa21介导的抗病途径、抗病机理等,并对今后的研究进行了展望。  相似文献   

18.
The agronomically important Indica (group 1) rice varieties IR64, IR72, hybrid restorer line Minghui 63, and BG90-2 were co-transformed by microbombardment of embryogenic suspensions with plasmids that contain the Xa21 gene which confers resistance to Xanthomonas oryzae pv. oryzae and the hph gene for resistance to hygromycin B. Six of the 55 transgenic R0 plant lines containing the Xa21 gene displayed high levels of resistance to the pathogen, and no partial resistance was observed. The trait was stably inherited in subsequent generations, and transgenic plants are currently in field tests. The ability to transfer agronomically important genes into elite Indica rice varieties demonstrates the applicability of genetic engineering for the agronomic improvement of rice.  相似文献   

19.
Bacterial blight (BB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is a major disease of rice in the tropics for which genetic resistance in the host plants is the only effective solution. This study aimed at identification of resistance gene combinations effective against Xoo isolates and fingerprinting of the Xoo isolates of Andaman Islands (India). Here, we report the reaction of 21 rice BB differentials possessing Xa1 to Xa21 genes individually and in different combinations to various isolates of pathogen collected from Andaman Islands. Pathological screening results of 14 isolates revealed that among individual genes tested across 2 years, Xa4, Xa7 and Xa21 conferred resistance reaction across all isolates, whereas among combinations, IRBB 50 (Xa4 + xa5), IRBB 52 (Xa4 + Xa21) and IRBB 60 (Xa4 + xa5 + xa13 + Xa21) conveyed effective resistance against tested isolates. The nature of genetic diversity among four isolates selected on the basis of geographical isolation in the islands was studied through DNA finger printing. The RAPD primers S111, S119, S1117, S1109, S1103, S109 and S105 were found to be better indicators of molecular diversity among isolates than JEL primers. The diversity analysis grouped 14 isolates into three major clusters based on disease reaction wherein isolate no. 8 was found the most divergent as well as highly virulent. The remaining isolates were classified into two distinct groups. The importance of the study in the context of transfer of resistance gene(s) in the local cultivars specifically for tropical island conditions is presented and discussed.  相似文献   

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