首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
Gall midge is the third most destructive insect pests of rice after stem borers and planthoppers. Host plant resistance has been recognized as the most effective and economic, means for gall midge management. With the characterization of a new gall midge biotype (GMB) 4M, unique feature of gall midge resistance in the breeding line CR57-MR1523 was highlighted. Multi-location evaluation of F3 families derived from the cross TN1 × CR57-MR1523 against different gall midge biotypes helped to identify a new dominant gene conferring resistance against GMB4. This gene has been designated as Gm11t. Though CR57-MR1523 has been extensively used in breeding gall midge resistant rice varieties like Suraksha, neither the genetics of resistance nor chromosomal location of the resistance gene(s) is known. In the present study we have tagged and mapped the new gall midge resistance gene, Gm11t, on chromosome 12, using SSR markers. To map the gene locus, 466 F10 generation Recurrent Inbred Lines (RILs), from the cross of TN1 × CR57-MR1523 were used. Of the 471 SSR markers spread across the rice genome, 56 markers showed polymorphism and were used to screen a subset of the mapping population consisting of 10 resistant (R) and 10 susceptible (S) F10 RILs. Six SSR markers, RM28706, RM235, RM17, RM28784, RM28574 and RM28564 on chromosome 12 were initially found to be associated with resistance and susceptibility. Based on the linkage analysis in selected 158 RILs, we were able to map the locus between two flanking SSR markers, RM28574 and RM28706, on chromosome 12 within 4.4 and 3.8 cM, respectively. Further, two NILs with 99% genetic similarity, were identified from the RILs which differed in gall midge resistance. The tightly linked flanking SSR markers will facilitate marker-assisted gene pyramiding and map-based cloning of the resistant gene. NILs would be valuable materials for functional analysis of the identified candidate gene.  相似文献   

2.
Host plant resistance is the preferred management strategy for Asian rice gall midge (Orseolia oryzae), a serious pest in many rice-growing countries. Identification of simple sequence repeat (SSR) markers that are tightly linked to pest resistance genes can accelerate development of gene pyramids for durable/multiple resistance. Based on conventional and molecular allelism tests, we report herein that rice genotype Aganni possesses Gm8 gene, conferring hypersensitive independent (HR– type) resistance to gall midge biotypes GMB1, GMB2, GMB3, GMB4, and GMB4M. The gene Gm8 was mapped to chromosome 8 within a 400-kbp region, and the SSR markers RM22685 and RM22709 flank the gene closely. Using these closely linked flanking markers, nine other gall midge-resistant genotypes were identified as carrying the same gene Gm8. Through marker-assisted selection, Gm8 has been introgressed into an elite bacterial blight-resistant cultivar, Improved Samba-Mahsuri (IS).  相似文献   

3.
Screening of rice germplasm against Asian rice gall midge, Orseolia oryzae (Wood-Mason), biotypes in India has led to identification of over 300 resistant rice genotypes. However, only ten resistance genes have been characterized so far. Identification of new genes through classical allelism test is tedious and time consuming. We propose to use closely linked flanking Simple Sequence Repeat (SSR) markers in allelism tests for identification of resistance genes. Of the ten known gall midge resistance genes, eight have been tagged and mapped. The Gm1 and Gm2 genes have closely linked flanking markers. Hence SSR markers RM219 and RM444, flanking the gene Gm1, and RM317, RM241 along with the SCAR marker F8, flanking the gene Gm2, were selected for this study. Tests with one set of 13 genotypes likely to carry Gm1 and another set of 17 genotypes suspected to contain Gm2 suggested the presence of the respective allele in all the 13 and 15 genotypes from these sets, respectively. Classical allelism test perfectly matched with the markers test. There were two exceptions involving amplification with RM444 in cultivar Kavya and with RM241 in genotype AE20, suggesting a single recombination which could have resulted in the mismatch. All the three markers in the genotype Bhumansan and the two flanking markers RM317 and F8 in AE20 indicated the absence of the Gm2 allele. This was validated through a classical test, revealing a segregation ratio of 15 resistant: 1 susceptible F2 progeny of both the crosses between the Gm2 source Phalguna and these genotypes. We performed the allelism test with the markers on another set of 56 randomly selected gall midge resistant genotypes to discover possible sources of new resistance genes.  相似文献   

4.
The Asian rice gall midge, Orseolia oryzae Wood Mason (Diptera: Cecidomyiidae), is a major pest of rice in several South and South East Asian countries. The maggots feed internally on the growing tips of the tillers and transform them into tubular galls, onion leaf-like structures called ‘silver shoots’ resulting into severe yield loss to the rice crop. We studied the mode of inheritance and allelic relationships of the resistance genes involved in resistant donor Line 9, a sib of a susceptible cultivar ‘Madhuri’. The segregation behaviour of F1, F2 and F3 populations of the cross between Line 9 and susceptible cultivar MW10 confirmed the presence of a single dominant gene for resistance. Tests of allelism with all the known genes giving resistance to this population indicated that Line 9 possessed a new gene which was designated Gm 9 This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

5.
华南抗稻瘿蚊分子标记辅助育种   总被引：1，自引：0，他引：1  
亚洲稻瘿蚊(Orseolia oryzae Wood-Mason)是华南的主要水稻害虫.选育抗虫品种是最有效的生态控制方法.本文综述1998-2006年抗性育种的进展.用AFLP方法对从中国广东省7个地点采集的4个生物型的DAN指纹进行分析;在对用RAPD和SSR技术分别对抗中国4个稻瘿蚊生物型的基因Gm6精细定位基础上,用与Gm6紧密连锁的STS和SSR标记开展分子标记辅助育种,创造了一批抗稻瘿蚊的新种质,包括育成了6个栽培稻和6个二系杂交稻和1个三系杂交稻并在农户试种,在中国广东成功地建立了分子标记辅助选育抗稻瘿蚊品种的技术体系.  相似文献   

6.
以携带抗纹枯病QTL qSB-9TQ的籼稻品种特青和携带抗条纹叶枯病基因Stv-bi的粳稻品种镇稻88为优良等位基因供体亲本,江苏省推广的粳稻品种武育粳3号和武粳15为受体亲本,分别杂交并连续回交。在回交及自交分离世代,利用开发的覆盖目标基因区间的双侧分子标记对目标基因进行辅助选择。至回交BC4F1世代,同一遗传背景2个回交方向的中选单株间聚合杂交,获得2个目标基因位点均纯合的聚合F3株系。条纹叶枯病抗性鉴定和纹枯病抗性接种鉴定结果表明,聚合株系对条纹叶枯病均表现抗病;以0~9级评级标准评价,聚合株系的纹枯病较相应的轮回亲本分别低1.1~1.6级和0.8~1.4级。结合回交低世代抗性鉴定结果分析,自行开发的分子标记对目标基因的辅助选择是有效的。讨论了抗纹枯病育种及分子标记辅助选择聚合育种的相关问题。  相似文献   

7.
A series of DNA markers for various agronomic traits may accelerate the success of marker-assisted selection in practical plant breeding programmes. Here, we developed DNA markers for the blast resistance gene Pi-cd. In this study, we examined the effects of the Pi-cd locus on not only blast resistance but also agronomic traits in agriculture. We developed three pyramiding lines (PLs) coupling Pi-cd with three blast resistance genes, pi21, Pi35 and Pi39. The effect of Pi-cd on blast resistance was dependent on the coupled resistance genes. Then, we evaluated the effects of Pi-cd on 13 agronomic traits. Amylose content and 1,000-grain weight showed significant differences between the PLs and current commercial varieties, which had no negative effects on agronomic trait values. Furthermore, we investigated the distribution of genotype for the Pi-cd locus among varieties of upland rice. The KT genotype specific to rice blast resistance may be predominant in the varieties. The results suggested that Pi-cd has the potential to be useful for improving blast resistance in rice breeding programmes.  相似文献   

8.
Aphis glycines Matsumura, the soybean aphid, first arrived in North America in 2000 and has since become the most important insect pest of domestic soybean, causing significant yield loss and increasing production costs annually in many parts of the USA soybean belt. Research to identify sources of resistance to the pest began shortly after it was found and several sources were quickly identified in the USDA soybean germplasm collection. Characterization of resistance expression and mapping of resistance genes in resistant germplasm accessions resulted in the identification of six named soybean aphid resistance genes: Rag1, rag1c, Rag2, Rag3, rag4, and Rag5 (proposed). Simple sequence repeat markers flanking the resistance genes were identified, facilitating efforts to use marker-assisted selection to develop resistant commercial cultivars. Saturation or fine-mapping with single nucleotide polymorphism markers narrowed the genomic regions containing Rag1 and Rag2 genes. Two potential NBS-LRR candidate genes for Rag1 and one NBS-LRR gene for Rag2 were found within the regions. Years before the release of the first resistant soybean cultivar with Rag1 in 2009, a soybean aphid biotype, named biotype 2, was found that could overcome the resistance gene. Later in 2010, biotype 3 was characterized for its ability to colonize plants with Rag2 and other resistance genes. At present, three biotypes have been reported that can be distinguished by their virulence on Rag1 and Rag2 resistance genes. Frequency and geographic distribution of soybean aphid biotypes are unknown. Research is in progress to determine the inheritance of virulence and develop DNA markers tagging virulence genes to facilitate monitoring of biotypes. With these research findings and the availability of host lines with different resistance genes and biotypes, the soybean aphid-soybean pest-host system has become an important model system for advanced research into the interaction of an aphid with its plant host, and also the tritrophic interaction that includes aphid endosymbionts.  相似文献   

9.
Pot and laboratory experiments were performed in order to elucidate the genetics of resistance of three cowpea (Vigna unguiculata (L.) Walp.) resistant sources to two biotypes of the parasitic weed Striga gesnerioides (Willd.) Vatke (witchweed). B301, Suvita-2 and IT82D-849 were crossed to susceptible cultivars. Roots of each plant of parental, F1, F2, BC1 and BC2 populations were washed free of soil and examined closely for S. gesnerioides attachment. Data on resistant and susceptible cowpea plants were analyzed using the chi-square test to ascertain the goodness of fit to different genetic ratios. Segregation patterns indicate monogenic dominant inheritance of resistance to both S. gesnerioides biotypes in B301. Suvita-2, which is susceptible to the biotype from Maradi, Niger, showed segregation patterns that indicate monogenic dominant inheritance of resistance to S. gesnerioides biotype from Cinzana, Mali. Results also indicate monogenic dominant inheritance of resistance to S. gesnerioides biotype from Cinzana in IT82D-849. However, the inheritance of resistance to the biotype from Maradi would be monogenic and recessive in this line. These results suggest that the resistance of all three sources would be easy to transfer to promising breeding lines. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

10.
Summary The Rp1 locus of maize is a complex rust resistance locus where multiple resistance genes are clustered. Rare recombination events between Rp1 genes or alleles can produce two or more detectable genes linked in coupling phase. Such compound genes can then be manipulated as a single gene in breeding programs. Several compound Rp1 genes, each carrying two or three tightly linked resistance genes, were constructed to test their utility in controlling common rust. While none of the lines carrying single Rp1 genes were resistant to all of the characterized North American P. sorghi biotypes, most of the two component and all of the three component Rp1 complexes were resistant. The potential for utilization of compound resistance genes in other crop species is discussed.  相似文献   

11.
We have constructed a linkage map of the rice brown planthopper (BPH)resistance gene, Bph1. RFLP and AFLP markers were selected by thebulked segregant analysis and used in the mapping study of 262 F2sthat were derived from a cross of `Tsukushibare', a susceptible japonica cultivar, and `Norin-PL3', an authentic japonicaBph1-introgression line. Twenty markers were mapped within a 28.9-cMregion containing the Bph1 locus on the long arm of rice chromosome12. Combining the result of segregation analysis of BPH resistance by themass seedling test and that of the markers, the Bph1 locus wasmapped within a 5.8-cM region between two flanking markers. The closestAFLP markers, em5814N and em2802N, was at 2.7 cM proximal to theBph1 locus. Together with the previously constructed high-resolutionmap of bph2 locating the locus at ca. 10 cM proximal to the Bph1 locus, this improved version of the linkage map would facilitatepyramiding these two important BPH resistance genes.  相似文献   

12.
稻褐飞虱(BPH,NilaparvatalugensSt#l)是中国和世界稻区最严重的水稻害虫之一,发现和利用新抗性基因和进行抗性种质创新对于稻褐飞虱抗性品种的培育具有重要的意义。本研究进行了1200多份普通野生稻(OryzarufipogonGriff)种质对多种BPH生物型的抗性鉴定,获得了30份抗性资源,其中6份对分布于世界主要稻区的稻褐飞虱生物型1和2、孟加拉、湄公河(越南)、九龙江(越南)、潘特纳加(印度)等6种生物型或其中5种具有广谱高抗性。遗传分析证明了这些种质对BPH生物型2和九龙江生物型的抗性受2对重复作用隐性基因控制,对潘特纳加生物型的抗性受1对隐性基因控制,表明抗源对不同褐飞虱生物型具有不同的遗传机制。普通野生稻材料2183存在的2对隐性基因很可能是新发现的基因,因为在这些染色体区域还没报道有BPH抗性基因,这两对基因暂命名为bph18(t)和bph19(t)。研究总共培育出143份抗性创新种质和6份抗性品系或高产优质杂交水稻组合,这些优良的抗性创新种质为培育抗性新品种建立了坚实的基础。  相似文献   

13.
The inheritance of resistance to rice gall midge (Ranchi biotype) was studied in 12 resistant cultivars by crossing with susceptible cultivars. By the study of F1, F2, F3, B1 and B2 generations, it was found that resistance was governed by a single dominant gene in ‘Surekha’, ‘Phalguna’, ‘Rajendra Dhan 202’, ‘IET 7918’‘IET 6187’, ‘BG 404-1’; by duplicate dominant genes in ‘W 1263’, ‘RPW 6-17’ and ‘WGL 48684’ and a monogenic recessive gene in ‘OB 677’ and ‘BKNBR 1008-21’. The allelism test of the resistant genes in the test cultivars with already known genes Gm1 and Gm2 was carried out. A single dominant gene that conveyed the resistance in ‘RPW 6–17’, ‘IET 7918’ and ‘IET 6187’ was allelic to Gm1 and segregated independently of Gm2. The resistance in ‘Phalguna’, ‘Rajendra Dhan 202’, ‘W 1263’ and ‘RPW 6–17’, ‘IR 36’ and ‘WGL 48684’ was governed by Gm2 gene which was independent of Gm1. Two additional genes were identified and designated as Gm3 and gm4. Three test cultivars ‘BG 404-1’, ‘W 1263’ and ‘WGL 48684’ were found to have Gm3 gene for resistance which was non-allelic and segregated independently of Gm1 and Gm2. Thus the cultivars ‘W 1263’ and ‘WGL 48684’ had two resistance genes Gw2 and Gm3 together. The cultivar ‘RPW 6–17’ also had two resistance genes Gm1 and Gm2 together. The recessive gene gm4 which conditioned the resistance in ‘OB 677’ and ‘BKNBR 1008-21’ was nonallelic to and segregated independently of Gm1, Gm2 and Gm3 genes. Linkage studies of the resistance gene with pigment characters were carried out in ‘Purple gora/IR 36’ cross. The resistance gene Gm2 was found to be linked with the genes governing the pigmentation in node, apiculus and stigma with crossover values of 15.78, 31.57 and 35.78 % respectively. By the trisomic analysis, it was found that the Gm2 gene was located on chromosome 3.  相似文献   

14.
The F2 progeny of a third backcross(BC3) line, BC line 240, derived from a Turkish accession of wild barley (Hordeum vulgare ssp. spontaneum),segregated for resistance to scald (Rhynchosporium secalis) in a manner indicating the presence of a single dominant resistance gene. Two SCAR marker slinked to this resistance were developed from AFLP markers. Screens of disomic and ditelosomic wheat-barley addition lines with the SCAR markers demonstrated that the scald resistance gene is located in the centromeric region of barley chromosome 3H,a region previously reported to contain a major scald resistance locus, Rrs1. Markers that flank the Rrs1 locus were used to screen the wild barley-derivedBC3F2 population. These markers also flank the wild barley-derived scald resistance, indicating that it maps to the same locus as Rrs1; it may beallelic, or a separate gene within a complex locus. However, BC line 240 does not respond to treatment with the Rhynchosporium secalis avirulence factorNIP1 in the same way as the Rrs1-carrying cultivar Atlas46. This suggests that the scald resistance gene derived from wild barley confers a different specificity of response to theRrs1 allele in Atlas46.In order to increase the durability of scald resistance in the field, we suggest that at least two scald resistances should be combined into barley cultivars before release. The scald resistance gene described here will be of value in the Australian environment, and the several markers linked to it will facilitate pyramiding. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

15.
Barley yellow mosaic virus disease caused by different strains of BaYMV and BaMMV is a major threat to winter barley cultivation in Europe. Different resistance genes against these viruses have been mapped and suitable PCR-based markers have been developed. In this respect doubled haploid (DH) populations proved to be advantageous as they facilitate a repeated test for resistance against all agents of the barley yellow mosaic virus complex and besides this, dominant marker systems are as informative as co-dominant ones in DHs due to the lack of heterozygous genotypes. Using DH populations resistance genes rym4, rym5, rym11, rym13, rym15 and the BaYMV/BaYMV-2 resistance of the barley cultivar ‘Chikurin Ibaraki 1’ have been mapped. DHs are also well suited to pyramiding resistance genes against BaMMV and BaYMV. Since homozygous recessive genotypes are more frequent in DHs than in segregating F2 populations, DHs can be efficiently used to create broad-spectrum resistance and to extend the usability of partly overcome resistance genes. Results from employing two different strategies for pyramiding, based on one and two DH-steps, respectively, combining three recessive resistance genes, i.e. rym4/rym5, rym9 and rym11, are presented. The faster strategy based on one haploidy step resulted in the identification of all three and two-way combinations of the respective resistance genes.  相似文献   

16.
The rice cultivar ‘Chumroo’ is commonly cultivated in the mid- and high-altitude areas of Bhutan. This cultivar has shown durable blast resistance in that area, without evidence of breakdown, for over 20 years. Chumroo was inoculated with 22 blast isolates selected from the race differential standard set of Japan. The cultivar showed resistance to all the isolates. To identify the resistance gene(s), Chumroo was crossed with a susceptible rice cultivar, Koshihikari. The F1 plants of the cross showed resistance. Segregation analyses of 300 F3 family lines fitted the segregation ratio of 1:2:1 and indicated that a single dominant gene controls the resistance to a blast isolate Ao 92-06-2 (race 337.1). The Chumroo resistance locus (termed Pi46(t)) was mapped between two SSR markers, RM6748 and RM5473, on the terminal region of the long arm of chromosome 4, using linkage analysis with SSR markers. The nearest marker, RM5473, was linked to the putative resistance locus at a map distance of 3.2 cM. At the chromosomal region, no true resistance genes were identified, whereas two field resistance genes were present. Therefore, we designated Pi46(t) as a novel blast resistance locus.  相似文献   

17.
Most of the commercial varieties of coffee (Coffea arabica L.) derived from the Timor hybrid (TH) have been shown to contain major genes for coffee leaf rust (CLR) resistance. To identify markers tightly linked to such genes, an F2 mapping population derived from a cross between ‘Caturra’ (susceptible variety) and the TH‐derived DI.200 line (highly resistant) was generated. Using expressed sequence information and a bioinformatics approach, both targeted region amplified polymorphism (TRAPs) markers and simple sequence repeat (SSR) markers were identified. Phenotypic evaluations in the field and under controlled conditions confirmed the existence of one quantitative trait locus for CLR resistance. Four candidate SSR markers were associated with high CLR resistance. They spanning a region of 2.5 cM designated QCLR_4 located within chromosome 4 of the international C. canephora map. The presence of this region was confirmed in a set of elite lines and commercial varieties. The QCLR_4 region corresponds to a new and genetically independent SH locus that could potentially be useful in gene pyramiding with other genes to enhance rust resistance in TH derivatives.  相似文献   

18.
Severe outbreaks of bipartite begomoviruses (family Geminiviridae) have been observed on tomatoes after the introduction of the whitefly Bemisia tabaci (biotype B) in Brazil. The Lycopersicon esculentum line ‘TX 468-RG’ was identified as one of the best sources of broad-spectrum resistance to species comprising the tomato-infecting Begomovirus complex in Brazil. The genetic basis of resistance to one Begomovirus isolate was investigated using populations from the cross between ‘TX 468-RG’ (P1) and the susceptible line ‘Ohio 8245’ (P2). Parental lines, F1, backcross (BC) to P1 and BC to P2 and F2 generations were inoculated at the two true-leaf stage using 20 viruliferous whiteflies per plant. Assessment was done two weeks after inoculation based upon visual analysis of symptom expression. The ratio of resistant to susceptible plants closely fit to a single recessive gene (locus) model. The sequence analysis indicated that the Begomovirus isolate used in this assay was closely related to the bipartite Tomato chlorotic mottle virus. Therefore, this gene/locus, was tentatively named tcm-1 (tomato chlorotic mottle virus resistance-1). This locus has been transferred to distinct tomato cultivars and levels of resistance similar to that of ‘TX 468-RG’ were observed in advanced (F8 and F9) generations. In addition, breeding lines carrying the tcm-1 locus were also resistant to other Brazilian bipartite tomato-infecting Begomovirus species.  相似文献   

19.
Bacterial blight (BB) is the most economically damaging disease of rice in Asia and other parts of the world. In this study, a multiplex PCR genotyping method was developed to simultaneously identify genotypes of five BB resistance genes, Xa4, xa5, Xa7, xa13 and Xa21. The resistance R alleles were amplified using five functional markers (FMs) to generate amplicons of 217, 103, 179, 381 and 595 bp in IRBB66. Amplicons of 198, 107, 87, 391 and 467 bp corresponded to susceptible alleles in Taiwanese japonica rice cultivars. In backcross breeding programmes, the multiplex PCR assay was integrated into selection from a population using BB resistance donor IRBB66 crossed to rice cultivar ‘Tainung82’. Two plants with homozygosity for Xa4, xa5, Xa7, xa13 and Xa21 were selected from 1100 BC2F2 plants. In addition, the five BB resistance genes were also accurately identified in F2 populations. This multiplex PCR method provides a rapid and efficient method for detecting various BB resistance genes, which will assist in pyramiding genes to improve durability of BB resistance in Taiwanese elite rice cultivars.  相似文献   

20.
Summary An Agropyron elongatum-derived leaf rust resistance gene Lr24 located on chromosome 3DL of wheat was tagged with six random amplified polymorphic DNA (RAPD) markers which co-segregated with the gene. The markers were identified in homozygous resistant F2 plants taken from a population segregating for leaf rust resistance generated from a cross between two near-isogenic lines (NILs) differing only for Lr24. Phenotyping was done by inoculating the plants with pathotype 77-5 of Puccinia triticina. To enable gene-specific selection, three RAPD markers (S1302609, S1326615 and OPAB-1388) were successfully converted to polymorphic sequence characterized amplified region (SCAR) markers, amplifying only the critical DNA fragments co-segregating with Lr24. The SCAR markers were validated for specificity to the gene Lr24 in wheat NILs possessing Lr24 in 10 additional genetic backgrounds including the Thatcher NIL, but not to 43 Thatcher NILs possessing designated leaf rust resistance genes other than Lr24. This indicated the potential usefulness of these SCAR markers in marker assisted selection (MAS) and for pyramiding leaf rust resistance genes in wheat.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号