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1.
T. R. Sharma P. Shanker B. K. Singh T. K. Jana M. S. Madhav K. Gaikwad N. K. Singh P. Plaha R. Rathour 《Journal of plant biochemistry and biotechnology.》2005,14(2):127-133
We have used rice line Tetep as a resistant donor with the aim of mapping a durable blast resistance gene Pi-k h using RAPD and AFLP techniques in conjunction with bulk segregant analysis. An F2 mapping population consisting of 205 plants was generated by crossing Tetep with HP2216, a highly susceptible cultivar. Inoculation with specific isolate (PLP-1) of Magnaporthe grisea at seeding stage showed that the Pi-k h gene inherited as a single dominant gene in F2 population. RAPD analysis was performed with 240 primers to detect polymorphism between resistant and susceptible parents. Of these, 48 primers produced polymorphic banding pattern between resistant and susceptible parents. Bulk segregant analysis was performed with 48 primers of which 5 showed polymorphism between resistant and susceptible bulks. A 700 bp DNA band was obtained in resistant F2 plants with primer 5-129 indicating its linkage to the resistance gene. Out of 64 AFLP primer combinations used for polymorphism survey between HP 2216 and Tetep, 11 AFLP primer combinations were able to distinguish the resistant and susceptible bulks. An AFLP band of 75 bp obtained with primer combination, E-TAlM-CTC co-segregated with the resistance gene. The RAPD marker 5-129700 and AFLP75 were placed on the linkage map at a distance of 2.1 eM and 15.1 eM flanking to Pi-k hgene, respectively. The RAPD band closely linked to Pi-k h gene was sequenced and used for the development of CAPs markers which also co-segregated with resistant phenotype in the mapping population. On sequence analysis and homology search of RAPD fragment with whole rice genome sequence database and the information available on physical, genetic and sequence maps of rice, the co-segregating CAPs marker was placed at long arm of rice chromosome 11. CAPs marker developed in this study showed polymorphism in different rice cultivars grown in North-Western Himalayan region and is being used for the pyramiding of Pi-k h gene along with other blast resistance genes using marker-assisted selection. 相似文献
2.
Qi He Dongbo Li Yongsheng Zhu Mingpu Tan Duanpin Zhang Xinghua Lin 《Molecular breeding : new strategies in plant improvement》2006,17(1):1-6
The rice bacterial blight resistance gene, Xa2, confers resistance to T7147 of the bacterial blight pathogen Xanthomonas oryzae pv. oryzae. It is located on the long arm of chromosome 4. Here, we report the fine mapping of Xa2 by genetic recombination analysis with simple sequence repeat (SSR) markers according to the genome sequence. Two F2 populations are constructed to localize Xa2. In a primary analysis with 136 random F2 plants of Zhenzhuai/IRBB2, it was found that Xa2 was located in approximately 20 cM region. To accurately determine the locus of Xa2, 120 new SSR markers were developed in this region by screening the sequence. Twelve new SSR markers were successfully used
in genetic recombination analysis in IR24/IRBB2 population, while 20 in ZZA/IRBB2 population. We found that the nearest SSR
markers to Xa2 are HZR950-5 and HZR970-4, which cover approximately 190-kb region. The sequence analysis of this 190-kb region revealed
the presence of a homologous sequence of leucine rich repeat (LRR)-kinase. These results are very useful for transferring
or pyramiding Xa2 by molecular marker-assistant selection in rice breeding programs and for cloning Xa2 by map-based cloning in combination with a long-range PCR strategy.
Electronic supplementary material Electronic supplementary material is available for this article at
and accessible for authorised users. 相似文献
3.
Luo-Ye Li Ling Wang Jin-Xue Jing Zhen-Qi Li Fei Lin Li-Fei Huang Qing-Hua Pan 《Molecular breeding : new strategies in plant improvement》2007,20(2):179-188
The Pik
m
gene in rice confers a high and stable resistance to many isolates of Magnaporthe oryzae collected from southern China. This gene locus was roughly mapped to the long arm of rice chromosome 11 with restriction
fragment length polymorphic (RFLP) markers in the previous study. To effectively utilize the resistance, a linkage analysis
was performed in a mapping population consisting of 659 highly susceptible plants collected from four F2 populations using the publicly available simple sequence repeat (SSR) markers. The result showed that the locus was linked
to the six SSR markers and defined by RM254 and RM144 with ≈13.4 and ≈1.2 cM, respectively. To fine map this locus, additional
10 PCR-based markers were developed in a region flanked by RM254 and RM144 through bioinformatics analysis (BIA) using the
reference sequence of cv. Nipponbare. The linkage analysis with these 10 markers showed that the locus was further delimited
to a 0.3-cM region flanked by K34 and K10, in which three markers, K27, K28, and K33, completely co-segregated with the locus.
To physically map the locus, the Pik
m
-linked markers were anchored to bacterial artificial chromosome clones of the reference cv. Nipponbare by BIA. A physical
map spanning ≈278 kb in length was constructed by alignment of sequences of the clones anchored by BIA, in which only six
candidate genes having the R gene conserved structure, protein kinase, were further identified in an 84-kb segment. 相似文献
4.
Wei Li Cailin Lei Zhijun Cheng Yulin Jia Dongyi Huang Jiulin Wang Jiankang Wang Xin Zhang Ning Su Xiuping Guo Huqu Zhai Jianmin Wan 《Molecular breeding : new strategies in plant improvement》2008,22(1):141-149
The Pi20(t) gene was determined to confer a broad-spectrum resistance against diverse blast pathotypes (races) in China based on inoculation
experiments utilizing 160 Chinese Magnaporthe oryzae (formerly Magnaporthe grisea) isolates, among which isolate 98095 can specifically differentiate the Pi20(t) gene present in cv. IR24. Two flanking and three co-segregating simple sequence repeat (SSR) markers for Pi20(t), located near the centromere region of chromosome 12, were identified using 526 extremely susceptible F2 plants derived from a cross of Asominori, an extremely susceptible cultivar, with resistant cultivar IR24. The SSR OSR32
was mapped at a distance of 0.2 cM from Pi20(t), and the SSR RM28050 was mapped to the other side of Pi20(t) at a distance of 0.4 cM. The other three SSR markers, RM1337, RM5364 and RM7102, co-segregated with Pi20(t). RM1337 and RM5364 were found to be reliable markers of resistance conditioned by Pi20(t) in a wide range of elite rice germplasm in China. As such, they are useful tags in marker-assisted rice breeding programs
aimed at incorporating Pi20(t) into advanced rice breeding lines and, ultimately, at obtaining a durable and broad spectrum of resistance to M. oryaze.
Wei Li and Cailin Lei contributed equally to this work. 相似文献
5.
Liu X Yang Q Lin F Hua L Wang C Wang L Pan Q 《Molecular genetics and genomics : MGG》2007,278(4):403-410
Blast, caused by the ascomycete fungus Magnaporthe oryzae, is one of the most devastating diseases of rice worldwide. The Chinese native cultivar (cv.) Q15 expresses the broad-spectrum
resistance to most of the isolates collected from China. To effectively utilize the resistance, three rounds of linkage analysis
were performed in an F2 population derived from a cross of Q15 and a susceptible cv. Tsuyuake, which segregated into 3:1 (resistant/susceptible)
ratio. The first round of linkage analysis employing simple sequence repeat (SSR) markers was carried out in the F2 population through bulked-segregant assay. A total of 180 SSR markers selected from each chromosome equally were surveyed.
The results revealed that only two polymorphic markers, RM247 and RM463, located on chromosome 12, were linked to the resistance
(R) gene. To further define the chromosomal location of the R gene locus, the second round of linkage analysis was performed using additional five SSR markers, which located in the region
anchored by markers RM247 and RM463. The locus was further mapped to a 0.27 cM region bounded by markers RM27933 and RM27940
in the pericentromeric region towards the short arm. For fine mapping of the R locus, seven new markers were developed in the smaller region for the third round of linkage analysis, based on the reference
sequences. The R locus was further mapped to a 0.18 cM region flanked by marker clusters 39M11 and 39M22, which is closest to, but away from
the Pita/Pita
2 locus by 0.09 cM. To physically map the locus, all the linked markers were landed on the respective bacterial artificial
chromosome clones of the reference cv. Nipponbare. Sequence information of these clones was used to construct a physical map
of the locus, in silico, by bioinformatics analysis. The locus was physically defined to an interval of ≈37 kb. To further
characterize the R gene, five R genes mapped near the locus, as well as 10 main R genes those might be exploited in the resistance breeding programs, were selected for differential tests with 475 Chinese
isolates. The R gene carrier Q15 conveys resistances distinct from those conditioned by the carriers of the 15 R genes. Together, this valuable R gene was, therefore, designated as Pi39(t). The sequence information of the R gene locus could be used for further marker-based selection and cloning.
Xinqiong Liu and Qinzhong Yang contributed equally to this work. 相似文献
6.
Rice blast, caused by the fungus Magnaporthe grisea, is a globally important disease of rice that causes annual yield losses. The segregation of genes controlling the virulence
of M. grisea on rice was studied to establish the genetic basis of cultivar specificity in the interaction of rice and M. grisea. The segregation of avirulence and virulence was studied in 87 M. grisea F1 progeny isolates from a cross of two isolates, Guy11 and JS153, using resistance-gene-differential rice cultivars. The segregation
ratio indicated that avirulence and virulence in the rice cultivars Aichi–asahi and K59, respectively, are controlled by single
major genes. Genetic analyses of backcrosses and full-sib crosses in these populations were also performed. The χ2 test of goodness-of-fitness for a 1:1 ratio indicated that one dominant gene controls avirulence in Aichi-asahi and K59 in
this population. Based on the resistance reactions of rice differential lines harboring known resistance genes to the parental
isolates, two genetically independent avirulence genes, AVR–Pit and AVR–Pia, were identified. Genetic linkage analysis showed that the SSR marker m355–356 is closely linked to AVR–Pit, on the telomere of chromosome 1 at a distance of approximately 2.3 cM. The RAPD marker S487, which was converted to a sequence-characterized
amplified region (SCAR) marker, was found to be closely linked to AVR–Pia, on the chromosome 7 telomere at a distance of 3.5 cM. These molecular markers will facilitate the positional cloning of
the two AVR genes, and can be applied to molecular-marker-assisted studies of M. grisea populations. 相似文献
7.
Jirapong Jairin Kittiphong Phengrat Sanguan Teangdeerith Apichart Vanavichit Theerayut Toojinda 《Molecular breeding : new strategies in plant improvement》2007,19(1):35-44
The brown planthopper (BPH) is one of the most destructive insect pests of rice in Thailand. We performed a cluster analysis
that revealed the existence of four groups corresponding to the variation of virulence against BPH resistance genes in 45
BPH populations collected in Thailand. Rice cultivars Rathu Heenati and PTB33, which carry Bph3, showed a broad-spectrum resistance against all BPH populations used in this study. The resistant gene Bph3 has been extensively studied and used in rice breeding programs against BPH; however, the chromosomal location of Bph3 in the rice genome has not yet been determined. In this study, a simple sequence repeat (SSR) analysis was performed to identify
and localize the Bph3 gene derived from cvs. Rathu Heenati and PTB33. For mapping of the Bph3 locus, we developed two backcross populations, BC1F2 and BC3F2, from crosses of PTB33 × RD6 and Rathu Heenati × KDML105, respectively, and evaluated these for BPH resistance. Thirty-six
polymorphic SSR markers on chromosomes 4, 6 and 10 were used to survey 15 resistant (R) and 15 susceptible (S) individuals
from the backcross populations. One SSR marker, RM190, on chromosome 6 was associated with resistance and susceptibility in
both backcross populations. Additional SSR markers surrounding the RM190 locus were also examined to define the location of
Bph3. Based on the linkage analysis of 208 BC1F2 and 333 BC3F2 individuals, we were able to map the Bph3 locus between two flanking SSR markers, RM589 and RM588, on the short arm of chromosome 6 within 0.9 and 1.4 cM, respectively.
This study confirms both the location of Bph3 and the allelic relationship between Bph3 and bph4 on chromosome 6 that have been previously reported. The tightly linked SSR markers will facilitate marker-assisted gene pyramiding
and provide the basis for map-based cloning of the resistant gene. 相似文献
8.
Robert Fjellstrom Anna M. McClung A. Robert Shank 《Molecular breeding : new strategies in plant improvement》2006,17(2):149-157
Pi-z is a disease resistance gene that has been effectively used to combat a broad-spectrum of races of the rice blast fungus
Magnaporthe grisea. Although DNA markers have been reported for selection of the Pi2(t) and Pi-z resistance genes at the Pi-z locus, markers that are more tightly linked to the Pi-z locus would benefit rapid and effective cultivar development. Analysis of the publicly available genome sequence of Nipponbare
near the Pi-z locus revealed numerous SSRs that could be converted into markers. Three SSRs on rice PAC AP005659 were found to be very
tightly linked to the Pi-z locus, with one marker, AP5659-3, co-segregating with the Pi-z resistance reaction. The Pi-z factor conferring resistance to two races of blast was mapped to a 57 kb region on the physical map of Nipponbare in a location
where the Pi2(t) gene was physically mapped. Two SSR marker haplotypes were unique for cultivars carrying the Pi-z gene, which indicates these markers are useful for selection of resistance genes at the Pi-z locus in rice germplasm. 相似文献
9.
Amit Kumar Rai Satya Pal Kumar Santosh Kumar Gupta Naveen Gautam Nagendera Kumar Singh Tilak Raj Sharma 《Journal of plant biochemistry and biotechnology.》2011,20(1):55-65
Blast disease of rice, caused by Magnaporthe oryzae is an explosive disease that can spread rapidly in conducive conditions. R-gene mediated resistance offers an environmentally sustainable solution for management of this important disease of rice. We have earlier identified a unique R-gene of rice, on chromosome 11 of Oryza sativa ssp. indica cultivar Tetep. In this study we report functional validation of the Pi-k h (Pi54) gene using complementation assay. The blast resistance candidate gene Pi-k h (Pi54) was cloned into a plant transformation vector and the construct was used to transform a japonica cultivar of rice Taipei 309, which is susceptible to M. oryzae. Transgenic lines containing Pi-k h (Pi54) gene were found to confer high degree of resistance to diverse isolates of M. oryzae. The callose deposition was analyzed and compared between the transgenic and non-transgenic rice plants and widespread deposition was observed at the infection sites in plants showing incompatible interaction. Successful complementation of Pi-k h (Pi54) gene confirmed that the gene is responsible for resistance to M. oryzae in transgenic lines developed during this study. Expression analysis of the gene in resistant plants revealed that the gene is pathogen inducible in nature and is not expressed constitutively. Detection of callose deposition in resistant plants containing Pi-k h (Pi54) gene implicates its involvement in the initiation of defense response cascade. 相似文献
10.
Genetic and physical mapping of <Emphasis Type="Italic">Pi36</Emphasis>(t), a novel rice blast resistance gene located on rice chromosome 8 总被引:12,自引:0,他引:12
Blast resistance in the indica cultivar (cv.) Q61 was inherited as a single dominant gene in two F2 populations, F2-1 and F2-2, derived from crosses between the donor cv. and two susceptible japonica cvs. Aichi Asahi and Lijiangxintuanheigu (LTH), respectively. To rapidly determine the chromosomal location of the resistance
(R) gene detected in Q61, random amplified polymorphic DNA (RAPD) analysis was performed in the F2-1 population using bulked-segregant analysis (BSA) in combination with recessive-class analysis (RCA). One of the three linked
markers identified, BA1126550, was cloned and sequenced. The R gene locus was roughly mapped on rice chromosome 8 by comparison of the BA1126550 sequence with rice sequences in the databases (chromosome landing). To confirm this finding, seven known markers, including
four sequence-tagged-site (STS) markers and three simple-sequence repeat (SSR) markers flanking BA1126550 on chromosome 8, were subjected to linkage analysis in the two F2 populations. The locus was mapped to a 5.8 cM interval bounded by RM5647 and RM8018 on the short arm of chromosome 8. This
novel R gene is therefore tentatively designated as Pi36(t). For fine mapping of the Pi36(t) locus, five additional markers including one STS marker and four candidate resistance gene (CRG) markers were developed
in the target region, based on the genomic sequence of the corresponding region of the reference japonica cv. Nipponbare. The Pi36(t) locus was finally localized to an interval of about 0.6 cM flanked by the markers RM5647 and CRG2, and co-segregated with
the markers CRG3 and CRG4. To physically map this locus, the Pi36(t)-linked markers were mapped by electronic hybridization to bacterial artificial chromosome (BAC) or P1 artificial chromosome
(PAC) clones of Nipponbare, and a contig map was constructed in silico through Pairwise BLAST analysis. The Pi36(t) locus was physically delimited to an interval of about 17.0 kb, based on the genomic sequence of Nipponbare. 相似文献
11.
Identification and fine mapping of AvrPi15, a novel avirulence gene of Magnaporthe grisea 总被引:6,自引:0,他引:6
Ma JH Wang L Feng SJ Lin F Xiao Y Pan QH 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,113(5):875-883
Avirulence of Magnaporthe grisea isolate CHL346 on rice cultivar GA25 was studied with 242 ascospore progenies derived from the cross CHL346 × CHL42. Segregation analysis of the avirulence in the progeny population was in agreement with the existence of a single avirulence (Avr) gene, designated as AvrPi15. For mapping the Avr gene, we developed a total of 121 microsatellite DNA markers [simple sequence repeat (SSR)], which evenly distributed in the whole-genome of M. grisea through bioinformatics analysis (BIA) using the publicly available sequence. Linkage analysis of the AvrPi15 gene with these SSR markers showed that six markers on chromosome 6, MS6-1, MS6-2, MS6-3, MS6-7, MS6-8 and MS6-10, were linked to the AvrPi15 locus. To further define the chromosomal location of the AvrPi15 locus, two additional markers, MS6-17 and STS6-6, which were developed based on the sequences of telomeric region 11 (TEL11), were subjected to linkage analysis. The results showed that MS6-17 and STS6-6 were associated with the locus by 3.3 and 0.8 cM, respectively. To finely map the Avr gene, two additional candidate avirulence gene (CAG) markers, CAG6-1 and CAG6-2, were developed based on the gene annotation of the sequence of TEL 11. Linkage analysis of the Avr gene with these two markers revealed that both of them completely cosegregated with the AvrPi15 locus. Finally, this locus was physically mapped into ∼ 7.2-kb interval of the TEL11 by BIA using these sequence-ready markers. This is the key step toward positional cloning of the AvrPi15 gene. 相似文献
12.
Berruyer R Adreit H Milazzo J Gaillard S Berger A Dioh W Lebrun MH Tharreau D 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2003,107(6):1139-1147
Rice blast disease is a major constraint for rice breeding. Nevertheless, the genetic basis of resistance remains poorly understood for most rice varieties, and new resistance genes remain to be identified. We identified the resistance gene corresponding to the cloned avirulence gene ACE1 using pairs of isogenic strains of Magnaporthe grisea differing only by their ACE1 allele. This resistance gene was mapped on the short arm of rice chromosome 8 using progenies from the crosses IR64 (resistant) × Azucena (susceptible) and Azucena × Bala (resistant). The isogenic strains also permitted the detection of this resistance gene in several rice varieties, including the differential isogenic line C101LAC. Allelism tests permitted us to distinguish this gene from two other resistance genes [Pi11 and Pi-29(t)] that are present on the short arm of chromosome 8. Segregation analysis in F2 populations was in agreement with the existence of a single dominant gene, designated as Pi33. Finally, Pi33 was finely mapped between two molecular markers of the rice genetic map that are separated by a distance of 1.6 cM. Detection of Pi33 in different semi-dwarf indica varieties indicated that this gene could originate from either one or a few varieties.Communicated by D.J. Mackill 相似文献
13.
The rice lesion mimic mutant spotted leaf 1 ( spl1) was first identified in the rice ( Oryza sativa) cultivar Asahi in 1965. This mutant displayed spontaneous disease-like lesions in the absence of any pathogen, and was found to confer resistance to multiple isolates of rice blast. We employed a map-based cloning strategy to localize the Spl1 gene. A total of ten cleaved amplified polymorphic sequence (CAPS) markers linked to the Spl1 gene were identified and mapped to an 8.5-cM region on chromosome 12. A high-resolution genetic map was developed using these ten CAPS markers and a segregating population consisting of 3202 individuals. A BAC contig containing four BAC clones was constructed, and Spl1 was localized to a 423-kb region. Seven spl1 mutants were obtained from the IR64 deletion mutant collection, and molecular analysis using these mutants delimited the Spl1 gene to a 70-kb interval, covered by two BAC clones. These results provide the basis for cloning this gene, which is involved in cell death and disease resistance in rice.Communicated by R. HagemannThe first two authors contributed equally to the work 相似文献
14.
A major quantitative trait locus (QTL) associated with resistance to Fusarium head blight (FHB) was identified on chromosome 3BS between simple sequence repeat (SSR) markers Xgwm389 and Xgwm493 in wheat “Ning 7840”, a derivative from “Sumai 3”. However, the marker density of SSR in the QTL region was much lower than that required for marker-assisted selection (MAS) and map-based cloning. The objective of this study was to exploit new markers to increase marker density in this QTL region by using single-strand conformational polymorphism (SSCP) markers developed from wheat-expressed sequence tags (ESTs) on 3BS bin 8-0.78-1.0. Sixty-nine out of 85 SSCP primer pairs amplified PCR (polymerase chain reaction) products from the genomic DNA of “Chinese Spring”. Thirty-four primer pairs amplified PCR products that could form clear ssDNA (single strand DNA) bands through denaturation treatment. Ten SSCP markers had polymorphisms between Ning 7840 and “Clark”. Five of the ten polymorphic SSCP markers were located on chromosome 3B by nullitetrasomic analysis. Three SSCP markers (Xsscp6, Xsscp20, and Xsscp21) were mapped into the region between Xgwm493 and Xgwm533 and possessed a higher coefficient of determination (R2) than Xgwm493 and Xgwm533. The SSCP markers, Xsscp6, Xsscp20, and Xsscp21, can be used for map-based cloning of the QTL and for marker-assisted selection in FHB resistance breeding. 相似文献
15.
Z. H. Yu D. J. Mackill J. M. Bonman S. R. McCouch E. Guiderdoni J. L. Notteghem S. D. Tanksley 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1996,93(5-6):859-863
Two dominant genes conferring complete resistance to specific isolates of the rice blast fungus, Pyricularia grisea Sacc., were located on the molecular map of rice in this study. Pi-l(t) is a blast resistance gene derived from the cultivar LAC23. Its map location was determined using a pair of nearly isogenic lines (NILs) and a B6F3 segregating population from which the isoline was derived. RFLP analysis showed that Pi-l(t) is located near the end of chromosome 11, linked to RZ536 at a distance of 14.0±4.5 centiMorgans (cM). A second gene, derived from the cultivar Apura, was mapped using a rice doubled-haploid (DH) population. This gene was located on chromosome 12, flanked by RG457 and RG869, at a distance of 13.5+-4.3 cM and 17.7+-4.5 cM, respectively. The newly mapped gene on chromosome 12 may be allelic or closely linked toPi-ta. (=Pi-4(t)), a gene derived from Tetep that was previously reported to be linked to RG869 at a distance of 15.4±4.7 cM. The usefulness of markers linked to blast resistance genes will be discussed in the context of breeding for durable blast resistance. 相似文献
16.
Shen Chen Zhanghui Huang Liexian Zeng Jianyuan Yang Qiongguang Liu Xiaoyuan Zhu 《Molecular breeding : new strategies in plant improvement》2008,22(3):433-441
Bacterial blight (BB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is a devastating disease in rice worldwide. The resistance gene Xa7, which provides dominant resistance against the pathogen with avirulence (Avr) gene AvrXa7, has proved to be durably resistant to BB. A set of SSR markers were selected from the “gramene” database based on the Xa7 gene initial mapping region on chromosome 6. These markers were used to construct a high-resolution genetic map of the chromosomal
region surrounding the Xa7 gene. An F2 mapping population with 721 highly susceptible individuals derived from a cross between the near isogenic lines (NILs) IRBB7
and IR24 were constructed to localize the Xa7 gene. In a primary analysis with eleven polymorphic SSR markers, Xa7 was located in approximately the 0.28-cM region. To walk closer to the target gene, recombinant F2 individuals were tested using newly developed STMS (sequence tagged microsatellite) markers. Finally, the Xa7 gene was mapped to a 0.21-cM interval between the markers GDSSR02 and RM20593. The Xa7-linked markers were landed on the reference sequence of cv. Nipponbare through bioinformatics analysis. A contig map corresponding
to the Xa7 gene was constructed. The target gene was assumed to span an interval of approximately 118.5-kb which contained a total of
fourteen genes released by the TIGR Genome Annotation Version 5.0. Candidate-gene analysis of Xa7 revealed that the fourteen genes encode novel domains that have no amino acid sequence similar to other cloned Xa(xa) genes.
Shen Chen and Zhanghui Huang are contributed equally to this work. 相似文献
17.
Changes in plant architecture have been central to the domestication of wild species. Tillering or the degree of branching
determines shoot architecture and is a key component of grain yield and/or biomass. Previously, a tiller inhibition mutant with monoculm phenotype was isolated and the mutant gene (tin3) was mapped in the distal region of chromosome arm 3AmL of Triticum monococcum. As a first step towards isolating a candidate gene for tin3, the gene was mapped in relation to physically mapped expressed sequence tags (ESTs) and sequence tag site (STS) markers
developed based on synteny with rice. In addition, we investigated the relationship of the wheat region containing tin3 with the corresponding region in rice by comparative genomic analysis. Wheat ESTs that had been previously mapped to deletion
bins provided a useful framework to identify closely related rice sequences and to establish the most likely syntenous region
in rice for the wheat tin3 region. The tin3 gene was mapped to a 324-kb region spanned by two overlapping bacterial artificial chromosomes (BACs) of rice chromosome
arm 1L. Wheat–rice synteny was exceptionally high at the tin3 region despite being located in the high-recombination, gene-rich region of wheat. Identification of tightly linked flanking
EST and STS markers to the tin3 gene and its localization to highly syntenic rice BACs will assist in the future development of a high-resolution map and
map-based cloning of the tin3 gene.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
18.
Chen S Wang L Que Z Pan R Pan Q 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2005,111(8):1563-1570
The famous rice cultivar (cv.), St. No. 1, confers complete resistance to many isolates collected from the South China region.
To effectively utilize the resistance, a linkage assay using microsatellite markers (SSR) was performed in the three F2 populations derived from crosses between the donor cv. St. No. 1 and each of the three susceptible cvs. C101PKT, CO39 and
AS20-1, which segregated into 3R:1S (resistant/susceptible) ratio, respectively. A total of 180 SSR markers selected from
each chromosome equally were screened. The result showed that the two markers RM128 and RM486 located on chromosome 1 were
linked to the resistance gene in the respective populations above. This result is not consistent with those previously reported,
in which a well-known resistance gene Pif in the St. No. 1 is located on chromosome 11. To confirm this result, additional four SSR markers, which located in the region
lanked by RM128 and RM486, were tested. The results showed that markers RM543 and RM319 were closer to, and RM302 and RM212
completely co-segregated with the resistance locus detected in the present study. These results indicated that another resistance
gene involved in the St. No. 1, which is located on chromosome 1, and therefore tentatively designated as Pi37(t). To narrow down genomic region of the Pi37(t) locus, eight markers were newly developed in the target region through bioinformatics analysis (BIA) using the publicly
available sequences. The linkage analysis with these markers showed that the Pi37(t) locus was mapped to a ≈ 0.8 centimorgans (cM) interval flanked by RM543 and FPSM1, where a total of seven markers co-segregated
with it. To physically map the locus, the Pi37(t)-linked markers were landed on the reference sequence of cv. Nipponbare through BIA. A contig map corresponding to the
locus was constructed based on the reference sequence aligned by the Pi37(t)-linked markers. Consequently, the Pi37(t) locus was defined to 374 kb interval flanking markers RM543 and FPSM1, where only four candidate genes with the resistance
gene conserved structure (NBS-LRR) were further identified to a DNA fragment of 60 kb in length by BIA. 相似文献
19.
R. B. Li Y. Z. Chen Y. P. Wei Ch. Liu Z. F. Ma D. H. Huang Y. X. Zhang W. L. Lu 《Molecular breeding : new strategies in plant improvement》2009,24(2):135-140
Hybrid sterility between indica and japonica subspecies in rice is basically caused by partial abortion of gametes and hybrid fertility could be recovered by a single
wide compatibility (WC) allele. In this study, a typical indica germplasm source of rice, UPRI 95-162, with strong wide compatibility
in cross with japonica rice was studied for location of its WC locus. Bulked segregant analysis was performed and SSRs (simple
sequence repeats) were conducted on a F1 population derived from a three-way cross (UPRI 95-162/T8//Akihikari). The locus was located on chromosome 1 approximately
0.2 cM to SSR markers RM581 on one side and 1.5 cM to RM292 on another. This WC locus, tentatively designated as S-20
n
(t), and its tight linkage markers, RM581 and RM292, would be very useful for efficient marker-assisted selection for breeding
new WC varieties and for map-based cloning of the gene. 相似文献
20.
Xiaochun Sun Guihua Bai Brett F. Carver 《Molecular breeding : new strategies in plant improvement》2009,23(2):311-321
Leaf rust, caused by Puccinia triticina Eriks., is an important foliar disease of common wheat (Triticum aestivum L.) worldwide. Pyramiding several major rust-resistance genes into one adapted cultivar is one strategy for obtaining more
durable resistance. Molecular markers linked to these genes are essential tools for gene pyramiding. The rust-resistance gene
Lr41 from T.
tauschii has been introgressed into chromosome 2D of several wheat cultivars that are currently under commercial production. To discover
molecular markers closely linked to Lr41, a set of near-isogenic lines (NILs) of the hard winter wheat cultivar Century were developed through backcrossing. A population
of 95 BC3F2:6 NILs were evaluated for leaf rust resistance at both seedling and adult plant stages and analyzed with simple sequence repeat
(SSR) markers using bulked segregant analysis. Four markers closely linked to Lr41 were identified on chromosome 2DS; the closest marker, Xbarc124, was about 1 cM from Lr41. Physical mapping using Chinese Spring nullitetrasomic and ditelosomic genetic stocks confirmed that markers linked to Lr41 were on chromosome arm 2DS. Marker analysis in a diverse set of wheat germplasm indicated that primers BARC124, GWM210, and
GDM35 amplified polymorphic bands between most resistant and susceptible accessions and can be used for marker-assisted selection
in breeding programs. 相似文献