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1.
Yeong Deuk Jo Young-Min Kim Mi-Na Park Jae-Hyoung Yoo MinKyu Park Byung-Dong Kim Byoung-Cheorl Kang 《Molecular breeding : new strategies in plant improvement》2010,25(2):187-201
The Restorer-of-fertility (Rf) gene is used for efficient hybrid seed production in chili pepper. Although molecular markers linked to Rf in pepper are available, their applications have been limited by lack of agreement between marker genotype and phenotype.
To overcome this limitation, we developed new molecular markers using an Rf-segregating population for which most of previously developed markers are not suitable, because of lack of polymorphism.
The petunia Rf gene was used as a candidate for marker development. First of all, a pepper bacterial artificial chromosome (BAC) library
was screened using a pepper homolog of the petunia Rf gene. The 52 selected BAC clones were classified into three contig groups and each contig group was mapped to chromosome
6. Three markers were developed using the three groups; their genetic distances from the Rf locus were 1.4, 3.2 and 14 cM, respectively. In the second place, an Rf-linked marker was developed from the sequence of a tomoto BAC clone containing three genes which are homologous to petunia
Rf gene. Genetic distance between this marker and Rf gene was 1.4 cM. When newly-, and previously-developed molecular markers linked to Rf were applied to 55 pepper breeding lines, one marker named CRF-SCAR was found to be the most broadly applicable, based on
correct determination of phenotypes. In the present study, we demonstrate that previously cloned Rf genes can be used as candidate genes for development of new markers for the reliable detection of restorer lines. We expect
that the newly-developed markers and information obtained from application of markers will be useful for reliable detection
of restorer lines. 相似文献
2.
Tomita R Murai J Miura Y Ishihara H Liu S Kubotera Y Honda A Hatta R Kuroda T Hamada H Sakamoto M Munemura I Nunomura O Ishikawa K Genda Y Kawasaki S Suzuki K Meksem K Kobayashi K 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2008,117(7):1107-1118
The tobamovirus resistance gene L
3 of Capsicum chinense was mapped using an intra-specific F2 population (2,016 individuals) of Capsicum annuum cultivars, into one of which had been introduced the C. chinense
L
3 gene, and an inter-specific F2 population (3,391 individuals) between C. chinense and Capsicum frutescence. Analysis of a BAC library with an AFLP marker closely linked to L
3-resistance revealed the presence of homologs of the tomato disease resistance gene I2. Partial or full-length coding sequences were cloned by degenerate PCR from 35 different pepper I2 homologs and 17 genetic markers were generated in the inter-specific combination. The L
3 gene was mapped between I2 homolog marker IH1-04 and BAC-end marker 189D23M, and located within a region encompassing two different BAC contigs consisting
of four and one clones, respectively. DNA fiber FISH analysis revealed that these two contigs are separated from each other
by about 30 kb. DNA fiber FISH results and Southern blotting of the BAC clones suggested that the L
3 locus-containing region is rich in highly repetitive sequences. Southern blot analysis indicated that the two BAC contigs
contain more than ten copies of the I2 homologs. In contrast to the inter-specific F2 population, no recombinant progeny were identified to have a crossover point
within two BAC contigs consisting of seven and two clones in the intra-specific F2 population. Moreover, distribution of the
crossover points differed between the two populations, suggesting linkage disequilibrium in the region containing the L locus.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
R. Tomita and J. Murai contributed equally to this work. 相似文献
3.
Development and mapping of AFLP markers linked to the sorghum fertility restorer gene <Emphasis Type="Italic">rf4</Emphasis> 总被引:2,自引:2,他引:0
Wen L Tang HV Chen W Chang R Pring DR Klein PE Childs KL Klein RR 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2002,104(4):577-585
The restoration of male fertility in the sorghum IS1112 C (A3) male-sterile cytoplasm is through a two-gene gametophytic system
involving complementary action of the restoring alleles Rf3 and Rf4. To develop markers suitable for mapping rf4, AFLP technology was applied to bulks of sterile and fertile individuals from a segregating BC3F1 population. Three AFLP markers linked to rf4 were identified and subsequently converted to STS/CAPS markers, two of which are co-dominant. Based on a population of 378
BC1F1 individuals, two STS/CAPS markers, LW7 and LW8, mapped to within 5.31 and 3.18 cM, respectively, of rf4, while an STS marker, LW9, was positioned 0.79 cM on the flanking side of rf4. Markers LW8 and LW9 were used to screen sorghum BAC libraries to identify the genomic region encoding rf4. A series of BAC clones shown to represent a genomic region of linkage group E were identified by the rf4-linked markers. A contig of BAC clones flanking the LW9 marker represent seed clones on linkage group E, from which fine
mapping of the rf4 locus and chromosome walking can be initiated.
Received: 20 June 2001 / Accepted: 3 August 2001 相似文献
4.
Azhaguvel P Rudd JC Ma Y Luo MC Weng Y 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2012,124(3):555-564
The greenbug, Schizaphis graminum (Rondani), is an important aphid pest of small grain crops especially wheat (Triticum aestivum L., 2n = 6x = 42, genomes AABBDD) in many parts of the world. The greenbug-resistance gene Gb3 originated from Aegilops tauschii Coss. (2n = 2x = 14, genome DtDt) has shown consistent and durable resistance against prevailing greenbug biotypes in wheat fields. We previously mapped Gb3 in a recombination-rich, telomeric bin of wheat chromosome arm 7DL. In this study, high-resolution genetic mapping was carried
out using an F2:3 segregating population derived from two Ae. tauschii accessions, the resistant PI 268210 (original donor of Gb3 in the hexaploid wheat germplasm line ‘Largo’) and susceptible AL8/78. Molecular markers were developed by exploring bin-mapped
wheat RFLPs, SSRs, ESTs and the Ae. tauschii physical map (BAC contigs). Wheat EST and Ae. tauschii BAC end sequences located in the deletion bin 7DL3-0.82–1.00 were used to design STS (sequence tagged site) or CAPS (Cleaved
Amplified Polymorphic Sequence) markers. Forty-five PCR-based markers were developed and mapped to the chromosomal region
spanning the Gb3 locus. The greenbug-resistance gene Gb3 now was delimited in an interval of 1.1 cM by two molecular markers (HI067J6-R and HI009B3-R). This localized high-resolution
genetic map with markers closely linked to Gb3 lays a solid foundation for map based cloning of Gb3 and marker-assisted selection of this gene in wheat breeding. 相似文献
5.
Currently, the only genetic resistance against root-knot nematodes in the cultivated tomato Solanum lycopersicum (Lycopersicon esculentum) is due to the gene Mi-1. Another resistance gene, Mi-3, identified in the related wild species Solanum peruvianum (Lycopersicon peruvianum) confers resistance to nematodes that are virulent on tomato lines that carry Mi-1, and is effective at temperatures at which Mi-1 is not effective (above 30°C). Two S. peruvianum populations segregating for Mi-3 were used to develop a high-resolution map of the Mi-3 region of chromosome 12. S. lycopersicum BACs carrying flanking markers were identified and used to construct a contig spanning the Mi-3 region. Markers generated from BAC-end sequences were mapped in S. peruvianum plants in which recombination events had occurred near Mi-3. Comparison of the S. peruvianum genetic map with the physical map of S. lycopersicum indicated that marker order is conserved between S. lycopersicum and S. peruvianum. The 600 kb contig between Mi-3-flanking markers TG180 and NR18 corresponds to a genetic distance of about 7.2 cM in S. peruvianum. We have identified a marker that completely cosegregates with Mi-3, as well as flanking markers within 0.25 cM of the gene. These markers can be used to introduce Mi-3 into cultivated tomato, either by conventional breeding or cloning strategies. 相似文献
6.
Budiman MA Chang SB Lee S Yang TJ Zhang HB de Jong H Wing RA 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2004,108(2):190-196
Abstract Abscission is a universal process whereby plants shed their organs, such as flowers, fruit and leaves. In tomato, the non-allelic mutations jointless and jointless-2 have been discovered as recessive mutations that completely suppress the formation of pedicel abscission zones. A high resolution genetic map of jointless-2 was constructed using 1,122 jointless F2 plants. Restriction fragment length polymorphism (RFLP) marker RPD140 completely co-segregated with the jointless-2 locus and mapped in a 2.4 cM interval between RFLP markers CD22 and TG618. To chromosome walk to jointless-2, all three markers were used to screen a bacterial artificial chromosome (BAC) library and contigs were developed. Intensive efforts to expand and merge the BAC contigs were unsuccessful because of the highly repetitive sequence content on the distal ends of each contig. To determine the physical distance between and the orientation of the three contigs, we used high resolution pachytene fluorescence in situ hybridization (FISH) mapping. The RPD140 contig was positioned in the centromeric region of chromosome 12 between two large pericentric heterochromatin blocks, about 50 Mb from the TG618 contig on the short arm and 10 Mb from the CD22 contig on the long arm, respectively. Based on high resolution genetic and physical mapping, we conclude that the jointless-2 gene is located within or near the chromosome 12 centromere where 1 cM is approximately 25 Mb in length.Communicated by Q. ZhangM.A. Budiman, S-B. Chang and S. Lee contributed equally to the work. 相似文献
7.
Jo KR Arens M Kim TY Jongsma MA Visser RG Jacobsen E Vossen JH 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2011,123(8):1331-1340
The use of resistant varieties is an important tool in the management of late blight, which threatens potato production worldwide.
Clone MaR8 from the Mastenbroek differential set has strong resistance to Phytophthora infestans, the causal agent of late blight. The F1 progeny of a cross between the susceptible cultivar Concurrent and MaR8 were assessed for late blight resistance in field trials inoculated with an incompatible P. infestans isolate. A 1:1 segregation of resistance and susceptibility was observed, indicating that the resistance gene referred to
as R8, is present in simplex in the tetraploid MaR8 clone. NBS profiling and successive marker sequence comparison to the potato and tomato genome draft sequences, suggested
that the R8 gene is located on the long arm of chromosome IX and not on the short arm of chromosome XI as was suggested previously. Analysis
of SSR, CAPS and SCAR markers confirmed that R8 was on the distal end of the long arm of chromosome IX. R gene cluster directed profiling markers CDPSw54 and CDPSw55 flanked the R8 gene at the distal end (1 cM). CDPTm21-1, CDPTm21-2 and CDPTm22 flanked the R8 gene on the proximal side (2 cM). An additional co-segregating marker (CDPHero3) was found, which will be useful for marker assisted breeding and map based cloning of R8. 相似文献
8.
Paolo Galli Giovanni Antonio Lodovico Broggini Markus Kellerhals Cesare Gessler Andrea Patocchi 《Molecular breeding : new strategies in plant improvement》2010,26(4):561-572
The Rvi15 (Vr2) apple scab resistance locus found in the GMAL 2473 accession has been previously mapped to the top of the Linkage Group
2 (LG2) by analyzing 89 progeny plants of a cross between ‘Idared’ and GMAL 2473. A new population of 989 progeny plants,
derived from a cross between ‘Golden Delicious’ and GMAL 2473, has been analyzed with the two SSR markers CH02c02a and CH02f06,
previously found to be associated with Rvi15 (Vr2), and with two published markers derived from NBS sequences (ARGH17 and ARGH37) estimated to map close to the Rvi15 (Vr2) locus. ARGH17 and ARGH37, were found to be the closest markers to the resistance locus, bracketing it within an interval
of 1.5 cM. The SSRs mapped one on each side of Rvi15 (Vr2). CH02f06 mapped at 2.9 cM from ARGH37 while CH02a02a mapped at 1.7 from ARGH17. The position of Rvi15 (Vr2) respect to CH02a02a indicates that Rvi15 (Vr2) and Rvi4 (Vh4), a second apple scab gene mapped on the top of LG2, are two different resistance genes. In order to develop even more tightly
linked markers to Rvi15 (Vr2), ARGH17 was used as the starting point for chromosome walking through the Rvi15 (Vr2) homolog region of the cv. ‘Florina’. A single ‘Florina’ BAC clone, 36I17, was sufficient to span the homologous locus in
the new population’s recombinant progeny. Sequencing of the 36I17 BAC clone allowed identifying seven putative ORFs, including
two showing a TIR-NBS-LRR structure. Ten additional markers could be developed mapping within a 1.8 cM interval around the
Rvi15 (Vr2) resistance gene. ARGH17 and GmTNL1 markers, the latter also derived from NBS-LRR resistance gene homolog sequence, are the
closest markers to Rvi15 (Vr2) bracketing it within a 0.5 cM interval. The availability of 12 markers within the Rvi15 (Vr2) region, all within a small physical distance (kbp) in ‘Florina’, suggests that cloning of the Rvi15 (Vr2) apple scab resistance gene from GMAL 2473 will be possible. 相似文献
9.
A bacterial artificial chromosome (BAC) library of banana (Musa acuminata) was used to select BAC clones that carry low amounts of repetitive DNA sequences and could be suitable as probes for fluorescence
in situ hybridization (FISH) on mitotic metaphase chromosomes. Out of eighty randomly selected BAC clones, only one clone gave a
single-locus signal on chromosomes of M. acuminata cv. Calcutta 4. The clone localized on a chromosome pair that carries a cluster of 5S rRNA genes. The remaining BAC clones
gave dispersed FISH signals throughout the genome and/or failed to produce any signal. In order to avoid the excessive hybridization
of repetitive DNA sequences, we subcloned nineteen BAC clones and selected their ‘low-copy’ subclones. Out of them, one subclone
gave specific signal in secondary constriction on one chromosome pair; three subclones were localized into centromeric and
peri-centromeric regions of all chromosomes. Other subclones were either localized throughout the banana genome or their use
did not result in visible FISH signals. The nucleotide sequence analysis revealed that subclones, which localized on different
regions of all chromosomes, contained short fragments of various repetitive DNA sequences. The chromosome-specific BAC clone
identified in this work increases the number of useful cytogenetic markers for Musa. 相似文献
10.
Tae-Ho?Park Vivianne G.A.A.?Vleeshouwers Ronald C.B.?Hutten Herman J.?van Eck Edwin?van der Vossen Evert?Jacobsen Richard G.F.?Visser
Introduction of more durable resistance against Phytophthora infestans causing late blight into the cultivated potato is of importance for sustainable agriculture. We identified a new monogenically inherited resistance locus that is localized on chromosome 4. The resistance is derived from an ABPT clone, which is originally a complex quadruple hybrid in which Solanum acaule, S. bulbocastanum, S. phureja and S. tuberosum were involved. Resistance data of the original resistant accessions of the wild species and analysis of mobility of AFLP markers linked to the resistance locus suggest that the resistance locus is originating from S. bulbocastanum. A population of 1383 genotypes was screened with two AFLP markers flanking the Rpi-abpt locus and 98 recombinants were identified. An accurate high-resolution map was constructed and the Rpi-abpt locus was localized in a 0.5 cM interval. One AFLP marker was found to co-segregate with the Rpi-abpt locus. Its DNA sequence was highly similar with sequences found on a tomato BAC containing several resistance gene analogues on chromosome 4 and its translated protein sequence appeared to be homologous to several disease resistance related proteins. The results indicated that the Rpi-abpt gene is a member of an R gene cluster. 相似文献
11.
12.
Yan HH Mudge J Kim DJ Larsen D Shoemaker RC Cook DR Young ND 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2003,106(7):1256-1265
A growing body of research indicates that microsynteny is common among dicot genomes. However, most studies focus on just one or a few genomic regions, so the extent of microsynteny across entire genomes remains poorly characterized. To estimate the level of microsynteny between Medicago truncatula (Mt) and Glycine max (soybean), and also among homoeologous segments of soybean, we used a hybridization strategy involving bacterial artificial chromosome (BAC) contigs. A Mt BAC library consisting of 30,720 clones was screened with a total of 187 soybean BAC subclones and restriction fragment length polymorphism (RFLP) probes. These probes came from 50 soybean contig groups, defined as one or more related BAC contigs anchored by the same low-copy probe. In addition, 92 whole soybean BAC clones were hybridized to filters of HindIII-digested Mt BAC DNA to identify additional cases of cross-hybridization after removal of those soybean BACs found to be repetitive in Mt. Microsynteny was inferred when at least two low-copy probes from a single soybean contig hybridized to the same Mt BAC or when a soybean BAC clone hybridized to three or more low-copy fragments from a single Mt BAC. Of the 50 soybean contig groups examined, 54% showed microsynteny to Mt. The degree of conservation among 37 groups of soybean contigs was also investigated. The results indicated substantial conservation among soybean contigs in the same group, with 86.5% of the groups showing at least some level of microsynteny. One contig group was examined in detail by a combination of physical mapping and comparative sequencing of homoeologous segments. A TBLASTX similarity search was performed between 1,085 soybean sequences on the 50 BAC contig groups and the entire Arabidopsis genome. Based on a criterion of sequence homologues <100 kb apart, each with an expected value of < or =1e-07, seven of the 50 soybean contig groups (14%) exhibited microsynteny with Arabidopsis. 相似文献
13.
Kang H Weng Y Yang Y Zhang Z Zhang S Mao Z Cheng G Gu X Huang S Xie B 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2011,122(4):795-803
Scab, caused by Cladosporium cucumerinum, is an important disease of cucumber, Cucumis sativus. In this study, we conducted fine genetic mapping of the single dominant scab resistance gene, Ccu, with 148 F9 recombinant inbred lines (RILs) and 1,944 F2 plants derived from the resistant cucumber inbred line 9110Gt and the susceptible line 9930, whose draft genome sequence
is now available. A framework linkage map was first constructed with simple sequence repeat markers placing Ccu into the terminal 670 kb region of cucumber Chromosome 2. The 9110Gt genome was sequenced at 5× genome coverage with the
Solexa next-generation sequencing technology. Sequence analysis of the assembled 9110Gt contigs and the Ccu region of the 9930 genome identified three insertion/deletion (Indel) markers, Indel01, Indel02, and Indel03 that were closely
linked with the Ccu locus. On the high-resolution map developed with the F2 population, the two closest flanking markers, Indel01 and Indel02, were 0.14 and 0.15 cM away from the target gene Ccu, respectively, and the physical distance between the two markers was approximately 140 kb. Detailed annotation of the 180 kb
region harboring the Ccu locus identified a cluster of six resistance gene analogs (RGAs) that belong to the nucleotide binding site (NBS) type R
genes. Four RGAs were in the region delimited by markers Indel01 and Indel02, and thus were possible candidates of Ccu. Comparative DNA analysis of this cucumber Ccu gene region with a melon (C. melo) bacterial artificial chromosome (BAC) clone revealed a high degree of micro-synteny and conservation of the RGA tandem repeats
in this region. 相似文献
14.
Xifeng Chen Jianwei Pan Jing Cheng Guanghuai Jiang Yang Jin Zhimin Gu Qian Qian Wenxue Zhai Bojun Ma 《Molecular breeding : new strategies in plant improvement》2009,24(4):387-395
Spotted leaf 5 (spl5), a lesion mimic mutant, was first identified in rice (Oryza sativa L.) japonica cv. Norin8 in 1978. This mutant exhibits spontaneous disease-like lesions in the absence of any pathogens and resistance
to rice blast and bacterial blight; however, the target gene has not yet been isolated. In the present study, we employed
a map-based cloning strategy to finely map the spl5 gene. In an initial mapping with 100 F2 individuals (spl5/spl5) derived from a cross between the spl5 mutant and indica cv. 93-11, the spl5 gene was located in a 3.3-cM region on chromosome 7 using six simple sequence repeat (SSR) markers. In a high-resolution
genetic mapping, two F2 populations with 3,149 individuals (spl5/spl5) were derived from two crosses between spl5 mutant and two indica cvs. 93-11 and Zhefu802 and six sequence-tagged site (STS) markers were newly developed. Finally, the spl5 gene was mapped to a region of 0.048 cM between two markers SSR7 and RM7121. One BAC/PAC contig map covering these markers’
loci and the spl5 gene was constructed through Pairwise BLAST analysis. Our bioinformatics analysis shows that the spl5 gene is located in the 80-kb region between two markers SSR7 and RM7121 with a high average ratio of physical to genetic
distance (1.67 Mb/cM) and eighteen candidate genes. The analysis of these candidate genes indicates that the spl5 gene represents a novel class of regulators controlling cell death and resistance response in plants. 相似文献
15.
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
16.
Two experiments were performed to determine how application of the cytokinin benzyladenine (BA) influenced flowering in Doritaenopsis and Phalaenopsis orchid clones. In the first experiment, two vegetative orchid clones growing in 15-cm pots were transferred from a 28°C greenhouse
that inhibited flowering to a 23°C greenhouse for flower induction (day 0). A foliar spray (0.2 L m−2) containing BA at 100, 200, or 400 mg L−1 or 25, 50, or 100 mg L−1 each of BA and gibberellins A4 + A7 (BA+GA) was applied on days 0, 7, and 14. Plants treated with BA alone at 200 or 400 mg L−1 had a visible inflorescence 3–9 days earlier and had a mean of 0.7–3.5 more inflorescences and 3–8 more flowers per plant
than nontreated plants. The application of BA+GA had no effect on inflorescence number and total flower number at the rates
tested. In the second experiment, three orchid clones received a single foliar spray of BA at 200 mg L−1 at six time points relative to time of transfer from 29°C to 23°C (−1, 0, +1, +2, +4, or +6 weeks). A separate group of plants
received a BA application at week 0 but was maintained at 29°C. Inflorescence number was greatest in all three orchid clones
when plants were treated with BA 1 week after the temperature transfer. Plants that were sprayed with BA and maintained at
29°C did not initiate inflorescences. The promotion of flowering by the application of BA suggests that cytokinins at least
partially regulate inflorescence initiation of Doritaenopsis and Phalaenopsis, but its promotion is conditional and BA application cannot completely substitute for an inductive low temperature. 相似文献
17.
To understand the molecular basis of broad-spectrum resistance to rice blast, fine-scale mapping of the two blast resistance (R) genes, Pi9( t) and Pi2( t), was conducted. These two genes were introgressed from different resistance donors, previously reported to confer resistance to many blast isolates in the Philippines, and were mapped to an approximately 10-cM interval on chromosome 6. To further test their resistance spectrum, 43 blast isolates collected from 13 countries were used to inoculate the Pi2( t) and Pi9( t) plants. Pi9( t)-bearing lines were highly resistant to all isolates tested, and lines carrying Pi2( t) were resistant to 36 isolates, confirming the broad-spectrum resistance of these two genes to diverse blast isolates. Three RAPD markers tightly linked to Pi9( t) were identified using the bulk segregant analysis technique. Twelve positive bacterial artificial chromosome (BAC) clones were identified and a BAC contig covering about 100 kb was constructed when the Pi9( t) BAC library was screened with one of the markers. A high-resolution map of Pi9( t) was constructed using BAC ends. The Pi2( t) gene was tightly linked to all of the Pi9( t) markers in 450 F(2) plants. These data suggest that Pi9( t) and Pi2( t) are either allelic or tightly linked in an approximately 100-kb region. The mapping results for Pi9( t) and Pi2( t) provide essential information for the positional cloning of these two important blast resistance genes in rice. 相似文献
18.
Laetitia Mahé Marie-Christine Combes Vitor M. P. Várzea Claire Guilhaumon Philippe Lashermes 《Molecular breeding : new strategies in plant improvement》2008,21(1):105-113
Coffee leaf rust due to Hemileia vastatrix is one of the most serious diseases in Arabica coffee (Coffea arabica). A resistance gene (SH3) has been transferred from C. liberica into C. arabica. The present work aimed at developing sequence-characterized genetic markers for leaf rust resistance. Linkage between markers
and leaf rust resistance was tested by analysing two segregating populations, one F2 population of 101 individuals and one backcross (BC2) population of 43 individuals, derived from a cross between a susceptible and a SH3-introgressed resistant genotype. A total
of ten sequence-characterized genetic markers closely associated with the SH3 leaf rust resistance gene were generated. These included simple sequence repeats (SSR) markers, sequence-characterised amplified
regions (SCAR) markers resulting from the conversion of amplified fragment length polymorphism (AFLP) markers previously identified
and SCAR markers derived from end-sequences of bacterial artificial chromosome (BAC) clones. Those BAC clones were identified
by screening of C. arabica genomic BAC library using a cloned AFLP-marker as probe. The markers we developed are easy and inexpensive to run, requiring
one PCR step followed by gel separation. While three markers were linked in repulsion with the SH3 gene, seven markers were clustered in coupling around the SH3 gene. Notably, two markers appeared to co-segregate perfectly with the SH3 gene in the two plant populations analyzed. These markers are suitable for marker-assisted selection for leaf rust resistance
and to facilitate pyramiding of the SH3 gene with other leaf rust resistance genes. 相似文献
19.
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
20.
Perugini LD Murphy JP Marshall D Brown-Guedira G 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2008,116(3):417-425
Powdery mildew is an important foliar disease in wheat, especially in areas with a cool or maritime climate. A dominant powdery
mildew resistance gene transferred to the hexaploid germplasm line NC99BGTAG11 from T. timopheevii subsp. armeniacum was mapped distally on the long arm of chromosome 7A. Differential reactions were observed between the resistance gene in
NC99BGTAG11 and the alleles of the Pm1 locus that is also located on chromosome arm 7AL. Observed segregation in F2:3 lines from the cross NC99BGTAG11 × Axminster (Pm1a) demonstrate that germplasm line NC99BGTAG11 carries a novel powdery mildew resistance gene, which is now designated as Pm37. This new gene is highly effective against all powdery mildew isolates tested so far. Analyses of the population with molecular
markers indicate that Pm37 is located 16 cM proximal to the Pm1 complex. Simple sequence repeat (SSR) markers Xgwm332 and Xwmc790 were located 0.5 cM proximal and distal, respectively, to Pm37. In order to identify new markers in the region, wheat expressed sequence tags (ESTs) located in the distal 10% of 7AL that
were orthologous to sequences from chromosome 6 of rice were targeted. The two new EST-derived STS markers were located distal
to Pm37 and one marker was closely linked to the Pm1a region. These new markers can be used in marker-assisted selection schemes to develop wheat cultivars with pyramids of powdery
mildew resistance genes, including combinations of Pm37 in coupling linkage with alleles of the Pm1 locus. 相似文献