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1.
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
2.
Rathu Heenati (RHT) is a Sri Lankan rice cultivar that carries a brown planthopper (BPH) resistance gene, Bph3, and shows broad-spectrum resistance to all four biotypes of BPH. The BPH-resistance loci in RHT has been studied extensively
and assigned to four different rice chromosomes (3, 4, 6, and 10) by different research groups, but the gene has not been
cloned previously. An Affymetrix rice genome array containing 48,564 japonica and 1,260 indica sequences was used to analyze the potential resistance-related genes on the four chromosomes by comparative analysis of the
differentially expressed genes between resistant and susceptible rice cultivars exposed to BPH attack. The microarray results
showed that at least 17 genes related to induced resistance and at least 193 genes related to constitutive resistance in RHT.
On chromosome 3, the AOC4 was hypothesized to be the most important candidate gene. On chromosome 6, no valuable candidate resistance gene was identified
in the Bph3 localization region. In the three Quantitative trait locus regions of chromosomes 3, 4, and 10, the numbers of constitutive
and induced resistance-related genes found were 17, 26, and 12, respectively. The major probe on chromosome 10 represents
a constitutive expression gene with a very high absolute fold-change of 2,588.82. The microarray analysis indicated that BPH
resistance in RHT is probably controlled by a series of resistance-related genes. This study provides valuable information
for cloning, functional analysis and marker-assisted breeding of these BPH resistance genes. 相似文献
3.
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
4.
Qiu Y Guo J Jing S Zhu L He G 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2012,124(3):485-494
The brown planthopper (Nilaparvata lugens Stål; BPH) has become a severe constraint on rice production. Identification and pyramiding BPH-resistance genes is an economical and effective solution to increase the resistance level of rice varieties. All the BPH-resistance genes identified to date have been from indica rice or wild species. The BPH12 gene in the indica rice accession B14 is derived from the wild species Oryza latifolia. Using an F2 population from a cross between the indica cultivar 93-11 and B14, we mapped the BPH12 gene to a 1.9-cM region on chromosome 4, flanked by the markers RM16459 and RM1305. In this population, BPH12 appeared to be partially dominant and explained 73.8% of the phenotypic variance in BPH resistance. A near-isogenic line (NIL) containing the BPH12 locus in the background of the susceptible japonica variety Nipponbare was developed and crossed with a NIL carrying BPH6 to generate a pyramid line (PYL) with both genes. BPH insects showed significant differences in non-preference in comparisons between the lines harboring resistance genes (NILs and PYL) and Nipponbare. BPH growth and development were inhibited and survival rates were lower on the NIL-BPH12 and NIL-BPH6 plants compared to the recurrent parent Nipponbare. PYL-BPH6 + BPH12 exhibited 46.4, 26.8 and 72.1% reductions in population growth rates (PGR) compared to NIL-BPH12, NIL-BPH6 and Nipponbare, respectively. Furthermore, insect survival rates were the lowest on the PYL-BPH6 + BPH12 plants. These results demonstrated that pyramiding different BPH-resistance genes resulted in stronger antixenotic and antibiotic effects on the BPH insects. This gene pyramiding strategy should be of great benefit for the breeding of BPH-resistant japonica rice varieties. 相似文献
5.
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
6.
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
7.
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
8.
Burt C Nicholson P 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2011,123(8):1387-1400
Introgressions into wheat from related species have been widely used as a source of agronomically beneficial traits. One such
example is the introduction of the potent eyespot resistance gene Pch1 from the wild relative Aegilops ventricosa onto chromosome 7DL of wheat. In common with genes carried on many other such introgressions, the use of Pch1 in commercial wheat varieties has been hindered by linkage drag with yield-limiting traits. Attempts to break this linkage
have been frustrated by a lack of co-dominant PCR markers suitable for identifying heterozygotes in F2 populations. We developed conserved orthologous sequence (COS) markers, utilising the Brachypodium distachyon (Brachypodium) genome sequence, to provide co-dominant markers in the Pch1 region. These were supplemented with previously developed sequence-tagged site (STS) markers and simple sequence repeat (SSR)
markers. Markers were applied to a panel of varieties and to a BC6 F2 population, segregating between wheat and Ae. ventricosa over the distal portion of 7DL, to identify recombinants in the region of Pch1. By exploiting co-linearity between wheat chromosome 7D, Brachypodium chromosome 1, rice chromosome 6 and sorghum chromosome
10, Pch1 was located to an interval between the flanking markers Xwg7S and Xcos7-9. Furthermore candidate gene regions were identified in Brachypodium (364 Kb), rice (178 Kb) and sorghum (315 Kb) as a prelude
to the map-based cloning of the gene. In addition, using homoeologue transferable markers, we obtained evidence that the eyespot
resistances Pch1 and Pch2 on chromosomes 7D and 7A, respectively, are potentially homoeoloci. It is anticipated that the COS marker methodology could
be used for the identification of recombinants in other introgressions into wheat from wild relatives. This would assist the
mapping of genes of interest and the breaking of deleterious linkages to enable greater use of these introgressions in commercial
varieties. 相似文献
9.
Runli He Zhijian Chang Zujun Yang Zongying Yuan Haixian Zhan Xiaojun Zhang Jianxia Liu 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,118(6):1173-1180
Powdery mildew resistance from Thinopyrum intermedium was introgressed into common wheat (Triticum aestivum L.). Genetic analysis of the F1, F2, F3 and BC1 populations from powdery mildew resistant line CH5025 revealed that resistance was controlled by a single dominant allele.
The gene responsible for powdery mildew resistance was mapped by the linkage analysis of a segregating F2 population. The resistance gene was linked to five co-dominant genomic SSR markers (Xcfd233, Xwmc41, Xbarc11, Xgwm539 and Xwmc175) and their most likely order was Xcfd233–Xwmc41–Pm43–Xbarc11–Xgwm539–Xwmc175 at 2.6, 2.3, 4.2, 3.5 and 7.0 cM, respectively. Using the Chinese Spring nullisomic-tetrasomic and ditelosomic lines, the
polymorphic markers and the resistance gene were assigned to chromosome 2DL. As no powdery mildew resistance gene was previously
assigned to chromosome 2DL, this new resistance gene was designated Pm43. Pm43, together with the identified closely linked markers, could be useful in marker-assisted selection for pyramiding powdery
mildew resistance genes.
Runli He and Zhijian Chang contributed equally to this work. 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.
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
12.
P. Kumar S. Pathania P. Katoch T. R. Sharma P. Plaha R. Rathour 《Molecular breeding : new strategies in plant improvement》2010,25(2):217-228
We have identified, genetically mapped and physically delimited the chromosomal location of a new blast resistance gene from a broad spectrum resistant genotype ‘DHR9’. The segregation analysis of an F2 progeny of a cross between a susceptible cv. ‘HPU741’ and the resistant genotype ‘DHR9’ suggested that the resistance was conditioned by a single dominant gene. A RAPD marker, OPA82000, linked to the resistance gene was identified by the linkage analysis of 109 F2 individuals. By chromosomal landing of the sequence of RAPD marker on the sequence of reference cv. Nipponbare, the gene was mapped onto rice chromosome 12. Further linkage analysis with two polymorphic simple sequence repeat (SSR) markers, RM2529 and RM1337 of chromosome 12, confirmed the chromosomal localization of the resistance gene. Based on linkage analysis of 521 susceptible F2 plants and comparative haplotype structure analysis of the parental genotypes with SSR and sequence tagged site (STS) markers developed from the Nipponbare PAC/BAC clones of chromosome 12, the resistance gene was delimited within a 2 cM interval defined by STS marker, STS5, on the telomeric side and SSR marker, RRS6 on the centromeric side. By aligning the sequences of linked markers on the sequence of cv. Nipponbare, a ~4.18 Mb cross-over cold region near the centromere of chromosome 12 was delineated as the region of blast resistance gene. In this region, six putatively expressed NBS-LRR genes were identified by surveying the equivalent genomic region of cv. Nipponbare in the TIGR Whole Genome Annotation Database (http://www.tigr.org). NBS-LRR locus, LOC_Os12g18374 situated in BAC clone OJ1115_G02 (Ac. No. AL772419) was short-listed as a potential candidate for the resistance gene identified from DHR9. The new gene was tentatively designated as Pi-42(t). The markers tightly linked to gene will facilitate marker-assisted gene pyramiding and cloning of the resistance gene. 相似文献
13.
Bulgarelli D Collins NC Tacconi G Dellaglio E Brueggeman R Kleinhofs A Stanca AM Valè G 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2004,108(7):1401-1408
The dominant gene Rdg2a of barley conferring resistance to the hemi-biotrophic seed-borne pathogen Pyrenophora graminea is located in the distal region of chromosome arm 1 (7H)S. As the first step towards isolating the gene, a high-resolution genetic map of the region was constructed using an F2 population of 1,400 plants (ThibautRdg2a×Mirco). The map included six classes of resistance gene analogues (RGAs) tightly associated with Rdg2a. Rdg2a was delimited to a genetic interval of 0.14 cM between the RGAs ssCH4 and MWG851. Additional markers were generated using the sequence from the corresponding region on rice chromosome 6, allowing delimitation of the Rdg2a syntenic interval in rice to a 115 kbp stretch of sequence. Analysis of the rice sequence failed to reveal any genes with similarity to characterized resistance genes. Therefore, either the rice-barley synteny is disrupted in this region, or Rdg2a encodes a novel type of resistance protein.Communicated by P. Langridge 相似文献
14.
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
15.
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
16.
Xiaorong Shen Herbert Ohm 《Molecular breeding : new strategies in plant improvement》2007,20(2):131-140
Resistance to Fusarium head blight (FHB) caused by Fusarium graminearum Schwabe in wheat (Triticum aestivum L.) was identified in disomic chromosome substitution and translocation lines, into which chromosome 7el2 had been introgressed from wheatgrass, Thinopyrum ponticum. In this study, two chromosome substitution lines with different origins (designated as el1 and el2) and with different reactions to infection by F. graminearum were crossed to develop a segregating mapping population. The objectives of this study were to determine the effectiveness
of this type II resistance and map it on chromosome 7el2. Type II resistance to FHB was characterized in the F2, F2:3 families, F4:5 plants and F5:6 recombinant inbred lines developed by single-seed descent; and the population was characterized in the F2 and F5 with DNA markers along the long arm of 7el. Composite interval mapping revealed a FHB resistance QTL, designated Qfhs.pur-7EL, located in the distal region of the long arm of 7el2 and delimited with flanking markers XBE445653 and Xcfa2240. Additive effects of Qfhs.pur-7EL reduced the number of diseased spikelets per spike following inoculation of one floret in four experiments by 1.5–2.6 and
explained 15.1–32.5% of the phenotypic variation in the populations. Several STS-derived and EST-derived PCR or CAPS markers
were developed in this chromosomal region, and showed the specificity of 7el2 compared to an array of wheat lines possessing other sources of FHB resistance. These markers are useful in an effort to
shorten the chromosome segment of 7el2 and to use for marker-assisted introgression of this resistance into wheat. 相似文献
17.
Zhang YX Wang Q Jiang L Liu LL Wang BX Shen YY Cheng XN Wan JM 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2011,122(8):1591-1604
Rice stripe disease, caused by rice stripe virus (RSV), is one of the most serious diseases in temperate rice-growing areas.
In the present study, we performed quantitative trait locus (QTL) analysis for RSV resistance using 98 backcross inbred lines
derived from the cross between the highly resistant variety, Kasalath, and the highly susceptible variety, Nipponbare. Under
artificial inoculation in the greenhouse, two QTLs for RSV resistance, designated qSTV7 and qSTV11
KAS
, were detected on chromosomes 7 and 11 respectively, whereas only one QTL was detected in the same location of chromosome
11 under natural inoculation in the field. The stability of qSTV11
KAS
was validated using 39 established chromosome segment substitution lines. Fine mapping of qSTV11
KAS
was carried out using 372 BC3F2:3 recombinants and 399 BC3F3:4 lines selected from 7,018 BC3F2 plants of the cross SL-234/Koshihikari. The qSTV11
KAS
was localized to a 39.2 kb region containing seven annotated genes. The most likely candidate gene, LOC_Os11g30910, is predicted
to encode a sulfotransferase domain-containing protein. The predicted protein encoded by the Kasalath allele differs from
Nipponbare by a single amino acid substitution and the deletion of two amino acids within the sulfotransferase domain. Marker-resistance
association analysis revealed that the markers L104-155 bp and R48-194 bp were highly correlated with RSV resistance in the
148 landrace varieties. These results provide a basis for the cloning of qSTV11
KAS
, and the markers may be used for molecular breeding of RSV resistant rice varieties. 相似文献
18.
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
19.
Xie W Ben-David R Zeng B Distelfeld A Röder MS Dinoor A Fahima T 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2012,124(5):911-922
Powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt) is one of the most important wheat diseases worldwide. Wild emmer wheat, Triticum turgidum ssp. dicoccoides, the tetraploid ancestor (AABB) of domesticated bread and durum wheat, harbors many important alleles for resistance to various
diseases, including powdery mildew. In the current study, two tetraploid wheat mapping populations, derived from a cross between
durum wheat (cv. Langdon) and wild emmer wheat (accession G-305-3M), were used to identify and map a novel powdery mildew
resistance gene. Wild emmer accession G-305-3M was resistant to all 47 Bgt isolates tested, from Israel and Switzerland. Segregation ratios of F2 progenies and F6 recombinant inbred line (RIL) mapping populations, in their reactions to inoculation with Bgt, revealed a Mendelian pattern (3:1 and 1:1, respectively), indicating the role of a single dominant gene derived from T. dicoccoides accession G-305-3M. This gene, temporarily designated PmG3M, was mapped on chromosome 6BL and physically assigned to chromosome deletion bin 6BL-0.70-1.00. The F2 mapping population was used to construct a genetic map of the PmG3M gene region consisted of six simple sequence repeats (SSR), 11 resistance gene analog (RGA), and two target region amplification
polymorphism (TRAP) markers. A second map, constructed based on the F6 RIL population, using a set of skeleton SSR markers, confirmed the order of loci and distances obtained for the F2 population. The discovery and mapping of this novel powdery mildew resistance gene emphasize the importance of the wild emmer
wheat gene pool as a source for crop improvement. 相似文献
20.
Judd J. Maxwell Jeanette H. Lyerly Christina Cowger David Marshall Gina Brown-Guedira J. Paul Murphy 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,119(8):1489-1495
Wheat powdery mildew is an economically important disease in cool and humid environments. Powdery mildew causes yield losses
as high as 48% through a reduction in tiller survival, kernels per head, and kernel size. Race-specific host resistance is
the most consistent, environmentally friendly and, economical method of control. The wheat (Triticum aestivum L.) germplasm line NC06BGTAG12 possesses genetic resistance to powdery mildew introgressed from the AAGG tetraploid genome
Triticum timopheevii subsp. armeniacum. Phenotypic evaluation of F3 families derived from the cross NC06BGTAG12/‘Jagger’ and phenotypic evaluation of an F2 population from the cross NC06BGTAG12/‘Saluda’ indicated that resistance to the ‘Yuma’ isolate of powdery mildew was controlled
by a single dominant gene in NC06BGTAG12. Bulk segregant analysis (BSA) revealed simple sequence repeat (SSR) markers specific
for chromosome 7AL segregating with the resistance gene. The SSR markers Xwmc273 and Xwmc346 mapped 8.3 cM distal and 6.6 cM proximal, respectively, in NC06BGTAG12/Jagger. The multiallelic Pm1 locus maps to this region of chromosome 7AL. No susceptible phenotypes were observed in an evaluation of 967 F2 individuals in the cross NC06BGTAG12/‘Axminster’ (Pm1a) which indicated that the NC06BGTAG12 resistance gene was allelic or in close linkage with the Pm1 locus. A detached leaf test with ten differential powdery mildew isolates indicated the resistance in NC06BGTAG12 was different
from all designated alleles at the Pm1 locus. Further linkage and allelism tests with five other temporarily designated genes in this very complex region will be
required before giving a permanent designation to this gene. At this time the gene is given the temporary gene designation
MlAG12. 相似文献