共查询到20条相似文献,搜索用时 31 毫秒
1.
Irigoyen ML Loarce Y Fominaya A Ferrer E 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2004,109(4):713-724
Degenerate primers based on conserved regions of the nucleotide binding site (NBS) domain (encoded by the largest group of cloned plant disease resistance genes) were used to isolate a set of 15 resistance gene analogs (RGA) from the diploid species Avena strigosa Schreb. These were grouped into seven classes on the basis of 60% or greater nucleic acid sequence identity. Representative clones were used for genetic mapping in diploid and hexaploid oats. Two RGAs were mapped at two loci of the linkage group AswBF belonging to the A. strigosa × A. wiestii Steud map, and ten RGAs were mapped at 15 loci in eight linkage groups belonging to the A. byzantina C. Koch cv. Kanota × A. sativa L. cv. Ogle map. A similar approach was used for targeting genes encoding receptor-like kinases. Three different sequences were obtained and mapped to two linkage groups of the hexaploid oat map. Associations were explored between already known disease resistance loci mapped in different populations and the RGAs. Molecular markers previously linked to crown rust and barley yellow dwarf resistance genes or quantitative trait loci were found in the Kanota × Ogle map linked to RGAs at a distance ranging from 0 cM to 20 cM. Homoeologous RGAs were found to be linked to loci either conferring resistance to different isolates of the same pathogen or to different pathogens. This suggests that these RGAs identify genome regions containing resistance gene clusters. 相似文献
2.
C L McIntyre R E Casu J Drenth D Knight V A Whan B J Croft D R Jordan J M Manners 《Génome》2005,48(3):391-400
Fifty-four different sugarcane resistance gene analogue (RGA) sequences were isolated, characterized, and used to identify molecular markers linked to major disease-resistance loci in sugarcane. Ten RGAs were identified from a sugarcane stem expressed sequence tag (EST) library; the remaining 44 were isolated from sugarcane stem, leaf, and root tissue using primers designed to conserved RGA motifs. The map location of 31 of the RGAs was determined in sugarcane and compared with the location of quantitative trait loci (QTL) for brown rust resistance. After 2 years of phenotyping, 3 RGAs were shown to generate markers that were significantly associated with resistance to this disease. To assist in the understanding of the complex genetic structure of sugarcane, 17 of the 31 RGAs were also mapped in sorghum. Comparative mapping between sugarcane and sorghum revealed syntenic localization of several RGA clusters. The 3 brown rust associated RGAs were shown to map to the same linkage group (LG) in sorghum with 2 mapping to one region and the third to a region previously shown to contain a major rust-resistance QTL in sorghum. These results illustrate the value of using RGAs for the identification of markers linked to disease resistance loci and the value of simultaneous mapping in sugarcane and sorghum. 相似文献
3.
Candidate defense genes from rice,barley, and maize and their association with qualitative and quantitative resistance in rice 总被引:23,自引:0,他引:23
Ramalingam J Vera Cruz CM Kukreja K Chittoor JM Wu JL Lee SW Baraoidan M George ML Cohen MB Hulbert SH Leach JE Leung H 《Molecular plant-microbe interactions : MPMI》2003,16(1):14-24
4.
5.
Identification of genetically linked RGAs by BAC screening in maize and implications for gene cloning,mapping and MAS 总被引:3,自引:0,他引:3
Quint M Dussle CM Melchinger AE Lübberstedt T 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2003,106(7):1171-1177
The resistance gene analogue (RGA) pic19 in maize, a candidate for sugarcane mosaic virus (SCMV) resistance gene (R gene) Scmv1, was used to screen a maize BAC library to identify homologous sequences in the maize genome and to investigate their genomic organisation. Fifteen positive BAC clones were identified and could be classified into five physically independent contigs consisting of overlapping clones. Genetic mapping clustered three contigs into the same genomic region as Scmv1 on chromosome 6S. The two remaining contigs mapped to the same region as a QTL for SCMV resistance on chromosome 1. Thus, RGAs mapping to a target region can be successfully used to identify further-linked candidate sequences. The pic19 homologous sequences of these clones revealed a sequence similarity of 94-98% on the nucleotide level. The high sequence similarity reveals potential problems for the use of RGAs as molecular markers. Their application in marker-assisted selection (MAS) and the construction of high-density genetic maps is complicated by the existence of closely linked homologues resulting in 'ghost' marker loci analogous to 'ghost' QTLs. Therefore, implementation of genomic library screening, including genetic mapping of potential homologues, seems necessary for the safe application of RGA markers in MAS and gene isolation. 相似文献
6.
Carmen Palomino M. D. Fernández-Romero J. Rubio A. Torres M. T. Moreno T. Millán 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,118(4):671-682
A composite linkage map was constructed based on two interspecific recombinant inbred line populations derived from crosses
between Cicer arietinum (ILC72 and ICCL81001) and Cicer reticulatum (Cr5-10 or Cr5-9). These mapping populations segregate for resistance to ascochyta blight (caused by Ascochyta rabiei), fusarium wilt (caused by Fusarium oxysporum f. sp. ciceris) and rust (caused by Uromyces ciceris-arietini). The presence of single nucleotide polymorphisms in ten resistance gene analogs (RGAs) previously isolated and characterized
was exploited. Six out of the ten RGAs were novel sequences. In addition, classes RGA05, RGA06, RGA07, RGA08, RGA09 and RGA10
were considerate putatively functional since they matched with several legume expressed sequences tags (ESTs) obtained under
infection conditions. Seven RGA PCR-based markers (5 CAPS and 2 dCAPS) were developed and successfully genotyped in the two
progenies. Six of them have been mapped in different linkage groups where major quantitative trait loci conferring resistance
to ascochyta blight and fusarium wilt have been reported. Genomic locations of RGAs were compared with those of known Cicer R-genes and previously mapped RGAs. Association was detected between RGA05 and genes controlling resistance to fusarium wilt
caused by races 0 and 5. 相似文献
7.
Di Gaspero G Cipriani G Adam-Blondon AF Testolin R 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,114(7):1249-1263
Genetic maps functionally oriented towards disease resistance have been constructed in grapevine by analysing with a simultaneous
maximum-likelihood estimation of linkage 502 markers including microsatellites and resistance gene analogs (RGAs). Mapping
material consisted of two pseudo-testcrosses, ‘Chardonnay’ × ‘Bianca’ and ‘Cabernet Sauvignon’ × ‘20/3’ where the seed parents
were Vitis vinifera genotypes and the male parents were Vitis hybrids carrying resistance to mildew diseases. Individual maps included 320–364 markers each. The simultaneous use of two
mapping crosses made with two pairs of distantly related parents allowed mapping as much as 91% of the markers tested. The
integrated map included 420 Simple Sequence Repeat (SSR) markers that identified 536 SSR loci and 82 RGA markers that identified
173 RGA loci. This map consisted of 19 linkage groups (LGs) corresponding to the grape haploid chromosome number, had a total
length of 1,676 cM and a mean distance between adjacent loci of 3.6 cM. Single-locus SSR markers were randomly distributed
over the map (CD = 1.12). RGA markers were found in 18 of the 19 LGs but most of them (83%) were clustered on seven LGs, namely
groups 3, 7, 9, 12, 13, 18 and 19. Several RGA clusters mapped to chromosomal regions where phenotypic traits of resistance
to fungal diseases such as downy mildew and powdery mildew, bacterial diseases such as Pierce’s disease, and pests such as
dagger and root-knot nematode, were previously mapped in different segregating populations. The high number of RGA markers
integrated into this new map will help find markers linked to genetic determinants of different pest and disease resistances
in grape.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
8.
Genetic mapping and transcription analyses of resistance gene loci in potato using NBS profiling 总被引:1,自引:0,他引:1
Brugmans B Wouters D van Os H Hutten R van der Linden G Visser RG van Eck HJ van der Vossen EA 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2008,117(8):1379-1388
9.
Junrey C. Amas Philipp E. Bayer Wei Hong Tan Soodeh Tirnaz William J. W. Thomas David Edwards Jacqueline Batley 《Plant biotechnology journal》2023,21(10):2100-2112
Brassica rapa is grown worldwide as economically important vegetable and oilseed crop. However, its production is challenged by yield-limiting pathogens. The sustainable control of these pathogens mainly relies on the deployment of genetic resistance primarily driven by resistance gene analogues (RGAs). While several studies have identified RGAs in B. rapa, these were mainly based on a single genome reference and do not represent the full range of RGA diversity in B. rapa. In this study, we utilized the B. rapa pangenome, constructed from 71 lines encompassing 12 morphotypes, to describe a comprehensive repertoire of RGAs in B. rapa. We show that 309 RGAs were affected by presence-absence variation (PAV) and 223 RGAs were missing from the reference genome. The transmembrane leucine-rich repeat (TM-LRR) RGA class had more core gene types than variable genes, while the opposite was observed for nucleotide-binding site leucine-rich repeats (NLRs). Comparative analysis with the B. napus pangenome revealed significant RGA conservation (93%) between the two species. We identified 138 candidate RGAs located within known B. rapa disease resistance QTL, of which the majority were under negative selection. Using blackleg gene homologues, we demonstrated how these genes in B. napus were derived from B. rapa. This further clarifies the genetic relationship of these loci, which may be useful in narrowing-down candidate blackleg resistance genes. This study provides a novel genomic resource towards the identification of candidate genes for breeding disease resistance in B. rapa and its relatives. 相似文献
10.
Characterization and linkage mapping of R-gene analogous DNA sequences in pea (Pisum sativum L.) 总被引:2,自引:0,他引:2
G. M. Timmerman-Vaughan T. J. Frew N. F. Weeden 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,101(1-2):241-247
Pea (Pisum sativum L.) sequences that are analogous to the conserved nucleotide binding site (NBS) domain found in a number of plant disease
resistance genes (R-genes) were cloned. Using redundant oligonucleotide primers and the polymerase chain reaction (PCR), we
amplified nine pea sequences and characterised their sequences. The pea R-gene analog (RGA)- deduced amino acid sequences
demonstrated significant sequence similarity with known R-gene sequences lodged in public databases. The genomic locations
of eight of the pea RGAs were determined by linkage mapping. The eight RGAs identified ten loci that mapped to six linkage
groups. In addition, the genomic organization of the RGAs was inferred. Both single-copy and multicopy sequence families were
present among the RGAs, and the multicopy families occurred most often as tightly linked clusters of related sequences. Intraspecific
copy number variability was observed in three of the RGA sequence families, suggesting that these sequence families are evolving
rapidly. The genomic locations of the pea RGAs were compared with the locations of known pea R-genes and sym genes involved in the pea-rhizobia symbiosis. Two pea RGAs mapped in the genomic region containing a pea R-gene, Fw, and four pea RGAs mapped in regions of the genome containing sym genes.
Received: 4 August 1999 / Accepted: 11 November 1999 相似文献
11.
Characterisation and genetic mapping of resistance and defence gene analogs in cocoa (Theobroma cacao L.) 总被引:1,自引:0,他引:1
Lanaud Claire Risterucci Ange Marie Pieretti Isabelle N'Goran Jeanne A.K. Fargeas Dominique 《Molecular breeding : new strategies in plant improvement》2004,13(3):211-227
Disease resistance and defence gene analog (RGA/DGA) sequences were isolated in cocoa using a PCR approach with degenerate primers designed from conserved domains of plant resistance and defence genes: the NBS (nucleotide binding site) motif present in a number of resistance genes such as the tobacco N, sub-domains of plant serine/threonine kinases such as the Pto tomato gene, and conserved domains of two defence gene families: pathogenesis-related proteins (PR) of classes 2 and 5. Nucleotide identity between thirty six sequences isolated from cocoa and known resistance or defence genes varied from 58 to 80%. Amino acid sequences translated from corresponding coding sequences produced sequences without stop codons, except for one NBS –like sequence. Most of the RGAs could be mapped on the cocoa genome and three clusters of genes could be observed : NBS-like sequences clustered in two regions located on chromosomes 7 and 10, Pto-like sequences mapped in five genome regions of which one, located on chromosome 4, corresponded to a cluster of five different sequences. PR2-like sequences mapped in two regions located on chromosome 5 and 9 respectively. An enrichment of the genetic map with microsatellite markers allowed us to identify several co-localisations of RGAs, DGAs and QTL for resistance to Phytophthora detected in several progenies, particularly on chromosome 4 where a cluster of Pto-like sequences and 4 QTL for resistance to Phytophthora were observed. Many other serious diseases affect cocoa and the candidate genes, isolated in this study, could be of broader interest in cocoa disease management. 相似文献
12.
Regions of amino acid conservation in the NBS domain of NBS-LRR resistance proteins facilitated the PCR isolation of eight resistance gene analog (RGA) sequences from genomic DNA of rice, barley, and Aegilops tauschii. These clones and other RGAs previously isolated from maize, rice, and wheat were assigned to 13 classes by DNA-sequence comparison and by their patterns of hybridisation to restricted barley DNA. Using a doubled-haploid mapping population, probes from 12 RGA classes were used to map 17 loci in the barley genome. Many of these probes have been used for mapping in wheat, and the collective data indicate that the positions of orthologous RGAs are conserved between barley and wheat. RGA loci were identified in the vicinity of barley leaf rust resistance loci Rph4, Rph7, and Rph10. Recombinants were identified between RGA loci and Rph7 and Rph10, while a cluster of RGA sequences detected by probe 5.2 cosegregated with Rph4 in 55 F2 lines. 相似文献
13.
Suren K. Samuelian Angela M. Baldo Jeremy A. Pattison Courtney A. Weber 《Tree Genetics & Genomes》2008,4(4):881-896
Plant R genes confer resistance to pathogens in a gene-for-gene mode. Seventy-five putative resistance gene analogs (RGAs) containing
conserved domains were cloned from Rubus idaeus L. cv. ‘Latham’ using degenerate primers based on RGAs identified in Rosaceae species. The sequences were compared to 195
RGA sequences identified from five Rosaceae family genera. Multiple sequence alignments showed high similarity at multiple
nucleotide-binding site (NBS) motifs with homology to Drosophila Toll and mammalian interleukin-1 receptor (TIR) and non-TIR
RNBSA-A motifs. The TIR sequences clustered separately from the non-TIR sequences with a bootstrap value of 76%. There were
11 clusters each of TIR and non-TIR type sequences of multiple genera with bootstrap values of more than 50%, including nine
with values of more than 75% and seven of more than 90%. Polymorphic sequence characterized amplified region and cleaved amplified
polymorphic sequence markers were developed for nine Rubus RGA sequences with eight placed on a red raspberry genetic linkage map. Phylogenetic analysis indicated four of the mapped
sequences share sequence similarity to groupTIR I, while three others were spread in non-TIR groups. Of the 75 Rubus RGA sequences analyzed, members were placed in five TIR groups and six non-TIR groups. These group classifications closely
matched those in 12 of 13 studies from which these sequences were derived. The analysis of related DNA sequences within plant
families elucidates the evolutionary relationship and process involved in pest resistance development in plants. This information
will aid in the understanding of R genes and their proliferation within plant genomes.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
14.
Huettel B Santra D Muehlbauer J Kahl G 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2002,105(2-3):479-490
Resistance gene analogues (RGAs) of Cicer were isolated by different PCR approaches and mapped in an inter-specific cross segregating for fusarium wilt by RFLP and CAPS analysis. Initially, two pairs of degenerate primers targeting sequences encoded at nucleotide-binding sites (NBS), which are conserved in plant disease resistance genes such as RPS2, L6 and N, were selected for amplification. Cloning and sequence analysis of amplified products from C. arietinum DNA revealed eight different RGAs. Additionally, five RGAs were identified after characterisation of the presumptive RGA alleles from C. reticulatum. Therefore, a total of 13 different RGAs were isolated from Cicer and classified through pair-wise comparison into nine distinct classes with sequence similarities below a 68% amino acid identity threshold. Sequence comparison of seven RGA alleles of C. arietinum and C. reticulatum revealed polymorphisms in four RGAs with identical numbers of synonymous and non-synonymous substitutions. An NlaIII site, unique in the RGA-A allele of C. arietinum, was exploited for CAPS analysis. Genomic organisation and map position of the NBS-LRR candidate resistance genes was probed by RFLP analysis. Both single-copy as well as multi-copy sequence families were present for the selected RGAs, which represented eight different classes. Five RGAs were mapped in an inter-specific population segregating for three race-specific Fusarium resistances. All RGAs mapped to four of the previously established eight linkage groups for chickpea. Two NBS-LRR clusters were identified that could not be resolved in our mapping population. One of these clusters, which is characterised by RFLP probe CaRGA-D, mapped to the linkage group harbouring two of three Fusarium resistance genes characterised in the inter-specific population. Our study provides a starting point for the characterisation and genetic mapping of candidate resistance genes in Cicer that is useful for marker-assisted selection and as a pool for resistance genes of Cicer. 相似文献
15.
Lewers K.S. Crane E.H. Bronson C.R. Schupp J.M. Keim P. Shoemaker R.C. 《Molecular breeding : new strategies in plant improvement》1999,5(1):33-42
The objective of this study was to map the gene(s) conferring resistance to brown stem rot in the soybean cultivar BSR 101. A population of 320 recombinant inbred lines (RIL) was derived from a cross of BSR 101 and PI 437.654. Seedlings of each RIL and parent were inoculated by injecting stems with a suspension of spores and mycelia of Phialophora gregata, incubated in a growth chamber at 17°C, and assessed for resistance by monitoring the development of foliar and stem symptoms. The population also was evaluated with 146 RFLPs, 760 AFLPs, and 4 probes for resistance gene analogs (RGAs). Regression analysis identified a significant association between resistance and several markers on Linkage Group J of the USDA-ARS molecular marker linkage map. Interval analysis with Mapmaker QTL identified a major peak between marker RGA2V-1 and AFLP marker AAGATG152M on Linkage Group J. A second peak, associated only with stem symptoms, was identified between the RFLP B122I-1 and RGA2V-1, also on Linkage Group J. When composite interval mapping with QTL Cartographer was used, two linked QTL were identified with both foliar and stem disease assessment methods: a major QTL between AFLP markers AAGATG152E and ACAAGT260, and a minor QTL between RGA3I-3 and RGA3I-2. These results demonstrate that composite interval mapping gives increased precision over interval mapping and is capable of distinguishing two linked QTL. The minor QTL associated with the cluster of RGA3I loci is of special interest because it is the first example of a disease resistance QTL associated with a resistance gene analog. 相似文献
16.
Tanhuanpää P 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2004,108(6):1039-1046
The objective of this investigation was to tag a locus for white rust resistance in a Brassica rapa ssp. oleifera F2 population segregating for this trait, using bulked segregant analysis with random amplified polymorphic DNA (RAPD) markers, linkage mapping and a candidate gene approach based on resistance gene analogs (RGAs). The resistance source was the Finnish line Bor4109. The reaction against white rust races 7a and 7v was scored in 20 seedlings from each self-pollinated F2 individual. The proportion of resistant plants among these F3 families varied from 0 to 67%. Bulked segregant analysis did not reveal any markers linked with resistance and, therefore, a linkage map with 81 markers was created. A locus that accounted for 18.4% of the variation in resistance to white rust was mapped to linkage group (LG) 2 near the RAPD marker Z19a. During the study, a bacterial resistance gene homologous to Arabidopsis RPS2 and six different RGAs were sequenced. RPS2 and five of the RGAs were mapped to linkage groups LG1, LG4 and LG9. Unfortunately, none of the RGAs could be shown to be associated with white rust resistance.Communicated by H.C. BeckerThe nucleotide sequence data reported has been deposited in the Genbank under the accession numbers AF315081–AF315087. 相似文献
17.
Harsh Raman Jessica Dalton‐Morgan Simon Diffey Rosy Raman Salman Alamery David Edwards Jacqueline Batley 《Plant biotechnology journal》2014,12(7):851-860
An Illumina Infinium array comprising 5306 single nucleotide polymorphism (SNP) markers was used to genotype 175 individuals of a doubled haploid population derived from a cross between Skipton and Ag‐Spectrum, two Australian cultivars of rapeseed (Brassica napus L.). A genetic linkage map based on 613 SNP and 228 non‐SNP (DArT, SSR, SRAP and candidate gene markers) covering 2514.8 cM was constructed and further utilized to identify loci associated with flowering time and resistance to blackleg, a disease caused by the fungus Leptosphaeria maculans. Comparison between genetic map positions of SNP markers and the sequenced Brassica rapa (A) and Brassica oleracea (C) genome scaffolds showed several genomic rearrangements in the B. napus genome. A major locus controlling resistance to L. maculans was identified at both seedling and adult plant stages on chromosome A07. QTL analyses revealed that up to 40.2% of genetic variation for flowering time was accounted for by loci having quantitative effects. Comparative mapping showed Arabidopsis and Brassica flowering genes such as Phytochrome A/D, Flowering Locus C and agamous‐Like MADS box gene AGL1 map within marker intervals associated with flowering time in a DH population from Skipton/Ag‐Spectrum. Genomic regions associated with flowering time and resistance to L. maculans had several SNP markers mapped within 10 cM. Our results suggest that SNP markers will be suitable for various applications such as trait introgression, comparative mapping and high‐resolution mapping of loci in B. napus. 相似文献
18.
Geffroy V Sévignac M De Oliveira JC Fouilloux G Skroch P Thoquet P Gepts P Langin T Dron M 《Molecular plant-microbe interactions : MPMI》2000,13(3):287-296
Anthracnose, one of the most important diseases of common bean (Phaseolus vulgaris), is caused by the fungus Colletotrichum lindemuthianum. A "candidate gene" approach was used to map anthracnose resistance quantitative trait loci (QTL). Candidate genes included genes for both pathogen recognition (resistance genes and resistance gene analogs [RGAs]) and general plant defense (defense response genes). Two strains of C. lindemuthianum, identified in a world collection of 177 strains, displayed a reproducible and differential aggressiveness toward BAT93 and JaloEEP558, two parental lines of P. vulgaris representing the two major gene pools of this crop. A reliable test was developed to score partial resistance in aerial organs of the plant (stem, leaf, petiole) under controlled growth chamber conditions. BAT93 was more resistant than JaloEEP558 regardless of the organ or strain tested. With a recombinant inbred line (RIL) population derived from a cross between these two parental lines, 10 QTL were located on a genetic map harboring 143 markers, including known defense response genes, anthracnose-specific resistance genes, and RGAs. Eight of the QTL displayed isolate specificity. Two were co-localized with known defense genes (phenylalanine ammonia-lyase and hydroxyproline-rich glycoprotein) and three with anthracnose-specific resistance genes and/or RGAs. Interestingly, two QTL, with different allelic contribution, mapped on linkage group B4 in a 5.0 cM interval containing Andean and Mesoamerican specific resistance genes against C. lindemuthianum and 11 polymorphic fragments revealed with a RGA probe. The possible relationship between genes underlying specific and partial resistance is discussed. 相似文献
19.
Targeted isolation,sequence analysis,and physical mapping of nonTIR NBS-LRR genes in soybean 总被引:2,自引:0,他引:2
Peñuela S Danesh D Young ND 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2002,104(2-3):261-272
Most cloned plant disease resistance genes (R-genes) code for proteins belonging to the nucleotide binding site (NBS) leucine-rich
repeat (LRR) superfamily. NBS-LRRs can be divided into two classes based on the presence of a TIR domain (Toll and interleukin receptor-like sequence) or a coiled coil motif (nonTIR) in their N-terminus. We used conserved motifs specific
to nonTIR-NBS-LRR sequences in a targeted PCR approach to generate nearly 50 genomic soybean sequences with strong homology
to known resistance gene analogs (RGAs) of the nonTIR class. Phylogenetic analysis classified these sequences into four main
subclasses. A representative clone from each subclass was used for genetic mapping, bacterial artificial chromosome (BAC)
library screening, and construction of RGA-containing BAC contigs. Of the 14 RGAs that could be mapped genetically, 12 localized
to a 25-cM region of soybean linkage group F already known to contain several classical disease resistance loci. A majority
of the genomic region encompassing the RGAs was physically isolated in eight BAC contigs, together spanning more than 1 Mb
of genomic sequence with at least 12 RGA copies. Phylogenetic and sequence analysis, together with genetic and physical mapping,
provided insights into the genome organization and evolution of this large cluster of soybean RGAs.
Received: 8 May 2001 / Accepted: 30 June 2001 相似文献
20.
Jun TH Rouf Mian MA Michel AP 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2012,124(1):13-22
The soybean aphid (Aphis glycines Matsumura) is the most damaging insect pest of soybean [Glycine max (L.) Merr.] in North America. New soybean aphid biotypes have been evolving quickly and at least three confirmed biotypes
have been reported in USA. These biotypes are capable of defeating most known aphid resistant soybean genes indicating the
need for identification of new genes. Plant Introduction (PI) 567301B was earlier identified to have antixenosis resistance
against biotype 1 and 2 of the soybean aphid. Two hundred and three F7:9 recombinant inbred lines (RILs) developed from a cross of soybean aphid susceptible cultivar Wyandot and resistant PI 567301B
were used for mapping aphid resistance genes using the quantitative trait loci (QTL) mapping approach. A subset of 94 RILs
and 516 polymorphic SNP makers were used to construct a genome-wide molecular linkage map. Two candidate QTL regions for aphid
resistance were identified on this linkage map. Fine mapping of the QTL regions was conducted with SSR markers using all 203
RILs. A major gene on chromosome 13 was mapped near the previously identified Rag2 gene. However, an earlier study revealed that the detached leaves of PI 567301B had no resistance against the soybean aphids
while the detached leaves of PI 243540 (source of Rag2) maintained aphid resistance. These results and the earlier finding that PI 243540 showed antibiosis resistance and PI 567301B
showed antixenosis type resistance, indicating that the aphid resistances in the two PIs are not controlled by the same gene.
Thus, we have mapped a new gene near the Rag2 locus for soybean aphid resistance that should be useful in breeding for new aphid-resistant soybean cultivars. Molecular
markers closely linked to this gene are available for marker-assisted breeding. Also, the minor locus found on chromosome
8 represents the first reported soybean aphid-resistant locus on this chromosome. 相似文献