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1.
L. Augusto Becerra Lopez-Lavalle Vanessa J. Gillespie Walter A. Tate Marc H. Ellis Warwick N. Stiller Danny L. Llewellyn Iain W. Wilson 《Molecular breeding : new strategies in plant improvement》2012,30(2):1181-1191
Fusarium wilt (FW) disease is an economically important disease of cotton worldwide and a major cause of crop losses in Australia and many other cotton-producing countries. Symptoms include wilting, vascular browning and death. Australian races of the causal agent Fusarium oxysporum f. sp. vasinfectum (Fov) are genetically distinct from those in other countries and are thought to have evolved from indigenous races. New sources of resistance for breeding are rare, as cotton cultivars with significant FW resistance against Fov isolates from other cotton-producing regions are usually susceptible to Australian Fov races. MCU-5, an Upland Indian cotton cultivar, has been identified as having improved resistance to Australian Fov and is being used to breed new commercial cultivars with higher resistance to FW. To investigate the genetic basis of the FW resistance in MCU-5, QTL analysis was performed on 244 F3 and 244 F4 families derived from an intraspecific cross between MCU-5 and Siokra 1-4, a cultivar highly sensitive to Australian Fov races. Resistance, as measured by leaf symptoms, vascular browning and survival, showed low to moderate heritability between generations. MCU-5 resistance to FW was found to be complex with three quantitative trait loci (QTL) identified in the F3, and eight in the F4, that explained between 9 and 41% of the phenotypic variation. The QTL were located on four linkage groups including chromosomes A6 (Chr 6), D4 (Chr 22) and D6 (Chr 25), with two QTL located in similar regions to previously identified FW resistance from the Sea Island cultivar Pima 3-79. The QTL identified in this study represent the first targets for marker-assisted selection of FW resistance in Australia. 相似文献
2.
Wang C Ulloa M Roberts PA 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,112(4):770-777
Host-plant resistance is the most economic and effective strategy for root-knot nematode (RKN) Meloidogyne incognita control in cotton (Gossypium hirsutum L.). Molecular markers linked to resistance are important for incorporating resistance genes into elite cultivars. To screen
for microsatellite markers (SSR) closely linked to RKN resistance in G. hirsutum cv. Acala NemX, F1, F2, BC1F1, and F2:7 recombinant inbred lines (RILs) from intraspecific crosses and an F2 from an interspecific cross with G. barbadense cv. Pima S-7 were used. Screening of 284 SSR markers, which cover all the known identified chromosomes and most linkage groups
of cotton, was performed by bulked segregant analysis, revealing informative SSRs. The informative SSRs were then mapped on
the above populations. One co-dominant SSR marker CIR316 was identified tightly linked to a major resistance gene (designated
as rkn1), producing amplified DNA fragments of approximately 221 bp (CIR316a) and 210 bp (CIR316c) in Acala NemX and susceptible
Acala SJ-2, respectively. The linkage between CIR316a marker and resistance gene rkn1 in Acala NemX had an estimated distance of 2.1–3.3 cM depending on the population used. Additional markers, including BNL1231
with loose linkage to rkn1 (map distance 25.1–27.4 cM), BNL1066, and CIR003 allowed the rkn1 gene to be mapped to cotton linkage group A03. This is the first report in cotton with a closely linked major gene locus
determining nematode resistance, and informative SSRs may be used for marker-assisted selection. 相似文献
3.
Although the phenomenon of innate resistance to flaviviruses in mice was recognized many years ago, it was only recently that the genetic locus (Flv) controlling this resistance was mapped to mouse Chromosome (Chr) 5. Here we report the fine mapping of the Flv locus, using 12 microsatellite markers which have recently been developed for mouse Chr 5. The new markers were genotyped in 325 backcross mice of both (C3H/HeJxC3H/ RV)F1xC3H/HeJ and (BALB/cxC3H/RV)F1xBALB/c backgrounds, relative to Flv. The composite genetic map that has been constructed identifies three novel microsatellite loci, D5Mit68, D5Mit159, and D5Mit242, tightly linked to the Flv locus. One of those loci, D5Mit159, showed no recombinations with Flv in any of the backcross mice analyzed, indicating tight linkage (<0.3 cM). The other two, D5Mit68 and D5Mit242, exhibited two and one recombinations with Flv (0.6 and 0.3 cM) respectively, defining the proximal and distal boundaries of a 0.9-cM segment around this locus. The proximal flanking marker, D5Mit68, maps to a segment on mouse Chr 5 homologous to human Chr 4. This, together with the previous data produced by our group, locates Flv to a region on mouse Chr 5 carrying segments that are conserved on either human Chr 4, 12, or 7, but present knowledge does not allow precise identification of the syntenic element. 相似文献
4.
Ulloa M Wang C Hutmacher RB Wright SD Davis RM Saski CA Roberts PA 《Molecular genetics and genomics : MGG》2011,286(1):21-36
Knowledge of the inheritance of disease resistance and genomic regions housing resistance (R) genes is essential to prevent
expanding pathogen threats such as Fusarium wilt [Fusarium oxysporum f.sp. vasinfectum (FOV) Atk. Sny & Hans] in cotton (Gossypium spp.). We conducted a comprehensive study combining conventional inheritance, genetic and quantitative trait loci (QTL) mapping,
QTL marker-sequence composition, and genome sequencing to examine the distribution, structure and organization of disease
R genes to race 1 of FOV in the cotton genome. Molecular markers were applied to F2 and recombinant inbred line (RIL) interspecific mapping populations from the crosses Pima-S7 (G. barbadense L.) × ‘Acala NemX’ (G. hirsutum L.) and Upland TM-1 (G. hirsutum) × Pima 3-79 (G. barbadense), respectively. Three greenhouse tests and one field test were used to obtain sequential estimates of severity index (DSI)
of leaves, and vascular stem and root staining (VRS). A single resistance gene model was observed for the F2 population based on inheritance of phenotypes. However, additional inheritance analyses and QTL mapping indicated gene interactions
and inheritance from nine cotton chromosomes, with major QTLs detected on five chromosomes [Fov1-C06, Fov1-C08, (Fov1-C11
1
and Fov1-C11
2)
, Fov1-C16 and Fov1-C19 loci], explaining 8–31% of the DSI or VRS variation. The Fov1-C16 QTL locus identified in the F2 and in the RIL populations had a significant role in conferring FOV race 1 resistance in different cotton backgrounds. Identified
molecular markers may have important potential for breeding effective FOV race 1 resistance into elite cultivars by marker-assisted
selection. Reconciliation between genetic and physical mapping of gene annotations from marker-DNA and new DNA sequences of
BAC clones tagged with the resistance-associated QTLs revealed defenses genes induced upon pathogen infection and gene regions
rich in disease-response elements, respectively. These offer candidate gene targets for Fusarium wilt resistance response
in cotton and other host plants. 相似文献
5.
M. Mohan P. V. Sathyanarayanan A. Kumar M. N. Srivastava S. Nair 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,95(5-6):777-782
A PCR-based marker (E20570) linked to the gene Gm4t, which confers resistance to a dipteran pest gall midge (Orseolia oryzae), has been mapped using the restriction fragment length polymorphism (RFLP) technique in rice. Gm4t is a dominant resistance gene. We initially failed to detect useful polymorphism for this marker in a F3 mapping population derived from a cross between two indica parents, ‘Abhaya’בShyamala’, with as many as 35 restriction enzymes. ‘Abhaya’ carries the resistance gene Gm4t and ‘Shyamala’ is susceptible to gall midge. Subsequently, E20570 was mapped using another mapping population represented by a F2 progeny from a cross between ‘Nipponbare’, a japonica variety, and ‘Kasalath’, an indica variety, in which the gene Gm4t was not known to be present. Gm4t mapped onto chromosome 8 between markers R1813 and S1633B. Our method, thus, presents an alternative way of mapping genes
which otherwise would be difficult to map because of a lack of polymorphism between closely related parents differing in desired
agronomic traits.
Received: 1 April 1997 / Accepted: 13 May 1997 相似文献
6.
Toshiyuki Takai Akihiro Ohsumi Yumiko San-oh Ma. Rebecca C. Laza Motohiko Kondo Toshio Yamamoto Masahiro Yano 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,118(7):1401-1410
Increasing leaf photosynthesis offers a possible way to improve yield potential in rice (Oryza sativa L.). Carbon isotope discrimination (Δ13C) has potential as an indirect selection criterion. In this study, we searched for quantitative trait loci (QTLs) controlling
Δ13C, and assessed their association with leaf photosynthesis. Substitution mapping by using chromosome segment substitution
lines (CSSLs), that carry segments from the indica cultivar Kasalath in the genetic background of the japonica cultivar Koshihikari, identified genomic regions affecting Δ13C on chromosomes (Chr.) 2, 3, 6, 7, and 12. One of the CSSLs, SL208, in which most regions on Chr. 3 were substituted with
Kasalath segments, showed higher leaf stomatal conductance for CO2 (g
s) and Δ13C than Koshihikari during the vegetative stage although leaf photosynthetic rate did not differ between them. These results
suggest an association between Δ13C and g
s. To test this association, we performed a QTL analysis for Δ13C at vegetative and heading stages in an F2 population derived from a cross between SL208 and Koshihikari. The results confirmed a QTL controlling Δ13C on the long arm of Chr. 3. By using a near-isogenic line specific to Hd6, we ruled out the possibility that variation in Δ13C was generated through the pleiotropic effect of heading date. 相似文献
7.
Sybil A. Herrera-Foessel Evans S. Lagudah Julio Huerta-Espino Matthew J. Hayden Harbans S. Bariana Davinder Singh Ravi P. Singh 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2011,122(1):239-249
The common wheat genotype ‘RL6077’ was believed to carry the gene Lr34/Yr18 that confers slow-rusting adult plant resistance (APR) to leaf rust and stripe rust but located to a different chromosome
through inter-chromosomal reciprocal translocation. However, haplotyping using the cloned Lr34/Yr18 diagnostic marker and the complete sequencing of the gene indicated Lr34/Yr18 is absent in RL6077. We crossed RL6077 with the susceptible parent ‘Avocet’ and developed F3, F4 and F6 populations from photoperiod-insensitive F3 lines that were segregating for resistance to leaf rust and stripe rust. The populations were characterized for leaf rust
resistance at two Mexican sites, Cd. Obregon during the 2008–2009 and 2009–2010 crop seasons, and El Batan during 2009, and
for stripe rust resistance at Toluca, a third Mexican site, during 2009. The F3 population was also evaluated for stripe rust resistance at Cobbitty, Australia, during 2009. Most lines had correlated responses
to leaf rust and stripe rust, indicating that either the same gene, or closely linked genes, confers resistance to both diseases.
Molecular mapping using microsatellites led to the identification of five markers (Xgwm165, Xgwm192, Xcfd71, Xbarc98 and Xcfd23) on chromosome 4DL that are associated with this gene(s), with the closest markers being located at 0.4 cM. In a parallel
study in Canada using a Thatcher × RL6077 F3 population, the same leaf rust resistance gene was designated as Lr67 and mapped to the same chromosomal region. The pleiotropic, or closely linked, gene derived from RL6077 that conferred stripe
rust resistance in this study was designated as Yr46. The slow-rusting gene(s) Lr67/Yr46 can be utilized in combination with other slow-rusting genes to develop high levels of durable APR to leaf rust and stripe
rust in wheat. 相似文献
8.
U. Kumar A. K. Joshi S. Kumar R. Chand M. S. R?der 《Molecular breeding : new strategies in plant improvement》2010,26(3):477-491
Spot blotch caused by Bipolaris sorokiniana is a destructive disease of wheat in warm and humid wheat growing regions of the world. To identify quantitative trait loci
(QTLs) for spot blotch resistance, two mapping populations were developed by making the crosses between common susceptible
cultivar ‘Sonalika’ with the resistant breeding lines ‘Ning 8201’ and ‘Chirya 3’. Single seed descent derived F6, F7, F8 lines of the first cross ‘Ning 8201’ × ‘Sonalika’ were evaluated for resistance to spot blotch in three blocks in each of
the 3 years. After screening of 388 pairs of simple sequence repeat primers between the two parents, 119 polymorphic markers
were used to genotype the mapping population. Four QTLs were identified on the chromosomes 2AS, 2BS, 5BL and 7DS and explained
62.9% of phenotypic variation in a simultaneous fit. The QTL on chromosome 2A was detected only in 1 year and explained 22.7%
of phenotypic variation. In the second cross (‘Chirya 3’ × ‘Sonalika’), F7 and F8 population were evaluated in three blocks in each of the 2 years. In this population, five QTLs were identified on chromosomes
2BS, 2DS, 3BS, 7BS and 7DS. The QTLs identified in the ‘Chirya 3’ × ‘Sonalika’ population explained 43.4% of phenotypic variation
in a simultaneous fit. The alleles for reduced disease severity in both the populations were derived from the respective resistant
parent. The QTLs QSb.bhu-2B and QSb.bhu-7D from both populations were placed in the same deletion bins, 2BS1-0.53-0.75 and 7DS5-0.36-0.61, respectively. The closely
linked markers Xgwm148 to the QTL on chromosome 2B and Xgwm111 to the QTL on chromosome 7D are potentially diagnostic markers for spot blotch resistance. 相似文献
9.
Yusaku Uga Kazutoshi Okuno Masahiro Yano 《Molecular breeding : new strategies in plant improvement》2010,26(3):533-538
The stele (root vascular cylinder) in plants plays an important role in the transport of water and nutrients from the root
to the shoot. A quantitative trait locus (QTL) on rice chromosome 9 that controls stele transversal area (STA) was previously
detected in an F3 mapping population derived from a cross between the lowland cultivar ‘IR64’, with a small STA, and the upland cultivar ‘Kinandang
Patong’, with a large STA. To identify the gene(s) underlying this QTL, we undertook fine mapping of the locus. We screened
eight plants from BC2F3 lines in which recombination occurred near the QTL. Progeny testing of BC2F4 plants was used to determine the genotype classes for the QTL in each BC2F3 line. Accordingly, the STA QTL Sta1 (Stele Transversal Area 1) was mapped between the InDel markers ID07_12 and ID07_14. A candidate genomic region for Sta1 was defined more precisely between markers RM566 and RM24334, which delimit a 359-kb interval in the reference cultivar ‘Nipponbare’.
A line homozygous for the ‘Kinandang Patong’ allele of Sta1 had an STA approximately 28.4% larger than that of ‘IR64’. However, Sta1 did not influence maximum or total root length, suggesting that this QTL specifically controls STA. 相似文献
10.
Identification of the novel recessive gene pi55(t) conferring resistance to Magnaporthe oryzae 总被引:2,自引:0,他引:2
XiuYing He XinQiong Liu Li Wang Ling Wang Fei Lin YongSheng Cheng ZhaoMing Chen YaoPing Liao QingHua Pan 《中国科学:生命科学英文版》2012,55(2):141-149
The elite rice cultivar Yuejingsimiao 2 (YJ2) is characterized by a high level of grain quality and yield, and resistance
against Magnaporthe oryzae. YJ2 showed 100% resistance to four fungal populations collected from Guangdong, Sichuan, Liaoning, and Heilongjiang Provinces,
which is a higher frequency than that shown by the well-known resistance (R) gene donor cultivars such as Sanhuangzhan 2 and 28zhan. Segregation analysis for resistance with F2 and F4 populations indicated the resistance of YJ2 was controlled by multiple genes that are dominant or recessive. The putative
R genes of YJ2 were roughly tagged by SSR markers, located on chromosomes 2, 6, 8, and 12, in a bulked-segregant analysis using
genome-wide selected SSR markers with F4 lines that segregated into 3 resistant (R):1 susceptible (S) or 1R:3S. The recessive R gene on chromosome 8 was further mapped to an interval ≈1.9 cM/152 kb in length by linkage analysis with genomic position-ready
markers in the mapping population derived from an F4 line that segregated into 1R:3S. Given that no major R gene was mapped to this interval, the novel R gene was designated as pi55(t). Out of 26 candidate genes predicted in the region based on the reference genomic sequence of the cultivar Nipponbare,
two genes that encode a leucine-rich repeat-containing protein and heavy-metal-associated domain-containing protein, respectively,
were suggested as the most likely candidates for pi55(t). 相似文献
11.
F. Vear L. Gentzbittel J. Philippon S. Mouzeyar E. Mestries P. Roeckel-Drevet D. Tourvieille de Labrouhe P. Nicolas 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,95(4):584-589
These studies were undertaken to determine whether downy mildew resistance genes in sunflower were independent as first reported,
or linked as suggested by more recent hypotheses. The segregations for downy mildew reaction of 111 F3 progenies from a cross between a susceptible line and a line with Pl2 were used to locate this gene on the sunflower consensus RFLP linkage map. It was shown that Pl2 was linked to the same RFLP markers on linkage group 1 as Pl1 and Pl6, mapped earlier, and at a very similar distance. The F3 progenies showed exactly the same segregation patterns when tested with race 1 and race D. One hundred and fifty four progenies
from a cross between a susceptible line and HA335, containing Pl6 (considered as giving resistance to all Plasmopara halstedii races), were tested with the five French downy mildew races, 1, A, B, C and D. Two progenies were observed to show segregation
for races 1 and D, while appearing homozygous-resistant to races A , B and C. Tests on F4 progenies confirmed this separation of resistances with fixation of susceptibility to races 1 and D and resistance to races
A, B and C. It is concluded that the Pl6 gene is not a “strong” gene, giving resistance to all downy mildew races, but rather a cluster of genes, each providing resistance
to one, or a few, downy mildew races. The genes giving resistance to races 1 and D, on one hand, and to races A, B and C,
on the other hand, must be very closely linked, with about 0.6 cM between the two groups.
Received: 23 December 1996 / Accepted: 18 April 1997 相似文献
12.
Xiaochun Sun Guihua Bai Brett F. Carver 《Molecular breeding : new strategies in plant improvement》2009,23(2):311-321
Leaf rust, caused by Puccinia triticina Eriks., is an important foliar disease of common wheat (Triticum aestivum L.) worldwide. Pyramiding several major rust-resistance genes into one adapted cultivar is one strategy for obtaining more
durable resistance. Molecular markers linked to these genes are essential tools for gene pyramiding. The rust-resistance gene
Lr41 from T.
tauschii has been introgressed into chromosome 2D of several wheat cultivars that are currently under commercial production. To discover
molecular markers closely linked to Lr41, a set of near-isogenic lines (NILs) of the hard winter wheat cultivar Century were developed through backcrossing. A population
of 95 BC3F2:6 NILs were evaluated for leaf rust resistance at both seedling and adult plant stages and analyzed with simple sequence repeat
(SSR) markers using bulked segregant analysis. Four markers closely linked to Lr41 were identified on chromosome 2DS; the closest marker, Xbarc124, was about 1 cM from Lr41. Physical mapping using Chinese Spring nullitetrasomic and ditelosomic genetic stocks confirmed that markers linked to Lr41 were on chromosome arm 2DS. Marker analysis in a diverse set of wheat germplasm indicated that primers BARC124, GWM210, and
GDM35 amplified polymorphic bands between most resistant and susceptible accessions and can be used for marker-assisted selection
in breeding programs. 相似文献
13.
P. K. Singh M. Mergoum J. L. Gonzalez-Hernandez S. Ali T. B. Adhikari S. F. Kianian E. M. Elias G. R. Hughes 《Molecular breeding : new strategies in plant improvement》2008,21(3):293-304
Race 5 of Pyrenophora tritici-repentis, causal agent of tan spot, induces two distinct symptoms, necrosis and chlorosis in susceptible tetraploid and hexaploid
wheat, respectively. This study was conducted under controlled environmental conditions to determine the inheritance of resistance
to P. tritici-repentis, race 5, in a tetraploid wheat population and to map the resistance genes. Additionally, the relationship between the resistance
genes effective against necrosis inducing races 3 and 5 in tetraploid wheat was determined. A population of 98 recombinant-inbred
lines (RIL) was developed from a cross between the resistant genotype Triticum turgidum # 283 (PI352519) and the susceptible durum cultivar Coulter. This RIL population was screened individually with race 3 and
race 5 and molecular mapping of the resistance gene(s) in this population was conducted. Additionally, the F2 and F4:5 generations of this population were screened with race 5 to determine the genetic control of resistance. Plants were inoculated
at the two-leaf stage and disease reaction was assessed based on 1 to 5 lesion-type rating scale eight days after inoculation.
Segregation analysis of the F2 generation and of the F4:5 and F6:7 families indicated that a single recessive gene controlled resistance to necrosis induced by race 5. Analysis of the mapping
data of the T. turgidum # 283/Coulter RIL population indicate that a major gene, designated tsn5, controlling resistance to race 5 is located on the long arm of chromosome 3B. The tsn5 gene is 8.3 cM proximal to the gene tsn2 that controls resistance to necrosis induced by race 3. 相似文献
14.
W. Tadesse M. Schmolke S. L. K. Hsam V. Mohler G. Wenzel F. J. Zeller 《Journal of applied genetics》2010,51(3):235-242
The winter wheat cultivar Red Chief has been identified as the wheat cultivar most resistant toPyrenophora tritici-repentis (Ptr). This study was undertaken to determine the inheritance, chromosomal location and molecular mapping of a tan spot resistance
gene in Red Chief. χ2 analysis of the F2 segregation data of the hybrids between 21 monosomic lines of the susceptible wheat cultivar Chinese Spring and the resistant
cultivar Red Chief revealed that tan spot resistance in cv. Red Chief is controlled by a single recessive gene located on
chromosome 3A. Linkage analysis using SSR markers in the Red Chief/Chinese Spring F2 population showed that thetsr4 gene is clustered in the region aroundXgwm2a, on the short arm of chromosome 3A. This marker has also been identified as the closest marker to thetsr3 locus on chromosome 3D in synthetic wheat lines. Validation analysis of this marker for thetsr3 andtsr4 genes using 28 resistant and 6 susceptible genotypes indicated that the 120 bp allele (thetsr3 gene) specific fragment was observed in 11 resistant genotypes, including the three synthetic lines XX41, XX45 and XX110,
while the 130 bp allele was amplified only in cv. Red Chief and Dashen.Xgwm2a can be used to trace the presence of the target gene in successive backcross generations and pyramiding of thetsr3 &tsr4 genes into a commonly grown and adaptable cultivar. 相似文献
15.
Lambda clones of mouse DNA from BALB/c and C57BL/10, each containing an array of telomere hexamers, were localized by FISH
to a region close to the telomere of Chr 13. Amplification of mouse genomic DNA with primers flanking SSRs within the cloned
DNA showed several alleles, which were used to type eight sets of RI strains. The two lambda clones contained allelic versions
of the interstitial telomere array, Tel-rs4, which is 495 bp in C57BL/10 and which includes a variety of sequence changes from the consensus telomere hexamer.
Comparison of the segregation of the amplification products of the SSRs with the segregation of other loci in an interspecies
backcross (C57BL/6JEi × SPRET/Ei) F1× SPRET/Ei shows recombination suppression, possibly associated with ribosomal DNA sequences present on distal Chr 13 in Mus spretus, when compared with recombination in an interstrain backcross, (C57BL/6J × DBA/J) F1× C57BL/6J, and with the MIT F2 intercross. Analysis of recombination in females using a second interstrain backcross, (ICR/Ha × C57BL/6Ha) F1× C57BL/6Ha, also indicates recombination suppression when compared with recombination in males of the same strains, using
backcross C57BL/6Ha × (ICR/Ha × C57BL/6Ha) F1. Thus, more than one cause may contribute to recombination suppression in this region. The combined order of the loci typed
was D13Mit37–D13Mit30–D13Mit148–(D13Rp1, 2, 3, 4, Tel-rs4)–D13Mit53–D13Mit196–D13Mit77–(D13Mit78, 35). Data from crosses where apparently normal frequencies of recombination occur suggest that the telomere array is about 6
map units proximal to the most distal loci on Chr 13. This distance is consistent with evidence from markers identified in
two YAC clones obtained from the region.
Received: 24 September 1996/Accepted: 20 January 1997 相似文献
16.
S. Fondevilla D. Rubiales M. T. Moreno A. M. Torres 《Molecular breeding : new strategies in plant improvement》2008,22(2):193-200
Three genes, er1, er2 and Er3, conferring resistance to powdery mildew (Erysiphe pisi) in pea have been described so far. Because single gene-controlled resistance tends to be overcome by evolution of pathogen
virulence, accumulation of several resistance genes into a single cultivar should enhance the durability of the resistance.
Molecular markers linked to genes controlling resistance to E. pisi may facilitate gene pyramiding in pea breeding programs. Molecular markers linked to er1 and er2 are available. In the present study, molecular markers linked to Er3 have been obtained. A segregating F2 population derived from the cross between a breeding line carrying the Er3 gene, and the susceptible cultivar ‘Messire’ was developed and genotyped. Bulk Segregant Analysis (BSA) was used to identify
Random Amplified Polymorphic DNA (RAPD) markers linked to Er3. Four RAPD markers linked in coupling phase (OPW04_637, OPC04_640, OPF14_1103, and OPAH06_539) and two in repulsion phase
(OPAB01_874 and OPAG05_1240), were identified. Two of these, flanking Er3, were converted to Sequence Characterized Amplified Region (SCAR) markers. The SCAR marker SCW4637 co-segregated with the resistant gene, allowing the detection of all the resistant individuals. The SCAR marker SCAB1874, in repulsion phase with Er3, was located at 2.8 cM from the gene and, in combination with SCW4637, was capable to distinguish homozygous resistant individuals from heterozygous with a high efficiency. In addition, the validation
for polymorphism in different genetic backgrounds and advanced breeding material confirmed the utility of both markers in
marker-assisted selection. 相似文献
17.
A new SNP haplotype associated with blue disease resistance gene in cotton (Gossypium hirsutum L.) 总被引:1,自引:0,他引:1
David D. Fang Jinhua Xiao Paulo C. Canci Roy G. Cantrell 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2010,120(5):943-953
Resistance to cotton blue disease (CBD) was evaluated in 364 F2.3 families of three populations derived from resistant variety ‘Delta Opal’. The CBD resistance in ‘Delta Opal’ was controlled
by one single dominant gene designated Cbd. Two simple sequence repeat (SSR) markers were identified as linked to Cbd by bulked segregant analysis. Cbd resides at the telomere region of chromosome 10. SSR marker DC20027 was 0.75 cM away from Cbd. DC20027 marker fragments amplified from 3 diploid species and 13 cotton varieties whose CBD resistance was known were cloned
and sequenced. One single nucleotide polymorphism (SNP) was identified at the 136th position by sequence alignment analysis.
Screening SNP markers previously mapped on chromosome 10 identified an additional 3 SNP markers that were associated with
Cbd. A strong association between a haplotype based on four SNP markers and Cbd was developed. This demonstrates one of the first examples in cotton where SNP markers were used to effectively tag a trait
enabling marker-assisted selection for high levels of CBD resistance in breeding programs. 相似文献
18.
Nearly all F1 male mice with Dh/+ genotype between DDD female and DH–Dh/+ male die within a few days after birth; however, this is not observed in the reciprocal cross. The F1
Dh/+ males usually exhibit growth retardation prior to death. To identify the putative genetic locus or loci in DDD genome that
cause the abnormalities in the presence of the Dh, a linkage analysis was carried out in backcross progeny of a cross of (DDD female × DH–+/+ male) F1 female × DH–Dh/+ male. Appearance of growth retardation was examined from the day of birth, and both growth-retarded and normally weaned
Dh/+ males were genotyped for microsatellite marker loci spanning autosomes and the X Chromosome (Chr). Significant evidence
for linkage was identified on the distal edge of the X Chr, near the microsatellite marker of DXMit135. Furthermore, among mice from DDD female × reciprocal F1
Dh/+ male produced between DH–Dh/+ and progenitor strains (C57BL/6J, C3H/HeJ and BALB/cA), only the progeny from ♀DDD ×♂(♀DH–Dh/+×♂C3H/HeJ) F1
Dh/+ male did not show any lethality and/or growth retardation. Thus, the lethality in F1
Dh/+ males accompanied by growth retardation is caused by the interactions between the Dh gene, X Chr, and Y Chr. Based on the CAG repeat sequence length polymorphism among Mus musculus musculus Sry gene, C3H/HeJ was different from C57BL/6J, BALB/cA, and DH. These data suggest that there are at least two functional types
of Y Chr in Mus musculus musculus.
Received: 22 January 1999 / Accepted: 5 April 1999 相似文献
19.
Ki-Seung Kim Stephanie Bellendir Karen A. Hudson Curtis B. Hill Glen L. Hartman David L. Hyten Matthew E. Hudson Brian W. Diers 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2010,120(5):1063-1071
The soybean aphid (Aphis glycines Matsumura) is an important soybean [Glycine max (L.) Merr.] pest in North America. The dominant aphid resistance gene Rag1 was previously mapped from the cultivar ‘Dowling’ to a 12 cM marker interval on soybean chromosome 7 (formerly linkage group
M). The development of additional genetic markers mapping closer to Rag1 was needed to accurately position the gene to improve the effectiveness of marker-assisted selection (MAS) and to eventually
clone it. The objectives of this study were to identify single nucleotide polymorphisms (SNPs) near Rag1 and to position these SNPs relative to Rag1. To generate a fine map of the Rag1 interval, 824 BC4F2 and 1,000 BC4F3 plants segregating for the gene were screened with markers flanking Rag1. Plants with recombination events close to the gene were tested with SNPs identified in previous studies along with new SNPs
identified from the preliminary Williams 82 draft soybean genome shotgun sequence using direct re-sequencing and gene-scanning
melt-curve analysis. Progeny of these recombinant plants were evaluated for aphid resistance. These efforts resulted in the
mapping of Rag1 between the two SNP markers 46169.7 and 21A, which corresponds to a physical distance on the Williams 82 8× draft assembly
(Glyma1.01) of 115 kilobase pair (kb). Several candidate genes for Rag1 are present within the 115-kb interval. The markers identified in this study that are closely linked to Rag1 will be a useful resource in MAS for this important aphid resistance gene. 相似文献
20.
E. Bauer J. Weyen A. Schiemann A. Graner F. Ordon 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,95(8):1263-1269
In the present study three novel genes from barley accessions 10247 (ym8), Bulgarian 347 (ym9), and Russia 57 (ym11), which confer resistance to Barley Mild Mosaic Virus (BaMMV), were mapped using molecular markers. Bulked segregant analysis
of four progenies segregating for resistance to BaMMV was followed by fine-scale mapping of the resistance genes using individual
F2 or BC1F2 plants. The resistance genes are inherited recessively and are located on the long arm of barley chromosome 4HL. A series
of closely linked molecular markers are available for marker-assisted breeding programs. A marker (MWG2134) linked with resistance
gene ym11 from Russia 57 was identified, which is diagnostic for the resistance gene.
Received: 25 July 1997 / Accepted: 22 August 1997 相似文献