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1.
Wild emmer wheat, Triticum dicoccoides, the progenitor of modern tetraploid and hexaploid wheats, is an important resource for new variability for disease resistance genes. T. dicoccoides accession pau4656 showed resistance against prevailing leaf rust and stripe rust races in India and was used for developing stable introgression lines (IL) in T. durum cv Bijaga yellow and named as IL pau16068. F5 Recombinant inbred lines (F5 RILs) were developed by crossing IL pau16068 with T. durum cultivar PBW114 and RIL population was screened against highly virulent Pt and Pst pathotypes at the seedling and adult plant stages. Inheritance analyses revealed that population segregated for two genes for all stage resistance (ASR) against leaf rust, one ASR gene against stripe rust and three adult plant resistance (APR) genes for stripe rust resistance.
For mapping these genes a set of 483 SSR marker was used for bulked segregant analysis. The markers showing diagnostic polymorphism in the resistant and susceptible bulks were amplified on all RILs. Single marker analysis placed all stage leaf rust resistance genes on chromosome 6A and 2A linked to the SSR markers Xwmc256 and Wpaus268, respectively. Likewise one all stage stripe rust resistance gene were mapped on long arm of chromosome 6A linked to markers 6AL-5833645 and 6AL-5824654 and two APR genes mapped on chromosomes 2A and 2B close to the SSR marker Wpaus268 and Xbarc70, respectively. The current study identified valuable leaf rust and stripe rust resistance genes effective against multiple rust races for deployment in the wheat breeding programme. 相似文献
2.
A sequence-tagged-site (STS) marker is reported linked to Lr28, a leaf rust resistance gene in wheat. RAPD (random amplified polymorphic DNA) analysis of near-isogenic lines (NILs) of
Lr28 in eight varietal backgrounds was carried out using random primers. Genomic DNA enriched for low-copy sequences was used
for RAPD analysis to overcome the lack of reproducibility due to the highly repetitive DNA sequences present in wheat. Of
80 random primers tested on the enriched DNA, one RAPD marker distinguished the NILs and the donor parent from the susceptible
recurrent parents. The additional band present in resistant lines was cloned, sequenced, and STS primers specific for Lr28 were designed. The STS marker (Indian patent pending: 380 Del98) was further confirmed by bulk segregation analysis of F 3 families. It was consistently present in the NILs, the resistant F 3 bulk and the resistant F 3 lines, but was absent in recurrent parents, the susceptible F 3 bulk and the susceptible F 3 lines.
Received: 20 February 1998 / Accepted: 4 March 1998 相似文献
3.
We have previously reported Xgwm382 as a diagnostic marker for disease resistance against yellow rust in Izgi2001 × ES14 F 2 population. Among the same earlier tested 230 primers, one SSR marker ( Xgwm311) also amplified a fragment which is present in the resistant parent and in the resistant bulks, but absent in the susceptible parent and in the susceptible bulks. To understand the chromosome group location of these diagnostic markers, Xgwm382 and Xgwm311, in the same population, we selected 16 SSR markers mapped only in one genome of chromosome group 2 around 1–21 cM distance to these diagnostic markers based on the SSR consensus map of wheat. Out of 16 SSRs, Xwmc658 identified resistant F 2 individuals as a diagnostic marker for yellow rust disease and provided the location of Xgwm382 and Xgwm311 on chromosome 2AL in our plant material. 相似文献
4.
Stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the most destructive diseases of wheat worldwide. Growing resistant cultivars is the most effective approach to
control the disease, but only a few genes confer effective all-stage resistance against the current populations of the pathogen
worldwide. It is urgent to identify new genes for diversifying sources of resistance genes and for pyramiding genes for different
types of resistance in order to achieve high levels of durable resistance for sustainable control of stripe rust. The common
spring wheat genotype ‘PI 181434’, originally from Afghanistan, was resistant in all greenhouse and field tests in our previous
studies. To identify the resistance gene(s) PI 181434 was crossed with susceptible genotype ‘Avocet Susceptible’. Adult plants
of 103 F 2 progeny were tested in the field under the natural infection of P. striiformis f. sp. tritici. Seedlings of the parents, F 2 and F 3 were tested with races PST-100 and PST-127 of the pathogen under controlled greenhouse conditions. The genetic study showed
that PI 181434 has a single dominant gene conferring all-stage resistance. Resistance gene analog polymorphism (RGAP) and
simple sequence repeat (SSR) techniques were used to identify molecular markers linked to the gene. A linkage map of 8 RGAP
and 2 SSR markers was constructed for the gene using data from the 103 F 2 plants and their derived F 3 lines tested in the greenhouse. Amplification of the complete set of nulli-tetrasomic lines and selected ditelosomic lines
of Chinese Spring with an RGAP marker and the two SSR markers mapped the gene on the long arm of chromosome 3D. Because it
is the first gene for stripe rust resistance mapped on chromosome 3DL and different from all previously named Yr genes, the gene in PI 181434 was designated Yr45. Polymorphism rates of the two closest flanking markers, Xwgp115 and Xwgp118, in 45 wheat genotypes were 73.3 and 82.2%, respectively. Single nucleotide polymorphisms (SNPs) were identified in the eight
wheat genotypes sharing both flanking markers. The RGAP markers and potential SNP markers should be useful in incorporating
the gene into wheat cultivars and in pyramiding it with other genes for durable resistance. 相似文献
5.
The gene Yr26 confers resistance to all races of Puccinia striiformis f. sp. tritici (PST), the casual pathogen of wheat stripe rust in China. Here, we report development of a molecular marker closely linked
to Yr26 using a resistance gene-analog polymorphism (RGAP) technique. A total of 787 F 2 plants and 165 F 3 lines derived from the cross Chuanmai 42/Taichung 29 were used for linkage analysis. Eighteen near-isogenic lines (NILs)
and 18 Chinese wheat cultivars and advanced lines with different genes for stripe rust resistance were employed for the validation
of STS markers. A total of 1,711 RGAP primer combinations were used to test the parents and resistant and susceptible bulks.
Five polymorphic RGAP markers were used for genotyping all F 2 plants. Linkage analysis showed that the five RGAP markers were closely linked to Yr26 with genetic distances ranging from 0.5 to 2.9 cM. These markers were then converted into STS markers, one, CYS-5, of which was located 0.5 cM to Yr26 and was closely associated with the resistance gene when validated over 18 NILs and 18 Chinese wheat cultivars and lines.
The results indicated that CYS-5 can be used in marker-assisted selection targeted at pyramiding Yr26 and other genes for stripe rust resistance. 相似文献
6.
Inheritance of partial leaf rust and stripe rust resistance of a Thatcher wheat 90RN2491, earlier reported to carry two doses
of the gene pair Lr34-Yr18 and the reference line RL6058 (6*Thatcher/PI58548) for the Lr34-Yr18 gene pair was studied against predominant and highly virulent Indian races. Thatcher derivatives 90RN2491 and RL6058 were
intercrossed as well as crossed with the leaf rust and stripe rust susceptible Indian cultivar WL711. The F 1, F 2 and F 3 generations from these crosses were assessed for rust severity against leaf rust race 77-5 and stripe rust race 46S119. The
F 2 and F 3 generations from the crosses of RL6058 and 90RN2491 with WL711, segregated 15 resistant : 1 susceptible (F 2) and 7 homozygous resistant : 8 segregating : 1 homozygous susceptible (F 3) ratios, respectively, both for leaf rust and stripe rust severity. Therefore, partial resistance against each of the leaf
rust and stripe rust races in both RL6058 and 90RN2491 is ascribed to two independently inherited dominant genes. One of the
two genes for leaf rust and stripe rust resistance in 90RN2491 and RL6058 is Lr34 and the linked gene Yr18, respectively. The second leaf rust resistance gene in both the Thatcher lines segregated independently of stripe rust resistance.
Therefore, it is not Lr34 and it remains unidentified. 相似文献
7.
Stripe rust, caused by Puccinia striiformis Westend. f. sp. tritici (PST), is one of the most destructive diseases of common wheat ( Triticum aestivum L.). To determine inheritance of stripe rust resistance and map the resistance gene(s) in wheat variety C591, F 1, F 2, and F 3 progenies derived from the Taichung 29 × C591 cross were inoculated with Chinese PST race CY32 in the greenhouse. Genetic
analysis identified a single dominant gene, temporarily designated YrC591. A total of 178 SSR and 130 AFLP markers were used to test the parents and resistant and susceptible bulks. From the bulk
segregant analysis, seven polymorphic SSR and two AFLP markers were selected for genotyping the F 2 population. SSR marker Xcfa2040-7B, and SCAR marker SC-P35M48 derived from AFLP marker P35M48
373
were identified to be closely linked to the resistance gene with genetic distances of 8.0 and 11.7 cM, respectively. The
SSR markers mapped the resistance gene on chromosome arm 7BL. In the seedling test with five PST races, the reaction patterns
of C591 were different from wheat cultivars or lines carrying Yr2 or Yr6 that also are found on chromosome 7B. The results indicate that YrC591 is probably a novel stripe rust resistance gene. 相似文献
8.
Stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the most widespread and destructive wheat diseases worldwide. Growing resistant cultivars is the preferred means
of control of the disease. The winter wheat cultivar Xiaoyan 54 has high-temperature resistance to stripe rust. To identify
genes for stripe rust resistance, Xiaoyan 54 was crossed with Mingxian 169, a winter wheat genotype susceptible to all Chinese
races of the pathogen. Seedlings and adult plants of the parents and F 1, F 2, F 3 and F 4 progeny were tested with Chinese race CYR32 under controlled greenhouse conditions and in the field. Xiaoyan 54 has two recessive
resistance genes, designated as Yrxy1 and Yrxy2, conferring high-temperature resistance. Simple sequence repeat (SSR) primers were used to identify molecular markers flanking
Yrxy2 using 181 plants from one segregating F 3 line. A total of nine markers, two of which flanked the locus at genetic distances of 4.0 and 6.4 cM on the long arm of chromosome
2A were identified. Resistance gene analog polymorphism (RGAP) and SSR techniques were used to identify molecular markers
linked to Yrxy1. A linkage group of nine RGAP and two SSR markers was constructed for Yrxy1 using 177 plants of another segregating F 3 line. Two RGAP markers were closely linked to the locus with genetic distances of 2.3 and 3.5 cM. Amplification of a set
of nulli-tetrasomic Chinese Spring lines with RGAP markers M8 and M9 and the two SSR markers located Yrxy1 on the short arm of chromosome 7A. The SSR markers Xbarc49 and Xwmc422 were 15.8 and 26.1 cM, respectively, from the gene. The closely linked molecular markers should be useful for incorporating
the resistance genes into commercial cultivars and combining them with other genes for stripe rust resistance. 相似文献
9.
Complete F 1 and F 2 diallel crosses were used to investigate the inheritance of yellow rust resistance among eight bread wheat lines, developed
by CIMMYT for the East African Highlands, which showed a wide response to this disease. Both diallel sets were grown at a
site with a high incidence of yellow rust, although for one season, during which the F 1 diallel was grown, disease incidence was unusually low. Analyses disclosed the presence of additive, dominance and epistatic
effects among those genes controlling rust resistance, with the former being the most important. At normal disease levels,
excluding two arrays having resistant common parents removed non-allelic interactions from the F 1 diallels. For all F 2 diallels, and the remaining F 1 diallel, omitting two arrays based on susceptible parents removed these interactions. Local selection of material from a
broadly based germplasm appears to be a feasible method of developing adapted cultivars resistant to endemic diseases.
Received: 1 March 1998 / Accepted: 19 March 1998 相似文献
10.
An F 2 population from a cross between barley accession Q21861 and the Australian barley variety Galleon was used to develop RAPD markers for resistance to barley leaf rust ( Puccinia hordei). Resistant and susceptible DNA bulks were constructed following the classification of F 2 plants by leaf rust infection type. Bulked segregant analysis was then used to identify a 2.7-kb marker, designated OU02 2700 and located approximately 12cM from RphQ, a leaf rust resistance gene in Q21861. The marker was generated by PCR with the oligonucleotide primer OPU-02 (Operon). Infection types of F 3 progeny were used to confirm assignment of F 2 genotypes. OU02 2700 was shown, retrospectively, to be useful in the identification of individual F 2 plants that had been originally misclassified as having susceptible infection types. Both the RAPD marker and RphQ will be potentially useful in the development of new barley cultivars. 相似文献
11.
The wheat crop remains vulnerable to all three rust diseases (leaf rust, stem rust and yellow rust) caused by Puccinia spp. according to the prevalence of the pathogen in different wheat-growing areas worldwide. Stripe rust or yellow rust caused by Puccinia striiformis f. sp. tritici is the most significant rust pathogen which prefers cool, moist areas and highlands. The pathogen is recognised as responsible for huge production losses in wheat. Genetic variation in pathogen makes its control difficult. Therefore, resistance against all the races of the pathogen known as durable or race-non-specific resistance is preferred. The present study was carried out to identify durable resistance against stripe rust in selected wheat cultivars from Pakistan through seedling testing, field evaluation at adult stage, morphological marker studies and marker-assisted selection. Results revealed that 4% of the cultivars were resistant at the seedling stage while the rest were susceptible or intermediate. To confirm their field resistance, the same cultivars were evaluated under field conditions at Cereal Crops Research Institute Pirsabak (located in Khyber Pakhtunkhwa, KP) a hot spot of stripe rust in Pakistan. Observations exhibited that at the adult stage 4% of the cultivars were resistant, 70% intermediate or moderately resistant while the others were highly susceptible. Leaf tip necrosis was observed in 30% of the cultivars. Wheat cultivars showing susceptibility at the seedling stage were highly to moderately resistant at adult stage showing durable resistance. For further validation, morphological markers were also observed in cultivars indicating the presence of Yr18/Lr34 gene. Eleven cultivars (C-518, Mexipak, Kohinoor-83, Faisalabad-83, Zardana-93, Shahkar-95, Moomal-2002, Wattan-94, Pasban-90, Kiran-95, and Haider-2000) were identified, having durable or race non-specific resistance against stripe rust. These cultivars can further be utilised in wheat breeding programmes for deploying durable resistance to attain long lasting control against stripe rust. 相似文献
12.
Expressed sequence tag (EST) markers have been used to assess variety and genetic diversity in wheat ( Triticum aestivum). In this study, 1549 ESTs from wheat infested with yellow rust were used to examine the genetic diversity of six susceptible and resistant wheat cultivars. The aim of using these cultivars was to improve the competitiveness of public wheat breeding programs through the intensive use of modern, particularly marker-assisted, selection technologies. The F 2 individuals derived from cultivar crosses were screened for resistance to yellow rust at the seedling stage in greenhouses and adult stage in the field to identify DNA markers genetically linked to resistance. Five hundred and sixty ESTs were assembled into 136 contigs and 989 singletons. BlastX search results showed that 39 (29%) contigs and 96 (10%) singletons were homologous to wheat genes. The database-matched contigs and singletons were assigned to eight functional groups related to protein synthesis, photosynthesis, metabolism and energy, stress proteins, transporter proteins, protein breakdown and recycling, cell growth and division and reactive oxygen scavengers. PCR analyses with primers based on the contigs and singletons showed that the most polymorphic functional categories were photosynthesis (contigs) and metabolism and energy (singletons). EST analysis revealed considerable genetic variability among the Turkish wheat cultivars resistant and susceptible to yellow rust disease and allowed calculation of the mean genetic distance between cultivars, with the greatest similarity (0.725) being between Harmankaya99 and Sönmez2001, and the lowest (0.622) between Aytin98 and Izgi01. 相似文献
13.
Triticum monococcum L, a diploid wheat species closely related to the A genome of cultivated wheats, is highly resistant to leaf rust. A synthetic amphiploid, T. monococcum — T. durum was crossed with T. aestivum cv WL711, highly susceptible to leaf rust. Leaf rust resistant derivatives were selected among backcross generations with the recurrent parent WL711 and cytologically analysed. Chromosome number of the leaf rust resistant BC 1F 3 progenies varied from 39 to 44. Six leaf rust resistant and susceptible bulks from different BC 1F 3 progenies were analysed using 29 wheat microsatellite(WMS) markers already mapped on A genome of bread wheat and found polymorphic among parents. One T. monococcum specific allele of WMS gwm136 locus was found to be closely linked to the leaf rust resistance gene in all the resistant bulks. Differential chromosome number, frequency of univalents and multivalents, however, indicated that the critical T. monococcum chromosome might be present in addition to the A genome chromosomes of wheat, substituted either for the B or D genome chromosome of wheat or translocated to chromosome 1A of wheat in one or the other bulks. The association of the T. monococcum specific allele of WMS gwm136 locus to leaf rust resistance was further confirmed from bulked segregant analysis in BC 2F 1 generation. 相似文献
14.
A leaf rust resistance gene Lr19 on the chromosome 7DL of wheat derived from Agropyron elongatum was tagged with random amplified polymorphic DNA (RAPD) and microsatellite markers. The F 2 population of 340 plants derived from a cross between the leaf rust resistant near-isogenic line (NIL) of Thatcher (Tc + Lr19) and leaf rust susceptible line Agra Local that segregated for dominant monogenic leaf rust resistance was utilized for generating the mapping population. The molecular markers were mapped in the F 2 derived F 3 homozygous population of 140 seedlings. Sixteen RAPD markers were identified as linked to the alien gene Lr19 among which eight were in a coupling phase linkage. Twelve RAPD markers co-segregated with Lr19 locus. Nine microsatellite markers located on the long arm of chromosome 7D were also mapped as linked to the gene Lr19, including 7 markers which co-segregated with Lr19 locus, thus generating a saturated region carrying 25 molecular markers linked to the gene Lr19 within 10.2 ± 0.062 cM on either side of the locus. Two RAPD markers S265 512 and S253 737 which flanked the locus Lr19 were converted to sequence characterized amplified region markers SCS265 512 and SCS253 736, respectively. The marker SCS265 512 was linked with Lr19 in a coupling phase and the marker SCS253 736 was linked in a repulsion phase, which when used together mimicked one co-dominant marker capable of distinguishing the heterozygous resistant seedlings from the homozygous resistant. The molecular markers were validated on NILs mostly in Thatcher background isogenic for 44 different Lr genes belonging to both native and alien origin. The validation for polymorphism in common leaf rust susceptible cultivars also confirmed the utility of these tightly linked markers to the gene Lr19 in marker-assisted selection. 相似文献
15.
Host-plant resistance is the most economically viable and environmentally responsible method of control for Puccinia triticina, the causal agent of leaf rust in wheat ( Triticum aestivum L.). The identification and utilization of new resistance sources is critical to the continued development of improved cultivars as shifts in pathogen races cause the effectiveness of widely deployed genes to be short lived. The objectives of this research were to identify and tag new leaf rust resistance genes. Forty landraces from Afghanistan and Iran were obtained from the National Plant Germplasm System and evaluated under field conditions at two locations in Texas. PI 289824, a landrace from Iran, was highly resistant under field infection. Further evaluation revealed that PI 289824 is highly resistant to a broad spectrum of leaf rust races, including the currently prevalent races of leaf rust in the Great Plains area of the USA. Eight F 1 plants, 176 F 2 individuals and 139 F 2:3 families of a cross between PI 289824 and T112 (susceptible) were evaluated for resistance to leaf rust at the seedling stage. Genetic analysis indicated resistance in PI 289824 is controlled by a single dominant gene. The AFLP analyses resulted in the identification of a marker ( P39 M48-367) linked to resistance. The diagnostic AFLP band was sequenced and that sequence information was used to develop an STS marker (TXW 200) linked to the gene at a distance of 2.3 cM. The addition of microsatellite markers allowed the gene to be mapped to the short arm of Chromosome 5B. The only resistance gene to be assigned to Chr 5BS is Lr52. The Lr52 gene was reported to be 16.5 cM distal to Xgwm443 while the gene in PI 289824 mapped 16.7 cM proximal to Xgwm443. Allelism tests are needed to determine the relationship between the gene in PI 289824 and Lr52. If the reported map positions are correct, the gene in PI 289824 is unique. 相似文献
16.
Wheat production in Pakistan is seriously constrained due to rust diseases and stripe rust (yellow) caused by Puccinia striiformis f. sp. tritici, which could limit yields. Thus development and cultivation of genetically diverse and resistant varieties is the most sustainable
solution to overcome these diseases. The first objective of the present study was to evaluate 100 Pakistan wheat cultivars
that have been grown over the past 60 years. These cultivars were inoculated at the seedling stage with two virulent stripe
rust isolates from the United States and two from Pakistan. None of the wheat cultivars were resistant to all tested stripe
rust isolates, and 16% of cultivars were susceptible to the four isolates at the seedling stage. The data indicated that none
of the Pakistan wheat cultivars contained either Yr5 or Yr15 genes that were considered to be effective against most P. striiformis f. sp. tritici isolates from around the world. Several Pakistan wheat cultivars may have gene Yr10, which is effective against isolate PST-127 but ineffective against PST-116. It is also possible that these cultivars may
have other previously unidentified genes or gene combinations. The second objective was to evaluate the 100 Pakistan wheat
cultivars for stripe rust resistance during natural epidemics in Pakistan and Washington State, USA. It was found that a higher
frequency of resistance was present under field conditions compared with greenhouse conditions. Thirty genotypes (30% of germplasms)
were found to have a potentially high temperature adult plant (HTAP) resistance. The third objective was to determine the
genetic diversity in Pakistan wheat germplasms using molecular markers. This study was based on DNA fingerprinting using resistance
gene analog polymorphism (RGAP) marker analysis. The highest polymorphism detected with RGAP primer pairs was 40%, 50% and
57% with a mean polymorphism of 36%. A total of 22 RGAP markers were obtained in this study. RGAP, simple sequence repeat
(SSR) and sequence tagged site (STS) markers were used to determine the presence and absence of some important stripe rust
resistance genes, such as Yr5, Yr8, Yr9, Yr15 and Yr18. Of the 60 cultivars analyzed, 17% of cultivars showed a RGAP marker band for Yr9 and 12% of cultivars exhibited the Yr18 marker band. No marker band was detected for Yr5, Yr8 and Yr15, indicating a likely absence of these genes in the tested Pakistan wheat cultivars. Cluster analysis based on molecular and
stripe rust reaction data is useful in identifying considerable genetic diversity among Pakistan wheat cultivars. The resistant
germplasms identified with 22 RGAP markers and from the resistance evaluations should be useful in developing new wheat cultivars
with stripe rust resistance. 相似文献
17.
Leaf rust, caused by Puccinia triticina, is one of the most widespread diseases in common wheat ( Triticum aestivum L.) worldwide. With the objective of identifying and mapping new genes for resistance to leaf rust, F 1, F 2 plants and F 3 lines from a cross between resistant line Zhou 8425B and susceptible line Chinese Spring were inoculated with Chinese P. triticina races THTT and MBHP in the greenhouse. A total of 793 pairs of SSR primers were used to test the parents and resistant and
susceptible bulks. Seven polymorphic chromosome 1B markers were used for genotyping the F 2 and F 3 populations. Zhou 8425B carried a single dominant resistance gene, temporarily designated LrZH84, linked to SSR markers gwm582 and barc8 with genetic distances of 3.9 and 5.2 cM, respectively. The Xbarc8 allele co-segregated with Lr26 in the F 3 population . The Xgwm582 allele associated with LrZH84 was identified as a leaf rust resistance gene and shown to be present in the Predgornaia 2 parent of Zhou 8425B. The seedling
reaction pattern of LrZH84 was different from those of lines with Lr26, Lr33, Lr44 and Lr46, all of which are located in chromosome 1B. It was concluded that LrZH84 is likely to be a new leaf rust resistance gene. 相似文献
18.
Magnaporthe grisea, the blast fungus is one of the main pathological threats to finger millet crop worldwide. A systematic search for the blast
resistance gene analogs was carried out, using functional molecular markers. Three-fourths of the recognition-dependent disease
resistance genes ( R-genes) identified in plants encodes nucleotide binding site (NBS) leucine-rich repeat (LRR) proteins. NBS-LRR homologs have
only been isolated on a limited scale from Eleusine coracana. Genomic DNA sequences sharing homology with NBS region of resistance gene analogs were isolated and characterized from resistant
genotypes of finger millet using PCR based approach with primers designed from conserved regions of NBS domain. Attempts were
made to identify molecular markers linked to the resistance gene and to differentiate the resistant bulk from the susceptible
bulk. A total of 9 NBS-LRR and 11 EST-SSR markers generated 75.6 and 73.5% polymorphism respectively amongst 73 finger millet
genotypes. NBS-5, NBS-9, NBS-3 and EST-SSR-04 markers showed a clear polymorphism which differentiated resistant genotypes
from susceptible genotypes. By comparing the banding pattern of different resistant and susceptible genotypes, five DNA amplifications
of NBS and EST-SSR primers (NBS-05 504, NBS-09 711, NBS-07 688, NBS-03 509 and EST-SSR-04 241) were identified as markers for the blast resistance in resistant genotypes. Principal coordinate plot and UPGMA analysis
formed similar groups of the genotypes and placed most of the resistant genotypes together showing a high level of genetic
relatedness and the susceptible genotypes were placed in different groups on the basis of differential disease score. Our
results provided a clue for the cloning of finger millet blast resistance gene analogs which not only facilitate the process
of plant breeding but also molecular characterization of blast resistance gene analogs from Eleusine coracana. 相似文献
19.
Wheat yellow mosaic disease, which is caused by wheat yellow mosaic bymovirus (WYMV) and transmitted by soil-borne fungus, results in severe damage on wheat ( Triticum aestivum L.) production in China. For development of resistant cultivars to reduce wheat yield losses due to wheat yellow mosaic disease, resistance test and genetic analysis indicated that a single dominant gene in wheat cultivar Yangfu 9311 contributed to the resistance. Bulk segregant analysis was used to identify microsatellite markers linked to the resistance gene in an F 2 population derived from the cross Yangfu 9311 (resistant) × Yangmai 10 (susceptible). Microsatellite markers Xwmc41, Xwmc181, Xpsp3039, and Xgwm349 were co-dominantly or dominantly linked with the gene responsible for WYMV resistance at a distance of 8.1–11.6 cM. Based on the wheat microsatellite consensus map and the results from amplification of the cultivar Chinese Spring nulli-tetrasomic stocks, the resistance gene to wheat yellow mosaic disease derived from Yangfu 9311, temporarily named as YmYF, was thus mapped on the long arm of chromosome 2D (2DL). 相似文献
20.
Leaf rust and stripe rust are important foliar diseases of wheat worldwide. Leaf rust and stripe rust resistant introgression
lines were developed by induced homoeologous chromosome pairing between wheat chromosome 5D and 5M g of Aegilops geniculata (U gM g) . Characterization of rust resistant BC 2F 5 and BC 3F 6 homozygous progenies using genomic in situ hybridization with Aegilops comosa (M) DNA as probe identified three different types of introgressions; two cytologically visible and one invisible (termed
cryptic alien introgression). All three types of introgression lines showed similar and complete resistance to the most prevalent
pathotypes of leaf rust and stripe rust in Kansas (USA) and Punjab (India). Diagnostic polymorphisms between the alien segment
and recipient parent were identified using physically mapped RFLP probes. Molecular mapping revealed that cryptic alien introgression
conferring resistance to leaf rust and stripe rust comprised less than 5% of the 5DS arm and was designated T5DL·5DS-5M gS(0.95). Genetic mapping with an F 2 population of Wichita × T5DL·5DS-5M gS(0.95) demonstrated the monogenic and dominant inheritance of resistance to both diseases. Two diagnostic RFLP markers, previously
mapped on chromosome arm 5DS, co-segregated with the rust resistance in the F 2 population. The unique map location of the resistant introgression on chromosome T5DL·5DS-5M gS(0.95) suggested that the leaf rust and stripe rust resistance genes were new and were designated Lr57 and Yr40. This is the first documentation of a successful transfer and characterization of cryptic alien introgression from Ae. geniculata conferring resistance to both leaf rust and stripe rust in wheat. 相似文献
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