共查询到20条相似文献,搜索用时 31 毫秒
1.
Chunmei Wang Yiping Zhang Dejun Han Zhensheng Kang Guiping Li Aizhong Cao Peidu Chen 《Euphytica》2008,159(3):359-366
Stripe (yellow) rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most devastating wheat diseases worldwide. Triticum aestivum-Haynaldia villosa 6VS/6AL translocation lines carrying the Yr26 gene on chromosome 1B, are resistant to most races of Pst used in virulence tests. In order to better utilize Yr26 for wheat improvement, we attempted to screen SSR and EST-based STS markers closely linked with Yr26. A total of 500 F2 plants and the F2:3 progenies derived from a cross between 92R137 and susceptible cultivar Yangmai 5 were inoculated with race CYR32. The analysis
confirmed that stripe rust resistance was controlled by a single dominant gene, Yr26. Among 35 pairs of genomic SSR markers and 81 pairs of STS markers derived from EST sequences located on chromosome 1B, Yr26 was flanked by 5 SSR and 7 STS markers. The markers were mapped in deletion bins using CS aneuploid and deletion lines. The
closest flanking marker loci, Xwe173 and Xbarc181, mapped in 1BL and the genetic distances from Yr26 were 1.4 cM and 6.7 cM, respectively. Some of these markers were previously reported on 1BS. Eight common wheat cultivars
and lines developed from the T. aestivum-H. villosa 6VS/6AL translocation lines by different research groups were tested for presence of the markers. Five lines with Yr26 carried the flanking markers whereas three lines without Yr26 did not. The results indicated that the flanking markers should be useful in marker-assisted selection for incorporating
Yr26 into wheat cultivars. 相似文献
2.
Mohamed Somo Seyed Mostafa Pirseyedi Xiwen Cai Roshan Sharma Poudel Shiaoman Chao Francois Marais 《Plant Breeding》2016,135(4):413-419
In an attempt to transfer the Lr56/Yr38 resistance loci from Aegilops sharonensis to wheat, a 6A‐6Ssh chromosome translocation was produced. It involves essentially the entire chromosome 6Ssh with a small terminal segment of 6AL. Induced homoeologous recombination of the translocated chromosome with 6A produced numerous recombinants including three recombined chromosomes carrying Lr56 that could not be precisely mapped for lack of suitable markers. This study aimed to determine the chromosomal locations of the translocation breakpoints in these three recombinants using various DNA markers as well as physical and genetic mapping. The three recombinants Lr56‐39, ‐157 and ‐175 carry small segments of Ae. sharonensis chromatin distally to the Xgpw4329 and IWA5416 loci near the 6AS telomere. The Ae. sharonensis chromatin that remains in each line includes a homoeolocus of the wheat marker locus Xdupw217 (on 6BS) and its characteristic amplification product can be used as a dominant marker for the presence of Lr56. Of the three recombined chromosomes, Lr56‐157 retained the least alien chromatin and appears to be the best candidate for use in wheat breeding. 相似文献
3.
Brent D. McCallum D. Gavin Humphreys Daryl J. Somers Abdulsalam Dakouri Sylvie Cloutier 《Euphytica》2012,183(2):261-274
The wheat (Triticum aestivum L.) gene Lr34/Yr18 conditions resistance to leaf rust, stripe rust, and stem rust, along with other diseases such as powdery mildew. This makes
it one of the most important genes in wheat. In Canada, Lr34 has provided effective leaf rust resistance since it was first incorporated into the cultivar Glenlea, registered in 1972.
Recently, molecular markers were discovered that are either closely linked to this locus, or contained within the gene. Canadian
wheat cultivars released from 1900 to 2007, breeding lines and related parental lines, were tested for sequence based markers
caSNP12, caIND11, caIND10, caSNP4, microsatellite markers wms1220, cam11, csLVMS1, swm10, csLV34, and insertion site based
polymorphism marker caISBP1. Thirty different molecular marker haplotypes were found among the 375 lines tested; 5 haplotypes
had the resistance allele for Lr34, and 25 haplotypes had a susceptibility allele at this locus. The numbers of lines in each haplotype group varied from 1
to 140. The largest group was represented by the leaf rust susceptible cultivar “Thatcher” and many lines derived from “Thatcher”.
The 5 haplotypes that had the resistance allele for Lr34 were identical for the markers tested within the coding region of the gene but differed in the linked markers wms1220, caISBP1,
cam11, and csLV34. The presence of the resistance or susceptibility allele at the Lr34 locus was tracked through the ancestries of the Canadian wheat classes, revealing that the resistance allele was present
in many cultivars released since the 1970s, but not generally in the older cultivars. 相似文献
4.
D. Samsampour B. Maleki Zanjani J. K. Pallavi Anupam Singh A. Charpe S. K. Gupta K. V. Prabhu 《Euphytica》2010,174(3):337-342
The recessive adult plant resistance (APR) gene Lr48 in wheat was tagged with flanking random amplified polymorphic DNA (RAPD) markers. Markers S336775 in coupling and S3450 in repulsion with Lr48 were identified in wheat line CSP44. Tests of these markers on available Thatcher near-isogenic lines (NILs) detected the
likely presence of Lr48 in TcLr25. A test of allelism of APR involving the cross TcLr25 × CSP44 indicated that Lr48 was present in both lines. A separate experiment on inheritance of resistance in an F2 population of TcLr25 × Agra Local confirmed the presence of a dominant seedling resistance gene (Lr25) and a recessive APR gene (Lr48) in TcLr25. This study demonstrated the value of molecular markers in identifying the presence of masked genes in genetic
stocks where direct phenotyping failed to detect their presence. 相似文献
5.
Leaf rust caused by the fungus Puccinia triticina is one of the most important diseases of wheat (Triticum aestivum) worldwide. The use of resistant wheat cultivars is considered the most economical and environment-friendly approach in controlling
the disease. The Lr38 gene, introgressed from Agropyron intermedium, confers a stable seedling and adult plant resistance against multiple isolates tested in Europe. In the present study, 94
F2 plants resulting from a cross made between the resistant Thatcher-derived near-isogenic line (NIL) RL6097, and the susceptible
Ethiopian wheat cultivar Kubsa were used to map the Thatcher Lr38 locus in wheat using simple sequence repeat (SSR) markers. Out of 54 markers tested, 15 SSRs were polymorphic between the
two parents and subsequently genotyped in the population. The P. triticina isolate DZ7-24 (race FGJTJ), discriminating Lr38 resistant and susceptible plants, was used to inoculate seedlings of the two parents and the segregating population. The
SSR markers Xwmc773 and Xbarc273 flanked the Lr38 locus at a distance of 6.1 and 7.9 cM, respectively, to the proximal end of wheat chromosome arm 6DL. The SSR markers Xcfd5 and Xcfd60 both flanked the locus at a distance of 22.1 cM to the distal end of 6DL. In future, these SSR markers can be used by wheat
breeders and pathologists for marker assisted selection (MAS) of Lr38-mediated leaf rust resistance in wheat. 相似文献
6.
A set of 105 European wheat cultivars was assessed for seedling resistance and adult plant resistance (APR) to stripe (yellow)
rust in greenhouse and field tests with selected Australian isolates of Puccinia striiformis f. sp. tritici (Pst). Twelve cultivars were susceptible to all pathotypes, and among the remainder, 11 designated seedling genes (Yr1, Yr3, Yr4, Yr6, Yr7, Yr9, Yr17, Yr27, Yr32, YrHVII and YrSP) and a range of unidentified seedling resistances were detected either singly or in combination. The identity of seedling
resistance in 43 cultivars could not be determined with the available Pst pathotypes, and it is considered possible that at least some of these may carry uncharacterised seedling resistance genes.
The gene Yr9 occurred with the highest frequency, present in 19 cultivars (18%), followed by Yr17, present in 10 cultivars (10%). Twenty four cultivars lacked seedling resistance that was effective against the pathotype
used in field nurseries, and all but two of these displayed very high levels of APR. While the genetic identity of this APR
is currently unknown, it is potentially a very useful source of resistance to Pst. Genetic studies are now needed to characterise this resistance to expedite its use in efforts to breed for resistance to
stripe rust.
Colin R. Wellings seconded from NSW Department of Primary Industries. 相似文献
7.
Rust resistance genes (introgressions S24 and S13) transferred to hexaploid wheat from two Aegilops speltoides accessions could not be used commercially due to associated gametocidal (Gc) genes. Crosses to wheat followed by rigorous selection for increased fertility were employed in an attempt to separate the
unmapped S24 stem rust resistance from the Gc gene(s). However, improved fertility of the better selections could not be maintained in subsequent generations. Since the
S13 introgression (leaf, stripe and stem rust resistances) mapped to chromosome 3A, allosyndetic pairing induction was used
in an attempt to remove the Gc gene(s). This produced putative primary recombinants with improved fertility and plant type, the best of which had exchanged
a small region of Ae. speltoides chromatin, yet was still associated with (reduced) Gc effects. This selection (04M127-3, which appears to have the Su1-Ph1 suppressor) was then crossed with wheat. Surprisingly, the 04M127-3 gametocidal effect differed drastically from that of
the original introgression allowing the recovery of 35 recombinant, leaf rust resistant progeny. Microsatellite and DArT markers
showed that each secondary recombinant had exchanged most of the Ae. speltoides chromatin. Although the data suggested that a complex multigenic interaction may govern the gametocidal response, preliminary
indications are that the Gc effect had largely been removed and it now seems possible to completely separate the gametocidal genes from the S13 leaf
rust resistance gene (here designated Lr66). The associated (S13) stripe rust and stem rust resistance genes were lost during recombination. 相似文献
8.
Agropyron cristatum exhibits resistance to Blumeria graminis f. sp. tritici. Disomic and ditelosomic chromosome addition lines of A. cristatum in ‘Chinese Spring’ wheat were utilized to determine which A. cristatum chromosomes carry resistance gene(s). Resistance is conferred by gene(s) on chromosome arms 2PL and 6PL. The availability of molecular markers capable of detecting these chromosome arms in a wheat background would be very useful for marker-assisted introgression of 2PL and 6PL chromatin into common wheat. With this aim, 170 wheat conserved orthologous set (COS) markers (92 and 78 from wheat homoeologous groups 2 and 6 respectively) were assessed for their utility in A. cristatum. A total of 116 (68.2%) COS markers successfully amplified product in A. cristatum and 46 (40.0%) of these markers were polymorphic between A. cristatum and common wheat. From marker loci mapping on wheat homoeologous group 2 chromosomes, 23 markers (34.9%) were polymorphic between A. cristatum and common wheat and from them 13 markers were assigned to chromosome arm 2PL and six markers were mapped to chromosome 4P of A. cristatum showing that this chromosome is related to wheat homoeologous group 2. From marker loci mapping on wheat homoeologous group 6 chromosomes, 23 (46.0%) markers were polymorphic between A. cristatum and common wheat and from them 17 markers were located on chromosome 6P, six of them were mapped to chromosome arm 6PS and five to chromosome arm 6PL, respectively. The specific COS markers allocated on the long arms of chromosomes 2P and 6P may have a role in marker-assisted screening in wheat breeding for powdery mildew disease resistance. 相似文献
9.
Genetic male sterility (GMS) genes in wheat (Triticum aestivum L.) can be used for commercial hybrid seed production. A new wheat GMS mutant, LZ, was successfully used in the 4E-ms system
for producing hybrid wheat, a new approach of producing hybrid seed based on GMS. Our objective was to analyse the genetic
mechanism of male sterility and locate the GMS gene in mutant LZ to a chromosome. We firstly crossed male sterile line 257A
(2n = 42) derived from mutant LZ to Chinese Spring and several other cultivars for determining the self-fertility of the F1 hybrids and the segregation ratios of male-sterile and fertile plants in the F2 and BC1 generations. Secondly, we conducted nullisomic analysis by crossing male sterile plants of line 257A to 21 self-fertile nullisomic
lines as male to test the F1 fertilities and to locate the GMS gene in mutant LZ to a chromosome. Thirdly, we conducted an allelism test with Cornerstone,
which has ms1c located on chromosome 4BS. All F1s were male fertile and the segregation ratio of male-sterile: fertile plants in all BC1 and F2 populations fitted 1:1 and 1:3 ratios, respectively. The male sterility was stably inherited, and was not affected by environmental
factors in two different locations or by the cytoplasm of wheat cultivars in four reciprocal cross combinations. The results
of nullisomic analysis indicated the gene was on chromosome 4B. The allelism test showed that the mutant LZ was allelic to
ms1c. We concluded that the mutant LZ has common wheat cytoplasm and carries a stably inherited monogenic recessive gene named
ms1g. 相似文献
10.
Genetic Analysis of Resistance to Soil-Borne Wheat Mosaic Virus Derived from Aegilops tauschii. Euphytica. Soil-Borne Wheat Mosaic Virus (SBWMV), vectored by the soil inhabiting organism Polymyxa graminis, causes damage to wheat (Triticum aestivum) yields in most of the wheat growing regions of the world. In localized fields, the entire crop may be lost to the virus.
Although many winter wheat cultivars contain resistance to SBWMV, the inheritance of resistance is poorly understood. A linkage
analysis of a segregating recombinant inbred line population from the cross KS96WGRC40 × Wichita identified a gene of major
effect conferring resistance to SBWMV in the germplasm KS96WGRC40. The SBWMV resistance gene within KS96WGRC40 was derived
from accession TA2397 of Aegilops taushcii and is located on the long arm of chromosome 5D, flanked by microsatellite markers Xcfd10 and Xbarc144. The relationship of this locus with a previously identified QTL for SBWMV resistance and the Sbm1 gene conferring resistance to soil-borne cereal mosaic virus is not known, but suggests that a gene on 5DL conferring resistance to both viruses may be present in T. aestivum, as well as the D-genome donor Ae. tauschii. 相似文献
11.
Saurabh Badoni Reeku Chaudhary Ravi Shekhar Shweta Badoni Ekhlaque Ahmad Rishi Pal Gangwar Kashi Nath Tiwari Rajendra Singh Rawat Deepshikha Jai Prakash Jaiswal 《Journal of Crop Science and Biotechnology》2017,20(5):393-403
Stripe rust of wheat caused by the fungal pathogen is a destructive foliar disease of wheat. Thus, it is crucial step to characterize the resistant germplasm for stripe rust in a diverse germplasm pool for their ultimate utilization in efficient crop rust resistance breeding. In the present study, we followed two pronged strategies involving integrated phenotypic and molecular characterization of 440 diverse wheat germplasm lines for rust resistance. The germplasm panel was extensively evaluated in field epiphytotic conditions during two consecutive years. After rigorous screening, 72 accessions were successfully revealed as resistant to moderately resistant to stripe rust. Subsequently, entries were then evaluated for their field agronomicperformances, considering prerequisites for serving as a donor germplasm,particularly for yield and 33 potential rust-resistant accessions were identified. Furthermore, to detect the sources of resistance, accessions were molecular characterized for potential race-specific resistance genes Yr5, Yr10,Yr15, and effective adult plant resistance (APR) gene Lr34/Yr18/pm38. We identified the 22 accessions possessing one or more single resistance genes and two accessions were observed with at least three of them. Moreover, Lr34/Yr18/pm38 was determined to confer resistance when observed along with any of the race-specific genes. Thus, the study not only provides proof of concept methodology to identify candidate resistant sources from large germplasm collections but simultaneouslyconfirmed the contribution of combining race-specific andnon-specific APR genes. The finding could further assist in the potential deployment of resistant genes directly into the stripe rust breeding program by involving marker-assisted approaches. 相似文献
12.
Franceli R. Kulcheski Felipe A. S. Graichen José A. Martinelli Ana B. Locatelli Luiz C. Federizzi Carla A. Delatorre 《Euphytica》2010,175(3):423-432
Crown rust, which is caused by Puccinia
coronata f. sp. avenae, P. Syd. & Syd., is the most destructive disease of cultivated oats (Avena
sativa L.) throughout the world. Resistance to the disease that is based on a single gene is often short-lived because of the extremely
great genetic diversity of P. coronata, which suggests that there is a need to develop oat cultivars with several resistance genes. This study aimed to identify
amplified fragment length polymorphism AFLP markers that are linked to the major resistance gene, Pc68, and to amplify the F6 genetic map from Pc68/5*Starter × UFRGS8. Seventy-eight markers with normal segregation were discovered and distributed in
12 linkage groups. The map covered 409.4 cM of the Avena
sativa genome. Two AFLP markers were linked in repulsion to Pc68: U8PM22 and U8PM25, which flank the gene at 18.60 and 18.83 centiMorgans (cM), respectively. The marker U8PM25 is located
in the linkage group 4_12 in the Kanota × Ogle reference oat population. These markers should be useful for transferring Pc68 to genotypes with good agronomic characteristics and for pyramiding crown rust resistance genes. 相似文献
13.
Junghyun Shim Olivier Panaud Clémentine Vitte Merlyn S. Mendioro Darshan S. Brar 《Euphytica》2010,176(2):269-279
Molecular markers have been successfully used in rice breeding however available markers based on Oryza
sativa sequences are not efficient to monitor alien introgression from distant genomes of Oryza. We developed O. minuta (2n = 48, BBCC)-specific clones comprising of 105 clones (266–715 bp) from the initial library composed of 1,920 clones against
O. sativa by representational difference analysis (RDA), a subtractive cloning method and validated through Southern blot hybridization.
Chromosomal location of O. minuta-specific clones was identified by hybridization with the genomic DNA of eight monosomic alien additional lines (MAALs). The
37 clones were located either on chromosomes 6, 7, or 12. Different hybridization patterns between O. minuta-specific clones and wild species such as O. punctata, O. officinalis, O. rhizomatis, O. australiensis, and O. ridleyi were observed indicating conservation of the O. minuta fragments across Oryza spp. A highly repetitive clone, OmSC45 hybridized with O. minuta and O. australiensis (EE), and was found in 6,500 and 9,000 copies, respectively, suggesting an independent and exponential amplification of the
fragment in both species during the evolution of Oryza. Hybridization of 105 O. minuta specific clones with BB- and CC-genome wild Oryza species resulted in the identification of 4 BB-genome-specific and 14 CC-genome-specific clones. OmSC45 was identified as a fragment of RIRE1, an LTR-retrotransposon. Furthermore this clone was introgressed from O. minuta into the advanced breeding lines of O. sativa. 相似文献
14.
Durum or macaroni wheat (Triticum turgidum L., 2n = 4x = 28; AABB) is an allotetraploid with two related genomes, AA and BB, each with seven pairs of homologous chromosomes. Although
the corresponding chromosomes of the two genomes are potentially capable of pairing with one another, the Ph1 (Pairing homoeologous) gene in the long arm of chromosome 5B permits pairing only between homologous partners. As a result of this Ph1-exercised disciplinary control, durum wheat and its successor, bread wheat (Triticum aestivum L., 2n = 6x = 42; AABBDD) show diploid-like chromosome pairing and hence disomic inheritance. The Ph mutants in the form of deletions are available in bread wheat (ph1b) and durum wheat (ph1c). Thus, ph1b-haploids of bread wheat and ph1c-haploids of durum wheat show extensive homoeologous pairing that has been shown by us and several others. Here we study the
effect of ph1b allele of bread wheat on chromosome pairing in durum haploids, whereas we studied earlier the effect of ph1c allele in durum haploids that we synthesized. In durum wheat, the ph1b-haploids show much higher (49.4% of complement) pairing than the ph1c-haploids (38.6% of complement).
Mention of a trademark or proprietary product does not constitute a guarantee or warranty of the product by the USDA or imply
approval to the exclusion of other products that also may be suitable. 相似文献
15.
Grain hardness plays an important role in determining both milling performance and quality of the end-use products produced
from common or bread wheat. The objective of this study was to characterize allelic variations at the Pina and Pinb loci in Xinjiang wheat germplasm for further understanding the mechanisms involved in endosperm texture formation, and the
status of grain texture in Chinese bread wheat. A total of 291 wheat cultivars, including 56 landraces, and 95 introduced
and 140 locally improved cultivars, grown in Xinjiang, were used for SKCS measurement and molecular characterization. Among
the harvested grain samples, 185 (63.6%), 40 (13.7%), and 66 (22.7%) were classified as hard, mixed and soft, respectively.
Eight different genotypes for the Pina and Pinb loci were identified, including seven previously reported genotypes, viz., Pina-D1a/Pinb-D1a, Pina-D1a/Pinb-D1b, Pina-D1b/Pinb-D1a, Pina-D1a/Pinb-D1p, Pina-D1a/Pinb-D1q, Pina-D1a/Pinb-D1aa, Pina-D1a/Pinb-D1ab, and a novel Pinb allele, Pinb-D1ac. This new allele, detected in Kashibaipi (local landrace) and Red Star (from Russia) has a double mutation at the 257th (G
to A substitution) and 382nd (C to T substitution) nucleotide positions of the coding region. Pina-D1b, Pinb-D1b, and Pinb-D1p were the most common alleles in Xinjiang wheat germplasm, with frequencies of 14.3%, 38.1% and 28.6% in hard textured landraces,
25.5%, 56.9% and 11.8% in hard introduced cultivars, and 24.8%, 47.8% and 26.5% in hard locally improved cultivars, respectively.
The restriction enzymes ApaI, SapI, BstXI and SfaNI were used to identify Pinb-D1ab or Pinb-D1ac, Pinb-D1b, Pinb-D1e and Pinb-Dg, respectively, by digesting PCR products of the Pinb gene. The unique grain hardness distribution in Xinjiang bread wheat, as well as the CAPs markers for identification of the
Pinb alleles provided useful information for breeding wheat cultivars with optimum grain textures.
Liang Wang and Genying Li—contributed equally to this work. 相似文献
16.
Leaf rust resistance gene Lr58 derived from Aegilops triuncialis L. was transferred to the hard red winter wheat (HRWW) cultivars Jagger and Overley by standard backcrossing and marker-assisted
selection (MAS). A co-dominant PCR-based sequence tagged site (STS) marker was developed based on the sequence information
of the RFLP marker (XksuH16) diagnostically detecting the alien segment in T2BS·2BL-2tL(0.95). STS marker Xncw-Lr58-1 was used to select backcross F1 plants with rust resistance. The co-dominant marker polymorphism detected by primer pair NCW-Lr58-1 efficiently identified
the homozygous BC3F2 plants with rust resistance gene Lr58. The STS marker Xncw-Lr58-1 showed consistent diagnostic polymorphism between the resistant source and the wheat cultivars selected by the US Wheat Coordinated
Agricultural Project. The utility and compatibility of the STS marker in MAS programs involving robust genotyping platforms
was demonstrated in both agarose-based and capillary-based platforms. Screening backcross derivatives carrying Lr58 with various rust races at seedling stage suggested the transferred rust resistance in adapted winter wheats is stable in
both cultivar backgrounds. Lr58 in adapted winter wheat backgrounds could be used in combination with other resistance genes in wheat rust resistance breeding. 相似文献
17.
M. Wu J. P. Zhang J. C. Wang X. M. Yang A. N. Gao X. K. Zhang W. H. Liu L. H. Li 《Euphytica》2010,172(3):363-372
In previous studies, we successfully transferred the P genome of Agropyron cristatum into wheat using wide hybridization methods. In the current investigation, repetitive sequences were cloned and DNA markers
specific for the P genome of A. cristatum were developed. Three P genome-specific markers, designated OPX07-1036, OPX11-817 and OPC05-1539, were identified and isolated
using random amplified polymorphic DNAs. The three markers were successfully amplified in all tested materials that contained
Agropyron chromatin, such as Agropyron itself and wheat-Agropyron addition lines. These RAPD markers were converted into SCAR markers to be used in detection of P genome chromatin in wheat.
In situ probing with fluorescent-labeled marker DNA has shown that they are distributed in all arms of Agropyron hence they will be useful in a variety of studies on introgressions of the P-genome chromatin into wheat. 相似文献
18.
The 1BL.1RS wheat-rye translocation and a wheat-Triticum timopheevii chromosomal introgression carry the Sr31, Lr26, Yr9 and Pm8 genes and the Sr36/Pm6 gene cluster, respectively. The objective of this study was to determine the distribution and impact of these two translocations
in 220 wheat varieties registered in Hungary in the last 35 years until 2005. The 1BL.1RS translocation was introduced into
Hungary via wheat cultivars ‘Avrora’ and ‘Kavkaz’, which were registered in 1970. New 1BL.1RS cultivars developed in Hungary
first appeared in 1982. After reaching a maximum frequency of 50.0% among cultivars registered in Hungary in 1994, their presence
declined steadily to 13.3% by 2005. The Sr36/Pm6 cultivars first appeared in 1980. Their frequency quickly reached 31.8% (1983–1984), but then dropped to between 9.6 and
18.5% (1990–2005). The two main Hungarian breeding programs showed opposing trends in the exploitation of these two translocations.
In Martonvásár, 1BL.1RS played a dominant role, being present from 1993 to 1997 in ca. 95% of the released cultivars, while
at the same time the use of Sr36/Pm6 was marginal. Conversely, among the Szeged cultivars, Sr36/Pm6 was present at high frequency (44.7% in 2002) with a low share of 1BL.1RS. In artificial field inoculation tests (1985–2003)
both of the stem rust resistance genes provided significant resistance in all the years, though Sr36 proved more effective than Sr31. While Pm8 was not effective, except for the last 2 years, Pm6 exhibited significant resistance against powdery mildew in most of the 18 years tested. These data may help breeders to assess
the usefulness of wheat-rye 1BL.1RS chromosome translocations and the Sr36/Pm6 resistance gene clusters in their future wheat improvement programs. 相似文献
19.
The recessive mutation of the XANTHA gene (XNT) transforms seedlings and plants into a yellow color, visually distinguishable from normal (green) rice. Thus, it has been
introduced into male sterile lines as a distinct marker for rapidly testing and efficiently increasing varietal purity in
seed and paddy production of hybrid rice. To identify closely linked markers and eventually isolate the XNT gene, two mapping populations were developed by crossing the xantha mutant line Huangyu B (indica) with two wild type japonica varieties; a total of 1,720 mutant type F2 individuals were analyzed for fine mapping using polymorphic InDel markers and high dense microsatellite markers. The XNT gene was mapped on chromosome 11, within in a fragment of ~100 kb, where 13 genes are annotated. The NP_001067671.1 gene
within the delimited region is likely to be a candidate XNT gene, since it encodes ATP-dependent chloroplast protease ATP-binding subunit clp A. However, no sequence differences were
observed between the mutant and its parent. Bioinformatics analysis demonstrated that four chlorophyll deficient mutations
that were previously mapped on the same chromosome are located outside the XNT region, indicating XNT is a new gene. The results provide useful DNA markers not only for marker assisted selection of the xantha trait but also its eventual cloning. 相似文献
20.
Fusarium head blight (FHB) is a destructive disease of wheat worldwide. FHB resistance genes from Sumai 3 and its derivatives such as Ning 7840 have been well characterized through molecular mapping. In this study, resistance genes in Wangshuibai, a Chinese landrace with high and stable FHB resistance, were analyzed through molecular mapping. A population of 104 F2-derived F7 recombinant inbred lines (RILs) was developed from the cross between resistant landrace Wangshuibai and susceptible variety Alondras. A total of 32 informative amplified fragment length polymorphism (AFLP) primer pairs (EcoRI/MseI) amplified 410 AFLP markers segregating among the RILs. Among them, 250 markers were mapped in 23 linkage groups covering a genetic distance of 2,430 cM. In addition, 90 simple sequence repeat (SSR) markers were integrated into the AFLP map. Fifteen markers associated with three quantitative trait loci (QTL) for FHB resistance (P < 0.01) were located on two chromosomes. One QTL was mapped on 1B and two others were mapped on 3B. One QTL on 3BS showed a major effect and explained up to 23.8% of the phenotypic variation for type II FHB resistance. 相似文献