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1.
W. G. Xu C. X. Li L. Hu L. Zhang J. Z. Zhang H. B. Dong G. S. Wang 《Molecular breeding : new strategies in plant improvement》2010,26(1):31-38
The Chinese winter wheat cultivar Zhoumai 22 is highly resistant to powdery mildew. The objectives of this study were to map
a powdery mildew resistance gene in Zhoumai 22 using molecular markers and investigate its allelism with Pm13. A total of 278 F2 and 30 BC1 plants, and 143 F3 lines derived from the cross between resistant cultivar Zhoumai 22 and susceptible cultivar Chinese Spring were used for
resistance gene tagging. The 137 F2 plants from the cross Zhoumai 22/2761-5 (Pm13) were employed for the allelic test of the resistance genes. Two hundred and ten simple sequence repeat (SSR) markers were
used to test the two parents, and resistant and susceptible bulks. Subsequently, seven polymorphic markers were used for genotyping
the F2 and F3 populations. The results indicated that the powdery mildew resistance in Zhoumai 22 was conferred by a single dominant gene,
designated PmHNK tentatively, flanked by seven SSR markers Xgwm299, Xgwm108, Xbarc77, Xbarc84, Xwmc326, Xwmc291 and Xwmc687 on chromosome 3BL. The resistance gene was closely linked to Xwmc291 and Xgwm108, with genetic distances of 3.8 and 10.3 cM, respectively, and located on the chromosome bin 3BL-7-0.63-1.0 in the test with
a set of deletion lines. Seedling tests with seven isolates of Blumeria
graminis f. sp. tritici (Bgt) and allellic test indicated that PmHNK is different from Pm13, and Pm41 seems also to be different from PmHNK due to its origin from T. dicoccoides and molecular evidence. These results indicate that PmHNK is likely to be a novel powdery mildew resistance gene in wheat. 相似文献
2.
Blanco A Gadaleta A Cenci A Carluccio AV Abdelbacki AM Simeone R 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2008,117(1):135-142
Powdery mildew, caused by Blumeria graminis f.sp. tritici, is one of the most important wheat diseases in many regions of the world. Triticum turgidum var. dicoccoides (2n=4x=AABB), the progenitor of cultivated wheats, shows particular promises as a donor of useful genetic variation for several traits, including disease resistances. The wild emmer accession MG29896, resistant to powdery mildew, was backcrossed to the susceptible durum wheat cultivar Latino, and a set of backcross inbred lines (BC(5)F(5)) was produced. Genetic analysis of F(3) populations from two resistant introgression lines (5BIL-29 x Latino and 5BIL-42 x Latino) indicated that the powdery mildew resistance is controlled by a single dominant gene. Molecular markers and the bulked segregant analysis were used to characterize and map the powdery mildew resistance. Five AFLP markers (XP43M32((250)), XP46M31((410)), XP41M37((100)), XP41M39((250)), XP39M32((120))), three genomic SSR markers (Xcfd07, Xwmc75, Xgwm408) and one EST-derived SSR marker (BJ261635) were found to be linked to the resistance gene in 5BIL-29 and only the BJ261635 marker in 5BIL-42. By means of Chinese Spring nullisomic-tetrasomic, ditelosomic and deletion lines, the polymorphic markers and the resistance gene were assigned to chromosome bin 5BL6-0.29-0.76. These results indicated that the two lines had the same resistance gene and that the introgressed dicoccoides chromosome segment was longer (35.5 cM) in 5BIL-29 than that introgressed in 5BIL-42 (less than 1.5 cM). As no powdery mildew resistance gene has been reported on chromosome arm 5BL, the novel resistance gene derived from var. dicoccoides was designated Pm36. The 244 bp allele of BJ261635 in 5BIL-42 can be used for marker-assisted selection during the wheat resistance breeding process for facilitating gene pyramiding. 相似文献
3.
Runli He Zhijian Chang Zujun Yang Zongying Yuan Haixian Zhan Xiaojun Zhang Jianxia Liu 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,118(6):1173-1180
Powdery mildew resistance from Thinopyrum intermedium was introgressed into common wheat (Triticum aestivum L.). Genetic analysis of the F1, F2, F3 and BC1 populations from powdery mildew resistant line CH5025 revealed that resistance was controlled by a single dominant allele.
The gene responsible for powdery mildew resistance was mapped by the linkage analysis of a segregating F2 population. The resistance gene was linked to five co-dominant genomic SSR markers (Xcfd233, Xwmc41, Xbarc11, Xgwm539 and Xwmc175) and their most likely order was Xcfd233–Xwmc41–Pm43–Xbarc11–Xgwm539–Xwmc175 at 2.6, 2.3, 4.2, 3.5 and 7.0 cM, respectively. Using the Chinese Spring nullisomic-tetrasomic and ditelosomic lines, the
polymorphic markers and the resistance gene were assigned to chromosome 2DL. As no powdery mildew resistance gene was previously
assigned to chromosome 2DL, this new resistance gene was designated Pm43. Pm43, together with the identified closely linked markers, could be useful in marker-assisted selection for pyramiding powdery
mildew resistance genes.
Runli He and Zhijian Chang contributed equally to this work. 相似文献
4.
Perugini LD Murphy JP Marshall D Brown-Guedira G 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2008,116(3):417-425
Powdery mildew is an important foliar disease in wheat, especially in areas with a cool or maritime climate. A dominant powdery
mildew resistance gene transferred to the hexaploid germplasm line NC99BGTAG11 from T. timopheevii subsp. armeniacum was mapped distally on the long arm of chromosome 7A. Differential reactions were observed between the resistance gene in
NC99BGTAG11 and the alleles of the Pm1 locus that is also located on chromosome arm 7AL. Observed segregation in F2:3 lines from the cross NC99BGTAG11 × Axminster (Pm1a) demonstrate that germplasm line NC99BGTAG11 carries a novel powdery mildew resistance gene, which is now designated as Pm37. This new gene is highly effective against all powdery mildew isolates tested so far. Analyses of the population with molecular
markers indicate that Pm37 is located 16 cM proximal to the Pm1 complex. Simple sequence repeat (SSR) markers Xgwm332 and Xwmc790 were located 0.5 cM proximal and distal, respectively, to Pm37. In order to identify new markers in the region, wheat expressed sequence tags (ESTs) located in the distal 10% of 7AL that
were orthologous to sequences from chromosome 6 of rice were targeted. The two new EST-derived STS markers were located distal
to Pm37 and one marker was closely linked to the Pm1a region. These new markers can be used in marker-assisted selection schemes to develop wheat cultivars with pyramids of powdery
mildew resistance genes, including combinations of Pm37 in coupling linkage with alleles of the Pm1 locus. 相似文献
5.
Huang XQ Wang LX Xu MX Röder MS 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2003,106(5):858-865
Powdery mildew, caused by Erysiphe graminis DM f. sp. tritici (Em. Marchal), is one of the most important diseases of common wheat world-wide. Chinese wheat variety 'Fuzhuang 30' carries the powdery mildew resistance gene Pm5e and has proven to be a valuable resistance source of powdery mildew for wheat breeding. Microsatellite markers were employed to identify the gene Pm5e in a F(2) progeny from the cross 'Nongda 15' (susceptible) x 'Fuzhuang 30' (resistant). The gene Pm5e was mapped in the distal region of chromosome 7BL. Seven microsatellite markers were found to be linked to the gene Pm5e, of which two codominant markers Xgwm783 and Xgwm1267 were relatively close to Pm5e with a linkage distance of 11.0 cM and 6.6 cM, respectively. It is possible to use the 136-bp allele of Xgwm1267 in 'Fuzhuang 30' for marker-assisted selection during the wheat resistance breeding process for facilitation of gene pyramiding. The mapping information in the present study provides a starting point for fine mapping of the Pm5 locus and map-based cloning to clarify the molecular structure and function of the different alleles at the Pm5 locus. A microsatellite linkage map of chromosome 7B was constructed with 20 microsatellite loci, nine on the short arm and 11 on the long arm. This information will be very useful for further mapping of agronomically important genes of interest on chromosome 7B. 相似文献
6.
V. Katoch Susheel Sharma S. Pathania D. K. Banayal S. K. Sharma R. Rathour 《Molecular breeding : new strategies in plant improvement》2010,25(2):229-237
Powdery mildew caused by Erysiphe pisi D.C. is one of the most serious diseases that inflict heavy losses to pea crop world-wide. Identification of resistance sources
and their incorporation into susceptible cultivars remains the most effective method of controlling the disease. The present
study investigated the resistance phenotype, inheritance, and genomic location of gene(s) controlling resistance to powdery
mildew in pea genotype ‘JI2480’. The powdery mildew resistance in ‘JI2480’ appeared to be a spatial phenomenon showing expression
only in leaf tissues. By segregation analysis of an F2 progeny of cross ‘Lincoln/JI2480’, the leaf resistance of ‘JI2480’ was shown to be controlled by a single recessive gene,
presumed to be er2. Through linkage analysis of 111 resistant F2 progeny plants with simple sequence repeat (SSR) and random amplified polymorphic DNA (RAPD) markers adopted from the published
linkage maps, the er2 gene was localized on pea linkage group III (LGIII). The assignment of er2 to LGIII, a position different from that reported for er1, has resolved the long standing controversy in the literature regarding the existence and genomic location of er2 gene. A RAPD marker OPX-17_1400, exhibiting cis phase linkage (2.6 cM) to er2 was successfully converted to a sequence characterized amplified region (SCAR) marker, ScX17_1400. The SCAR marker ScX17_1400
will ensure speedy and precise introgression of er2 into susceptible cultivars by permitting selection of er2 heterozygotes amongst BC
n
F1s without progeny tests and resistance screening. 相似文献
7.
The aim of this study was to investigate the inheritance of powdery mildew disease and to tag it with a DNA marker to utilize
for the marker-assisted selection (MAS) breeding program. The powdery mildew resistant genotype Fallon
er
and susceptible genotype 11760-3
ER
were selected from 177 genotypes by heavy infestation of germplasm with Erysiphe pisi through artificial inoculation The F1 plants of the cross Fallon/11760-3 indicated the dominance of the susceptible allele, while F2 plants segregated in 3: 1 ratio (susceptible: resistant) that fit for goodness of fitness by χ2 (P > 0.07), indicating monogenic recessive inheritance for powdery mildew resistance in Pisum sativum. A novel RAPD marker OPB18 (5′-CCACAGCAGT-3′) was linked to the er-1 gene with 83% probability with a LOD score of 4.13, and was located at a distance of 11.2 cM from the er-1 gene. 相似文献
8.
This paper reports on the successful Agrobacterium-mediated transformation of oat, and on some factors influencing this process. In the first step of the experiments, three
cultivars, two types of explant, and three combinations of strain/vectors, which were successfully used for transformation
of other cereals were tested. Transgenic plants were obtained from the immature embryos of cvs. Bajka, Slawko and Akt and
from leaf base explants of cv. Bajka after transformation with A. thumefaciens strain LBA4404(pTOK233). The highest transformation rate (12.3%) was obtained for immature embryos of cv. Bajka. About 79%
of the selected plants proved to be transgenic; however, only 14.3% of the T0 plants and 27.5% of the T1 showed GUS expression. Cell competence of both types of explant differed in terms of their transformation ability and transgene
expression. The next step of the study was to test the suitability for oat transformation of the pGreen binary vector combined
with different selection cassettes: nptII or bar under the nos or 35S promoter. Transgenic plants were selected in combinations transformed with nos::nptII, 35S::nptII and nos::bar. The highest transformation efficiency (5.3%) was obtained for cv. Akt transformed with nos::nptII. A detailed analysis of the T0 plants selected from a given callus line and their progeny revealed that they were the mixture of transgenic, chimeric-transgenic
and non-transgenic individuals. Southern blot analysis of T0 and T1 showed simple integration pattern with the low copy number of the introduced transgenes. 相似文献
9.
Chhuneja P Kumar K Stirnweis D Hurni S Keller B Dhaliwal HS Singh K 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2012,124(6):1051-1058
Powdery mildew (PM) caused by Blumeria graminis f. sp. tritici (Bgt), is one of the important foliar diseases of wheat that can cause serious yield losses. Breeding for cultivars with diverse
resources of resistance is the most promising approach for combating this disease. The diploid A genome progenitor species
of wheat are an important resource for new variability for disease resistance genes. An accession of Triticum boeoticum (AbAb) showed resistance against a number of Bgt isolates, when tested using detached leaf segments. Inheritance studies in a recombinant inbred line population (RIL), developed
from crosses of PM resistant T. boeoticum acc. pau5088 with a PM susceptible T. monococcum acc. pau14087, indicated the presence of two powdery mildew resistance genes in T. boeoticum acc. pau5088. Analysis of powdery mildew infection and molecular marker data of the RIL population revealed that both powdery
mildew resistance genes are located on the long arm of chromosome 7A. Mapping was conducted using an integrated linkage map
of 7A consisting of SSR, RFLP, STS, and DArT markers. These powdery mildew resistance genes are tentatively designated as
PmTb7A.1 and PmTb7A.2. The PmTb7A.2 is closely linked to STS markers MAG2185 and MAG1759 derived from RFLP probes which are linked to powdery mildew resistance
gene Pm1. This indicated that PmTb7A.2 might be allelic to Pm1. The PmTb7A.1, flanked by a DArT marker wPt4553 and an SSR marker Xcfa2019 in a 4.3 cM interval, maps proximal to PmT7A.2. PmTb7A.1 is putatively a new powdery mildew resistance gene. The powdery mildew resistance genes from T. boeoticum are currently being transferred to cultivated wheat background through marker-assisted backcrossing, using T. durum as bridging species. 相似文献
10.
McIntosh RA Zhang P Cowger C Parks R Lagudah ES Hoxha S 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2011,123(3):359-367
Genetic suppression of disease resistance is occasionally observed in hexaploid wheat or in its interspecific crosses. The
phenotypic effects of genes moved to wheat from relatives with lower ploidy are often smaller than in the original sources,
suggesting the presence of modifiers or partial inhibitors in wheat, especially dilution effects caused by possible variation
at orthologous loci. However, there is little current understanding of the underlying genetics of suppression. The discovery
of suppression in some wheat genotypes of the cereal rye chromosome 1RS-derived gene Pm8 for powdery mildew resistance offered an opportunity for analysis. A single gene for suppression was identified at or near
the closely linked storage protein genes Gli-A1 and Glu-A3, which are also closely associated with the Pm3 locus on chromosome 1AS. The Pm3 locus is a complex of expressed alleles and pseudogenes embedded among Glu-A3 repeats. In the current report, we explain why earlier work indicated that the mildew suppressor was closely associated with
specific Gli-A1 and Glu-A3 alleles, and predict that suppression of Pm8 involves translated gene products from the Pm3 locus. 相似文献
11.
Protoplasts from cell suspensions of young-embryo-derived calli, whichwere non- regenerable for long-term subculture and protoplasts from embryogenic calli with the regeneration capacity of 75% of the same wheat Jinan 177, were mixed as recipient. Protoplasts from embryogenic calli of Avena sativa (with the regeneration capacity of less than 10%) irradiated with UV at an intensity of300 μW/cm2 for 30 s, 1 min, 2 min, 3 min, 5 min were used as the donor. Protoplasts of the recipient and the donor were fused by PEG method. Many calli and normal green plants were regenerated at high frequency, and were verified as somatic hybrids by chromosome counting, isozyme, 5S rDNA spacer sequence analysis and GISH (genomic in situ hybridization). Fusion combination between protoplasts either from the cell suspensions or from the calli and UV-treated Avena sativa protoplasts could not regenerate green plants. 相似文献
12.
Zhen-yi Li Rui-cai Long Tie-jun Zhang Qing-chuan Yang Jun-mei Kang 《Molecular biology reports》2016,43(8):815-826
Heat shock proteins (HSPs) are ubiquitous protective proteins that play crucial roles in plant development and adaptation to stress, and the aim of this study is to characterize the HSP gene in alfalfa. Here we isolated a small heat shock protein gene (MsHSP17.7) from alfalfa by homology-based cloning. MsHSP17.7 contains a 477-bp open reading frame and encodes a protein of 17.70-kDa. The amino acid sequence shares high identity with MtHSP (93.98 %), PsHSP17.1 (83.13 %), GmHSP17.9 (74.10 %) and SlHSP17.6 (79.25 %). Phylogenetic analysis revealed that MsHSP17.7 belongs to the group of cytosolic class II small heat shock proteins (sHSP), and likely localizes to the cytoplasm. Quantitative RT-PCR indicated that MsHSP17.7 was induced by heat shock, high salinity, peroxide and drought stress. Prokaryotic expression indicated that the salt and peroxide tolerance of Escherichia coli was remarkably enhanced. Transgenic Arabidopsis plants overexpressing MsHSP17.7 exhibited increased root length of transgenic Arabidopsis lines under salt stress compared to the wild-type line. The malondialdehyde (MDA) levels in the transgenic lines were significantly lower than in wild-type, although proline levels were similar between transgenic and wild-type lines. MsHSP17.7 was induced by heat shock, high salinity, oxidative stress and drought stress. Overexpression analysis suggests that MsHSP17.7 might play a key role in response to high salinity stress. 相似文献
13.
14.
Molecular markers for the crown rust resistance genes Pc38, Pc39, and Pc48 in cultivated oat (Avena sativa L.) were identified using near-isogenic lines and bulked segregant analysis. Six markers for Pc48, the closest being 6 cM away, were found in a Pendek-39 × Pendek-48 (Pendek3948) population, but none was found in a Pendek-48 × Pendek-38 (Pendek4838) population. Three markers for Pc39 were found in the Pendek3948 population, one of which cosegregated with the gene. This same marker was found to be 6 cM away from the gene in an OT328 × Dumont (OT328Du) population. Nine markers for Pc38 were found in the Pendek4838 population, eight of which are within 2 cM of the gene. One other marker for Pc38 was found in the OT328Du population; however, comparative mapping suggests that the Pc38 region in OT328Du is in a different location than that in Pendek4838. A number of markers unlinked to the genes under study formed linkage groups in both the Pendek3948 and Pendek4838 populations. Four of these show homology or homoeology to each other and to the Pc39 region in Pendek3948. Two RFLP clones closely linked to Pc38 code for a putative leucine-rich repeat transmembrane protein kinase and a cre3 resistance gene analogue. This study provides information to support molecular breeding in oat, and contributes to ongoing research into genomic regions associated with fungal pathogen resistance. 相似文献
15.
Genqiao Li Tilin Fang Hongtao Zhang Chaojie Xie Hongjie Li Tsomin Yang Eviatar Nevo Tzion Fahima Qixin Sun Zhiyong Liu 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,119(3):531-539
Powdery mildew caused by Blumeria graminis f. sp. tritici is an important wheat disease in China and other parts of the world. Wild emmer (Triticum turgidum var. dicoccoides) is the immediate progenitor of cultivated tetraploid and hexaploid wheats and thus an important resource for wheat improvement.
Wild emmer accession IW2 collected from Mount Hermon, Israel, is highly resistant to powdery mildew at the seedling and adult
plant stages. Genetic analysis using an F2 segregating population and F2:3 families, derived from a cross between susceptible durum cultivar Langdon and wild emmer accession IW2, indicated that a
single dominant gene was responsible for the resistance of IW2. Bulked segregant and molecular marker analyses detected that
six polymorphic SSR, one ISBP, and three EST-STS markers on chromosome 3BL bin 0.63–1.00 were linked to the resistance gene.
Allelic variations of resistance-linked EST-STS marker BE489472 revealed that the allele was present only in wild emmer but absent in common wheat. Segregation distortion was observed for
the powdery mildew resistance allele and its linked SSR markers with preferential transmission of Langdon alleles over IW2
alleles. The resistance gene was introgressed into common wheat by backcrossing and marker-assisted selection. Since no designated
powdery mildew resistance gene has been found on chromosome 3BL, the resistance gene derived from wild emmer accession IW2
appears to be new one and was consequently designated Pm41.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
16.
Prashant G. Golegaonkar Haydar Karaoglu Robert F. Park 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,119(7):1281-1288
An incompletely dominant gene conferring resistance to Puccinia hordei, Rph14, identified previously in an accession of Hordeum vulgare, confers resistance to all known pathotypes of P. hordei in Australia. Knowledge of the chromosomal location of Rph14 and the identification of DNA markers closely linked to it will facilitate combining it with other important leaf rust resistance
genes to achieve long lasting resistance. The inheritance of Rph14 was confirmed using 146 and 106 F3 lines derived from the crosses ‘Baudin’/‘PI 584760’ (Rph14) and ‘Ricardo’/‘PI 584760’ (Rph14), respectively. Bulk segregant analysis on DNA from the parental genotypes and resistant and susceptible DNA bulks using
DArT markers located Rph14 to the short arm of chromosome 2H. DArT marker bPb-1664 was identified as having the closest genetic association with Rph14. PCR based marker analysis identified a single SSR marker, Bmag692, linked closely to Rph14 at a map distance of 2.1 and 3.8 cm in the ‘Baudin’/‘PI 584760’and ‘Ricardo’/‘PI 584760’ populations, respectively. 相似文献
17.
Ming Zhang Zhao Liu Chao-Chien Jan 《Molecular breeding : new strategies in plant improvement》2016,36(3):32
Sunflower, the fifth largest oilseed crop in the world, plays an important role in human diets. Recently, sunflower production in North America has suffered serious yield losses from newly evolved races of sunflower rust (Puccinia helianthi Schwein.). The rust resistance gene, designated R 14 , in a germplasm line PH 3 originated from a wild Helianthus annuus L. population resistant to 11 rust races. PH 3 has seedling with an extraordinary purple hypocotyl color. The objectives of this study were to map both the R 14 rust resistance gene and the purple hypocotyl gene-designated PHC in PH 3, and to identify molecular markers for marker-assisted breeding for sunflower rust resistance. A set of 517 mapped SSR/InDel and four SNP markers was used to detect polymorphisms between the parents. Fourteen markers covering a genetic distance of 17.0 cM on linkage group (LG) 11 were linked to R 14 . R 14 was mapped to the middle of the LG, with a dominant SNP marker NSA_000064 as the closest marker at a distance of 0.7 cM, and another codominant marker ORS542 linked at 3.5 cM proximally. One dominant marker ZVG53 was linked on the distal side at 6.9 cM. The PHC gene was also linked to R 14 with a distance of 6.2 cM. Chi-squared analysis of the segregation ratios of R 14 , PHC, and ten linked markers indicated a deviation from an expected 1:2:1 or 3:1 ratio. The closely linked molecular or morphological markers could facilitate sunflower rust-resistant breeding and accelerate the development of rust-resistant hybrids. 相似文献
18.
Murat Akkurt Leocir Welter Erika Maul Reinhard Töpfer Eva Zyprian 《Molecular breeding : new strategies in plant improvement》2007,19(2):103-111
Sequence-characterized amplified regions markers (SCARs) were developed from six randomly amplified polymorphic DNA (RAPD)
markers linked to the major QTL region for powdery mildew (Uncinula necator) resistance in a test population derived from the cross of grapevine cultivars “Regent” (resistant) × “Lemberger”(susceptible).
RAPD products were cloned and sequenced. Primer pairs with at least 21 nucleotides primer length were designed. All pairs
were tested in the F1 progeny of “Regent” × “Lemberger”. The SCAR primers resulted in the amplification of specific bands
of expected sizes and were tested in additional genetic resources of resistant and susceptible germplasm. All SCAR primer
pairs resulted in the amplification of specific fragments. Two of the SCAR markers named ScORA7-760 and ScORN3-R produced
amplification products predominantly in resistant individuals and were found to correlate to disease resistance. ScORA7-760,
in particular, is suitable for marker-assisted selection for powdery mildew resistance and to facilitate pyramiding powdery
mildew resistance genes from various sources. 相似文献
19.
D. F. Ma Z. W. Fang J. L. Yin K. X. Chao J. X. Jing Q. Li B. T. Wang 《Molecular breeding : new strategies in plant improvement》2016,36(6):64
Wheat stripe rust is a destructive disease that affects most wheat-growing areas worldwide. Resistance genes from related species and genera add to the genetic diversity available to wheat breeding programs. The stripe rust-resistant introgression line H9020-17-25-6-4 was developed from a cross of resistant Psathyrostachys huashanica with the susceptible wheat cultivar 7182. H9020-17-25-6-4 is resistant to all existing Chinese stripe rust races, including the three most widely virulent races, CYR32, CYR33, and V26. We attempted to characterize this new line by genomic in situ hybridization (GISH) and genetic analysis. GISH using P. huashanica genomic DNA as a probe indicated that the translocated segment was too small to be detected. Genetic analysis involving F1, F2, and F2:3 materials derived from a cross of Mingxian 169 and H9020-17-25-6-4 indicated that a single dominant gene from H9020-17-25-6-4, temporarily designated YrHu, conferred resistance to CYR29 and CYR33. A genetic map consisting of four simple sequence repeat, two sequence-tagged site (STS), and two sequence-related amplified polymorphism markers was constructed. YrHu was located on the short arm of chromosome 3A and was about 0.7 and 1.5 cM proximal to EST-STS markers BG604577 and BE489244, respectively. Both the gene and the closely linked markers could be used in marker-assisted selection. 相似文献
20.
Shen Chen Zhanghui Huang Liexian Zeng Jianyuan Yang Qiongguang Liu Xiaoyuan Zhu 《Molecular breeding : new strategies in plant improvement》2008,22(3):433-441
Bacterial blight (BB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is a devastating disease in rice worldwide. The resistance gene Xa7, which provides dominant resistance against the pathogen with avirulence (Avr) gene AvrXa7, has proved to be durably resistant to BB. A set of SSR markers were selected from the “gramene” database based on the Xa7 gene initial mapping region on chromosome 6. These markers were used to construct a high-resolution genetic map of the chromosomal
region surrounding the Xa7 gene. An F2 mapping population with 721 highly susceptible individuals derived from a cross between the near isogenic lines (NILs) IRBB7
and IR24 were constructed to localize the Xa7 gene. In a primary analysis with eleven polymorphic SSR markers, Xa7 was located in approximately the 0.28-cM region. To walk closer to the target gene, recombinant F2 individuals were tested using newly developed STMS (sequence tagged microsatellite) markers. Finally, the Xa7 gene was mapped to a 0.21-cM interval between the markers GDSSR02 and RM20593. The Xa7-linked markers were landed on the reference sequence of cv. Nipponbare through bioinformatics analysis. A contig map corresponding
to the Xa7 gene was constructed. The target gene was assumed to span an interval of approximately 118.5-kb which contained a total of
fourteen genes released by the TIGR Genome Annotation Version 5.0. Candidate-gene analysis of Xa7 revealed that the fourteen genes encode novel domains that have no amino acid sequence similar to other cloned Xa(xa) genes.
Shen Chen and Zhanghui Huang are contributed equally to this work. 相似文献