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1.
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
2.
S. Mouzeyar P. Roeckel-Drevet L. Gentzbittel J. Philippon D. Tourvieille De Labrouhe F. Vear P. Nicolas 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1995,91(5):733-737
The Pl1 locus in sunflower, Helianthus annuus L., conferring resistance to downy mildew, Plasmopara halstedii, race 1 has been located in linkage group 1 of the consensus RFLP map of the cultivated sunflower. Bulked segregant analyses were used on 135 plants of an F2 progeny from a cross between a downy mildew susceptible line, GH, and RHA266, a line carrying Pl1. Two RFLP markers and one RAPD marker linked to the Pl1 locus have been identified. The RFLP markers are located at 5.6 cM and 7.1 cM on either side of Pl1. The RAPD marker is situated at 43.7 cM from Pl1. The significance and applications of these markers in sunflower breeding are discussed. 相似文献
3.
M A Gedil M B Slabaugh S Berry R Johnson R Michelmore J Miller T Gulya S J Knapp 《Génome》2001,44(2):205-212
Disease resistance gene candidates (RGCs) belonging to the nucleotide-binding site (NBS) superfamily have been cloned from numerous crop plants using highly conserved DNA sequence motifs. The aims of this research were to (i) isolate genomic DNA clones for RGCs in cultivated sunflower (Helianthus annuus L.) and (ii) map RGC markers and Pl1, a gene for resistance to downy mildew (Plasmopara halstedii (Farl.) Berl. & de Toni) race 1. Degenerate oligonucleotide primers targeted to conserved NBS DNA sequence motifs were used to amplify RGC fragments from sunflower genomic DNA. PCR products were cloned, sequenced, and assigned to 11 groups. RFLP analyses mapped six RGC loci to three linkage groups. One of the RGCs (Ha-4W2) was linked to Pl1, a downy mildew resistance gene. A cleaved amplified polymorphic sequence (CAPS) marker was developed for Ha-4W2 using gene-specific oligonucleotide primers. Downy mildew susceptible lines (HA89 and HA372) lacked a 276-bp Tsp5091 restriction fragment that was present in downy mildew resistant lines (HA370, 335, 336, 337, 338, and 339). HA370 x HA372 F2 progeny were genotyped for the Ha-4W2 CAPS marker and phenotyped for resistance to downy mildew race 1. The CAPS marker was linked to but did not completely cosegregate with Pl1 on linkage group 8. Ha-4W2 was found to comprise a gene family with at least five members. Although genetic markers for Ha-4W2 have utility for marker-assisted selection, the RGC detected by the CAPS marker has been ruled out as a candidate gene for Pl1. Three of the RGC probes were monomorphic between HA370 and HA372 and still need to be mapped and screened for linkage to disease resistance loci. 相似文献
4.
Sujatha Mulpuri Zhao Liu Jiuhuan Feng Thomas J. Gulya Chao-Chien Jan 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,119(5):795-803
The inheritance of resistance to sunflower downy mildew (SDM) derived from HA-R5 conferring resistance to nine races of the
pathogen has been determined and the new source has been designated as Pl
13
. The F2 individuals and F3 families of the cross HA-R5 (resistant) × HA 821 (susceptible) were screened against the four predominant SDM races 300,
700, 730, and 770 in separate tests which indicated dominant control by a single locus or a cluster of tightly linked genes.
Bulked segregant analysis (BSA) was carried out on 116 F2 individuals with 500 SSR primer pairs that resulted in the identification of 10 SSR markers of linkage groups 1 (9 markers)
and 10 (1 marker) of the genetic map (Tang et al. in Theor Appl Genet 105:1124–1136, 2002) that distinguished the bulks. Of these, the SSR marker ORS 1008 of linkage group 10 was tightly linked (0.9 cM) to the Pl
13
gene. Genotyping the F2 population and linkage analysis with 20 polymorphic primer pairs located on linkage group 10 failed to show linkage of the
markers with downy mildew resistance and the ORS 1008 marker. Nevertheless, validation of polymorphic SSR markers of linkage
group 1 along with six RFLP-based STS markers of linkage group 12 of the RFLP map of Jan et al. (Theor Appl Genet 96:15–22,
1998) corresponding to linkage group 1 of the SSR map, mapped seven SSR markers (ORS 965-1, ORS 965-2, ORS 959, ORS 371, ORS 716,
and ORS 605) including ORS 1008 and one STS marker (STS10D6) to linkage group 1 covering a genetic distance of 65.0 cM. The
Pl
13
gene, as a different source with its location on linkage group 1, was flanked by ORS 1008 on one side at a distance of 0.9 cM
and ORS 965-1 on another side at a distance of 5.8 cM. These closely linked markers to the Pl
13
gene provide a valuable basis for marker-assisted selection in sunflower breeding programs. 相似文献
5.
A Genetic Map of Lettuce (Lactuca sativa L.) with Restriction Fragment Length Polymorphism, Isozyme, Disease Resistance and Morphological Markers 总被引:7,自引:2,他引:5
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A detailed linkage map of lettuce was constructed using 53 genetic markers including 41 restriction fragment length polymorphism (RFLP) loci, five downy mildew resistance genes, four isozyme loci and three morphological markers. The genetic markers were distributed into nine linkage groups and cover 404 cM which may be 25-30% of the lettuce genome. The majority (31 of 34) of the RFLP probes detected single segregating loci, although seven of these may have been homologous to further monomorphic loci. When several loci were detected by a single probe, the loci were generally linked, suggesting tandem duplications. One probe, however, detected loci in three linkage groups suggesting translocations. The five downy mildew resistance genes (Dm1, Dm3, Dm4, Dm5/8 and Dm13), segregating in the Calmar x Kordaat cross, represented each of the four resistance gene linkage groups. Dm5/8 is flanked by two cDNA loci, each located 10 cM away. These flanking markers will be used to study the source of variation in downy mildew genes and are also part our strategy to clone resistance genes. 相似文献
6.
G. M. Timmerman T. J. Frew N. F. Weeden A. L. Miller D. S. Goulden 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1994,88(8):1050-1055
Linkage analysis was used to determine the genetic map location of er-1, a recessive gene conditioning resistance to powdery mildew, on the Pisum sativum genome. Genetic linkage was demonstrated between er-1 and linkage group 6 markers after analyzing the progeny of two crosses, an F2 population and a set of recombinant inbred lines. The classes of genetic markers surrounding er-1 include RFLP, RAPD and allozyme markers as well as the morphological marker Gty. A RAPD marker tightly linked to er-1 was identified by bulked segregant analysis. After DNA sequence characterization, specific PCR primers were designed to convert this RAPD marker into a sequence characterized amplified region (SCAR). 相似文献
7.
Ana Campa Ramón Giraldez Juan José Ferreira 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,119(1):1-11
Resistance to nine races of the pathogenic fungus Colletotrichum lindemuthianum, causal agent of anthracnose, was evaluated in F3 families derived from the cross between the anthracnose differential bean cultivars TU (resistant to races, 3, 6, 7, 31,
38, 39, 102, and 449) and MDRK (resistant to races, 449, and 1545). Molecular marker analyses were carried out in the F2 individuals in order to map and characterize the anthracnose resistance genes or gene clusters present in these two differential
cultivars. The results of the combined segregation indicate that at least three independent loci conferring resistance to
anthracnose are present in TU. One of them, corresponding to the previously described anthracnose resistance locus Co-5, is located in linkage group B7, and is formed by a cluster of different genes conferring specific resistance to races,
3, 6, 7, 31, 38, 39, 102, and 449. Evidence of intra-cluster recombination between these specific resistance genes was found.
The second locus present in TU confers specific resistance to races 31 and 102, and the third locus confers specific resistance
to race 102, the location of these two loci remains unknown. The resistance to race 1545 present in MDRK is due to two independent
dominant genes. The results of the combined segregation of two F4 families showing monogenic segregation for resistance to race 1545 indicates that one of these two genes is linked to marker
OF10530, located in linkage group B1, and corresponds to the previously described anthracnose resistance locus Co-1. The second gene conferring resistance to race 1545 in MDRK is linked to marker Pv-ctt001, located in linkage group B4,
and corresponds to the Co-3/Co-9 cluster. The resistance to race 449 present in MDRK is conferred by a single gene, located in linkage group B4, probably
included in the same Co-3/Co-9 cluster.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
8.
Vincourt P As-Sadi F Bordat A Langlade NB Gouzy J Pouilly N Lippi Y Serre F Godiard L Tourvieille de Labrouhe D Vear F 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2012,125(5):909-920
Major gene resistance to sunflower downy mildew (Plasmopara halstedii) races 304 and 314 was found to segregate independently from the resistance to races 334, 307 and 304 determined by the gene Pl2, already positioned on Linkage Group (LG) 8 of sunflower molecular maps. Using a consensus SSR-SNP map constructed from the INEDI RIL population and a new RIL population FU?×?PAZ2, the positions of Pl2 and Pl5 were confirmed and the new gene, denoted Pl21, was mapped on LG13, at 8?cM from Pl5. The two RIL populations were observed for their quantitative resistance to downy mildew in the field and both indicated the existence of a QTL on LG8 at 20-40?cM from the major resistance gene cluster. In addition, for the INEDI population, a strong QTL on LG10, reported previously, was confirmed and a third QTL was mapped on LG7. A growth chamber test methodology, significantly correlated with field results, also revealed the major QTL on LG10, explaining 65?% of variability. This QTL mapped in the same area as a gene involved in stomatal opening and root growth, which may be suggested as a possible candidate to explain the control of this character. These results indicate that it should be possible to combine major genes and other resistance mechanisms, a strategy that could help to improve durability of sunflower resistance to downy mildew. 相似文献
9.
Radwan O Bouzidi MF Nicolas P Mouzeyar S 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2004,109(1):176-185
Sunflower downy mildew, caused by Plasmopara halstedii, is one of the major diseases of this crop. Development of elite sunflower lines resistant to different races of this oomycete seems to be the most efficient method to limit downy mildew damage. At least two different gene clusters conferring resistance to different races of P. halstedii have been described. In this work we report the cloning and mapping of two full-length resistance gene analogs (RGA) belonging to the CC-NBC-LRR class of plant resistance genes. The two sequences were then used to develop 14 sequence tagged sites (STS) within the Pl5/Pl8 locus conferring resistance to a wide range of P. halstedii races. These STSs will be useful in marker-assisted selection programs.Communicated by C. Möllers 相似文献
10.
Liu Z Gulya TJ Seiler GJ Vick BA Jan CC 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2012,125(1):121-131
The major genes controlling sunflower downy mildew resistance have been designated as Pl genes. Ten of the more than 20 Pl genes reported have been mapped. In this study, we report the molecular mapping of gene Pl(16) in a sunflower downy mildew differential line, HA-R4. It was mapped on the lower end of linkage group (LG) 1 of the sunflower reference map, with 12 markers covering a distance of 78.9 cM. One dominant simple sequence repeat (SSR) marker, ORS1008, co-segregated with Pl(16), and another co-dominant expressed sequence tag (EST)-SSR marker, HT636, was located 0.3 cM proximal to the Pl(16) gene. The HT636 marker was also closely linked to the Pl(13) gene in another sunflower differential line, HA-R5. Thus the Pl(16) and Pl(13) genes were mapped to a similar position on LG 1 that is different from the previously reported Pl(14) gene. When the co-segregating and tightly linked markers for the Pl(16) gene were applied to other germplasms or hybrids, a unique band pattern for the ORS1008 marker was detected in HA-R4 and HA-R5 and their F(1) hybrids. This is the first report to provide two tightly linked markers for both the Pl(16) and Pl(13) genes, which will facilitate marker-assisted selection in sunflower resistance breeding, and provide a basis for the cloning of these genes. 相似文献
11.
Identification and mapping of pm2026: a recessive powdery mildew resistance gene in an einkorn (Triticum monococcum L.) accession 总被引:1,自引:1,他引:0
Xu H Yao G Xiong L Yang L Jiang Y Fu B Zhao W Zhang Z Zhang C Ma Z 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2008,117(4):471-477
Triticum monococcum accession TA2026 showed resistance to wheat powdery mildew. To identify the resistance gene and transfer it to common wheat,
genetic analysis and molecular mapping were conducted using an F2 population and derived F3 families from the cross of TA2026 × M389. The results indicated that TA2026 possessed a recessive powdery mildew resistance
gene. This gene was mapped to the terminal portion of chromosome 5AmL and flanked by SSR marker loci Xcfd39 and Xgwm126. Eight RFLP markers previously mapped to the terminal chromosome 5AmL were converted into STS markers. Three loci, detected by MAG1491, MAG1493 and MAG1494, the STS markers derived from RFLP
probes CDO1312, PSR164 and PSR1201, respectively, were linked to this resistance gene with Xmag1493 only 0.9 cM apart from it. In addition, the STS marker MAG2170 developed from the tentative consensus wheat cDNA encoding
the Mlo-like protein identified a locus co-segregating with Xmag1493. This is the first recessive powdery mildew resistance gene identified on chromosome 5Am, and is temporarily designated pm2026. We have successfully transferred it to a tetraploid background, and this resistance stock will now be used as the bridge
parent for its transfer to common wheat. 相似文献
12.
N. D. Young L. Kumar D. Menancio-Hautea D. Danesh N. S. Talekar S. Shanmugasundarum D. H. Kim 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1992,84(7-8):839-844
Summary Bruchids (genus Callosobruchus) are among the most destructive insect pests of mungbeans and other members of the genus, Vigna. Genetic resistance to bruchids was previously identified in a wild mungbean relative, TC1966. To analyze the underlying genetics, accelerate breeding, and provide a basis for map-based cloning of this gene, we have mapped the TC1966 bruchid resistance gene using restriction fragment length polymorphism (RFLP) markers. Fifty-eight F2 progeny from a cross between TC1966 and a susceptible mungbean cultivar were analyzed with 153 RFLP markers. Resistance mapped to a single locus on linkage group VIII, approximately 3.6 centimorgans from the nearest RFLP marker. Because the genome of mungbean is relatively small (estimated to be between 470 and 560 million base pairs), this RFLP marker may be suitable as a starting point for chromosome walking. Based on RFLP analysis, an individual was also identified in the F2 population that retained the bruchid resistance gene within a tightly linked double crossover. This individual will be valuable in developing resistant mungbean lines free of linkage drag. 相似文献
13.
E. Dirlewanger P. G. Isaac S. Ranade M. Belajouza R. Cousin D. de Vienne 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1994,88(1):17-27
An F2 population of pea (Pisum sativum L.) consisting of 174 plants was analysed by restriction fragment length polymorphism (RFLP) and random amplified polymorphic DNA (RAPD) techniques. Ascochyta pisi race C resistance, plant height, flowering earliness and number of nodes were measured in order to map the genes responsible for their variation. We have constructed a partial linkage map including 3 morphological character genes, 4 disease resistance genes, 56 RFLP loci, 4 microsatellite loci and 2 RAPD loci. Molecular markers linked to each resistance gene were found: Fusarium wilt (6 cM from Fw), powdery mildew (11 cM from er) and pea common Mosaic virus (15 cM from mo). QTLs (quantitative traits loci) for Ascochyta pisi race C resistance were mapped, with most of the variation explained by only three chromosomal regions. The QTL with the largest effect, on chromosome 4, was also mapped using a qualitative, Mendelian approach. Another QTL displayed a transgressive segregation, i.e. the parental line that was susceptible to Ascochyta blight had a resistance allele at this QTL. Analysis of correlations between developmental traits in terms of QTL effects and positions suggested a common genetic control of the number of nodes and earliness, and a loose relationship between these traits and height. 相似文献
14.
Radwan O Bouzidi MF Vear F Philippon J De Labrouhe DT Nicolas P Mouzeyar S 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2003,106(8):1438-1446
The resistance of sunflower, Helianthus annuus L., to downy mildew, caused by Plasmopara halstedii, is conferred by major genes denoted by Pl. Using degenerate and specific primers, 16 different resistance gene analogs (RGAs) have been cloned and sequenced. Sequence comparison and Southern-blot analysis distinguished six classes of RGA. Two of these classes correspond to TIR-NBS-LRR sequences while the remaining four classes correspond to the non-TIR-NBS-LRR type of resistance genes. The genetic mapping of these RGAs on two segregating F2 populations showed that the non-TIR-NBS-LRR RGAs are clustered and linked to the Pl5/ Pl8 locus for resistance to downy mildew in sunflower. These and other results indicate that different Pl loci conferring resistance to the same pathogen races may contain different sequences. 相似文献
15.
Z. W. Zhang G. J. Ma J. Zhao S. G. Markell L. L. Qi 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2017,130(1):29-39
Key message
A new downy mildew resistance gene, Pl 19 , was identified from wild Helianthus annuus accession PI 435414, introduced to confection sunflower, and genetically mapped to linkage group 4 of the sunflower genome.Abstract
Wild Helianthus annuus accession PI 435414 exhibited resistance to downy mildew, which is one of the most destructive diseases to sunflower production globally. Evaluation of the 140 BC1F2:3 families derived from the cross of CMS CONFSCLB1 and PI 435414 against Plasmopara halstedii race 734 revealed that a single dominant gene controls downy mildew resistance in the population. Bulked segregant analysis conducted in the BC1F2 population with 860 simple sequence repeat (SSR) markers indicated that the resistance derived from wild H. annuus was associated with SSR markers located on linkage group (LG) 4 of the sunflower genome. To map and tag this resistance locus, designated Pl 19 , 140 BC1F2 individuals were used to construct a linkage map of the gene region. Two SSR markers, ORS963 and HT298, were linked to Pl 19 within a distance of 4.7 cM. After screening 27 additional single nucleotide polymorphism (SNP) markers previously mapped to this region, two flanking SNP markers, NSA_003564 and NSA_006089, were identified as surrounding the Pl 19 gene at a distance of 0.6 cM from each side. Genetic analysis indicated that Pl 19 is different from Pl 17 , which had previously been mapped to LG4, but is closely linked to Pl 17 . This new gene is highly effective against the most predominant and virulent races of P. halstedii currently identified in North America and is the first downy mildew resistance gene that has been transferred to confection sunflower. The selected resistant germplasm derived from homozygous BC2F3 progeny provides a novel gene for use in confection sunflower breeding programs.16.
Inheritance of partial leaf rust and stripe rust resistance of a Thatcher wheat 90RN2491, earlier reported to carry two doses
of the gene pairLr34-Yr18 and the reference line RL6058 (6*Thatcher/PI58548) for theLr34-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 F1, F2 and F3 generations from these crosses were assessed for rust severity against leaf rust race 77-5 and stripe rust race 46S119. The
F2 and F3 generations from the crosses of RL6058 and 90RN2491 with WL711, segregated 15 resistant : 1 susceptible (F2) and 7 homozygous resistant : 8 segregating : 1 homozygous susceptible (F3) 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 isLr34 and the linked geneYr18, respectively. The second leaf rust resistance gene in both the Thatcher lines segregated independently of stripe rust resistance.
Therefore, it is notLr34 and it remains unidentified. 相似文献
17.
Molecular identification of powdery mildew resistance genes in common wheat (Triticum aestivum L.) 总被引:8,自引:0,他引:8
L. Hartl H. Weiss U. Stephan F. J. Zeller A. Jahoor 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1995,90(5):601-606
RFLP markers for the wheat powdery mildew resistance genes Pm1 and Pm2 were tagged by means of near-isogenic lines. The probe Whs178 is located 3 cM from the Pm1 gene. For the powdery mildew resistance gene Pm2, two markers were identified. The linkage between the Pm2 resistance locus and one of these two probes was estimated to be 3 cM with a F2 population. Both markers can be used to detect the presence of the corresponding resistance gene in commercial cultivars. Bulked segregant analysis was applied to identify linkage disequillibrium between the resistance gene Pm18 and the abovementioned marker, which was linked to this locus at a distance of 4 cM. Furthermore, the RAPD marker OPH-111900 (5-CTTCCGCAGT-3) was selected with pools created from a population segregating for the resistance of Trigo BR 34. The RAPD marker was mapped about 13 cM from this resistance locus. 相似文献
18.
Dussle CM Hahn V Knapp SJ Bauer E 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2004,109(5):1083-1086
The Pl
Arg
locus in the sunflower (Helianthus annuus L.) inbred line Arg1575-2 conferring resistance to at least four tested races (300, 700, 730, 770) of downy mildew (Plasmopara halstedii) was localized by the use of simple sequence repeat (SSR) markers. Bulked segregant analysis (BSA) was conducted on 126 individuals of an F2 progeny from a cross between a downy mildew susceptible line, CmsHA342, and Arg1575-2. Twelve SSR markers linked to the Pl
Arg
locus were identified. All markers were located proximal to Pl
Arg
on linkage group LG1 based on the map of Yu et al. (2003) in a window of 9.3 cM. Since Pl
Arg
was mapped to a linkage group different from all other Pl genes previously mapped with SSRs, it can be concluded that Pl
Arg
provides a new source of resistance against P. halstedii in sunflower. 相似文献
19.
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
20.
Qiu YC Zhou RH Kong XY Zhang SS Jia JZ 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2005,111(8):1524-1531
A powdery mildew resistance gene from Triticum urartu Tum. accession UR206 was successfully transferred into hexaploid wheat (Triticum aestivum L.) through crossing and backcrossing. The F1 plants, which had 28 chromosomes and an average of 5.32 bivalents and 17.36 univalents in meiotic pollen mother cells (PMC),
were obtained through embryos rescued owing to shriveling of endosperm in hybrid seed of cross Chinese Spring (CS) × UR206.
Hybrid seeds were produced through backcrossing F1 with common wheat parents. The derivative lines had normal chromosome numbers and powdery mildew resistance similar to the
donor UR206, indicating that the powdery mildew resistance gene originating from T. urartu accession UR206 was successfully transferred and expressed in a hexaploid wheat background. Genetic analysis indicated that
a single dominant gene controlled the powdery mildew resistance at the seedling stage. To map and tag the powdery mildew resistance
gene, 143 F2 individuals derived from a cross UR206 × UR203 were used to construct a linkage map. The resistant gene was mapped on the
chromosome 7AL based on the mapped microsatellite makers. The map spanned 52.1 cM and the order of these microsatellite loci
agreed well with the established microsatellite map of chromosome arm 7AL. The resistance gene was flanked by the microsatellite
loci Xwmc273 and Xpsp3003, with the genetic distances of 2.2 cM and 3.8 cM, respectively. On the basis of the origin and chromosomal location of the
gene, it was temporarily designated PmU. 相似文献