共查询到20条相似文献,搜索用时 15 毫秒
1.
Bernadette M. Henares Johannes W. Debler Lina M. FarfanCaceres Christina R. Grime Robert A. Syme Sara N. Blake Herdina Jennifer A. Davidson Richard P. Oliver Karam B. Singh Lars G. Kamphuis Robert C. Lee 《Molecular Plant Pathology》2022,23(7):984
Ascochyta lentis is a fungal pathogen that causes ascochyta blight in the important grain legume species lentil, but little is known about the molecular mechanism of disease or host specificity. We employed a map‐based cloning approach using a biparental A. lentis population to clone the gene AlAvr1‐1 that encodes avirulence towards the lentil cultivar PBA Hurricane XT. The mapping population was produced by mating A. lentis isolate P94‐24, which is pathogenic on the cultivar Nipper and avirulent towards Hurricane, and the isolate AlKewell, which is pathogenic towards Hurricane but not Nipper. Using agroinfiltration, we found that AlAvr1‐1 from the isolate P94‐24 causes necrosis in Hurricane but not in Nipper. The homologous corresponding gene in AlKewell, AlAvr1‐2, encodes a protein with amino acid variation at 23 sites and four of these sites have been positively selected in the P94‐24 branch of the phylogeny. Loss of AlAvr1‐1 in a gene knockout experiment produced a P94‐24 mutant strain that is virulent on Hurricane. Deletion of AlAvr1‐2 in AlKewell led to reduced pathogenicity on Hurricane, suggesting that the gene may contribute to disease in Hurricane. Deletion of AlAvr1‐2 did not affect virulence for Nipper and AlAvr1‐2 is therefore not an avirulence gene for Nipper. We conclude that the hemibiotrophic pathogen A. lentis has an avirulence effector, AlAvr1‐1, that triggers a hypersensitive resistance response in Hurricane. This is the first avirulence gene to be characterized in a legume pathogen from the Pleosporales and may help progress research on other damaging Ascochyta pathogens. 相似文献
2.
RAPD markers linked to a gene for resistance to pine needle gall midge in Japanese black pine (Pinus thunbergii) 总被引:2,自引:0,他引:2
T. Kondo K. Terada E. Hayashi N. Kuramoto M. Okamura H. Kawasaki 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,100(3-4):391-395
Linkage of RAPD markers to a single dominant gene for resistance to pine needle gall midge was investigated in Japanese black
pine (Pinus thunbergii). Three primers that generated linked markers were found after 1160 primers were screened by bulked segregant analysis. The
distances between the resistance gene, R, and the marker genes OPC06580, OPD01700, and OPAX192100 were 5.1 cM, 6.7 cM and 13.6 cM, respectively. OPC06580 was in coupling phase to R, whereas OPD01700 and OPAX192100 were in repulsion phase to R. A linkage map for a resistant tree was constructed using 96 macrogametophytes. In linkage analysis, 98 out of 127 polymorphic
markers were assigned to 17 linkage groups and six linked pairs. The total length of this map was 1469.8 cM, with an average
marker density of 15.6 cM. The genome length was estimated to be 2138.3 cM, and the derived linkage map covered 67.5% of the
genome. Although the linked markers OPC06580, OPAX192100, and OPD01700, belonged to the same linkage group, no precise positions were found for OPC06580 or OPD01700.
Received: 15 May 1999 / Accepted: 29 July 1999 相似文献
3.
O. E. Scholten R. M. Klein-Lankhorst D. G. Esselink T. S. M. De Bock W. Lange 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(1):123-130
Molecular markers linked to resistance genes are useful to facilitate the introgression of one or more of these genes in
breeding materials. Following the approach of bulked segregant analysis, RAPD markers linked to resistance genes against beet
necrotic yellow vein virus were identified in the four Beta accessions Holly-1-4, R104, R128 and WB42. Two primers were found which generate RAPD markers tightly linked to resistance
in segregating families of Holly-1-4, R104 and R128, indicating that the resistance genes in these accessions might be situated
at the same locus. Other, specific, primers were identified which generate RAPD markers linked to resistance in each of these
accessions. Short-range maps were established around the resistance locus in these accessions. For WB42, RAPD markers were
only identified at a relatively large distance from the resistance gene. Conversion of three RAPD primers of Holly-1-4, R104
and R128 into STS primers resulted in STS markers which can be readily used for marker-assisted selection in breeding programmes.
Received: 8 January 1996 / Accepted: 14 June 1996 相似文献
4.
S. M. Udupa F. Weigand M. C. Saxena G. Kahl 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(1-2):299-307
The poor definition of variation in the ascochyta blight fungus (Ascochyta rabiei) has historically hindered breeding for resistance to the chickpea (Cicer arietinum L.) blight disease in West Asia and North Africa. We have employed 14 RAPD markers and an oligonucleotide probe complementary
to the microsatellite sequence (GATA)4 to construct a genotype-specific DNA fragment profile from periodically sampled Syrian field isolates of this fungus. By
using conventional pathogenicity tests and genome analysis with RAPD and microsatellite markers, we demonstrated that the
DNA markers distinguish variability within and among the major pathotypes of A. rabiei and resolved each pathotypes into several genotypes. The genetic diversity estimate based on DNA marker analysis within pathotypes
was highest for the least-aggressive pathotype (pathotype I), followed by the aggressive (pathotype II) and the most-aggressive
pathotype (pathotype III). The pair-wise genetic distance estimated for all the isolates varied from 0.00 to 0.39, indicating
a range from a clonal to a diverse relationship. On the basis of genome analysis, and information on the spatial and temporal
distribution of the pathogen, a general picture of A. rabiei evolution in Syria is proposed.
Received: 10 January 1998 / Accepted: 23 January 1998 相似文献
5.
RAPD and SCAR markers linked to the Ma1 root-knot nematode resistance gene in Myrobalan plum (Prunus cerasifera Ehr.) 总被引:1,自引:0,他引:1
A. C. Lecouls M. J. Rubio-Cabetas J. C. Minot R. Voisin A. Bonnet G. Salesses E. Dirlewanger D. Esmenjaud 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,99(1-2):328-335
The Myrobalan plum (Prunus cerasifera) is a self-incompatible species in which the clones P.2175, P.1079 and P.2980 are highly resistant to all root-knot nematodes
(RKN), Meloidogyne spp. Each clone bears a single major dominant gene, designated Ma1, Ma2 and Ma3 respectively, that controls a high and wide-spectrum resistance. Bulked segregant analysis (BSA) and random amplified polymorphic
DNA (RAPD) analysis were both performed to detect markers linked to the Ma1 gene using three segregating progenies from P.2175 (Ma1 ma1) crossed by three host parents (ma1 ma1). Four dominant coupling-phase markers were identified from a total of 660 10-base primers tested. The resulting linkage
map spans 14.7 cM and comprises three markers located on the same side of Ma1 and one marker located on the other side. The nearest markers (OPAL19720 and OPA161400) are located at 3.7 and 6.7 cM, respectively, on each side of the gene. Among the three markers that could be successfully
converted into sequence characterized amplified region (SCAR) markers, two of them (SCAL19690 and SCAN12620) were scored as dominant markers whereas the third (SCAO19770) failed to produce any polymorphism. SCAL19, and to a lesser extent SCAN12, can be used reliably in the marker-assisted selection
of Prunus rootstocks. These markers are adequate to identify the Ma1 RKN resistance gene in intraspecific segregating progenies and will be suitable for the creation of interspecific rootstocks
involving Myrobalan plum. Some of the RAPD and SCAR markers for Ma1 were also recovered in clones P.1079 and P.2980, but not in additional host clones, suggesting that Ma1, Ma2 and Ma3 are either allelic or at least closely linked.
Received: 22 September 1998 / Accepted: 19 December 1998 相似文献
6.
I. Eujayl M. Baum W. Powell W. Erskine E. Pehu 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(1-2):83-89
A genetic linkage map of Lens sp. was constructed with 177 markers (89 RAPD, 79 AFLP, six RFLP and three morphological markers) using 86 recombinant inbred
lines (F6:8) obtained from a partially interspecific cross. The map covered 1073 cM of the lentil genome with an average distance of
6.0 cM between adjacent markers. Previously mapped RFLP markers were used as anchor probes. The morphological markers, pod
indehiscence, seed-coat pattern and flower-color loci were mapped. Out of the total linked loci, 8.4% showed segregation distortion.
More than one-fourth of the distorted loci were clustered in one linkage group. AFLP markers showed more segregation distortion
than the RAPD markers. The AFLP and RAPD markers were intermingled and clustering of AFLPs was seldom observed. This is the
most extensive genetic linkage map of lentil to-date. The marker density of this map could be used for the identification
of markers linked to quantitative trait loci in this population.
Received: 6 November 1997 / Accepted: 10 February 1998 相似文献
7.
Y. H. Lu J. M. Melero-Vara J. A. García-Tejada P. Blanchard 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,100(3-4):625-632
A consensus molecular linkage map of 61.9 cM containing the Or5 gene, which confers resistance to race E of broomrape orobanche cumana, five SCAR markers (three dominant, two codominant) and one RAPD marker were identified based on segregation data scored
from two F2 populations of susceptible×resistant sunflower line crosses. Bulked segregant analysis was carried out to generate the five
SCAR markers, while the single RAPD marker in the group was identified from 61 segregating RAPD markers that were directly
screened on one of the two F2 populations. The five SCAR markers, RTS05, RTS28, RTS40, RTS29 and RTS41, were significantly (LOD≥4.0) linked to the Or5 gene and mapped separately at 5.6, 13.6, 14.1, 21.4 and 39.4 cM from the Or5 locus on one side, while the RAPD marker, UBC120_660, was found at 22.5 cM (LOD=1.4) on the opposite side. These markers
should facilitate the efficient transfer of the resistance gene among sunflower breeding lines. As the first report on molecular
markers linked to a broomrape resistance gene, the present work provides a starting point to study other genes and to examine
the hypothesis of the clustering of broomrape resistance genes in sunflower.
Received: 16 September 1998 / Accepted: 22 June 1999 相似文献
8.
Identification of RAPD markers linked to a locus involved in quantitative resistance to TYLCV in tomato by bulked segregant analysis 总被引:8,自引:0,他引:8
V. Chagué J. C. Mercier M. Guénard A. de Courcel F. Vedel 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,95(4):671-677
In tomato, Bulked Segregant Analysis was used to identify random amplified polymorphic DNA (RAPD) markers linked to a quantitative
trait locus (QTL) involved in the resistance to the Tomato Yellow Leaf Curl Virus. F4 lines were distributed into two pools, each consisting of the most resistant and of the most susceptible individuals, respectively.
Both pools were screened using 600 random primers. Four RAPD markers were found to be linked to a QTL responsible for up to
27.7% of the resistance. These markers, localized in the same linkage group within a distance of 17.3 cM, were mapped to chromosome
6 on the tomato RFLP map.
Received: 21 August 1996 / Accepted: 4 April 1997 相似文献
9.
J. T. Ouédraogo V. Maheshwari D. K. Berner C.-A. St-Pierre F. Belzile M. P. Timko 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,102(6-7):1029-1036
AFLP and bulked segregant analysis were used to identify molecular markers linked to resistance of cowpea [Vigna ungiculata
(L.) Walp.] to parasitism by Striga gesnerioides (Willd.) Vatke. Segregation analysis of F2 progeny from a cross of Tvx3236, a Striga-susceptible line, with IT82D-849, a resistant cultivar, showed that resistance
to S. gesnerioides race 1 from Burkina Faso was controlled by a single dominant gene, designated Rsg2–1. Three AFLP markers
were identified that are tightly linked to Rsg2–1: E-AAC/M-CAA300 (2.6 cM), E-ACT/M-CAA524 (0.9 cM), and E-ACA/M-CAT140/150 (0.9 cM), which appears to be codominant. Segregation analysis of a different F2 population resulting from a cross of the Striga-susceptible line IT84S-2246–4 with Tvu 14676, a S. gesnerioides race 3 resistant
line, showed that resistance to S. gesnerioides race 3 was also controlled by a single dominant gene, designated Rsg4–3. Six
AFLP markers linked to Rsg4–3 were identified: E-ACA/M-CAG120 (10.1 cM), E-AGC/M-CAT80 (4.1 cM), E-ACA/M-CAT150 (2.7 cM), E-AGC/M-CAT150 (3.6 cM), E-AAC/M-CAA300 (3.6 cM), and E-AGC/M-CAT70 (5.1 cM). Segregation analysis of the E-AAC/M-CAA300 and E-ACA/M-CAG120 markers in recombinant inbred lines derived from IT84S-2049×524B determined that both are located within linkage group 1
of the cowpea genetic map. The identification of AFLP markers linked to Striga resistance provides a stepping stone for a
marker-assisted selection program and the eventual cloning and characterization of the gene(s) encoding resistance to this
noxious parasitic weed.
Received: 24 April 2000 / Accepted: 21 August 2000 相似文献
10.
D. K. Santra G. Singh W. J. Kaiser V. S. Gupta P. K. Ranjekar F. J. Muehlbauer 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,102(5):676-682
Genetic diversity in Ascochyta rabiei (Pass.) Labr., the causative agent of ascochyta blight of chickpea, was determined using 37 Indian, five American (USA),
three Syrian, and two Pakistani isolates. A total of 48 polymorphic RAPD markers were scored for each isolate and the data
used for cluster analysis. Most of the isolates clustered in the dendrogram essentially according to geographic origin. Based
on the two major clusters A and B, Indian isolates were grouped into two categories, type-A and type-B. Isolates of A. rabiei within the Punjab state were more diverse than isolates from other states in northwestern India. A DNA marker (ubc7561.6 kb), specific to Indian isolates was identified. This is the first report of a molecular diversity analysis of Indian isolates
of A. rabiei. The information may assist Indian chickpea breeders in the proper deployment of blight-resistant cultivars and in disease
management.
Received: 25 April 2000 / Accepted: 11 July 2000 相似文献
11.
P. Ling L. W. Duncan Z. Deng D. Dunn X. Hu S. Huang F.G. Gmitter Jr 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,100(7):1010-1017
Eleven RAPD markers linked to a gene region conferring resistance to citrus nematodes in an intergen-eric backcross family
were identified. Two sequence- characterized amplified region markers linked to a citrus tristeza virus resistance gene and
one selected resistance gene candidate marker were evaluated for their association with citrus nematode resistance. A nematode-susceptible
citrus hybrid, LB6-2 [Clementine mandarin (Citrus reticulata)×Hamlin orange (C. sinensis)], was crossed with the citrus nematode-resistant hybrid Swingle citrumelo (C. paradisi×Poncirus trifoliata) to produce 62 hybrids that were reproduced by rooted cuttings. The plants were grown in a greenhouse and inoculated with
nematodes isolated from infected field trees. The hybrids segregated widely for this trait in a continuous distribution, suggesting
possible polygenic control of the resistance. Bulked segregant analysis was used to identify markers associated with resistance
by bulking DNA samples from individuals at the phenotypic distribution extremes. Linkage relationships were established by
the inheritance of the markers in the entire population. A single major gene region that contributes to nematode resistance
was identified. The resistance was inherited in this backcross family from the grandparent Poncirus trifoliata as a single dominant gene. QTL analysis revealed that 53.6% of the phenotypic variance was explained by this major gene region.
The existence of other resistance-associated loci was suggested by the continuous phenotypic distribution and the fact that
some moderately susceptible hybrids possessed the resistance-linked markers. The markers may be useful in citrus rootstock
breeding programs if it can be demonstrated that they are valid in other genetic backgrounds.
Received: 4 May 1999 / Accepted: 21 September 1999 相似文献
12.
A. Lehmensiek A.M. Esterhuizen D. van Staden S. W. Nelson A. E. Retief 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,103(5):797-803
Bulked segregant analysis was used to identify amplified fragment length polymorphism markers (AFLPs) linked to quantitative
trait loci (QTLs) involved in the resistance to gray leaf spot (GLS) in maize. By using ten AFLP primer combinations 11 polymorphic
markers were identified and converted to sequence- specific PCR markers. Five of the 11 converted AFLPs were linked to three
GLS resistance QTLs. The markers were mapped to maize chromosomes 1, 3 and 5 using existing linkage maps of two commercially
available recombinant inbred-line populations. Converted restriction fragment length polymorphism markers and microsatellite
markers were used to obtain a more-precise localization for the detected QTLs. The QTL on chromosome 1 was localized in bin
1.05/06 and had a LOD score of 21. A variance of 37% was explained by the QTL. Two peaks were visible on chromosome 5, one
was localized in bin 5.03/04 and the other in bin 5.05/06. Both peaks had a LOD score of 5, and 11% of the variance was explained
by the QTLs. A variance of 8–10% was explained by the QTL on chromosome 3 (bin 3.04). The consistency of the QTLs was tested
across two F2 populations planted in consecutive years.
Received: 10.10.00 / Accepted: 26.01.01 相似文献
13.
A. Karthikeyan M. Sudha N. Senthil M. Pandiyan M. Raveendran P. Nagrajan 《Archives Of Phytopathology And Plant Protection》2013,46(6):712-716
Bulk segregant analysis (BSA) and random amplified polymorphic DNA (RAPD) techniques were used to analyse the F2 individuals of susceptible VBN (Gg) 2 × resistant KMG 189 to screen and identify the molecular marker linked to mungbean yellow mosaic virus (MYMV) resistant gene in mungbean. Two DNA bulks namely resistant bulks and susceptible bulks were setup by pooling equal amount of DNA from five randomly selected plants of each disease response. A total of 72 random sequence decamer oligonucleotide primers were used for RAPD analysis. Primer OPBB 05 (5′-GGGCCGAACA-3′) generated OPBB 05 260 fragment in resistant parent and their bulks but not in the susceptible parent and their bulks. Co segregation analysis was performed in resistant and susceptible F2 individuals, it confirmed that OPBB 05 260 marker was tightly linked to mungbean yellow mosaic virus resistant gene in mungbean. 相似文献
14.
C. Rameau D. Dénoue F. Fraval K. Haurogné J. Josserand V. Laucou S. Batge I. C. Murfet 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(5-6):916-928
Random amplified polymorphic DNA (RAPD) markers linked to two morphological markers ( fa and det), three ramosus genes (rms2, rms3 and rms4) and two genes conferring flowering response to photoperiod in pea (sn, dne) were selected by bulk segregant analysis on F2 populations. Two RAPD fragments were cloned and sequenced to generate the two SCAR markers V20 and S2 which are linked to
rms3 and dne, respectively. All these genes, except rms2, were previously located on the pea classical linkage map. Rms2 mapped to linkage group IB which contains the afila gene. Precise genetic maps of the regions containing the genes were obtained and compared to the RAPD map generated from
the recombinant inbred-lines population of the cross Térèse×K586. This cross was chosen because several mutants were obtained
from cultivars Térèse and Torsdag (K586 was derived from Torsdag). This collection of isogenic lines was used for the construction
of F2 mapping populations in which polymorphic RAPD markers were already known and mapped. Moreover, the well-known problem in
pea of variability in the linkage associations between crosses was avoided. This work contributes to the precise integration
between the classical map and the molecular maps existing in pea.
Received: 13 March 1998 / Accepted: 29 April 1998 相似文献
15.
A. Lehner M. A. Campbell N. C. Wheeler T. Pöykkö J. Glössl J. Kreike D. B. Neale 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1995,91(6-7):1092-1094
The pendula phenotype of Norway spruce [Picea abies (L.) Karst f. pendula] is characterized by narrow crowns and strong apical dominance and is controlled by a single dominant gene (P). This defined genetic control presents one of the few opportunities to map a single gene controlling a morphological trait in a forest tree. We used random amplified polymorphic DNA (RAPD) markers and bulked segregant analysis to identify one locus OPH10_720, linked to the pendula gene. The estimated recombination frequency (r) between OPH10_720 and P was 0.046 (SE
r
=0.032). Mapping of the pendula gene is an important first step towards the ultimate identification and cloning of this gene. 相似文献
16.
V. Chagué J. C. Mercier M. Guénard A. de Courcel F. Vedel 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1996,92(8):1045-1051
Bulked segregant analysis was used to identify random amplified polymorphic DNA (RAPD) markers linked to the Sw-5 gene for resistance to tomato spotted wilt virus (TSWV) in tomato. Using two pools of phenotyped individuals from one segregating population, we identified four RAPD markers linked to the gene of interest. Two of these appeared tightly linked to Sw-5, whereas another, linked in repulsion phase, enabled the identification of heterozygous and susceptible plants. After linkage analysis of an F2 population, the RAPD markers were shown to be linked to Sw-5 within a distance of 10.5 cM. One of the RAPD markers close to Sw-5 was used to develop a SCAR (sequence characterized amplified region) marker. Another RAPD marker was stabilized into a pseudo-SCAR marker by enhancing the specificity of its primer sequence without cloning and sequencing. RAPD markers were mapped to chromosome 9 on the RFLP tomato map developed by Tanksley et al. (1992). The analysis of 13 F3 families and eight BC2 populations segregating for resistance to TSWV confirmed the linkage of the RAPD markers found. These markers are presently being used in marker-assisted plant breeding. 相似文献
17.
L. C. Emebiri M. E. Devey A. C. Matheson M. U. Slee 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,95(1-2):119-124
Needle-to-stem unit rate (NESTUR) is a stem growth index of conifer seedlings that measures the efficiency of stemwood production
per unit of foliage growth. The random amplified polymorphic DNA (RAPD) technique was applied to haploid DNA from the megagametophytes
of a full-sib radiata pine cross to find markers linked to factors controlling the NESTUR trait. Using the bulked segregant
analysis approach, 23 of 933 primers displayed putative linkage to factors controlling NESTUR. Based on the genotypic analysis
of 174 individuals, two quantitative trait loci (QTLs) controlling NESTUR were identified at ANOVA P-levels of 0.01–0.001. The QTLs were identified by RAPD markers OPE-06450 and OPA-101200, which were linked to each other (r=7%), and UBC-333550, which was not linked to the other two. Linkage to components of NESTUR (increments in stem diameter and stem volume) was
demonstrated for UBC-333550, while the others were not linked to NESTUR components.
Received: 18 December 1996/Accepted: 24 January 1997 相似文献
18.
Mapping of QTLs conferring resistance to bacterial leaf streak in rice 总被引:13,自引:0,他引:13
D. Tang W. Wu W. Li H. Lu A. J. Worland 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,101(1-2):286-291
A large F2 and a RI population were separately derived from a cross between two indica rice varieties, one of which was highly resistant to bacterial leaf streak (BLS) and the other highly susceptible. Following
artificial inoculation of the RI population and over 2 years of testing, 11 QTLs were mapped by composite interval mapping
(CIM) on six chromosomes. Six of the QTLs were detected in both seasons. Eight of the QTLs were significant following stepwise
regression analysis, and of these, 5 with the largest effects were significant in both seasons. The detected QTLs explained
84.6% of the genetic variation in 1997. Bulked segregant analysis (BSA) of the extremes of the F2 population identified 3 QTLs of large effect. The 3 QTLs were dentical to 3 of the 5 largest QTLs detected by CIM. The independent
detection of the same QTLs using two methods of analysis in separate mapping populations verifies the existence of the QTLs
for BLS and provides markers to ease their introduction into elite varieties.
Received: 13 October 1999 / Accepted: 29 October 1999 相似文献
19.
M. Jean G. G. Brown B. S. Landry 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(3):431-438
We have used two targeting approaches [pairs of nearly isogenic lines (NILs) and bulked segregant analysis] to identify DNA
markers linked to the Rfp1 restorer gene for the pol CMS of canola (Brassica napus L.). We were able to target the Rfp1 locus as efficiently by comparing NILs as by bulked segregant analysis, and it was demonstrated in this instance that double-screening
strategies could significantly improve the overall targeting efficiency. The chance occurrence of shared homozygosity at specific
unlinked chromosomal regions in the bulks was found to limit the efficiency of bulked segregant analysis, while the efficiency
of NIL comparison was limited by residual DNA from the donor cultivar at scattered sites throughout the genome of the NILs.
Received: 6 June 1997 / Accepted: 12 February 1998 相似文献
20.
Identification of RAPD markers linked to genetic factors controlling the milling energy requirement of barley 总被引:2,自引:0,他引:2
K. J. Chalmers U. M. Barua C. A. Hackett W. T. B. Thomas R. Waugh W. Powell 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1993,87(3):314-320
Doubled haploid (DH) populations of barley have been used in combination with PCR-based polymorphic-assay procedures to identify molecular markers linked to genes controlling the milling energy requirement of the grain. Milling energy (ME) is a quantitative trait and locating individual quantitative trait loci (QTLs) involved the construction of bulks by combining DNA from DH families representing the extreme members of the distribution for ME. In addition, the individuals had alternative alleles at theRrn2 locus that has previously been shown to be linked to an ME QTL. The DNA bulks were screened with Randomly Amplified Polymorphic DNA (RAPD) markers and polymorphic amplification products tested for linkage to genes influencing the expression of ME in a DH population. Several markers were identified which are linked to a QTL controlling ME and the recombination fraction determined by maximum likelihood procedures. The results indicate that DHs in combination with RAPDs and bulked segregant analysis provide an efficient method for locating QTLs in barely. Furthermore, this approach is applicable to mapping other QTLs in a range of organisms from which DH or recombinant inbred lines can be extracted. 相似文献