scholarly journals A Molecular Genetic Map and Electrophoretic Karyotype of the Plant Pathogenic Fungus Cochliobolus sativus

2002 ◽  
Vol 15 (5) ◽  
pp. 481-492 ◽  
Author(s):  
Shaobin Zhong ◽  
Brian J. Steffenson ◽  
J. Patrick Martinez ◽  
Lynda M. Ciuffetti

A molecular genetic map was constructed and an electrophoretic karyotype was resolved for Cochliobolus sativus, the causal agent of spot blotch of barley and wheat. The genetic map consists of 27 linkage groups with 97 amplified fragment length polymorphism (AFLP) markers, 31 restriction fragment length polymorphism (RFLP) markers, two polymerase chain reaction amplified markers, the mating type locus (CsMAT), and a gene (VHv1) conditioning high virulence on barley cv. Bowman. These linkage groups covered a map distance of 849 cM. The virulence gene VHv1 cosegregated with six AFLP markers and was mapped on one of the major linkage groups. Fifteen chromosome-sized DNAs were resolved in C. sativus isolates ND93-1 and ND90Pr with contour-clamped homogeneous electric field (CHEF) electrophoresis combined with telo-mere probe analysis of comigrating chromosome-sized DNAs. The chromosome sizes ranged from 1.25 to 3.80 Mbp, and the genome size of the fungus was estimated to be approximately 33 Mbp. By hybridizing genetically mapped RFLP and AFLP markers to CHEF blots, 25 of the 27 linkage groups were assigned to specific chromosomes. The barley-specific virulence locus VHv1 was localized on a chromosome of 2.80 Mbp from isolate ND90Pr in the CHEF gel. The total map length of the fungus was estimated to be at least 1,329 cM based on the map distance covered by the linked markers and the estimated gaps. Therefore, the physical to genetic distance ratio is approximately 25 kb/cM. Construction of a high-resolution map around target loci will facilitate the cloning of the genes conferring virulence and other characters in C. sativus by a map-based cloning strategy.

Genetics ◽  
2002 ◽  
Vol 161 (4) ◽  
pp. 1673-1683 ◽  
Author(s):  
Niels Sandal ◽  
Lene Krusell ◽  
Simona Radutoiu ◽  
Magdalena Olbryt ◽  
Andrea Pedrosa ◽  
...  

Abstract A genetic map for the model legume Lotus japonicus has been developed. The F2 mapping population was established from an interspecific cross between L. japonicus and L. filicaulis. A high level of DNA polymorphism between these parents was the source of markers for linkage analysis and the map is based on a framework of amplified fragment length polymorphism (AFLP) markers. Additional markers were generated by restriction fragment length polymorphism (RFLP) and sequence-specific PCR. A total of 524 AFLP markers, 3 RAPD markers, 39 gene-specific markers, 33 microsatellite markers, and six recessive symbiotic mutant loci were mapped. This genetic map consists of six linkage groups corresponding to the six chromosomes in L. japonicus. Fluorescent in situ hybridization (FISH) with selected markers aligned the linkage groups to chromosomes as described in the accompanying article by Pedrosa  et al. (2002, this issue). The length of the linkage map is 367 cM and the average marker distance is 0.6 cM. Distorted segregation of markers was found in certain sections of the map and linkage group I could be assembled only by combining colormapping and cytogenetics (FISH). A fast method to position genetic loci employing three AFLP primer combinations yielding 89 markers was developed and evaluated by mapping three symbiotic loci, Ljsym1, Ljsym5, and Ljhar1-3.


Genome ◽  
2011 ◽  
Vol 54 (5) ◽  
pp. 391-401 ◽  
Author(s):  
M. Tyrka ◽  
P.T. Bednarek ◽  
A. Kilian ◽  
M. Wędzony ◽  
T. Hura ◽  
...  

A set of 90 doubled haploid (DH) lines derived from F1plants that originated from a cross between × Triticosecale Wittm. ‘Saka3006’ and ×Triticosecale Wittm. ‘Modus’, via wide crossing with maize, were used to create a genetic linkage map of triticale. The map has 21 linkage groups assigned to the A, B, and R genomes including 155 simple sequence repeat (SSR), 1385 diversity array technology (DArT), and 28 amplified fragment length polymorphism (AFLP) markers covering 2397 cM with a mean distance between two markers of 4.1 cM. Comparative analysis with wheat consensus maps revealed that triticale chromosomes of the A and B genomes were represented by 15 chromosomes, including combinations of 2AS.2AL#, 2AL#2BL, 6AS.6AL#, and 2BS.6AL# instead of 2A, 2B, and 6A. In respect to published maps of rye, substantial rearrangements were found also for chromosomes 1R, 2R, and 3R of the rye genome. Chromosomes 1R and 2R were truncated and the latter was linked with 3R. A nonhomogeneous distribution of markers across the triticale genome was observed with evident bias (48%) towards the rye genome. This genetic map may serve as a reference linkage map of triticale for efficient studies of structural rearrangements, gene mapping, and marker-assisted selection.


Genome ◽  
2009 ◽  
Vol 52 (8) ◽  
pp. 716-725 ◽  
Author(s):  
Andrea L. Blas ◽  
Qingyi Yu ◽  
Cuixia Chen ◽  
Olivia Veatch ◽  
Paul H. Moore ◽  
...  

A high-density genetic linkage map of papaya, previously developed using an F2 mapping population derived from the intraspecific cross AU9 × SunUp, was enriched with AFLP markers. The comprehensive genetic map presented here spans 945.2 cM and covers 9 major and 5 minor linkage groups containing 712 SSR, 277 AFLP, and 1 morphological markers. The average marker density for the 9 major linkage groups is 0.9 cM between adjacent markers, and the total number of gaps >5 cM was reduced from 48 to 27 in the current map. AFLPs generated by EcoRI/MseI primer combinations were distributed throughout the 14 linkage groups and resulted in several large locus order rearrangements within the 9 major linkage groups. Integration of AFLP markers provided tighter linkage association between loci, leading to a reduction in map distance on LGs 1, 2, and 4, which were inflated in the previous map, and correction of the marker order on LG8. Suppression of recombination in the male-specific Y region (MSY) of LG1 is further validated by the addition of 27 sex co-segregating AFLP markers. A large region of distorted segregation surrounding the MSY spans 54.4 cM and represents ∼71% of the linkage group. This comprehensive high-density genetic map provides a framework for mapping quantitative trait loci and for fine mapping as well as for comparative genomic studies of crop plant development and evolution.


Genome ◽  
2001 ◽  
Vol 44 (2) ◽  
pp. 213-221 ◽  
Author(s):  
Melaku Ayele Gedil ◽  
Crispin Wye ◽  
Simon Berry ◽  
Bart Segers ◽  
Johan Peleman ◽  
...  

Restriction fragment length polymorphism (RFLP) maps have been constructed for cultivated sunflower (Helianthus annuus L.) using three independent sets of RFLP probes. The aim of this research was to integrate RFLP markers from two sets with RFLP markers for resistance gene candidate (RGC) and amplified fragment length polymorphism (AFLP) markers. Genomic DNA samples of HA370 and HA372, the parents of the F2 population used to build the map, were screened for AFLPs using 42 primer combinations and RFLPs using 136 cDNA probes (RFLP analyses were performed on DNA digested with EcoRI, HindIII, EcoRV, or DraI). The AFLP primers produced 446 polymorphic and 1101 monomorphic bands between HA370 and HA372. The integrated map was built by genotyping 296 AFLP and 104 RFLP markers on 180 HA370 × HA372 F2 progeny (the AFLP marker assays were performed using 18 primer combinations). The HA370 × HA372 map comprised 17 linkage groups, presumably corresponding to the 17 haploid chromosomes of sunflower, had a mean density of 3.3 cM, and was 1326 cM long. Six RGC RFLP loci were polymorphic and mapped to three linkage groups (LG8, LG13, and LG15). AFLP markers were densely clustered on several linkage groups, and presumably reside in centromeric regions where recombination is reduced and the ratio of genetic to physical distance is low. Strategies for targeting markers to euchromatic DNA need to be tested in sunflower. The HA370 × HA372 map integrated 14 of 17 linkage groups from two independent RFLP maps. Three linkage groups were devoid of RFLP markers from one of the two maps.Key words: amplified fragment length polymorphism (AFLP), restriction fragment length polymorphism (RFLP), Helianthus, sunflower, genetic map.


Genetics ◽  
2001 ◽  
Vol 157 (3) ◽  
pp. 1277-1284 ◽  
Author(s):  
Yuan-De Tan ◽  
Chunling Wan ◽  
Yufang Zhu ◽  
Chen Lu ◽  
Zhonghuai Xiang ◽  
...  

Abstract The silkworm (Bombyx mori L.) is a lepidopteran insect with a long history of significant agricultural value. We have constructed the first amplified fragment length polymorphism (AFLP) genetic linkage map of the silkworm B. mori at a LOD score of 2.5. The mapping AFLP markers were genotyped in 47 progeny from a backcross population of the cross no. 782 × od100. A total of 1248 (60.7%) polymorphic AFLP markers were detected with 35 PstI/TaqI primer combinations. Each of the primer combinations generated an average of 35.7 polymorphic AFLP markers. A total of 545 (44%) polymorphic markers are consistent with the expected segregation ratio of 1:1 at the significance level of P = 0.05. Of the 545 polymorphic markers, 356 were assigned to 30 linkage groups. The number of markers on linkage groups ranged from 4 to 36. There were 21 major linkage groups with 7-36 markers and 9 relatively small linkage groups with 4-6 markers. The 30 linkage groups varied in length from 37.4 to 691.0 cM. The total length of this AFLP linkage map was 6512 cM. Genetic distances between two neighboring markers on the same linkage group ranged from 0.2 to 47 cM with an average of 18.2 cM. The sex-linked gene od was located between the markers P1T3B40 and P3T3B27 at the end of group 3, indicating that AFLP linkage group 3 was the Z (sex) chromosome. This work provides an essential basic map for constructing a denser linkage map and for mapping genes underlying agronomically important traits in the silkworm B. mori L.


2012 ◽  
Vol 38 (No. 2) ◽  
pp. 65-68 ◽  
Author(s):  
J. Salava ◽  
Y. Wang ◽  
B. Krška ◽  
J. Polák ◽  
P. Komínek ◽  
...  

A genetic linkage map for apricot (Prunus armeniaca L.) has been constructed using amplified fragment length polymorphism (AFLP) markers in 80 BC1 individuals derived from a cross LE-3246 × Vestar. From 26 different primer combinations, a total of 248 AFLP markers were scored, of which, 40 were assigned to 8 linkage groups covering 315.8 cM of the apricot nuclear genome. The average interval between these markers was 7.7 cM. One gene (PPVres1) involved in resistance to PPV (Plum pox virus) was mapped. Two AFLP markers (EAA/MCAG8 and EAG/MCAT14) were found to be closely associated with the PPVres1 locus (4.6 cM resp. 4.7 cM). These markers are being characterized and they will be studied for utilization in apricot breeding with marker-assisted selection (MAS).


Genome ◽  
1989 ◽  
Vol 31 (1) ◽  
pp. 137-142 ◽  
Author(s):  
M. D. Gale ◽  
P. J. Sharp ◽  
S. Chao ◽  
C. N. Law

A molecular map of wheat, Triticum aestivum, is being developed. Problems associated with the large genome size, the large number of linkage groups, polyploidy, and limited polymorphism at the DNA level are being overcome. In addition to the breeding applications expected from the map, various uses for restriction fragment length polymorphism markers as tools in cytogenetic manipulation of wheat chromosomes and those from related species are being found. These include identification of aneuploid genotypes, added precision in intervarietal chromosome manipulations, tests of chromosome stability, identification of alien chromosomes, and marker-aided introgression of genes of agronomic importance from related species.Key words: wheat, restriction fragment length polymorphism, genetic maps, aneuploidy, alien chromosomes.


1996 ◽  
Vol 7 (8) ◽  
pp. 616-618 ◽  
Author(s):  
J. H. Millonig ◽  
K. J. Millen ◽  
M. E. Hatten

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