scholarly journals Molecular Mapping of Capsicum and the Comparisons of Synteny with Tomato

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 615e-615
Author(s):  
Yiping Zhang ◽  
Vince K. Lackney ◽  
James P. Prince ◽  
Jim P. Blauth ◽  
Molly M. Kyle
Keyword(s):  
Mosaic Virus ◽  
Molecular Mapping ◽  
Basic Chromosome Number ◽  
Linkage Groups ◽  
Chi Square ◽  
Length Polymorphisms ◽  
Monogenic Resistance ◽  
Segregation Ratios ◽  
Solanaceous Plant ◽  
Two Populations

Pepper (Capsicum spp.) has the same basic chromosome number as tomato and other solanaceous plant species (2n = 2x = 24). By using the probes mostly from a tomato map, we have generated three molecular maps of pepper from interspecific F2 crosses of C. frutescens BG 2814-6, C. chinense PI 159234 and C. annuum `NuMex RNaky' with restriction fragment length polymorphisms, isozymes, random amplified polymorphic DNAs, and morphological traits. The best developed map is from C. annuum × C. chinense F2 cross, which currently has 366 markers covered 1081 cM in 18 linkage groups. Three linkage groups were assigned to three chromosomes based on primary trisomics. Several disease resistance genes including monogenic resistance to potyviruses and quantitative trait loci for resistance to tobacco mosaic virus and cucumber mosaic virus have been mapped. The distribution of allele frequency and marker segregation ratios have been analyzed. Chi-square analyses of all clones showed more skewing of segregation ratios in C. annuum × C. chinense population than the other two populations. The skewing occurs throughout the genome and tends towards heterozygote and one of the parents. The order of markers among three pepper maps will be compared and the comparisons of synteny between pepper and tomato maps will be described. A composite of three pepper maps will be presented using JoinMap software.

scholarly journals Linkage map of random amplified polymorphic DNAs (RAPDs) in the silkworm, Bombyx mori

1995 ◽  
Vol 66 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Amornrat Promboon ◽  
Toru Shimada ◽  
Haruhiko Fujiwara ◽  
Masahiko Kobayashi
Keyword(s):  
Linkage Map ◽  
Bombyx Mori ◽  
Mapping Function ◽  
Mendelian Inheritance ◽  
Linkage Groups ◽  
Lod Score ◽  
Chi Square ◽  
Segregation Ratios ◽  
Chi Square Test ◽  
Silkworm Bombyx Mori

SummaryWe have constructed a linkage map of random amplified polymorphic DNAs (RAPDs) in Bombyx mori. We screened 320 10-mer primers, and found 243 clear polymorphic bands between C108 and p50 strains. In the F2 generation, segregation ratios of 168 bands were nearly 3:1 in a chi square test, showing Mendelian inheritance. The MAPMAKER program sorted 168 bands into 29 linkage groups and 10 unlinked loci at minimum LOD score 3·0, and determined orders of loci in each group, which contained 2–11 markers. It also detected typing errors in our data. We calculated map distances between pairs of neighbouring loci using recombination values in males and the Kosambi mapping function. Our RAPD map consists of 169 loci including the p locus, and the sum of map distances is approximately 900 cM. Linkage groups 1 and 2 of our map correspond to chromosomes 1 and 2 on the conventional linkage map because of linkage to sex and p, respectively.

Mapping of duplicate genes in soybean

Genome ◽  
1999 ◽  
Vol 42 (5) ◽  
pp. 829-836 ◽  
Author(s):  
Jennifer M Lee ◽  
Arla L Bush ◽  
James E Specht ◽  
Randy C Shoemaker
Keyword(s):  
Genetic Factors ◽  
Duplicate Genes ◽  
Duplicated Genes ◽  
Linkage Groups ◽  
Complex Phenotype ◽  
Length Polymorphisms ◽  
Point Analysis ◽  
Definition Of ◽  
Two Populations ◽  
Simple Sequence

Appressed pubescence genes in soybean cause hairs on the upper surface of leaves to lie flat, while pubescence remains erect elsewhere on the plant. For decades this trait was believed to be controlled in soybean by duplicated single genes, Pa1 and Pa2. However, reports in the literature conflicted as to which phenotype was dominant or recessive. Two populations were developed, each approximately 100 individuals, and each segregating for one of the appressed pubescence genes. A combination of SSRs (simple sequence repeats) and RFLPs (restriction fragment length polymorphisms) were used in each of these populations to map the independent genes. Two-point analysis weakly linked Pa1 and Pa2 to separate linkage groups. Lack of strong linkage suggested the trait may not be controlled by single genes. When QTL (quantitative trait loci) analysis was performed, one major locus and several minor loci were detected in each population. We report the mapping of the genes controlling appressed pubescence in soybean and their placement in homologous regions. Although appressed pubescence was originally reported to be single duplicate genes, we report that it is actually a more complex phenotype with major duplicated genes and minor modifying genes. These results offer interesting implications regarding the evolution of duplicate genetic factors and the definition of qualitative traits.Key words: homoeologous, Glycine, evolution, appressed pubescence, quantitative genetics.

scholarly journals Molecular Mapping and Tagging of Cucumber Mosaic Virus Resistance Genes in Capsicum

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 612b-612
Author(s):  
Yiping Zhang ◽  
Vince Lackney ◽  
Molly Kyle
Keyword(s):  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Resistance Genes ◽  
Molecular Mapping ◽  
Interspecific Cross ◽  
Genetic Resistance ◽  
Linkage Groups ◽  
Breeding Programs ◽  
Cmv Resistance ◽  
Genomic Cdna

Genetic resistance to cucumber mosaic virus (CMV) in pepper (Capsicum spp.) is recessive, polygenic and, therefore, has been difficult to transfer in breeding programs. Although a few varieties have been released with some resistance, in our tests, these develop severe symptoms that are eventually indistinguishable from the susceptible reactions. Furthermore, accurate and consistent screens for the disease can be relatively difficult; therefore, we report on the detection molecular markers linked to two CMV resistance genes using distributional extreme analysis to identify the relevant quantitative trait loci (QTL). The 12 most resistant and 15 most susceptible individuals were selected from a segregating F2 population of 316 individuals that were derived from the interspecific cross (C. annuum `Jupiter' × C. frutescens BG2814-6). A total of 132 tomato genomic, cDNA, and pepper genomic clones were hybridized to filters with DNA extracted from the distributional extremes. These clones included framework markers representing all pepper linkage groups and also selected clones from regions of the genome identified in a preliminary analysis as possibly involved with CMV resistance. Several clones from the two regions of the genome previously identified appear to be nonrandomly cosegregating with the CMV resistance phenotype in this larger population. Further analysis will be done by adding more markers in the regions and refining the positions of the resistance QTL.

Molecular Mapping of Segregation Distortion Loci in Aegilops tauschii

Genetics ◽  
1998 ◽  
Vol 149 (1) ◽  
pp. 319-327 ◽  
Author(s):  
J D Faris ◽  
B Laddomada ◽  
B S Gill
Keyword(s):  
Segregation Distortion ◽  
Molecular Mapping ◽  
Aegilops Tauschii ◽  
Distorted Segregation ◽  
F2 Population ◽  
Male Gametes ◽  
Skewed Segregation ◽  
Segregation Ratios ◽  
Backcross Populations ◽  
Intraspecific Hybrids

Abstract Distorted segregation ratios of genetic markers are often observed in progeny of inter- and intraspecific hybrids and may result from competition among gametes or from abortion of the gamete or zygote. In this study, 194 markers mapped in an Aegilops tauschii F2 population were surveyed for distorted segregation ratios. Region(s) with skewed segregation ratios were detected on chromosomes 1D, 3D, 4D, and 7D. These distorter loci are designated as QSd.ksu-1D, QSd.ksu-3D, QSd.ksu-4D, and QSd.ksu-7D. Three regions of segregation distortion identified on chromosome 5D were analyzed in two sets of reciprocal backcross populations to analyze the effect of sex and cytoplasm on segregation distortion. Extreme distortion of marker segregation ratios was observed in populations in which the F1 was used as the male parent, and ratios were skewed in favor of TA1691 alleles. There was some evidence of differential transmission caused by nucleo-cytoplasmic interactions. Our results agree with other studies stating that loci affecting gametophyte competition in male gametes are located on 5DL. The distorter loci on 5DL are designated as QSd.ksu-5D.1, QSd.ksu-5D.2, and QSd.ksu-5D.3.

scholarly journals A genetic linkage map for the domesticated silkworm, Bombyx mori, based on restriction fragment length polymorphisms

1995 ◽  
Vol 66 (2) ◽  
pp. 109-126 ◽  
Author(s):  
Jinrui Shi ◽  
David G. Heckel ◽  
Marian R. Goldsmith
Keyword(s):  
Linkage Map ◽  
Bombyx Mori ◽  
Restriction Fragment ◽  
Fragment Length ◽  
Restriction Fragment Length Polymorphisms ◽  
Genetic Maps ◽  
Crossing Over ◽  
Linkage Groups ◽  
Length Polymorphisms ◽  
Restriction Fragment Length

SummaryWe present data for the initial construction of a molecular linkage map for the domesticated silkworm, Bombyx mori, based on 52 progeny from an F2 cross from a pair mating of inbred strains p50 and C108, using restriction fragment length polymorphisms (RFLPs). The map contains 15 characterized single copy sequences, 36 anonymous sequences derived from a follicular cDNA library, and 10 loci corresponding to a low copy number retrotransposon, mag. The 15 linkage groups and 8 ungrouped loci account for 23 of the 28 chromosomes and span a total recombination length of 413 cM; 10 linkage groups were correlated with established classic genetic maps. Scoring data from Southern blots were analysed using two Pascal programs written specifically to analyse linkage data in Lepidoptera, where females are the heterogametic sex and have achiasmatic meiosis (no crossing-over). These first examine evidence for linkage by calculating the maximum lod score under the hypothesis that the two loci are linked over the likelihood under the hypothesis that the two loci assort independently, and then determine multilocus linkage maps for groups of putatively syntenic loci by calculating the maximum likelihood estimate of the recombination fractions and the log likelihood using the EM algorithm for a specified order of loci along the chromosome. In addition, the possibility of spurious linkage was exhaustively tested by searching for genotypes forbidden by the absence of crossing-over in one sex.

Segregation of random amplified polymorphic DNA markers and strategies for molecular mapping in tetraploid alfalfa

Genome ◽  
1993 ◽  
Vol 36 (5) ◽  
pp. 844-851 ◽  
Author(s):  
K. F. Yu ◽  
K. P. Pauls
Keyword(s):  
Chromosome Segregation ◽  
Dna Markers ◽  
Rapd Markers ◽  
Molecular Mapping ◽  
Random Amplified Polymorphic Dna ◽  
Rapd Marker ◽  
Female Parent ◽  
Linkage Groups ◽  
Double Reduction ◽  
Chromatid Segregation

An F1 population was used to analyze the inheritance of random amplified polymorphic DNA (RAPD) markers in tetraploid alfalfa. Of the 32 RAPD markers that were used for a segregation analysis in this study, 27 gave ratios that are consistent with random chromosome and random chromatid segregation at meiosis. However, among all of the RAPD markers (121) that were screened in this study, only one example of a double reduction, that is typical of chromatid segregation, was observed. These results indicate that random chromosome segregation is likely the predominant but not the exclusive mode of inheritance for tetraploid alfalfa. χ2 analyses of cosegregation for RAPD marker pairs derived from the female parent revealed nine linkages that fell into four linkage groups. The recombination fractions among linked marker pairs ranged from 1 to 37%. These are the first molecular linkage groups reported in tetraploid alfalfa. In addition, various strategies for molecular mapping in the tetraploid alfalfa genome are proposed that should be of interest to plant breeders who are planning to use molecular markers for alfalfa or other tetraploid species.Key words: RAPD markers, tetraploid alfalfa, segregation, linkage groups.

scholarly journals Molecular mapping of QTLs for resistance to early and late Fusarium wilt in chickpea

2014 ◽  
Vol 50 (No. 2) ◽  
pp. 171-176 ◽  
Author(s):  
B.S. Patil ◽  
R.L. Ravikumar ◽  
J.S. Bhat ◽  
C.D. Soregaon
Keyword(s):  
Fusarium Wilt ◽  
Recombinant Inbred ◽  
Molecular Mapping ◽  
Recombinant Inbred Lines ◽  
Inbred Lines ◽  
Length Polymorphisms ◽  
Amplified Fragment Length Polymorphisms ◽  
Reference Map ◽  
Genomic Regions ◽  
Marker Distance

A molecular map of chickpea was constructed using F<sub>9</sub>:F<sub>10</sub> recombinant inbred lines from an intraspecific cross between Fusarium wilt susceptible (JG 62) and resistant (WR 315) genotypes. A total of 23 markers with LOD scores of &gt; 3.0 were mapped on the recombinant inbred lines (RILs). Twenty sequence tagged microsatellites (STMSs) and three amplified fragment length polymorphisms (AFLPs) covered 300.2 cM in five linkage groups at an average inter-marker distance of 13 cM. Early and late wilting due to Fusarium infection was recorded in RILs at 30&nbsp;and 60 DAS, respectively. There was a significant variation among RILs for wilt resistance for both early and late wilting. QTLs associated with early (30 days after sowing (DAS)) and late (60&nbsp;DAS) wilting are located on LG II. The flanking markers for these QTLs were the same as those of previous reports. Five STMS markers located on LG II of reference map (interspecific) were mapped on LG II of the present map (intraspecific) with minor changes in the order of markers indicating the conservation of these genomic regions across the Cicer species.

Molecular mapping of a major gene conferring resistance to maize mosaic virus

1997 ◽  
Vol 95 (1-2) ◽  
pp. 271-275 ◽  
Author(s):  
R. Ming ◽  
J. L. Brewbaker ◽  
R. C. Pratt ◽  
T. A. Musket ◽  
M. D. McMullen
Keyword(s):  
Mosaic Virus ◽  
Molecular Mapping ◽  
Major Gene ◽  
Maize Mosaic Virus

scholarly journals A Genetic Map of Gibberella zeae (Fusarium graminearum)

Genetics ◽  
2002 ◽  
Vol 160 (4) ◽  
pp. 1451-1460
Author(s):  
J E Jurgenson ◽  
R L Bowden ◽  
K A Zeller ◽  
J F Leslie ◽  
N J Alexander ◽  
...  
Keyword(s):  
Linkage Map ◽  
Fusarium Graminearum ◽  
Gibberella Zeae ◽  
Linkage Groups ◽  
Genetic Studies ◽  
Genomic Libraries ◽  
Trichodiene Synthase ◽  
Nit Mutants ◽  
Length Polymorphisms ◽  
Amplified Fragment Length Polymorphisms

Abstract We constructed a genetic linkage map of Gibberella zeae (Fusarium graminearum) by crossing complementary nitrate-nonutilizing (nit) mutants of G. zeae strains R-5470 (from Japan) and Z-3639 (from Kansas). We selected 99 nitrate-utilizing (recombinant) progeny and analyzed them for amplified fragment length polymorphisms (AFLPs). We used 34 pairs of two-base selective AFLP primers and identified 1048 polymorphic markers that mapped to 468 unique loci on nine linkage groups. The total map length is ~1300 cM with an average interval of 2.8 map units between loci. Three of the nine linkage groups contain regions in which there are high levels of segregation distortion. Selection for the nitrate-utilizing recombinant progeny can explain two of the three skewed regions. Two linkage groups have recombination patterns that are consistent with the presence of intercalary inversions. Loci governing trichothecene toxin amount and type (deoxynivalenol or nivalenol) map on linkage groups IV and I, respectively. The locus governing the type of trichothecene produced (nivalenol or deoxynivalenol) cosegregated with the TRI5 gene (which encodes trichodiene synthase) and probably maps in the trichothecene gene cluster. This linkage map will be useful in population genetic studies, in map-based cloning, for QTL (quantitative trait loci) analysis, for ordering genomic libraries, and for genomic comparisons of related species.

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