Genetic mapping of resistance factors to Phytophthora palmivora in cocoa

Genome ◽  
2001 ◽  
Vol 44 (1) ◽  
pp. 79-85 ◽  
Author(s):  
M -H Flament ◽  
I Kebe ◽  
D Clément ◽  
I Pieretti ◽  
A -M Risterucci ◽  
...  
Keyword(s):  
Quantitative Trait ◽  
Natural Infection ◽  
Genetic Maps ◽  
Aflp Markers ◽  
Phytophthora Palmivora ◽  
Good Prediction ◽  
Linkage Groups ◽  
Genetic Determination ◽  
Total Length ◽  
Adult Trees

Phytophthora palmivora causes pod rot, a serious disease on cocoa widespread throughout the producing regions. In order to ascertain the genetic determination of cocoa resistance to P. palmivora, a study was carried out on two progenies derived from crosses between a heterozygous, moderately resistant Forastero clone, T60/887, and two closely related and highly susceptible Forastero clones, one completely homozygous, IFC2, and one partially heterozygous, IFC5. The cumulative size of both progenies was 112 individuals. Plants were subjected to natural and artificial inoculation of P. palmivora in Côte d'Ivoire. The genetic maps of T60/887 and of IFC5 were constructed using amplified fragment length polymorphism (AFLP) markers and microsatellites. The map of T60/887 comprised 198 markers assembled in 11 linkage groups and representing a total length of 793 cM. The map of IFC5 comprised 55 AFLP markers that were assembled into six linkage groups for a total length of 244 cM. Ratio of rotten over total number of fruit under natural infection was measured for each tree over two harvests. Artificial inoculations were performed on leaves and pods. These tests were weakly correlated with the pod rot rate in the field. Five quantitative trait loci (QTLs) of resistance were detected for T60/887 but none were common between the three traits measured. Stability and reliability of the experimental procedures are discussed and revealed the difficult use of these artificial tests on adult trees for a good prediction of field resistance.Key words: Theobroma cacao, Phytophthora palmivora, cocoa black pod disease, genetic map, quantitative trait locus (QTL).

scholarly journals Evidence for Colinearity among Genetic Linkage Maps in Cucumber

HortScience ◽  
2007 ◽  
Vol 42 (1) ◽  
pp. 20-27 ◽  
Author(s):  
Jack E. Staub ◽  
Zhanyong Sun ◽  
Sang-Min Chung ◽  
Richard L. Lower
Keyword(s):  
Quantitative Trait Loci ◽  
Fragment Length ◽  
Quantitative Trait ◽  
Yield Component ◽  
Genetic Maps ◽  
Linkage Groups ◽  
Length Polymorphisms ◽  
Trait Loci ◽  
Processing Line ◽  
Simple Sequence

Cucumber (Cucumis sativus L. var. sativus; 2n = 2x = 14), has a narrow genetic base (3% to 8% polymorphism). Nevertheless, several genetic maps exist for this species. It is important to know the degree of colinearity among these maps. Thus, the positions of random amplified polymorphic DNAs, sequenced characterized amplified regions, simple sequence repeat, restriction fragment length polymorphisms, and fluorescent amplified fragment length polymorphism markers were compared in four maps. A previously unreported map was constructed in a narrow cross (processing line 2A × Gy8; C. s. var. sativus; ≈7% polymorphism) and compared with the three published maps [two narrow-based (processing type; C. s. var. sativus; 8% to 12% polymorphism) and a broad-based (C. s. var. sativus × C. s. var. hardwickii (R.) Alef. ≈12%)]. Common makers were identified in seven linkage groups, providing evidence for microsynteny. These common markers were used as anchor markers for map position comparisons of yield component quantitative trait loci. The relative order of anchor markers in each of six linkage groups (linkage groups 1, 2, and 4–7) that had two or more anchor markers within each group was colinear, and instances of microsynteny were detected. Commonalities in the position of some yield component quantitative trait loci exist in linkage groups 1 and 4 of the maps examined, and the general synteny among these maps indicates that identification and mapping of additional anchor markers would lead to successful map merging to increase cucumber map saturation for use in cucumber breeding.

scholarly journals Detection of Quantitative Trait Loci and Inheritance of Root-knot Nematode Resistance in Sweetpotato

2008 ◽  
Vol 133 (6) ◽  
pp. 844-851 ◽  
Author(s):  
Jim C. Cervantes-Flores ◽  
G. Craig Yencho ◽  
Kenneth V. Pecota ◽  
Bryon Sosinski ◽  
Robert O.M. Mwanga
Keyword(s):  
Quantitative Trait Loci ◽  
Quantitative Trait ◽  
Ipomoea Batatas ◽  
The United States ◽  
Genetic Maps ◽  
Aflp Markers ◽  
Root Knot Nematodes ◽  
Egg Masses ◽  
Positive Effects ◽  
Trait Loci

Resistance to root-knot nematodes [Meloidogyne incognita (Kofoid & White) Chitwood] in sweetpotato [Ipomoea batatas (L.) Lam.] was studied in a mapping population consisting of 240 progeny derived from a cross between ‘Beauregard’, the predominant cultivar in the United States, and ‘Tanzania’, an African landrace. Quantitative trait loci (QTL) analyses to locate markers associated with resistance to root-knot nematodes (RKN) were performed using genetic maps based on parental segregation in ‘Beauregard’ and ‘Tanzania’ consisting of 726 and 947 single-dose amplified fragment length polymorphism (AFLP) markers, respectively. RKN resistance in the progeny was highly skewed with most of the progeny exhibiting medium to high levels of resistance. Single-point analysis of variance and interval mapping revealed seven consistently significant QTL in ‘Tanzania’ and two significant QTL in ‘Beauregard’. In ‘Tanzania’, three QTL were associated with reduction in resistance as measured by the number of RKN egg masses and explained ≈20% of the variation. Another four QTL had positive effects on resistance and explained ≈21% of the variation. Other minor QTL explained ≈2% or less of the variation but were not always consistent across geographical locations. In ‘Beauregard’, two QTL had positive effects on RKN resistance and explained ≈6% of the observed variation. Based on molecular and phenotypic data, RKN resistance in sweetpotato is hypothesized to be conferred by several genes, but at least nine AFLP markers (seven from ‘Tanzania’ and two from ‘Beauregard’) are associated with genomic regions that have the biggest effect in the number of egg masses of RKN produced in the root system.

Molecular genetic linkage maps for allotetraploid Leymus wildryes (Gramineae: Triticeae)

Genome ◽  
2003 ◽  
Vol 46 (4) ◽  
pp. 627-646 ◽  
Author(s):  
Xiaolei Wu ◽  
Steven R Larson ◽  
Zanmin Hu ◽  
Antonio J Palazzo ◽  
Thomas A Jones ◽  
...  
Keyword(s):  
Molecular Genetic ◽  
Perennial Grass ◽  
Perennial Grasses ◽  
Genetic Maps ◽  
Aflp Markers ◽  
Linkage Maps ◽  
Linkage Groups ◽  
Genetic Linkage Maps ◽  
Leymus Triticoides ◽  
Leymus Cinereus

Molecular genetic maps were constructed for two full-sib populations, TTC1 and TTC2, derived from two Leymus triticoides × Leymus cinereus hybrids and one common Leymus triticoides tester. Informative DNA markers were detected using 21 EcoRI–MseI and 17 PstI–MseI AFLP primer combinations, 36 anchored SSR or STS primer pairs, and 9 anchored RFLP probes. The 164-sib TTC1 map includes 1069 AFLP markers and 38 anchor loci in 14 linkage groups spanning 2001 cM. The 170-sib TTC2 map contains 1002 AFLP markers and 36 anchor loci in 14 linkage groups spanning 2066 cM. Some 488 homologous AFLP loci and 24 anchor markers detected in both populations showed similar map order. Thus, 1583 AFLP markers and 50 anchor loci were mapped into 14 linkage groups, which evidently correspond to the 14 chromosomes of allotetraploid Leymus (2n = 4x = 28). Synteny of two or more anchor markers from each of the seven homoeologous wheat and barley chromosomes was detected for 12 of the 14 Leymus linkage groups. Moreover, two distinct sets of genome-specific STS markers were identified in these allotetraploid Leymus species. These Leymus genetic maps and populations will provide a useful system to evaluate the inheritance of functionally important traits of two divergent perennial grass species.Key words: AFLP, perennial grasses, RFLP, STS, SSR.

Construction of three linkage maps in bread wheat, Triticum aestivum

2001 ◽  
Vol 52 (12) ◽  
pp. 1089 ◽  
Author(s):  
K. J. Chalmers ◽  
A. W. Campbell ◽  
J. Kretschmer ◽  
A. Karakousis ◽  
P. H. Henschke ◽  
...  
Keyword(s):  
Microsatellite Markers ◽  
Doubled Haploid ◽  
Wheat Breeding ◽  
Genetic Maps ◽  
Aflp Markers ◽  
Linkage Maps ◽  
Linkage Groups ◽  
D Genome ◽  
Doubled Haploid Lines ◽  
Wide Range

Genetic maps were compiled from the analysis of 160–180 doubled haploid lines derived from 3 crosses: Cranbrook Halberd, CD87 Katepwa, and Sunco Tasman. The parental wheat lines covered a wide range of the germplasm used in Australian wheat breeding. The linkage maps were constructed with RFLP, AFLP, microsatellite markers, known genes, and proteins. The numbers of markers placed on each map were 902 for Cranbrook Halberd, 505 for CD87 Katepwa, and 355 for Sunco Tasman. Most of the expected linkage groups could be determined, but 10–20% of markers could not be assigned to a specific linkage group. Homologous chromosomes could be aligned between the populations described here and linkage groups reported in the literature, based around the RFLP, protein, and microsatellite markers. For most chromosomes, colinearity of markers was found for the maps reported here and those recorded on published physical maps of wheat. AFLP markers proved to be effective in filling gaps in the maps. In addition, it was found that many AFLP markers defined specific genetic loci in wheat across all 3 populations. The quality of the maps and the density of markers differs for each population. Some chromosomes, particularly D genome chromosomes, are poorly covered. There was also evidence of segregation distortion in some regions, and the distribution of recombination events was uneven, with substantial numbers of doubled haploid lines in each population displaying one or more parental chromosomes. These features will affect the reliability of the maps in localising loci controlling some traits, particularly complex quantitative traits and traits of low heritability. The parents used to develop the mapping populations were selected based on their quality characteristics and the maps provide a basis for the analysis of the genetic control of components of processing quality. However, the parents also differ in resistance to several important diseases, in a range of physiological traits, and in tolerance to some abiotic stresses.

Selection of cocoa clones for resistance to Phytophthora palmivora by artificial inoculation and natural infection in the field

2021 ◽  
Author(s):  
Vanusa Rodrigues de Souza ◽  
Edna Dora Martins Newman Luz ◽  
José Luis Pires ◽  
Marcos Vinicius Oliveira dos Santos ◽  
Elisângela dos Santos ◽  
...  
Keyword(s):  
Natural Infection ◽  
Artificial Inoculation ◽  
Phytophthora Palmivora ◽  
Selection Of

scholarly journals An enhanced molecular marker based genetic map of perennial ryegrass (Lolium perenne) reveals comparative relationships with other Poaceae genomes

Genome ◽  
2002 ◽  
Vol 45 (2) ◽  
pp. 282-295 ◽  
Author(s):  
Elizabeth S Jones ◽  
Natalia L Mahoney ◽  
Michael D Hayward ◽  
Ian P Armstead ◽  
J Gilbert Jones ◽  
...  
Keyword(s):  
Molecular Marker ◽  
Linkage Map ◽  
Genetic Map ◽  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Genetic Linkage Map ◽  
Population Based ◽  
Genetic Maps ◽  
Linkage Groups ◽  
Integrated Genetic Map

A molecular-marker linkage map has been constructed for perennial ryegrass (Lolium perenne L.) using a one-way pseudo-testcross population based on the mating of a multiple heterozygous individual with a doubled haploid genotype. RFLP, AFLP, isoenzyme, and EST data from four collaborating laboratories within the International Lolium Genome Initiative were combined to produce an integrated genetic map containing 240 loci covering 811 cM on seven linkage groups. The map contained 124 codominant markers, of which 109 were heterologous anchor RFLP probes from wheat, barley, oat, and rice, allowing comparative relationships between perennial ryegrass and other Poaceae species to be inferred. The genetic maps of perennial ryegrass and the Triticeae cereals are highly conserved in terms of synteny and colinearity. This observation was supported by the general agreement of the syntenic relationships between perennial ryegrass, oat, and rice and those between the Triticeae and these species. A lower level of synteny and colinearity was observed between perennial ryegrass and oat compared with the Triticeae, despite the closer taxonomic affinity between these species. It is proposed that the linkage groups of perennial ryegrass be numbered in accordance with these syntenic relationships, to correspond to the homoeologous groups of the Triticeae cereals.Key words: Lolium perenne, genetic linkage map, RFLP, AFLP, conserved synteny.

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.

Development of genetic maps of the citrus varieties ‘Murcott’ tangor and ‘Pêra’ sweet orange by using fluorescent AFLP markers

2007 ◽  
Vol 48 (3) ◽  
pp. 219-231 ◽  
Author(s):  
Antonio Carlos de Oliveira ◽  
Marinês Bastianel ◽  
Mariângela Cristofani-Yaly ◽  
Alexandre Morais do Amaral ◽  
Marcos Antonio Machado
Keyword(s):  
Sweet Orange ◽  
Genetic Maps ◽  
Aflp Markers ◽  
Citrus Varieties

Applications of genetic markers in cytogenetic manipulation of the wheat genomes

Genome ◽  
1989 ◽  
Vol 31 (1) ◽  
pp. 137-142 ◽  
Author(s):  
M. D. Gale ◽  
P. J. Sharp ◽  
S. Chao ◽  
C. N. Law
Keyword(s):  
Restriction Fragment Length Polymorphism ◽  
Restriction Fragment ◽  
Length Polymorphism ◽  
Fragment Length ◽  
Fragment Length Polymorphism ◽  
Genetic Maps ◽  
Linkage Groups ◽  
Large Genome ◽  
Large Genome Size ◽  
Restriction Fragment Length

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.

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