Identification by genome scanning approach (GSA) of a microsatellite tightly associated with the apple scab resistance gene Vm

Genome ◽  
2005 ◽  
Vol 48 (4) ◽  
pp. 630-636 ◽  
Author(s):  
A Patocchi ◽  
M Walser ◽  
S Tartarini ◽  
G A.L Broggini ◽  
F Gennari ◽  
...  
Keyword(s):  
Molecular Markers ◽  
Linkage Group ◽  
Resistance Gene ◽  
Resistance Genes ◽  
Simple Sequence Repeat ◽  
Apple Scab ◽  
Scab Resistance ◽  
Sequence Repeat ◽  
Genome Scanning ◽  
Simple Sequence

For all known major apple scab resistance genes except Vr, molecular markers have been published. However, the precise position of some of these genes, in the apple genome, remains to be identified. Knowledge about the relative position of apple scab resistance genes is necessary to preliminarily evaluate the probability of success of their pyramidization. Pyramidization of different resistance genes into the same genotype is a reliable way to create cultivars with durable apple scab resistance. Applying the genome scanning approach (GSA), we identified the linkage group of the scab resistance gene Vm, derived from Malus micromalus, and we found a new molecular marker tightly associated with the gene. The simple sequence repeat Hi07h02, previously mapped on linkage group 17, cosegregates with the Vm gene (no recombinants in the 95 plants tested). The already published sequence-characterized amplified region Vm marker OPB12687 was found to be linked at about 5 cM from the resistance gene and, therefore, this marker also maps on linkage group 17 of apple. This is the first report of the discovery of a major apple scab resistance gene on linkage group 17. The advantages of using GSA for the identification of molecular markers for qualitative traits are discussed.Key words: Malus, Venturia inaequalis, mapping, simple sequence repeat.

Mapping of the apple scab-resistance gene Vb

Genome ◽  
2006 ◽  
Vol 49 (10) ◽  
pp. 1238-1245 ◽  
Author(s):  
N. Erdin ◽  
S. Tartarini ◽  
G.A.L. Broggini ◽  
F. Gennari ◽  
S. Sansavini ◽  
...  
Keyword(s):  
Molecular Markers ◽  
Linkage Group ◽  
Resistance Gene ◽  
Ssr Markers ◽  
Resistance Genes ◽  
Venturia Inaequalis ◽  
Apple Scab ◽  
Scab Resistance ◽  
Fast Method ◽  
A Genome

Apple scab, caused by the fungus Venturia inaequalis , is the major production constraint in temperate zones with humid springs. Normally, its control relies on frequent and regular fungicide applications. Because this control strategy has come under increasing criticism, major efforts are being directed toward the breeding of scab-resistant apple cultivars. Modern apple breeding programs include the use of molecular markers, making it possible to combine several different scab-resistance genes in 1 apple cultivar (pyramiding) and to speed up the breeding process. The apple scab-resistance gene Vb is derived from the Siberian crab apple ‘Hansen’s baccata #2’, and is 1 of the 6 “historical” major apple scab-resistance genes (Vf, Va, Vr, Vbj, Vm, and Vb). Molecular markers have been published for all these genes, except Vr. In testcross experiments conducted in the 1960s, it was reported that Vb segregated independently from 3 other major resistance genes, including Vf. Recently, however, Vb and Vf have both been mapped on linkage group 1, a result that contrasts with the findings from former testcross experiments. In this study, simple sequence repeat (SSR) markers were used to identify the precise position of Vb in a cross of ‘Golden Delicious’ (vbvb) and ‘Hansen’s baccata #2’ (Vbvb). A genome scanning approach, a fast method already used to map apple scab-resistance genes Vr2 and Vm, was used, and the Vb locus was identified on linkage group 12, between the SSR markers Hi02d05 and Hi07f01. This finding confirms the independent segregation of Vb from Vf. With the identification of SSR markers linked to Vb, another major apple scab-resistance gene has become available; breeders can use it to develop durable resistant cultivars with several different resistance genes.

scholarly journals HcrVf paralogs are present on linkage groups 1 and 6 of Malus

Genome ◽  
2009 ◽  
Vol 52 (2) ◽  
pp. 129-138 ◽  
Author(s):  
Giovanni A.L. Broggini ◽  
Paolo Galli ◽  
Gabriella Parravicini ◽  
Luca Gianfranceschi ◽  
Cesare Gessler ◽  
...  
Keyword(s):  
Linkage Group ◽  
Resistance Gene ◽  
Resistance Genes ◽  
Genomic Library ◽  
Sequence Similarity ◽  
Apple Scab ◽  
Scab Resistance ◽  
Transcriptional Analysis ◽  
Linkage Groups ◽  
Bac Clones

Molecular markers derived from resistance gene analogs of HcrVf2, the first apple resistance gene cloned, may pave the way to the cloning of additional apple scab resistance genes. The Malus ×domestica ‘Florina’ (Vf) bacterial artificial chromosome (BAC) genomic library was screened by hybridization using HcrVf2 as a probe. Positive BAC clones were assembled into contigs and microsatellite markers developed from each contig mapped. Only linkage groups 1 and 6 contained HcrVf2 paralogs. On linkage group 1, five loci in addition to the Vf locus were identified. A single locus was detected on linkage group 6. Representative BAC clones of these loci including the Vf locus were sequenced and the gene structure compiled. A total of 22 sequences, showing high sequence similarity to HcrVf2, were identified. Nine sequences were predicted to encode all seven protein domains described in HcrVf2, while three were truncated. Transcriptional analysis indicated that six genes with a complete HcrVf-like structure were constitutively expressed in young uninfected leaves of ‘Florina’. The map position of each HcrVf analog was compared with the location of the major apple scab resistance genes. None of the major genes conferring scab resistance co-localized with HcrVf paralogs, indicating that they are unlikely to belong to the leucine-rich repeat – transmembrane class, which includes the Vf gene.

scholarly journals Genotyping of Peach and Nectarine Cultivars with SSR and SRAP Molecular Markers

2004 ◽  
Vol 129 (2) ◽  
pp. 204-210 ◽  
Author(s):  
Riaz Ahmad ◽  
Dan Potter ◽  
Stephen M. Southwick
Keyword(s):  
Molecular Markers ◽  
Ssr Markers ◽  
Simple Sequence Repeat ◽  
Sweet Cherry ◽  
Prunus Persica ◽  
Sequence Repeat ◽  
Srap Markers ◽  
Upgma Cluster Analysis ◽  
Commercially Important ◽  
Simple Sequence

Simple sequence repeat (SSR) and sequence related amplified polymorphism (SRAP) molecular markers were evaluated for detecting intraspecific variation in 38 commercially important peach and nectarine (Prunus persica) cultivars. Out of the 20 SSR primer pairs 17 were previously developed in sweet cherry and three in peach. The number of putative alleles revealed by SSR primer pairs ranged from one to five showing a low level of genetic variability among these cultivars. The average number of alleles per locus was 2.2. About 76% of cherry primers produced amplification products in peach and nectarine, showing a congeneric relationship within Prunus species. Only nine cultivars out of the 38 cultivars could be uniquely identified by the SSR markers. For SRAP, the number of fragments produced was highly variable, ranging from 10 to 33 with an average of 21.8 per primer combination. Ten primer combinations resulted in 49 polymorphic fragments in this closely related set of peaches and nectarines. Thirty out of the 38 peach and nectarine cultivars were identified by unique SRAP fingerprints. UPGMA Cluster analysis based on the SSR and SRAP polymorphic fragments was performed; the relationships inferred are discussed with reference to the pomological characteristics and pedigree of these cultivars. The results indicated that SSR and SRAP markers can be used to distinguish the genetically very close peach and nectarine cultivars as a complement to traditional pomological studies. However, for fingerprinting, SRAP markers appear to be much more effective, quicker and less expensive to develop than are SSR markers.

scholarly journals Study of Plant Genetic Variation through Molecular Markers: An Overview

2021 ◽  
pp. 464-473
Author(s):  
Zeina S. M. Al-Hadeithi ◽  
Saade Abdalkareem Jasim
Keyword(s):  
Molecular Markers ◽  
Simple Sequence Repeat Marker ◽  
Fragment Length ◽  
Simple Sequence Repeat ◽  
Plant Biotechnology ◽  
Molecular Techniques ◽  
Basic Material ◽  
Sequence Repeat ◽  
Simple Sequence

This article refers to viewing the role of molecular markers during analyzing the genome of plants and their importance in plant biotechnology. In recent years, we observed the role of molecular techniques in programs for improving plant breeding and preserving genetic resources has been observed, and molecular and biochemical indicators which represent basic material through determining the diversity between genotypes for indicators it is never affected by external surrounding conditions as always in the phenotype features. Molecular markers of DNA have been widely applied to answer a range of questions related to taxonomy, molecular evolution, population genetics, and genetic diversity, as well as monitoring trade in plants and food products , in addition to its having a role in studying gene expression , genetic mapping, and studies of species evolution providing fast and accurate results. In this work, the advantages and limitations of the molecular techniques applied in plant sciences such as: RAPD (Random Amplification Polymorphic DNA Marker); ISSR (Inter Simple Sequence Repeat Marker); SSR (Simple Sequence Repeat Marker); AFLP (Amplified Fragment Length Polymorphic Marker); RFLP (Restriction Fragment Length Polymorphism Marker); SNP (Single Nucleotide Polymorphism) and Real Time PCR.

scholarly journals A Novel Pear Scab (Venturia nashicola) Resistance Gene, Rvn3, from Interspecific Hybrid Pear (Pyrus pyrifolia × P. communis)

Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2632
Author(s):  
Sewon Oh ◽  
Hyeondae Han ◽  
Daeil Kim
Keyword(s):  
Resistance Gene ◽  
Resistance Genes ◽  
Interspecific Hybrid ◽  
Dominant Gene ◽  
Apple Scab ◽  
Scab Resistance ◽  
Hybrid Population ◽  
Pyrus Pyrifolia ◽  
Pear Scab ◽  
Venturia Nashicola

Asian pear scab is a fungal disease caused by Venturia nashicola. The identification of genes conferring scab resistance could facilitate the breeding of disease-resistant cultivars. Therefore, the present study aimed to identify a scab-resistance gene using an interspecific hybrid population ((Pyrus pyrifolia × P. communis) × P. pyrifolia). Artificial inoculation of V. nashicola was carried out for two years. The segregation ratio (1:1) of resistant to susceptible individuals indicated that resistance to V. nashicola was inherited from P. communis and controlled by a single dominant gene. Based on two years phenotypic data with the Kruskal–Wallis test and interval mapping, 12 common markers were significantly associated with scab resistance. A novel scab resistance gene, Rvn3, was mapped in linkage group 6 of the interspecific hybrid pear, and co-linearity between Rvn3 and one of the apple scab resistance genes, Rvi14, was confirmed. Notably, an insertion in pseudo-chromosome 6 of the interspecific hybrid cultivar showed homology with apple scab resistance genes. Hence, the newly discovered Rvn3 was considered an ortholog of the apple scab resistance gene. Since the mapping population used in the present study is a pseudo-BC1 population, pyramiding of multiple resistance genes to pseudo-BC1 could facilitate the breeding of pear cultivars with durable resistance.

scholarly journals Molecular markers linked to the apple scab resistance gene Vbj derived from Malus baccata jackii

2004 ◽  
Vol 109 (8) ◽  
pp. 1702-1709 ◽  
Author(s):  
M Gygax ◽  
L Gianfranceschi ◽  
R Liebhard ◽  
M Kellerhals ◽  
C Gessler ◽  
...  
Keyword(s):  
Molecular Markers ◽  
Resistance Gene ◽  
Apple Scab ◽  
Scab Resistance ◽  
Malus Baccata
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