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.

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 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 Virulence Characterization of Venturia inaequalis Reference Isolates on the Differential Set of Malus Hosts

Plant Disease ◽  
2015 ◽  
Vol 99 (3) ◽  
pp. 370-375 ◽  
Author(s):  
Valérie Caffier ◽  
Andrea Patocchi ◽  
Pascale Expert ◽  
Marie-Noëlle Bellanger ◽  
Charles-Eric Durel ◽  
...  
Keyword(s):  
Resistance Gene ◽  
Resistance Genes ◽  
Venturia Inaequalis ◽  
Apple Scab ◽  
Scab Resistance ◽  
Reference Set ◽  
Major Resistance Gene ◽  
Differential Hosts ◽  
Major Resistance Genes

A set of differential hosts has recently been identified for 17 apple scab resistance genes in an updated system for defining gene-for-gene (GfG) relationships in the Venturia inaequalis-Malus pathosystem. However, a set of reference isolates characterized for their complementary avirulence alleles is not yet available. In this paper, we report on improving the set of differential hosts for h(7) and propose the apple genotype LPG3-29 as carrying the single major resistance gene Rvi7. We characterized a reference set of 23 V. inaequalis isolates on 14 differential apple hosts carrying major resistance genes under controlled conditions. We identified isolates that were virulent on at least one of the following defined resistance gene hosts: h(1), h(2), h(3), h(4), h(5), h(6), h(7), h(8), h(9), h(10), and h(13). Sixteen different virulence patterns were observed. In general, the isolates carried one to three virulences, but some of them were more complex, with up to six virulences. This set of well-characterized isolates will be helpful for the identification of additional apple scab resistance genes in apple germplasm and the characterization of new GfG relationships to help improve our understanding of the host-pathogen interactions in the V. inaequalis-Malus pathosystem.

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

scholarly journals Quantitative Trait Loci (QTL) Analysis Reveals Both Broad-Spectrum and Isolate-Specific QTL for Scab Resistance in an Apple Progeny Challenged with Eight Isolates of Venturia inaequalis

2004 ◽  
Vol 94 (4) ◽  
pp. 370-379 ◽  
Author(s):  
F. Calenge ◽  
A. Faure ◽  
M. Goerre ◽  
C. Gebhardt ◽  
W. E. Van de Weg ◽  
...  
Keyword(s):  
Quantitative Trait Loci ◽  
Resistance Gene ◽  
Resistance Genes ◽  
Quantitative Trait ◽  
Venturia Inaequalis ◽  
Scab Resistance ◽  
Breeding Programs ◽  
Apple Breeding ◽  
Trait Loci ◽  
New Races

The major scab resistance gene Vf, extensively used in apple breeding programs, was recently overcome by the new races 6 and 7 of the fungal pathogen Venturia inaequalis. New, more durable, scab resistance genes are needed in apple breeding programs. F1 progeny derived from the cross between partially resistant apple cv. Discovery and apple hybrid ‘TN10-8’ were inoculated in the greenhouse with eight isolates of V. inaequalis, including isolates able to overcome Vf. One major resistance gene, Vg, and seven quantitative trait loci (QTL) were identified for resistance to these isolates. Three QTL on linkage group (LG)12, LG13, and LG15 were clearly isolate-specific. Another QTL on LG5 was detected with two isolates. Three QTL on LG1, LG2, and LG17 were identified with most isolates tested, but not with every isolate. The QTL on LG2 displayed alleles conferring different specificities. This QTL co-localized with the major scab resistance genes Vr and Vh8, whereas the QTL on LG1 colocalized with Vf. These results contribute to a better understanding of the genetic basis of the V. inaequalis-Malus × domestica interaction.

scholarly journals Identification of functional apple scab resistance gene promoters

2005 ◽  
Vol 110 (6) ◽  
pp. 1119-1126 ◽  
Author(s):  
E. Silfverberg-Dilworth ◽  
S. Besse ◽  
R. Paris ◽  
E. Belfanti ◽  
S. Tartarini ◽  
...  
Keyword(s):  
Resistance Gene ◽  
Apple Scab ◽  
Scab Resistance ◽  
Gene Promoters

scholarly journals Identification and mapping of the novel apple scab resistance gene Vd3

2009 ◽  
Vol 5 (3) ◽  
pp. 475-482 ◽  
Author(s):  
J.M. Soriano ◽  
S.G. Joshi ◽  
M. van Kaauwen ◽  
Y. Noordijk ◽  
R. Groenwold ◽  
...  
Keyword(s):  
Resistance Gene ◽  
Apple Scab ◽  
Scab Resistance ◽  
The Novel

scholarly journals Characterization of a Bacteroides Mobilizable Transposon, NBU2, Which Carries a Functional Lincomycin Resistance Gene

2000 ◽  
Vol 182 (12) ◽  
pp. 3559-3571 ◽  
Author(s):  
Jun Wang ◽  
Nadja B. Shoemaker ◽  
Gui-Rong Wang ◽  
Abigail A. Salyers
Keyword(s):  
Amino Acid ◽  
Resistance Gene ◽  
Resistance Genes ◽  
Sequence Similarity ◽  
Antibiotic Resistance Genes ◽  
Small Region ◽  
Amino Acid Sequences ◽  
Integrase Gene ◽  
Site Specific ◽  
Lincomycin Resistance

ABSTRACT The mobilizable Bacteroides element NBU2 (11 kbp) was found originally in two Bacteroides clinical isolates,Bacteroides fragilis ERL and B. thetaiotaomicron DOT. At first, NBU2 appeared to be very similar to another mobilizable Bacteroides element, NBU1, in a 2.5-kbp internal region, but further examination of the full DNA sequence of NBU2 now reveals that the region of near identity between NBU1 and NBU2 is limited to this small region and that, outside this region, there is little sequence similarity between the two elements. The integrase gene of NBU2, intN2, was located at one end of the element. This gene was necessary and sufficient for the integration of NBU2. The integrase of NBU2 has the conserved amino acids (R-H-R-Y) in the C-terminal end that are found in members of the lambda family of site-specific integrases. This was also the only region in which the NBU1 and NBU2 integrases shared any similarity (28% amino acid sequence identity and 49% sequence similarity). Integration of NBU2 was site specific in Bacteroidesspecies. Integration occurred in two primary sites in B. thetaiotaomicron. Both of these sites were located in the 3′ end of a serine-tRNA gene NBU2 also integrated in Escherichia coli, but integration was much less site specific than inB. thetaiotaomicron. Analysis of the sequence of NBU2 revealed two potential antibiotic resistance genes. The amino acid sequences of the putative proteins encoded by these genes had similarity to resistances found in gram-positive bacteria. Only one of these genes was expressed in B. thetaiotaomicron, the homolog of linA, a lincomycin resistance gene fromStaphylococcus aureus. To determine how widespread elements related to NBU1 and NBU2 are in Bacteroides species, we screened 291 Bacteroides strains. Elements with some sequence similarity to NBU2 and NBU1 were widespread inBacteroides strains, and the presence oflinAN in Bacteroides strains was highly correlated with the presence of NBU2, suggesting that NBU2 has been responsible for the spread of this gene amongBacteroides strains. Our results suggest that the NBU-related elements form a large and heterogeneous family, whose members have similar integration mechanisms but have different target sites and differ in whether they carry resistance genes.

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