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Euphytica, Vol. 124, No. 2. (1 March 2002), pp. 227-236.
Abstract
Abstract Strategies to deploy non-durable `major' or `R' genes for resistance to plant diseases are reviewed. The reasons for continuation of deployment of R genes singly despite its obvious failure are discussed. Alternative deployment strategies are described and the potential impact of plant biotechnology on the deployment of resistance genes is discussed. A strategy focusing on the crop phenotype, taking into account production practices, the nature of the pathogen and alternative control measures to determine the most appropriate deployment of host resistance ...
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TAG Theoretical and Applied Genetics (5 March 2010)
Abstract
Abstract Despite efforts to control late blight in potatoes by introducing R pi -genes from wild species into cultivated potato, there are still concerns regarding the durability and level of resistance. Pyramiding R pi -genes can be a solution to increase both durability and level of resistance. In this study, two resistance genes, R Pi-mcd1 and R Pi-ber , introgressed from the wild tuber-bearing potato species Solanum microdontum and S. berthaultii were combined in a diploid S. tuberosum population. Individual genotypes from ...
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Plant Cell, Vol. 16, No. 11. (1 November 2004), pp. 2870-2894.
Abstract
Resistance Gene Candidate2 (RGC2) genes belong to a large, highly duplicated family of nucleotide binding site-leucine rich repeat (NBS-LRR) encoding disease resistance genes located at a single locus in lettuce (Lactuca sativa). To investigate the genetic events occurring during the evolution of this locus, [~]1.5- to 2-kb 3' fragments of 126 RGC2 genes from seven genotypes were sequenced from three species of Lactuca, and 107 additional RGC2 sequences were obtained from 40 wild accessions of Lactuca spp. The copy number of ...
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Euphytica, Vol. 90, No. 3. (1 January 1996), pp. 331-336.
Abstract
For RFLP mapping of R-genes, determining resistance to specific races of Phytophthora infestans in tetraploid potato, it is necessary to develop well segregating populations at the 2x level. During mapping studies, evidence was obtained that more genetic factor(s) are involved in the expression of R-genes than conventionally believed. Two experiments are described in which such an additional genetic factor was suppressing or enhancing the expression of unknown Rnand Rifactors. Rnand Riappeared to be present in the investigated plant material, containing R4 ...
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TAG Theoretical and Applied Genetics, Vol. 111, No. 3. (17 August 2005), pp. 591-597.
Abstract
Identification of resistance (R) genes to Phytophthora infestans is an essential step in molecular breeding of potato. We identified three specific R genes segregating in a diploid mapping population. One of the R genes is located on chromosome 4 and proved phenotypically indistinguishable from the Solanum demissum-derived R2, although S. demissum is not directly involved in the pedigree of the population. By bulked segregant analysis combined with a resistance assay, a genetic linkage map of the R2-like locus was constructed with ...
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Molecular Breeding, Vol. 16, No. 1. (1 August 2005), pp. 33-43.
Abstract
Introduction of more durable resistance against Phytophthora infestans causing late blight into the cultivated potato is of importance for sustainable agriculture. We identified a new monogenically inherited resistance locus that is localized on chromosome 4. The resistance is derived from an ABPT clone, which is originally a complex quadruple hybrid in which Solanum acaule, S. bulbocastanum, S. phureja and S. tuberosum were involved. Resistance data of the original resistant accessions of the wild species and analysis of mobility of AFLP ...
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Potato Research, Vol. 14, No. 4. (13 December 1971), pp. 263-270.
Abstract
The conflicting evidence of the literature is reviewed. It is concluded that resistance is stable. A differential interaction between cultivars without R genes and races of the pathogen is absent or at most small. The evidence to the contrary was examined and found unconvincing. ...
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Plant Pathology, Vol. 56, No. 1. (February 2007), pp. 150-155.
Abstract
A total of 23 Scottish and 14 Dutch potato R-gene differentials as well as five Austrian, two Dutch and two German commercial potato cultivars were screened for the R1 allele conferring resistance to Phytophthora infestans carrying Avr1, via PCR amplification and sequencing. A single 1400 bp fragment with complete sequence identity to the corresponding part of the R1 allele, was obtained from genomic DNA of all potato R-gene differential clones whose denomination indicates R1 or a combination of R1 and other ...
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European Journal of Plant Pathology, Vol. 101, No. 4. (1 July 1995), pp. 387-397.
Abstract
Twenty-two R gene-free cultivars, introduced between 1900 and 1954, were field-tested for their level of partial resistance to a complex race ofPhytophthora infestans. Disease assessments, expressed as areas under the disease progress curve, appeared closely correlated to resistance ratings given between 1929 and 1954. This, and the stability in time since 1929 of the ratings in the Dutch Descriptive List of Varieties of Field Crops, suggest that the resistance concerned is durable. Lesion growth rate was found to be a very ...
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Plant Pathology, Vol. 52, No. 2. (2003), pp. 193-198.
Abstract
The differential genotypes R1, R10 and R11, as originally defined by Black, were crossed with R-gene-free cultivars and the progenies divided into two subpopulations comprising those which had inherited the R-gene and those which had not. The underlying level of field resistance of the two groups was compared in a field trial in which they were inoculated with an isolate that could overcome the relevant R-genes. The R-gene-bearing group was significantly (P < 0·001) more resistant than the R-gene-free group, with mean scores ...
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Molecular and General Genetics MGG, Vol. 242, No. 6. (1 March 1994), pp. 749-754.
Abstract
Phytophthora infestans (Mont.) de Bary is the most important fungal pathogen of the potato (Solanum tuberosum). The introduction of major genes for resistance from the wild species S. demissum into potato cultivars is the earliest example of breeding for resistance using wild germplasm in this crop. Eleven resistance alleles (R genes) are known, differing in the recognition of corresponding avirulence alleles of the fungus. The number of R loci, their positions on the genetic map and the allelic relationships between different ...
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The Plant Journal, Vol. 36, No. 6. (2003), pp. 867-882.
Abstract
Late blight, caused by the oomycete pathogen Phytophthora infestans, is the most devastating disease for potato cultivation. Here, we describe the positional cloning of the Rpi-blb1 gene from the wild potato species Solanum bulbocastanum known for its high levels of resistance to late blight. The Rpi-blb1 locus, which confers full resistance to complex isolates of P. infestans and for which race specificity has not yet been demonstrated, was mapped in an intraspecific S. bulbocastanum population on chromosome 8, 0.3 cM from marker CT88. Molecular ...
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Genetics, Vol. 155, No. 2. (1 June 2000), pp. 873-887.
Abstract
Genomic positions of phenotypically defined disease resistance genes (R genes) and R gene homologues were analyzed in three solanaceous crop genera, Lycopersicon (tomato), Solanum (potato), and Capsicum (pepper). R genes occurred at corresponding positions in two or more genomes more frequently than expected by chance; however, in only two cases, both involving Phytophthora spp., did genes at corresponding positions have specificity for closely related pathogen taxa. In contrast, resistances to Globodera spp., potato virus Y, tobacco mosaic virus, and tomato spotted ...
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TAG Theoretical and Applied Genetics, Vol. 116, No. 7. (1 May 2008), pp. 933-943.
Abstract
Abstract Allele mining facilitates the discovery of novel resistance (R) genes that can be used in breeding programs and sheds light on the evolution of R genes. Here we focus on two R genes, Rpi-blb1 and Rpi-blb2, originally derived from Solanum bulbocastanum. The Rpi-blb1 gene is part of a cluster of four paralogues and is flanked by RGA1-blb and RGA3-blb. Highly conserved RGA1-blb homologues were discovered in all the tested tuber-bearing (TB) and non-tuber-bearing (NTB) Solanum species, suggesting RGA1-blb was present before ...
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Euphytica, Vol. 165, No. 2. (1 January 2009), pp. 269-278.
Abstract
Abstract For breeding potato varieties resistant to late blight, identification of resistance genes to Phytophthora infestans (Rpi genes) is essential. Introduction of Rpi genes from wild Solanum species into cultivated potato is likely to be a good method to achieve durable resistance to P. infestans. In this study, we identified two Rpi genes (Rpi-ber1 and Rpi-ber2) derived from two different accessions of Solanum berthaultii. These two genes are closely linked on the long arm of chromosome 10. There are similarities between the predicted genetic locations ...
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Molecular plant-microbe interactions : MPMI, Vol. 22, No. 3. (March 2009), pp. 269-281.
Abstract
The AVR3a protein of Phytophthora infestans is a polymorphic member of the RXLR class of cytoplasmic effectors with dual functions. AVR3a(KI) but not AVR3a(EM) activates innate immunity triggered by the potato resistance protein R3a and is a strong suppressor of the cell-death response induced by INF1 elicitin, a secreted P. infestans protein that has features of pathogen-associated molecular patterns. To gain insights into the molecular basis of AVR3a activities, we performed structure-function analyses of both AVR3a forms. We utilized saturated high-throughput ...
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J. Exp. Bot., Vol. 60, No. 4. (1 March 2009), pp. 1133-1140.
by Paul R. J. Birch, Miles Armstrong, Jorunn Bos, et al.Petra Boevink, Eleanor M. Gilroy, Rosalind M. Taylor, Stephan Wawra, Leighton Pritchard, Lucio Conti, Richard Ewan, Stephen C. Whisson, Pieter van West, Ari Sadanandom, Sophien Kamoun
Abstract
Plant pathogens establish infection by secretion of effector proteins that may be delivered inside host cells to manipulate innate immunity. It is increasingly apparent that the ubiquitin proteasome system (UPS) contributes significantly to the regulation of plant defences and, as such, is a target for pathogen effectors. Bacterial effectors delivered by the type III and IV secretion systems have been shown to interact with components of the host UPS. Some of these effectors possess functional domains that are conserved in UPS ...
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BMC Genomics, Vol. 8 (02 May 2007), 112.
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Molecular Plant Pathology, Vol. 7, No. 5. (September 2006), pp. 437-448.
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Molecular Breeding, Vol. 17, No. 2. (2 February 2006), pp. 137-148.
Abstract
Abstract Resistance (R) genes and the proteins they encode are key components of the defense system of plants. The exploration of R gene diversity enables the study of R gene evolution and may facilitate the isolation of new and functional alleles. Most cloned R genes occur in clusters of related sequences. Thus, the development of a tool for reliable recovery of orthologous R gene sequences to the exclusion of paralogous sequences will facilitate R gene diversity analysis. The late blight resistance gene ...
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