... 1995). Brassica sect. Brassica (2n = 18), occurring in Sicily and in the small islands around... more ... 1995). Brassica sect. Brassica (2n = 18), occurring in Sicily and in the small islands around, is represented by five distinct species: B. incana Ten., B. insularis Moris, B. macrocarpa Guss., B. rupestris Rafin. and B. villosa Biv. ... 1987, 1991, Hosaka et al. 1990, Song et al. ...
ABSTRACT The hybrid Brassica napus × B. nigra was produced and backcrossed three times to rapesee... more ABSTRACT The hybrid Brassica napus × B. nigra was produced and backcrossed three times to rapeseed. BC3 genotypes with one or two additional chromosomes were either selfed or haplodiploidized by using anther culture followed by colchicine doubling. Thirty-four fertile disomic addition lines have so far been obtained. Meiotic pairing in most of them was close to 20 II at metaphase I of meiosis. Their characterization is in progress. This material obtained for the first time in B. napus should be of great interest in the study of genome structure and basic chromosome number in Brassica species.Key words: Brassica, genome, disomic addition lines, meiotic behaviour.
ABSTRACT In order to assess the risk of commercial Fl hybrid seed contamination due to outcrossin... more ABSTRACT In order to assess the risk of commercial Fl hybrid seed contamination due to outcrossing on male sterile radish line pollinated by wild mustard, two isolated field experiments were performed in the presence or absence of garden radish pollen. Additionally, spontaneous wild radish plants were observed under 200 m away from both fields. Seeds were harvested on the female radish line and sieved. Isozyme analyses combined with cytogenetical characterisation revealed that morphological observations were not efficient enough to distinguish the interspecific hybrids among the seedlings obtained. The radish-wild mustard interspecific hybrid production was higher without than with radish pollen competition: 42 and 3 interspecific hybrid seeds per 1 000 seeds were observed, respectively. Numerous cultivated-wild radish hybrids were observed from the two experiments without and with radish pollinator: 551 and 144 per 1 000 seeds, respectively. Sieving seems to be efficient in preventing the commercialisation of cultivated radish-wild mustard hybrids. (C) Inra/Elsevier, Paris.
The assessment of the likelihood of transgene spread from cultivated species to their wild relati... more The assessment of the likelihood of transgene spread from cultivated species to their wild relatives is relevant for oilseed rape (Brassica napus, AACC, 2n=38) as it is partially allogamous and presents numerous wild relatives growing nearby in cultivated areas and having an overlapping of the flowering period. We have assessed the probability of F1 interspecific hybrid formation between oilseed rape
In oilseed rape, genetic transformation offers new opportunities for the selection of characters ... more In oilseed rape, genetic transformation offers new opportunities for the selection of characters such as male sterility to increase yields, grain quality, pest resistance and herbicide tolerance. Potential impacts of new introduced genes on food quality and the environment should be assessed. Regarding the environmental impact, the spread of introduced genes is dependant on pollen and seed dispersal. Oilseed rape is partially allogamous (20 to 30% of outcrossing) and pollen is carried by the wind and insects. Some studies have indicated that viable pollen can be found 1.5 km from the pollen source (3). In discontinuous pollen-dispersal experiments, cross-hybridization rates were estimated to be 0.0156% and 0.0038% at 200 m and 400 m, respectively (4) whereas in a continuous pollen dispersal experiment, only 0.00033% of hybrids were found 47 m from the central plot (5). To obtain a pollen dispersal curve, a square field (90 m X 90 m) was planted, and a herbicide-tolerant variety as p...
A Review on Interspecific Gene Flow from Oilseed Rape to Wild Relatives Anne-Marie Chèvre1,Henrie... more A Review on Interspecific Gene Flow from Oilseed Rape to Wild Relatives Anne-Marie Chèvre1,Henriette Ammitzbøll2, Broder Breckling3, Antje Dietz ... A model was also developed by Thompson et al.(2003) to study the mechanisms of introgression of a transgene from a ...
Introgressions into Brassica napus from the B genome, either the B. nigra chromosome B4 or the B.... more Introgressions into Brassica napus from the B genome, either the B. nigra chromosome B4 or the B. juncea fragment carrying the Jlm1 gene, have given rise to the B. napus-B. nigra addition line (LA4+) and the B. napus-B. juncea recombinant line (MXS), respectively. The resistance of these two lines to Leptosphaeria maculans is characterized by a hypersensitive reaction (HR) on both the cotyledons and leaves, while the collar displays a high degree of resistance. Responses induced in cotyledons of the two lines by L. maculans inoculation were investigated with emphasis on cytological events underlying the HR and on host defense reactions. Features of host cell changes including condensation and lobing of nuclei, fragmentation of chromatin, disruption of the nuclear membranes, and plasma membrane withdrawal were reminiscent of HR cell death in MXS and LA4+ plants. Restriction of pathogen growth to the infection areas in LA4+ was correlated to reinforcement of cell wall barriers, includ...
Specific resistance genes are an effective means of disease control when the pathogen population ... more Specific resistance genes are an effective means of disease control when the pathogen population is mainly avirulent on the cultivated varieties carrying the corresponding resistance gene. Development of new races of Leptosphaeria maculans (Desmaz.) Ces. & de Not., the species responsible for the most damaging symptoms of blackleg disease of canola (Brassica napus L.), increases the risk that host genetic resistance may be rapidly overcome. This study aims to elucidate the race structure of L. maculans by determining, under controlled conditions, the frequency of avirulence alleles at eleven avirulence loci in pathogen populations collected from nine locations across western Canada. The avirulence allele at AvrLm6 was present in all isolates tested (63) from three locations. At eight locations >88% of the isolates (423) carried the avirulence allele at AvrLm2, but only 37% at another location. For all other avirulence genes (AvrLm1, AvrLm3, AvrLm4, AvrLm7, AvrLm9, AvrLmLepR1, Avr...
ABSTRACT Jusqu'à présent les flux de gènes du colza au sein de Vespèce et vers les espèce... more ABSTRACT Jusqu'à présent les flux de gènes du colza au sein de Vespèce et vers les espèces sauvages apparentées étaient mal cernés. Les travaux présentés ici montrent que, dans les conditions naturelles, les risques de dissémination par le pollen et les graines existent bien mais que le transfert de gènes dans le génome des populations sauvages, s'il semble possible, est fonction de l'espèce cible considérée.
... Oléagineux, Corps Gras, Lipides. ... 4. Brun H, Pinochet X, Tanguy X, Caceres F, Sauzet G, Re... more ... Oléagineux, Corps Gras, Lipides. ... 4. Brun H, Pinochet X, Tanguy X, Caceres F, Sauzet G, Renard M. The potential durability of the resistance to Leptosphaeria maculans conferred to Brassica napus by a new major gene originating from B.juncea B genome depends on the ...
... Gene-flow assessment is discussed based on these data. Communicated by K. Glimelius AM Che`vr... more ... Gene-flow assessment is discussed based on these data. Communicated by K. Glimelius AM Che`vre ( ) · F. Eber · A. Baranger · G. Hureau · P. Barret · H. Picault · M. Renard INRA, Station d'Ame´lioration des Plantes, BP 29, 35653 Le Rheu Cedex, France ...
The F1 hybrids produced after crosses between B. gra and B. oleracea were backcrossed two or thre... more The F1 hybrids produced after crosses between B. gra and B. oleracea were backcrossed two or three times to B. oleracea. Among the 14 plants analysed, five were monosomic addition lines (2n=19), six were double monosomic addition lines (2n=20) and three had three or four additional chromosomes. From these lines, 14 isozyme and 80 RAPD loci were localized on the
The screening of wild populations for evidence of gene flow from a crop to a wild related species... more The screening of wild populations for evidence of gene flow from a crop to a wild related species requires the unambiguous detection of crop genes within the genome of the wild species, taking into account the intraspecific variability of each species. If the crop and wild relatives share a common ancestor, as is the case for the Brassica crops and their wild relatives (subtribe Brassiceae), the species-specific markers needed to make this unambiguous detection are difficult to identify. In the model oilseed rape (Brassica napus, AACC, 2n = 38)-wild radish (Raphanus raphanistrum, RrRr, 2n = 18) system, we utilized the presence or absence of a short-interspersed element (SINE) at a given locus to develop oilseed rape-specific markers, as SINE insertions are irreversible. By means of sequence-specific amplified polymorphism (SINE-SSAP) reactions, we identified and cloned 67 bands specific to the oilseed rape genome and absent from that of wild radish. Forty-seven PCR-specific markers were developed from three combinations of primers anchored either in (1) the 5'- and 3'-genomic sequences flanking the SINE, (2) the 5'-flanking and SINE internal sequences or (3) the SINE internal and flanking 3'-sequences. Seventeen markers were monomorphic whatever the oilseed rape varieties tested, whereas 30 revealed polymorphism and behaved either as dominant (17) or co-dominant (13) markers. Polymorphic markers were mapped on 19 genomic regions assigned to ten linkage groups. The markers developed will be efficient tools to trace the occurrence and frequency of introgressions of oilseed rape genomic region within wild radish populations.
... 1995). Brassica sect. Brassica (2n = 18), occurring in Sicily and in the small islands around... more ... 1995). Brassica sect. Brassica (2n = 18), occurring in Sicily and in the small islands around, is represented by five distinct species: B. incana Ten., B. insularis Moris, B. macrocarpa Guss., B. rupestris Rafin. and B. villosa Biv. ... 1987, 1991, Hosaka et al. 1990, Song et al. ...
ABSTRACT The hybrid Brassica napus × B. nigra was produced and backcrossed three times to rapesee... more ABSTRACT The hybrid Brassica napus × B. nigra was produced and backcrossed three times to rapeseed. BC3 genotypes with one or two additional chromosomes were either selfed or haplodiploidized by using anther culture followed by colchicine doubling. Thirty-four fertile disomic addition lines have so far been obtained. Meiotic pairing in most of them was close to 20 II at metaphase I of meiosis. Their characterization is in progress. This material obtained for the first time in B. napus should be of great interest in the study of genome structure and basic chromosome number in Brassica species.Key words: Brassica, genome, disomic addition lines, meiotic behaviour.
ABSTRACT In order to assess the risk of commercial Fl hybrid seed contamination due to outcrossin... more ABSTRACT In order to assess the risk of commercial Fl hybrid seed contamination due to outcrossing on male sterile radish line pollinated by wild mustard, two isolated field experiments were performed in the presence or absence of garden radish pollen. Additionally, spontaneous wild radish plants were observed under 200 m away from both fields. Seeds were harvested on the female radish line and sieved. Isozyme analyses combined with cytogenetical characterisation revealed that morphological observations were not efficient enough to distinguish the interspecific hybrids among the seedlings obtained. The radish-wild mustard interspecific hybrid production was higher without than with radish pollen competition: 42 and 3 interspecific hybrid seeds per 1 000 seeds were observed, respectively. Numerous cultivated-wild radish hybrids were observed from the two experiments without and with radish pollinator: 551 and 144 per 1 000 seeds, respectively. Sieving seems to be efficient in preventing the commercialisation of cultivated radish-wild mustard hybrids. (C) Inra/Elsevier, Paris.
The assessment of the likelihood of transgene spread from cultivated species to their wild relati... more The assessment of the likelihood of transgene spread from cultivated species to their wild relatives is relevant for oilseed rape (Brassica napus, AACC, 2n=38) as it is partially allogamous and presents numerous wild relatives growing nearby in cultivated areas and having an overlapping of the flowering period. We have assessed the probability of F1 interspecific hybrid formation between oilseed rape
In oilseed rape, genetic transformation offers new opportunities for the selection of characters ... more In oilseed rape, genetic transformation offers new opportunities for the selection of characters such as male sterility to increase yields, grain quality, pest resistance and herbicide tolerance. Potential impacts of new introduced genes on food quality and the environment should be assessed. Regarding the environmental impact, the spread of introduced genes is dependant on pollen and seed dispersal. Oilseed rape is partially allogamous (20 to 30% of outcrossing) and pollen is carried by the wind and insects. Some studies have indicated that viable pollen can be found 1.5 km from the pollen source (3). In discontinuous pollen-dispersal experiments, cross-hybridization rates were estimated to be 0.0156% and 0.0038% at 200 m and 400 m, respectively (4) whereas in a continuous pollen dispersal experiment, only 0.00033% of hybrids were found 47 m from the central plot (5). To obtain a pollen dispersal curve, a square field (90 m X 90 m) was planted, and a herbicide-tolerant variety as p...
A Review on Interspecific Gene Flow from Oilseed Rape to Wild Relatives Anne-Marie Chèvre1,Henrie... more A Review on Interspecific Gene Flow from Oilseed Rape to Wild Relatives Anne-Marie Chèvre1,Henriette Ammitzbøll2, Broder Breckling3, Antje Dietz ... A model was also developed by Thompson et al.(2003) to study the mechanisms of introgression of a transgene from a ...
Introgressions into Brassica napus from the B genome, either the B. nigra chromosome B4 or the B.... more Introgressions into Brassica napus from the B genome, either the B. nigra chromosome B4 or the B. juncea fragment carrying the Jlm1 gene, have given rise to the B. napus-B. nigra addition line (LA4+) and the B. napus-B. juncea recombinant line (MXS), respectively. The resistance of these two lines to Leptosphaeria maculans is characterized by a hypersensitive reaction (HR) on both the cotyledons and leaves, while the collar displays a high degree of resistance. Responses induced in cotyledons of the two lines by L. maculans inoculation were investigated with emphasis on cytological events underlying the HR and on host defense reactions. Features of host cell changes including condensation and lobing of nuclei, fragmentation of chromatin, disruption of the nuclear membranes, and plasma membrane withdrawal were reminiscent of HR cell death in MXS and LA4+ plants. Restriction of pathogen growth to the infection areas in LA4+ was correlated to reinforcement of cell wall barriers, includ...
Specific resistance genes are an effective means of disease control when the pathogen population ... more Specific resistance genes are an effective means of disease control when the pathogen population is mainly avirulent on the cultivated varieties carrying the corresponding resistance gene. Development of new races of Leptosphaeria maculans (Desmaz.) Ces. & de Not., the species responsible for the most damaging symptoms of blackleg disease of canola (Brassica napus L.), increases the risk that host genetic resistance may be rapidly overcome. This study aims to elucidate the race structure of L. maculans by determining, under controlled conditions, the frequency of avirulence alleles at eleven avirulence loci in pathogen populations collected from nine locations across western Canada. The avirulence allele at AvrLm6 was present in all isolates tested (63) from three locations. At eight locations >88% of the isolates (423) carried the avirulence allele at AvrLm2, but only 37% at another location. For all other avirulence genes (AvrLm1, AvrLm3, AvrLm4, AvrLm7, AvrLm9, AvrLmLepR1, Avr...
ABSTRACT Jusqu'à présent les flux de gènes du colza au sein de Vespèce et vers les espèce... more ABSTRACT Jusqu'à présent les flux de gènes du colza au sein de Vespèce et vers les espèces sauvages apparentées étaient mal cernés. Les travaux présentés ici montrent que, dans les conditions naturelles, les risques de dissémination par le pollen et les graines existent bien mais que le transfert de gènes dans le génome des populations sauvages, s'il semble possible, est fonction de l'espèce cible considérée.
... Oléagineux, Corps Gras, Lipides. ... 4. Brun H, Pinochet X, Tanguy X, Caceres F, Sauzet G, Re... more ... Oléagineux, Corps Gras, Lipides. ... 4. Brun H, Pinochet X, Tanguy X, Caceres F, Sauzet G, Renard M. The potential durability of the resistance to Leptosphaeria maculans conferred to Brassica napus by a new major gene originating from B.juncea B genome depends on the ...
... Gene-flow assessment is discussed based on these data. Communicated by K. Glimelius AM Che`vr... more ... Gene-flow assessment is discussed based on these data. Communicated by K. Glimelius AM Che`vre ( ) · F. Eber · A. Baranger · G. Hureau · P. Barret · H. Picault · M. Renard INRA, Station d'Ame´lioration des Plantes, BP 29, 35653 Le Rheu Cedex, France ...
The F1 hybrids produced after crosses between B. gra and B. oleracea were backcrossed two or thre... more The F1 hybrids produced after crosses between B. gra and B. oleracea were backcrossed two or three times to B. oleracea. Among the 14 plants analysed, five were monosomic addition lines (2n=19), six were double monosomic addition lines (2n=20) and three had three or four additional chromosomes. From these lines, 14 isozyme and 80 RAPD loci were localized on the
The screening of wild populations for evidence of gene flow from a crop to a wild related species... more The screening of wild populations for evidence of gene flow from a crop to a wild related species requires the unambiguous detection of crop genes within the genome of the wild species, taking into account the intraspecific variability of each species. If the crop and wild relatives share a common ancestor, as is the case for the Brassica crops and their wild relatives (subtribe Brassiceae), the species-specific markers needed to make this unambiguous detection are difficult to identify. In the model oilseed rape (Brassica napus, AACC, 2n = 38)-wild radish (Raphanus raphanistrum, RrRr, 2n = 18) system, we utilized the presence or absence of a short-interspersed element (SINE) at a given locus to develop oilseed rape-specific markers, as SINE insertions are irreversible. By means of sequence-specific amplified polymorphism (SINE-SSAP) reactions, we identified and cloned 67 bands specific to the oilseed rape genome and absent from that of wild radish. Forty-seven PCR-specific markers were developed from three combinations of primers anchored either in (1) the 5'- and 3'-genomic sequences flanking the SINE, (2) the 5'-flanking and SINE internal sequences or (3) the SINE internal and flanking 3'-sequences. Seventeen markers were monomorphic whatever the oilseed rape varieties tested, whereas 30 revealed polymorphism and behaved either as dominant (17) or co-dominant (13) markers. Polymorphic markers were mapped on 19 genomic regions assigned to ten linkage groups. The markers developed will be efficient tools to trace the occurrence and frequency of introgressions of oilseed rape genomic region within wild radish populations.
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