Six genetically different inbred genotypes of spring-type rye Secale cereale with differences in ... more Six genetically different inbred genotypes of spring-type rye Secale cereale with differences in the average number and in the positional distribution of chiasmata were used in this study. The line with the lowest chiasma frequency was chosen as the female parent and crossed with the other five lines. Parental, F1, and F2 data were collected on chiasma number and on chiasma distribution between and within bivalents. Evidence for a polygenic control of both phenomena was found. Chiasma distribution between bivalents within pollen mother cells obviously follows a binomial distribution. This is effected by a mechanism that prevents the formation of a second chiasma on a chromosome arm as long as chromosome arms without chiasma remain; i.e., with 14 chiasmata seven ring bivalents will generally be formed. This mechanism causes a very strong negative correlation between frequency and between-cell variance of chiasmata. The number of chiasmata is independent of their position within the bivalents. A very close correlation between the number of pollen mother cells without univalents and the number of fertile pollen grains was found. Key words: inbred rye, genetic control, chiasma frequency, chiasma distribution, heterosis.
An inbred genotype of cultivated rye was found that produces unreduced gametes in a very regular ... more An inbred genotype of cultivated rye was found that produces unreduced gametes in a very regular fashion. In the cross progeny of this line with another inbred line, which did not show unreduced gametes, the inheritance of this phenomenon was studied. The formation of unreduced gametes appears to be a recessive trait controlled by more than one gene. Chiasma frequency in 4n PMCs is exactly twice that in 2n PMCs. In first metaphase of 4n PMCs only bivalents (no multivalents) were seen. The possible mechanism leading to unreduced gametes and its evolutionary implications are discussed. Key words: rye, unreduced gametes, polyploidy, genetic control, chiasma frequency.
The environmental stability of breadmaking quality of wheat flours i.e. the absence of fluctuatio... more The environmental stability of breadmaking quality of wheat flours i.e. the absence of fluctuation across environments and genotype×environment interactions is as important as their performance in milling and baking. Many statistical approaches have been used to assess cultivar stability parameters across environments. Quality stability parameters were studied using a set of eleven bread wheat cultivars and five hybrid wheats grown
Nom QTL Stade épidémique Composante(s) Spécificité Source Qlr.inra 1Aa Précoce oui Apa Qlr.inra 2... more Nom QTL Stade épidémique Composante(s) Spécificité Source Qlr.inra 1Aa Précoce oui Apa Qlr.inra 2Ab Tardif SPL, LS non Apa Qlr.inra 2B Tardif LP oui Bal Qlr.inra 2D Tous SPS Quantitative Bal Qlr.inra 3Bb.1 Tardif SPS oui Apa Qlr.inra 3Bb.2 Précoce All oui Bal Qlr.inra 3Db Intermédiaire LP, LS Quantitative Apa Qlr.inra 4Bb Intermédiaire SPS oui Apa Qlr.inra 4Da Précoce SPL, LS oui Bal Qlr.inra -5Bb/7Bb Tous non Bal Qlr.inra 6Aa Tardif LP Quantitative Bal Qlr.inra 6B Tous Quantitative Bal Qlr.inra 7Aa Tous SPL non Bal Objectifs Caractériser la diversité de la résistance partielle dans le matériel de sélection français à trois échelles : 1) Au niveau épidémique au champ 2) Au niveau des composantes du cycle infectieux 3) Au niveau génétique
Near isogenic lines differing for plant height QTL on chromosomes 2A, 2D, 3A, 3B and 6A in two ge... more Near isogenic lines differing for plant height QTL on chromosomes 2A, 2D, 3A, 3B and 6A in two genetic backgrounds (Avalon and Cadenza) were assessed for FHB resistance. The 2D and 3B QTL had the greatest influence on plant height and on FHB resistance. In general, the allele conferring increased plant height was also associated with reduced FHB disease. The exceptions to this were the 6A QTL across both backgrounds in 2014 and the 2A QTL in the Cadenza background in both 2014 and 2015.
ABSTRACT Abstract: The Green Revolution genes considerably increased the yield potential of moder... more ABSTRACT Abstract: The Green Revolution genes considerably increased the yield potential of modern wheat varieties, but also rendered them more susceptible to Fusarium head blight (FHB) causing problems with mycotoxin contamination. In order to study the association of “reduced height” (Rht) genes and FHB resistance, Rht-B1b, Rht-D1b and Rht8 genes were introduced in tall high-yielding wheat cultivars expressing a good level of Fusarium head blight (FHB) resistance via marker-assisted selection (MAS). The F1 plants of five crosses were backcrossed twice and 189 BC1 lines were genotyped. MAS was performed with Rht-B1b and Rht-D1b specific markers, with SSR Xgwm261 being diagnostic for Rht8, and with a Ppd-D1 specific marker. During the first phase of selection corresponding chromosomes were screened with 48 SSRs for polymorphisms followed by the use of 3 to 5 polymorphic SSRs for the detection of recombination around these loci. Based on this procedure a total of 42 lines were selected for the selection phase two. 152 genome-wide SSRs had been screened among the parent lines, and from these a set of 80 polymorphic SSRs (4 per chromosome) was chosen for background fingerprinting of the 42 lines. This process is ongoing. We expect that Rht alleles will be quickly integrated into tall and high-yielding cultivars with excellent quantitative FHB resistance carrying only small chromosomal fragments of the Rht donor lines. Finally, in multi-location field trials these new lines will be tested to analyse the association of the three Rht genes and FHB susceptibility.
Six genetically different inbred genotypes of spring-type rye Secale cereale with differences in ... more Six genetically different inbred genotypes of spring-type rye Secale cereale with differences in the average number and in the positional distribution of chiasmata were used in this study. The line with the lowest chiasma frequency was chosen as the female parent and crossed with the other five lines. Parental, F1, and F2 data were collected on chiasma number and on chiasma distribution between and within bivalents. Evidence for a polygenic control of both phenomena was found. Chiasma distribution between bivalents within pollen mother cells obviously follows a binomial distribution. This is effected by a mechanism that prevents the formation of a second chiasma on a chromosome arm as long as chromosome arms without chiasma remain; i.e., with 14 chiasmata seven ring bivalents will generally be formed. This mechanism causes a very strong negative correlation between frequency and between-cell variance of chiasmata. The number of chiasmata is independent of their position within the bivalents. A very close correlation between the number of pollen mother cells without univalents and the number of fertile pollen grains was found. Key words: inbred rye, genetic control, chiasma frequency, chiasma distribution, heterosis.
An inbred genotype of cultivated rye was found that produces unreduced gametes in a very regular ... more An inbred genotype of cultivated rye was found that produces unreduced gametes in a very regular fashion. In the cross progeny of this line with another inbred line, which did not show unreduced gametes, the inheritance of this phenomenon was studied. The formation of unreduced gametes appears to be a recessive trait controlled by more than one gene. Chiasma frequency in 4n PMCs is exactly twice that in 2n PMCs. In first metaphase of 4n PMCs only bivalents (no multivalents) were seen. The possible mechanism leading to unreduced gametes and its evolutionary implications are discussed. Key words: rye, unreduced gametes, polyploidy, genetic control, chiasma frequency.
The environmental stability of breadmaking quality of wheat flours i.e. the absence of fluctuatio... more The environmental stability of breadmaking quality of wheat flours i.e. the absence of fluctuation across environments and genotype×environment interactions is as important as their performance in milling and baking. Many statistical approaches have been used to assess cultivar stability parameters across environments. Quality stability parameters were studied using a set of eleven bread wheat cultivars and five hybrid wheats grown
Nom QTL Stade épidémique Composante(s) Spécificité Source Qlr.inra 1Aa Précoce oui Apa Qlr.inra 2... more Nom QTL Stade épidémique Composante(s) Spécificité Source Qlr.inra 1Aa Précoce oui Apa Qlr.inra 2Ab Tardif SPL, LS non Apa Qlr.inra 2B Tardif LP oui Bal Qlr.inra 2D Tous SPS Quantitative Bal Qlr.inra 3Bb.1 Tardif SPS oui Apa Qlr.inra 3Bb.2 Précoce All oui Bal Qlr.inra 3Db Intermédiaire LP, LS Quantitative Apa Qlr.inra 4Bb Intermédiaire SPS oui Apa Qlr.inra 4Da Précoce SPL, LS oui Bal Qlr.inra -5Bb/7Bb Tous non Bal Qlr.inra 6Aa Tardif LP Quantitative Bal Qlr.inra 6B Tous Quantitative Bal Qlr.inra 7Aa Tous SPL non Bal Objectifs Caractériser la diversité de la résistance partielle dans le matériel de sélection français à trois échelles : 1) Au niveau épidémique au champ 2) Au niveau des composantes du cycle infectieux 3) Au niveau génétique
Near isogenic lines differing for plant height QTL on chromosomes 2A, 2D, 3A, 3B and 6A in two ge... more Near isogenic lines differing for plant height QTL on chromosomes 2A, 2D, 3A, 3B and 6A in two genetic backgrounds (Avalon and Cadenza) were assessed for FHB resistance. The 2D and 3B QTL had the greatest influence on plant height and on FHB resistance. In general, the allele conferring increased plant height was also associated with reduced FHB disease. The exceptions to this were the 6A QTL across both backgrounds in 2014 and the 2A QTL in the Cadenza background in both 2014 and 2015.
ABSTRACT Abstract: The Green Revolution genes considerably increased the yield potential of moder... more ABSTRACT Abstract: The Green Revolution genes considerably increased the yield potential of modern wheat varieties, but also rendered them more susceptible to Fusarium head blight (FHB) causing problems with mycotoxin contamination. In order to study the association of “reduced height” (Rht) genes and FHB resistance, Rht-B1b, Rht-D1b and Rht8 genes were introduced in tall high-yielding wheat cultivars expressing a good level of Fusarium head blight (FHB) resistance via marker-assisted selection (MAS). The F1 plants of five crosses were backcrossed twice and 189 BC1 lines were genotyped. MAS was performed with Rht-B1b and Rht-D1b specific markers, with SSR Xgwm261 being diagnostic for Rht8, and with a Ppd-D1 specific marker. During the first phase of selection corresponding chromosomes were screened with 48 SSRs for polymorphisms followed by the use of 3 to 5 polymorphic SSRs for the detection of recombination around these loci. Based on this procedure a total of 42 lines were selected for the selection phase two. 152 genome-wide SSRs had been screened among the parent lines, and from these a set of 80 polymorphic SSRs (4 per chromosome) was chosen for background fingerprinting of the 42 lines. This process is ongoing. We expect that Rht alleles will be quickly integrated into tall and high-yielding cultivars with excellent quantitative FHB resistance carrying only small chromosomal fragments of the Rht donor lines. Finally, in multi-location field trials these new lines will be tested to analyse the association of the three Rht genes and FHB susceptibility.
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