Major gene and polygenic resistance to Leptosphaeria maculans in oilseed rape (Brassica napus)

2006 ◽  
pp. 41-52
Author(s):  
R. Delourme ◽  
A. M. Chèvre ◽  
H. Brun ◽  
T. Rouxel ◽  
M. H. Balesdent ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Oilseed Rape ◽  
Major Gene ◽  
Leptosphaeria Maculans ◽  
Polygenic Resistance

Major Gene and Polygenic Resistance to Leptosphaeria maculans in Oilseed Rape (Brassica napus)

2006 ◽  
Vol 114 (1) ◽  
pp. 41-52 ◽  
Author(s):  
R. Delourme ◽  
A. M. Chèvre ◽  
H. Brun ◽  
T. Rouxel ◽  
M. H. Balesdent ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Oilseed Rape ◽  
Major Gene ◽  
Leptosphaeria Maculans ◽  
Polygenic Resistance

Major gene resistance in Brassica napus (oilseed rape) is overcome by changes in virulence of populations of Leptosphaeria maculans in France and Australia

2006 ◽  
Vol 114 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Susan J. Sprague ◽  
Marie-Hélène Balesdent ◽  
Hortense Brun ◽  
Helen L. Hayden ◽  
Stephen J. Marcroft ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Oilseed Rape ◽  
Major Gene ◽  
Leptosphaeria Maculans ◽  
Major Gene Resistance

PrBn, a Major Gene Controlling Homeologous Pairing in Oilseed Rape (Brassica napus) Haploids

Genetics ◽  
2003 ◽  
Vol 164 (2) ◽  
pp. 645-653 ◽  
Author(s):  
Eric Jenczewski ◽  
Frédérique Eber ◽  
Agnès Grimaud ◽  
Sylvie Huet ◽  
Marie Odile Lucas ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Oilseed Rape ◽  
Chromosome Pairing ◽  
Major Gene ◽  
Major Effect ◽  
F1 Hybrids ◽  
Precise Control ◽  
Ph1 Locus ◽  
Likelihood Approach ◽  
Likelihood Ratio Statistics

Abstract Precise control of chromosome pairing is vital for conferring meiotic, and hence reproductive, stability in sexually reproducing polyploids. Apart from the Ph1 locus of wheat that suppresses homeologous pairing, little is known about the activity of genes that contribute to the cytological diploidization of allopolyploids. In oilseed rape (Brassica napus) haploids, the amount of chromosome pairing at metaphase I (MI) of meiosis varies depending on the varieties the haploids originate from. In this study, we combined a segregation analysis with a maximum-likelihood approach to demonstrate that this variation is genetically based and controlled mainly by a gene with a major effect. A total of 244 haploids were produced from F1 hybrids between a high- and a low-pairing variety (at the haploid stage) and their meiotic behavior at MI was characterized. Likelihood-ratio statistics were used to demonstrate that the distribution of the number of univalents among these haploids was consistent with the segregation of a diallelic major gene, presumably in a background of polygenic variation. Our observations suggest that this gene, named PrBn, is different from Ph1 and could thus provide complementary information on the meiotic stabilization of chromosome pairing in allopolyploid species.

scholarly journals Effect of Water Flooding on Survival of Leptosphaeria biglobosa ‘brassicae’ in Stubble of Oilseed Rape (Brassica napus) in Central China

Plant Disease ◽  
2015 ◽  
Vol 99 (10) ◽  
pp. 1426-1433 ◽  
Author(s):  
Xiang Cai ◽  
Jing Zhang ◽  
Mingde Wu ◽  
Daohong Jiang ◽  
Guoqing Li ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Field Experiment ◽  
Oilseed Rape ◽  
Leptosphaeria Maculans ◽  
Soil Surface ◽  
Dry Weight ◽  
Central China ◽  
Water Flooding ◽  
Cotton Field ◽  
Winter Oilseed Rape

Blackleg (Phoma stem canker) caused by Leptosphaeria maculans and L. biglobosa is an economically important disease on oilseed rape and many cruciferous vegetables. Oilseed rape–rice rotation is a routine cultivation practice in central China. This study was conducted to assess the effect of flooding on survival of L. biglobosa ‘brassicae’ in the stubble of winter oilseed rape (Brassica napus). Basal stems with typical blackleg symptoms were collected and cut into small pieces (2 cm) that were either submerged in water at 16 and 20, 20 and 28, 28 and 33, and 33 and 40°C (12 and 12 h) or kept dry at room temperature (control). Moreover, in a field experiment, the stem pieces were placed on the soil surface in a rice field or in a cotton field and either flooded in water or not flooded, respectively. After 1, 2, 4, 6, and 8 weeks, the stem pieces were sampled for retrieval of L. biglobosa ‘brassicae’ on V8-juice agar and for determination of dry weight. Selected L. biglobosa ‘brassicae’ isolates from the stem pieces were identified by polymerase chain reaction (PCR). Results from the two experiments showed that, compared with the controls, flooding for 1 to 2 weeks substantially reduced recovery of L. biglobosa ‘brassicae’ and flooding for 4 weeks resulted in negligible recovery of L. biglobosa ‘brassicae’. All of the 99 selected isolates produced a 444-bp DNA fragment in the PCR, confirming that they belong to L. biglobosa ‘brassicae’. Results also indicated that flooding caused rapid decomposition of the stem pieces. After flooding for 8 weeks, the dry weight of the stem pieces was reduced by 28 to 42% in the laboratory experiment and by 26 to 36% in the field experiment. These results suggest that oilseed rape–rice rotation is probably an efficient way to reduce longevity of L. biglobosa ‘brassicae’ in stubble of winter oilseed rape in central China.

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