scholarly journals Sensitivity of winter rapeseed (Brassica napus L.) to isolates of the fungus Leptosphaeria maculans (Desm.) Ces. et de Not

2017 ◽  
Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽  
pp. 572-574
Author(s):  
E. Plachká ◽  
L. Odstrčilová

The pure cultures of the fungus Leptosphaeria maculans were isolated from the rapeseed leaves collected in Moravia. Two isolates were collected on the basis of their ability to produce yellow colour. The isolate producing yellow colour was classified as aggressive, while the isolate without the ability to produce yellow colour was not aggressive. The sensitivity to these isolates was verified in 11 rapeseed genotypes. This test was based on the method from the document Crucifer Genetics Cooperative (information document from the Department of Plant Pathology, University of Wisconsin). This method is based on the inoculation of cruciferous leaflets with suspension from the isolate of the pathogen observed. The scale from 0 to 9 was used for evaluation (0 = no darkening around the wound, 9 = accompanied by profuse sporulation in large, more than 5 mm, lesions with diffuse margins). The infection degree of the aggressive isolate ranged in different genotypes from 1.45 to 4.5, the results of the non-aggressive isolate ranged from 1.0 to 1.5. Based on these results the aggressive isolate was used for further tests of the selected breeding lines. The tests involved selected breeding materials, registered varieties, control varieties with different sensitivity to the isolate of Leptosphaeria maculans and control varieties included in state trials. The maximal difference in the sensitivity exhibited by individual genotypes was five degrees.

1995 ◽  
Vol 75 (2) ◽  
pp. 437-439 ◽  
Author(s):  
G. R. Stringam ◽  
V. K. Bansal ◽  
M. R. Thiagarajah ◽  
D. F. Degenhardt ◽  
J. P. Tewari

The doubled haploid breeding method and greenhouse screening using cotyledon bio-assay were successfully applied to transfer blackleg resistance from the Australian cultivar Maluka (Brassicas napus), into susceptible advanced B. napus lines from the University of Alberta. This approach for blackleg resistance breeding was effective and efficient as several superior blackleg resistant breeding lines were identified within 4 yr from the initial cross. One of these lines (91–21864NA) was entered in the 1993 trials of the Western Canada Canola/Rapeseed Recommending Committee. Key words: Blackleg resistance, Leptosphaeria maculans, doubled haploid, Brassica napus


2009 ◽  
Vol 120 (5) ◽  
pp. 921-931 ◽  
Author(s):  
Wolfgang Ecke ◽  
Rosemarie Clemens ◽  
Nora Honsdorf ◽  
Heiko C. Becker

1986 ◽  
Vol 66 (3) ◽  
pp. 425-430 ◽  
Author(s):  
R. R. DUNCAN ◽  
C. S. HOVELAND

Since rainfall generally exceeds 500 mm during the winter months and soil erosion is a problem in the southern U.S.A., a cover crop is essential to reduce soil losses. Continuous cultivation of a crop on the same land also provides the opportunity for pest problems to develop. A winter rapeseed (Brassica napus L.)-grain sorghum (Sorghum bicolor (L). Moench.) double-cropping system was investigated in the field from 1981 to 1984. Conventional tillage (CT) and no-till (NT) systems were used for both crops. Gullivar rape was planted in October and harvested in June. Winter rapeseed yields averaged 2.87 t ha−1 on CT plots in 1982. Averaged over 1983 and 1984, rape yields were 1.66 and 0.73 t ha−1 on CT and NT plots, respectively. However, the seeding method biased the rapeseed performance. Problems were encountered with winter weed control and pod shattering in the winter rape plots. Two sorghum hybrids, R. C. Young Oro Txtra and Funks G-550, were planted in June and harvested in October. Grain yields were not significantly different between hybrids (Oro 5.69 t ha−1, Funk 5.67 t ha−1) or between tillage systems (CT 5.59 t ha−1, NT 5.78 t ha−1). Grain yield differences were noted for year × hybrid × tillage interactions. Rape was a weed problem in the sorghum plots. The winter rape-sorghum double-cropping system offers an alternative to current winter small grains-sorghum/soybean (Glycine max (L.) Merr.) or winter annual legume-sorghum/soybean (Glycine max (L.) Merr.) systems; however, markets for the winter rapeseed and production economic analyses are needed prior to adoption of the system. Additional winter rapeseed research is needed to evaluate yields properly under NT conditions.Key words: Sorghum bicolor (L.) Moench, Brassica napus L., conservation tillage, multiple cropping, sorghum, rapeseed


1987 ◽  
Vol 67 (3) ◽  
pp. 675-684 ◽  
Author(s):  
G. C. BEAULIEU ◽  
D. J. HUME

In order to determine regions of adaptation of winter rapeseed (Brassica napus L.), field trials were planted at about 30 locations in Ontario in 1981 and 1982. Four cultivars were tested each year. Winter survival was poor in northern Ontario in both years, and along the north shore of Lake Erie in the first year. Over all sites, mean winter survival was 52%. At sites which did not completely winterkill, plant survival and yield averaged 70% and 2.38 t ha−1. Best winter rapeseed performance in Ontario occurred at well-drained sites with good winter snow cower and an absence of excessive flooding or cold temperatures in the spring. Cultivars did not differ in survival or yield in 1981–1982. The cultivar Jet Neuf had higher yields than the other cultivars in 1982–1983. There were differences in oil and protein content among the cultivars. The results suggest that winter rapeseed could become a viable crop in Ontario.Key words: Rapeseed (winter), Brassica napus, seed yield, winter survival, adaptation


Genome ◽  
2008 ◽  
Vol 51 (1) ◽  
pp. 64-72 ◽  
Author(s):  
Fengqun Yu ◽  
Derek J. Lydiate ◽  
S. Roger Rimmer

The spectrum of resistance to isolates of Leptosphaeria maculans and the map location of a new blackleg resistance gene found in the canola cultivar Brassica napus ‘Surpass 400’ are described. Two blackleg resistance genes, LepR1 and LepR2, from B. rapa subsp. sylvestris and introgressed in B. napus were identified previously. ‘Surpass 400’ also has blackleg resistance introgressed from B. rapa subsp. sylvestris. Using 31 diverse isolates of L. maculans, the disease reaction of ‘Surpass 400’ was compared with those of the resistant breeding lines AD9 (which contains LepR1), AD49 (which contains LepR2), and MC1-8 (which contains both LepR1 and LepR2). The disease reaction on ‘Surpass 400’ was different from those observed on AD9 and MC1-8, indicating that ‘Surpass 400’ carries neither LepR1 nor both LepR1 and LepR2 in combination. Disease reactions of ‘Surpass 400’ to most of the isolates tested were indistinguishable from those of AD49, which suggested ‘Surpass 400’ might contain LepR2 or a similar resistance gene. Classical genetic analysis of F1 and BC1 plants showed that a dominant allele conferred resistance to isolates of L. maculans in ‘Surpass 400’. The resistance gene, which mapped to B. napus linkage group N10 in an interval of 2.9 cM flanked by microsatellite markers sR12281a and sN2428Rb and 11.7 cM below LepR2, was designated LepR3. A 9 cM region of the B. napus genome containing LepR3 was found to be syntenic with a segment of Arabidopsis chromosome 5.


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