Transgenic Brassica napus fields and Brassica rapa weeds in Quebec: sympatry and weed-crop in situ hybridization

2006 ◽  
Vol 84 (12) ◽  
pp. 1842-1851 ◽  
Author(s):  
Marie-Josée Simard ◽  
Anne Légère ◽  
Suzanne I. Warwick

Hybridization between the herbicide-resistant transgenic crop Brassica napus L. (canola) and its weedy relative Brassica rapa L. (bird rape) has been documented in Quebec. Our goal was to evaluate the actual hybridization potential based on range overlap and actual in situ hybridization rates. This was done by mapping B. napus canola fields, comparing them with the sampling locations of B. rapa herbarium specimens from Quebec, gathering information on the presence of B. rapa in certified canola seed production fields, and surveying for B. rapa populations located in, or close to B. napus field margins. Progeny from these populations were screened for herbicide resistance (HR) and for the presence of the HR transgene. Two fields were also selected to evaluate B. rapa density effects on hybridization rates. Significant sympatry was observed in several areas of the province; hybridization occurred in all eight populations (1.1% to 17.5% hybrid seed) located in field margins and in one (1.1%) out of three populations located less than 10 m from a B. napus field. Hybridization rates decreased exponentially as B. rapa density increased, but interplant rates (0% to 68%) were highly variable. Environmental problems could be generated by the release of B. napus crops with traits conferring fitness benefits in nonmanaged areas.

2005 ◽  
Vol 47 (12) ◽  
pp. 1479-1484 ◽  
Author(s):  
Wen-Hui WEI ◽  
Wan-Peng ZHAO ◽  
Li-Jun WANG ◽  
Bo CHEN ◽  
Yun-Chang LI ◽  
...  

OCL ◽  
2020 ◽  
Vol 27 ◽  
pp. 45
Author(s):  
Ainash Daurova ◽  
Dias Daurov ◽  
Dmitriy Volkov ◽  
Kuanysh Zhapar ◽  
Daniyar Raimbek ◽  
...  

Doubled haploids (DH) were obtained from two interspecific hybrids between Brassica napus and Brassica rapa. Seeds of doubled haploid plants differed in colour and size. The hybridity of the obtained doubled haploid is shown using genomic in situ hybridization (GISH) analysis. Evaluation of drought tolerance during seed germination on PEG-6000 showed the advantage of doubled haploid plants of interspecific hybrids over the parent cultivars. The oil from seeds of doubled haploid plants showed good nutritional value.


1990 ◽  
Vol 70 (2) ◽  
pp. 399-407 ◽  
Author(s):  
R. J. MAILER ◽  
J. E. PRATLEY

Field studies of water availability during development and glucosinolate concentration in mature seed showed that glucosinolate concentration was closely correlated (R2 = 34 – 82%) with evapotranspiration between anthesis and maturity. Glucosinolate concentration increased with increasing moisture to a maximum and then declined again at high water levels. Oil concentration also increased with increasing moisture availability.Key words: Rapeseed, Brassica napus L., Cruciferae, glucosinolate, water availability


2004 ◽  
Vol 84 (4) ◽  
pp. 1171-1182 ◽  
Author(s):  
J. J. Soroka ◽  
L. M. Dosdall ◽  
O. O. Olfert ◽  
E. Seidle

The levels of infestation and damage to canola taproots caused by crucifer-feeding root maggots (Delia spp.)(Diptera: Anthomyiidae) were determined through surveys of commercial crops across the canola growing regions of western Canada. Canola root damage caused by Delia spp. maggots was measured at the end of the season by determining the percentage of plants infested (PPI) per field and estimating average damage levels (DL, on a scale of 0 to 5) to taproots. Over the course of the survey, 2890 canola fields were sampled. Infestation by root maggots occurred wherever canola is grown in western Canada. In the study, 96% of the fields surveyed in Manitoba and Saskatchewan and 99.8% of the fields in Alberta showed evidence of root maggot feeding, with PPI much higher than in provincial surveys of a decade previously. Geographical ecoregion significantly affected both PPI and DL. The greatest amount of damage over the largest area was found in western and northwestern Alberta, although localized areas with severely damaged roots occurred along the northern edge of the entire Parkland ecoregion. Over the entire survey area, Brassica rapa L. roots had greater PPI and DL than B. napus L. roots, although species differences were not significant in Saskatchewan or Manitoba. Data from the survey were correlated with weather variables to develop a model predicting the levels of damage inflicted by root maggots to canola roots. Of the weather variables investigated, temperature, especially the average temperature in the preceding July and August, had the greatest in fluence on PPI and DL. The warmer the temperatures of the preceding July and August, the lower the PPI and DL in the current year. Likewise, previous year’s July and August precipitation influenced PPI and DL negatively. Other weather parameters had little consistent influence on PPI and DI. The predictive model for PPI and DL, developed from the 1995–1998 survey data, incorporated canola species, ecoregion, previous July-August and September-October temperatures and precipitation. The validity of the model was assessed using a set of survey data collected in Alberta from 1981 to 1983. Regression equations of predicted results on actual results were significant. However, r2 values for the regressions were low, in part because of the few ecoregions surveyed and the lack of canola species data recorded in the earlier survey, and because of the large increase in infestation levels since the earlier data were collected. The study is a first step in forecasting the effects of root maggots across a wide geographic area featuring many different canola production practices. Key words: Crucifer-feeding root maggots, Delia spp., canola, Brassica rapa, Brassica napus, pest forecasting, distribution of damage


2001 ◽  
Vol 81 (1) ◽  
pp. 59-60 ◽  
Author(s):  
L. J. Lewis ◽  
D. L. Woods ◽  
B. F. Cheng

Long pod character from a summer Brassica napus L. line was introgressed into turnip rape B. rapa L. cultivar AC Sunshine resulting in progeny lines with significantly longer pods and larger seed size than those of AC Sunshine, but producing no yield advantage. Key words: Brassica rapa, Brassica napus, pod length, summer turnip rape, spring rape, interspecific hybridisation


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