Effectiveness of border areas in confining the spread of transgenic Brassica napus pollen

2000 ◽  
Vol 80 (3) ◽  
pp. 521-526 ◽  
Author(s):  
Beverly K. Staniland ◽  
Peter B. E. McVetty ◽  
Lyle F. Friesen ◽  
Stephen Yarrow ◽  
Georges Freyssinet ◽  
...  

The development of transgenic Brassica napus L. cultivars requires field trials in agricultural settings. For field testing of transgenic constructs that have not been granted full environmental release, current Canadian Government regulations require either large isolation zones (200 m) or 10 m wide borders of synchronously flowering, non-transgenic B. napus to contain transgenic pollen. To investigate the effectiveness of border areas in containing transgenic B. napus pollen, border areas 15 to 30 m wide were planted around 30 m × 60 m central plots of bromoxynil-herbicide-resistant transgenic B. napus strains. Four field trials were conducted at Carman and Winnipeg, Manitoba, Canada in 1994 and 1995. Seed samples were harvested from the border area at 0, 2.5, 5, 10, and 15 m for the four cardinal directions and additionally at 20, 25, and 30 m for two cardinal directions. These seed samples were planted in the field in 1995 and 1996 and the seedlings screened for the presence of bromoxynil-resistant plants (i.e., from outcrossed seeds). Distance from the central plot significantly affected outcrossing rates while environment (site–year) and direction effects were non-significant. Outcrossing rates averaged 0.70% at 0 m and declined exponentially to 0.02% at 30 m. More than four-fifths of the total outcross events detected occurred in the first 10 m of border area indicating that border areas effectively reduce pollen-mediated gene flow in B. napus but cannot completely eliminate it. Key words: Transgenic canola; Brassica napus; pollen containment

2001 ◽  
Vol 81 (4) ◽  
pp. 657-664 ◽  
Author(s):  
J. L. Cuthbert ◽  
P. B. E. McVetty

Unidirectional outcrossing rates were assessed between neighboring plots, rows (spaced 40, 80 and 120 cm apart) and plants of oilseed rape (Brassica napus L.) grown in simulated plant breeding field trials, using the transgenic dominant bromoxynil herbicide resistance gene as a marker. Bromoxynil susceptible (pollen recipient) plots, rows and plants were planted in the field and surrounded by bromoxynil-resistant plots, rows and plants, respectively. The field trials were conducted at Winnipeg, Carman, and Portage la Prairie, Manitoba, in 1996 and 1997. Seed produced on the susceptible plots and rows was harvested and then planted in the field the following year with all emerged seedlings sprayed at 750 g a.i. ha–1 bromoxynil to identify resistant individuals. Approximately 420 000 seedlings were screened in 1997 and 1998 with 23 816 resistant individuals identified, each resistant individual being the result of an outcrossing event. The overall mean plot-to-plot outcrossing rate was 4.0% (± 0.23). The overall mean row-to-row outcrossing rate was 9.5% (± 0.62) for the 40-cm row spacing, 5.6% (± 0.37) for the 80-cm row spacing and 3.9% (± 0.25) for the 120-cm row spacing. For the plant-to-plant trials, seed produced on the susceptible plants was harvested and then a sample was planted in the greenhouse with all emerged seedlings sprayed at 560 g a.i. ha–1 bromoxynil to identify resistant individuals. The overall mean plant-to-plant outcrossing rate was 21.0% (± 1.73). Outcrossing rates of this magnitude have significant implications for all oilseed rape breeding programs. Methods to minimize outcrossing are discussed. Key words: Brassica napus L., outcrossing rates, transgenic dominant bromoxynil resistance marker


1982 ◽  
Vol 62 (4) ◽  
pp. 989-993 ◽  
Author(s):  
P. A. O’SULLIVAN ◽  
V. C. KOSSATZ

Control of Canada thistle (Cirsium arvense L. Scop.) topgrowth and regrowth, and tolerance of rapeseed (Brassica campestris L. and Brassica napus L.) to 3,6-dichloropicolinic acid at 0.2–0.3 kg/ha were excellent in greenhouse and field trials. Rapeseed yields following postemergence treatment were increased in 12 of 17 trials conducted on infested farm fields.


2020 ◽  
Vol 21 (4) ◽  
pp. 1345
Author(s):  
Qianxin Huang ◽  
Jinyang Lv ◽  
Yanyan Sun ◽  
Hongmei Wang ◽  
Yuan Guo ◽  
...  

The use of herbicides is an effective and economic way to control weeds, but their availability for rapeseed is limited due to the shortage of herbicide-resistant cultivars in China. The single-point mutation in the acetohydroxyacid synthase (AHAS) gene can lead to AHAS-inhibiting herbicide resistance. In this study, the inheritance and molecular characterization of the tribenuron-methyl (TBM)-resistant rapeseed (Brassica napus L.) mutant, K5, are performed. Results indicated that TBM-resistance of K5 was controlled by one dominant allele at a single nuclear gene locus. The novel substitution of cytosine with thymine at position 544 in BnAHAS1 was identified in K5, leading to the alteration of proline with serine at position 182 in BnAHAS1. The TBM-resistance of K5 was approximately 100 times that of its wild-type ZS9, and K5 also showed cross-resistance to bensufuron-methyl and monosulfuron-ester sodium. The BnAHAS1544T transgenic Arabidopsis exhibited higher TBM-resistance than that of its wild-type, which confirmed that BnAHAS1544T was responsible for the herbicide resistance of K5. Simultaneously, an allele-specific marker was developed to quickly distinguish the heterozygous and homozygous mutated alleles BnAHAS1544T. In addition, a method for the fast screening of TBM-resistant plants at the cotyledon stage was developed. Our research identified and molecularly characterized one novel mutative AHAS allele in B. napus and laid a foundation for developing herbicide-resistant rapeseed cultivars.


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


2000 ◽  
Vol 80 (2) ◽  
pp. 255-260
Author(s):  
L. J. Lewis ◽  
D. L. Woods ◽  
H. W. Klein-Gebbinck

S-alleles W1 and T2 and an incompletely dominant white petal character were introgressed into the self-compatible (SC) summer rape (Brassica napus L. ssp. oleifera {Metzg.}) cultivars Global, Topas and Westar. The derived self-incompatible (SI) lines were evaluated for strength of incompatibility by ultraviolet fluorescence of pollen tubes, and by seed set. Pollen tube and seed set analyses showed the W1 and T2 alleles were strongly, moderately and weakly expressed in Topas, Global and Westar, respectively. Seed set data showed a significant difference between SI lines, but not between S-alleles, or between homozygous or heterozygous lines from the same SI cultivar. SI cultivar yellow petal (wild type) lines were field pollinated with SC white petal lines. Seed collected from the SI cultivars were evaluated for proportion of outcrossed progeny by recording the frequency of yellow petal and cream petal plants, which were the result of self- and cross-pollination, respectively. The proportion of outcrossed progeny (i.e., outcrossing rates) ranged from 23% to 79%. Topas SI lines had significantly higher outcrossing rates than Global SI lines, which corresponded to SI line seed set data. Environment, S-allele selection and genotype significantly affected outcrossing rates. Key words: Brassica napus, sporophytic incompatibility, S-allele, outcrossing rate


2008 ◽  
Vol 88 (5) ◽  
pp. 951-996 ◽  
Author(s):  
R. H. Gulden ◽  
S. I. Warwick ◽  
A. G. Thomas

Brassica napus and B. rapa are native to Eurasia. In Canada, these species are commonly referred to as volunteer canola, while feral populations of B. rapa are referred to as birdrape. Brassica napus and B. rapa have been grown commercially for their seed oil content in western Canada since the middle of the last century and volunteer populations are common in fields. Escaped populations of both species are also found along roadways, railways and in waste areas; however, only B. rapa is known to have naturalized, self-sustaining feral populations in these habitats in eastern Canada. Despite these escaped and feral populations, B. napus and B. rapa are mainly a concern in agricultural fields where their combined relative abundance has increased over the past few decades. In the mid 1990s, herbicide-resistant genotypes of B. napus were released for commercial production. Herbicide-resistance and the stacking of genes in volunteer populations conferring resistance to multiple herbicides have contributed to increased difficulties in controlling volunteer B. napus in some crops. However, yield loss resulting from volunteer populations is not well documented in Canada. Key words: Brassica napus, Brassica rapa, herbicide resistance, transgene escape, volunteer canola, weed biology


1979 ◽  
Vol 59 (4) ◽  
pp. 959-962 ◽  
Author(s):  
JOHN M. CLARKE

Field trials were conducted at Saskatoon in 1976, and at Swift Current in 1977, to investigate intra-plant variation in number of seeds per pod and seed weight in Brassica napus L. ’Tower’. Number of pods was greatest on the main raceme, least on the lowest branch. Seed number per pod was also highest on the main raceme, as was seed weight. In 1976, number of seeds per pod and seed weight were higher in pods from the lower half of the main raceme than from those on the upper half. A study of the trends in number of seeds per pod between the end of flowering and maturity revealed a general decline in number of seeds per pod and an increase in the number of aborted seeds at the lower branch positions. At the end of flowering, pods from all branch positions had equal numbers of developing seeds.


1989 ◽  
Vol 40 (3) ◽  
pp. 617 ◽  
Author(s):  
RJ Mailer

The effect of sulfur availability on glucosinolate concentration in seed meal of glasshouse grown Brassica nupus cv. Wesbrook and Brassica rapa cv. Runyip was studied. In addition, field trials were evaluated to determine the degree of variability of glucosinolate concentrations in the seed and of sulfur in the plants of rapeseed grown at a number of sites throughout New South Wales.Glucosinolate concentration in seeds grown in the glasshouse increased (P < 0.01) in both cultivars with increasing sulfur application, ranging from an average of 5 8mol at 4 8g g-1 to 55 8mol at 100 8g g-1 sulfur. Bunyip containcd significantly higher concentrations (Pt0-01) than Wesbrook. Increased rates of sulfur application resulted in increased (P < 0.01) seed oil concentrations (from 28.7 to 37.6%), yield (3.1-27.1 g) and 1000-grain weights (2.1-2.9 g). Field trials showed site (P < 0.01) and cultivar (P<0.01) variation in glucosinolate levels. However, sulfur did not appear to be an independently limiting factor in field-grown plants.


2014 ◽  
Vol 94 (2) ◽  
pp. 453-455 ◽  
Author(s):  
P. B. E. McVetty ◽  
J. L. Cuthbert ◽  
V. Marwede ◽  
W. Paulmann ◽  
O. Sass ◽  
...  

McVetty, P. B. E., Cuthbert, J. L., Marwede, V., Paulmann, W., Sass, O., Duncan, R. W., Fernando, W. G. D., Li, G. and Zelmer, C. D. 2014. HYHEAR 1 hybrid Roundup Ready™ high erucic acid, low glucosinolate summer rape. Can. J. Plant Sci. 94: 453–455. HYHEAR 1 summer rape (Brassica napus L.) is the world's first hybrid Roundup Ready™ high erucic acid, low glucosinolate cultivar. On average, HYHEAR 1 yielded 33% more seed, 23 g kg−1 more seed oil but 17 g kg −1 less meal protein than MillenniUM 03 high erucic acid, low glucosinolate, open pollinated population summer rape. HYHEAR 1 has an erucic acid content of 52.2% in isolated field trials of HEAR lines and is adapted to the southern B. napus growing regions of western Canada.


Sign in / Sign up

Export Citation Format

Share Document