The Biology of Canadian Weeds. 137. Brassica napus L. and B. rapa L.

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

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.


2003 ◽  
Vol 83 (4) ◽  
pp. 1039-1066 ◽  
Author(s):  
M. Costea and F. J. Tardif

A review of biological information is provided for three species of the genus Amaranthus: A. albus L., A. blitoides S. Watson and A. blitum L. The last species has been revised taxonomically and a new subspecies for Canada is presented-A. blitum subsp. emarginatus (Moq. ex Uline & Bray) Carretero, Munoz Garmendia & Pedrol. Amaranthus albus and A. blitoides are native to the U.S.A. and introduced to Canada. Both species are annual ruderal and agrestal weeds. During the past 100 yr the two species have spread across most provinces of Canada, but the greatest frequency and abundance have been recorded in Saskatchewan. Originating from Europe, Asia and North Africa, A. blitum was initially considered a non-persistent species. The present study shows that A. blitum especially, subsp. emarginatus, has continued to spread in Québec. The three species are alternate hosts to many insects, nematodes, viruses, bacteria and fungi that affect cultivated plants. In other areas (U.S.A., Europe and Asia), the three species have developed multiple resistance to triazine and acetolactate-synthase-inhibiting herbicides. Key words: Amaranthus albus, Amaranthus blitoides, Amaranthus blitum, weed biology, ecology, taxonomy, herbicide resistance


Weed Science ◽  
2021 ◽  
pp. 1-33
Author(s):  
Lucas K. Bobadilla ◽  
Andrew G. Hulting ◽  
Pete A Berry ◽  
Marcelo L. Moretti ◽  
Carol Mallory-Smith

Abstract Italian ryegrass [Lolium perenne L. spp. multiflorum (Lam.) Husnot] is one of the most troublesome weeds worldwide. L. multiflorum is also a grass seed crop cultivated on 50,000 ha in Oregon, where both diploid and tetraploid cultivars are grown. A survey was conducted to understand the distribution, frequency, and susceptibility of L. multiflorum to selected herbicides used to control L. multiflorum. The herbicides selected were clethodim, glufosinate, glyphosate, mesosulfuron-methyl (mesosulfuron), paraquat, pinoxaden, pyroxsulam, quizalofop-P-ethyl (quizolafop), pronamide, flufenacet + metribuzin, and pyroxasulfone. The ploidy levels of the populations were also tested. A total of 150 fields were surveyed between 2017 and 2018, of which 75 (50%) had L. multiflorum present. Herbicide-resistant populations were documented in 88% of the 75 populations collected. The most frequent mechanisms of action were resistance to Acetyl-CoA carboxylase (ACCase), Acetolactate Synthase (ALS), 5-enolpyruvylshikimate-3-phosphate (EPSPs) inhibitors, and combinations thereof. Multiple and cross-resistance, found in 75% of the populations, were the most frequent patterns of resistance. Paraquat-resistant biotypes were confirmed in six orchard crop populations for the first time in Oregon. Herbicide resistance was spatially clustered, with most cases of resistance in the northern part of the surveyed area. ALS and ACCase resistant populations were prevalent in wheat (Triticum aestivum L.) fields. Multiple-resistance was positively correlated with plant density. Tetraploid feral populations were identified, but no cases of herbicide resistance were documented. This is the first survey of herbicide resistance and ploidy diversity in L. multiflorum in western Oregon. Resistant populations were present across the surveyed area, indicating that the problem is widespread.


2010 ◽  
Vol 10 (1) ◽  
pp. 63 ◽  
Author(s):  
Kathrin Pascher ◽  
Susanne Macalka ◽  
Domenico Rau ◽  
Günter Gollmann ◽  
Helmut Reiner ◽  
...  

2001 ◽  
Vol 81 (3) ◽  
pp. 367-372 ◽  
Author(s):  
Janice L. Cuthbert ◽  
Peter B. E. McVetty ◽  
Georges Freyssinet ◽  
Martine Freyssinet

Bromoxynil herbicide resistance is the newest type of broad-spectrum, non-selective herbicide resistance to be introduced into oilseed rape (Brassica napus L.). This herbicide resistance is conferred by a single transgene (the oxy gene), taken from a soil bacterium, which confers the ability to metabolize hydroxybenzonitrile herbicides such as bromoxynil. The level of resistance to bromoxynil herbicide in oilseed rape is high, but it is not known whether there are any performance changes associated with the oxy transgene or with the derived herbicide resistance. To determine if there are changes in performance related to the oxy transgene, or the derived herbicide resistance, two near-isogenic transgenic bromoxynil-resistant populations, with two different forms of the oxy gene, Westar 235 and Westar 237, were developed at the University of Manitoba, grown in the field in Manitoba for several years and evaluated for comparative performance. Westar 235 and Westar 237 near-isogenic populations, either sprayed with bromoxynil at 280 g a.i. ha–1 or left unsprayed, were compared with the non-transgenic near-isogenic population cultivar, Westar, in Winnipeg, Carman, and Portage la Prairie from 1994 to 1997. There were no consistent differences in the performance of the sprayed or unsprayed transgenic near-isogenic populations in comparison to Westar for any trait. The few significant and minimal differences that were found were evenly divided between positive effects and negative effects of the oxy gene and derived herbicide resistance. There were no significant effects of spraying bromoxynil herbicide detected in paired comparisons of Westar 235 and Westar 237 sprayed versus Westar 235 and Westar 237 unsprayed, respectively. The effects of the oxy transgenes and the effects of bromoxynil spraying of herbicide-resistant lines were negligible, indicating that there is little, if any biological cost associated with the bromoxynil resistance transgenes or related herbicide resistance. Key words: Transgenic oilseed rape, Brassica napus, biological cost


2019 ◽  
Vol 25 ◽  
pp. 67-73
Author(s):  
V. A. Lemesh ◽  
M Bahdanava ◽  
G. Mozgova ◽  
A. Burakova

Aim. The aim of the work was to compare the polymorphism of commercial varieties and populations of B. napus growing outside cultivation to assess the genetic diversity of feral rapeseed populations in Belarus. Methods. The study assessed genetic diversity according to the data of 7 microsatellite loci genotyping. Results. The results indicate a greater genetic diversity in feral oilseed rape populations. An analysis of the structure of the genotypes distribution in the STRUCTURE software showed the division into three clusters – commertial varieties, feral populations and samples of B. rapa. Conclusions. The established genetic divergence between feral populations and commercial varieties indicates that feral oilseed rape is able to maintain persistent populations in Belarus. In practice, this should be taken into account when assessing the environmental risk when transgenic rape is released into the environment. And in the cultivation of transgenic rapeseed, special attention should be paid to measures to prevent the occurrence of its free-growing populations. Keywords: oilseed rape, feral populations, microsatellite loci, genetic diversity.


1993 ◽  
Vol 73 (2) ◽  
pp. 615-623 ◽  
Author(s):  
R. J. Lamb ◽  
P. Palaniswamy ◽  
R. P. Bodnaryk ◽  
P. B. E. McVetty ◽  
S. E. Jeong

Seventy-seven inbred lines of Brassica napus L. were assessed for antixenosis to damage by die crucifer flea beetle, Phyllotreta cruciferae (Goeze). The resistance was quantified by measuring the level of damage inflicted on seedlings of each line in laboratory tests. One of these lines, M12, was more susceptible than another line, L19, in a series of replicated tests, but individual seedlings could not be identified as resistant or susceptible because inter-seedling variation in the damage level was high. The F3 families from reciprocal crosses between L19 and M12 showed segregation for the resistance, demonstrating that the antixenosis has a genetic basis. Two or more genes probably control the expression of the resistance, but the number could not be estimated. Electrophoresis of seed endosperm proteins revealed a band, P-74, that occurred in M12 and eight cultivars of B. napus, but not in L19. This banding pattern was inherited as a simple recessive allele, but it proved not to be linked with the resistance in the F3 families. Further screening of B. napus for highly resistant genotypes and identification of linked genetic markers are needed to establish agronomically useful levels of flea beetle resistance in this crop. Key words: Insecta, resistance, canola, electrophoresis, endosperm proteins


2016 ◽  
Vol 67 (4) ◽  
pp. 266 ◽  
Author(s):  
Phillip A. Salisbury ◽  
Wallace A. Cowling ◽  
Trent D. Potter

Innovation has been integral in the development of the current Australian canola (Brassica napus L.) industry. From the initial introduction of poorly adapted Canadian germplasm, Australian breeders have developed high yielding, high quality, disease-resistant canola cultivars. The Australian canola industry has transitioned from being reliant on imports to becoming one of the world’s major exporters of canola. This review details the progressive innovations in the Australian canola breeding programs from the initial introduction of rapeseed to more recent developments including herbicide resistance, hybrid cultivars, speciality oil types and genetically modified canola.


Author(s):  
Valiantsina A. Lemesh ◽  
Maryna V. Bahdanava ◽  
Galina V. Mozgova ◽  
Aryna A. Burakova ◽  
Mikalai E. Kharuzhy

The study assessed the genetic diversity of commercial varieties and feral populations of oilseed rape (Brassica napus L.) grown in the Republic of Belarus according to the genotyping data of 7 microsatellite loci – Na12D08, Ol12D04-1, Ol12D04-2, Ra2A05, Na10H03, Na14H11, Ol11B05. The following parameters were calculated: the average number of alleles per locus, the effective number of alleles, the levels of expected and observed heterozygosity, % of polymorphic loci. The results indicate a greater genetic diversity in feral oilseed rape populations. According to the cluster analysis, one feral population fell into a cluster of commercial varieties and demonstrated similarities with the variety Atora, which indicates its recent wildness and the preservation of the genetic characteristics inherent in cultivated varieties. The variety Mercedes was clustered together with samples of feral populations, which may indicate its hybrid origin. An analysis of the structure of the genotype distribution in the Structure software showed the division into three clusters – commercial varieties, feral populations and samples of B. rapa. The established genetic divergence between feral populations and commercial varieties indicates that feral oilseed rape is able to maintain persistent populations inBelarus. In practice, this should be taken into account while assessing the environmental risk when transgenic rape is released into the environment. When cultivating transgenic rapeseed, special attention should be paid to measures to prevent the occurrence of its free-growing populations.


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