This sample of abstracts from Weed Abstracts on herbicide-resistant crops illustrates some of the issues regarding their use. Engineering crops to be resistance or tolerant to particular herbicides allows the use of the correct concentrations of the herbicide without phytotoxicity, thus allowing, for example, control of grasses in cereal crops, or of Brassica species in Brassica crops. It allows greater choice of herbicides that could be used in control of weeds already resistant to herbicides. Crops with greater tolerance to a herbicide might be able to grow on ground bearing residues of that herbicide from a previous crop. Problems resulting from their use include increased occurrence of herbicide-resistant volunteer crops, resulting in the need for careful selection of different herbicides to control them. Concerns about transfer of resistance from an engineered crop to non-engineered crops and to related weeds are additionally part of the general worry on the use of genetically engineered crops. The occurrence of field trials and field use of herbicide-resistant crops varies throughout the world: news on aspects such as registration of new varieties, legislation, and the on-going public debate is available from AgBiotech News and Information; abstracts from the world's scientific literature are published in Weed Abstracts.

New for May   - relevant samples from AgBiotech News and Information, one of a number of CABI News and Information journals which provide recent News as well as abstracts from the literature.
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TI: ROUNDUP® pre-emergence treatment to determine the presence
of the Roundup Ready® gene in soybean seed: a laboratory test.
AU: Goggi, A. S.\ Stahr, M. G.
JN: Seed Technology
YR: 1997
VL: 19
NO: 1
PP: 99-102
LA: En
MS: 1 ref.
AA: Seed Testing Laboratory, Seed Science Center, Iowa State University, Ames, Iowa 50011, USA.
AB: A laboratory test for determining the presence of the Roundup Ready™ (glyphosate-resistance) gene in soyabean seeds was developed by the ISU Seed Testing Laboratory and approved by Monsanto. The procedure recommended to evaluate the percentage expression of the Roundup Ready™ gene includes a seed lot of unknown tolerance and two controls, a susceptible soyabean seed lot and a known Roundup Ready™ soyabean seed lot. All seed lots are imbibed in a 2% solution of the ROUNDUP™ ULTRA formulation (41% active ingredient), for a concentration of 0.82% active ingredient (glyphosate) in the solution. Two replications of 100 seeds of each lot are placed overnight in paper towels treated with the ROUNDUP™ solutions. Imbibed seeds are then germinated following the prescribed procedure for soyabeans (AOSA Rules for Testing Seeds) and evaluated after 7 days. A standard germination test is also planted to use as a comparison of the abnormal seedlings. Susceptible seeds present severe toxicity symptoms. Radicles of the affected seedlings are yellow to brown and stunted, with little or no secondary root growth. Seedlings of Roundup Ready™ soybeans develop normally.
DE:
glyphosate\genes\seed testing\soyabeans\Glycine max\seeds\gene
expression\herbicide resistance\tolerance\imbibition\seed germination\phytotoxicity\pigments\roots\
growth\plant development


TI: Weed control and crop injury in ecofallow corn (Zea mays) using imazethapyr.
AU: Wicks, G. A.\ Mahnken, G. W.\ Hanson, G. E.
JN: Weed Technology
YR: 1997
VL: 11
NO: 4
PP: 748-754
LA: En
MS: 28 ref.
AA: University of Nebraska, Department of Agronomy, North Platte, NE 69101, USA.
AB: Field experiments were conducted during 1993-94 on a loamy soil in Nebraska, USA, to evaluate imazethapyr (35 and 70 g/ha) for controlling weeds in no-tillage corn [maize] planted into winter wheat stubble. Imidazolinone-tolerant (IT) and imidazolinone-resistant (IR) maize hybrids (cv. Pioneer Brand 3417, Pioneer Brand 3417 IR, ICI Seeds 8532 and ICI Seeds 8532 IT) were protected genetically from injury by imazethapyr that was applied pre-plant, pre-emergence or post-emergence. No difference in injury occurred between IR and IT maize. Imazethapyr controlled triazine-resistant Kochia scoparia better than the mixture of metolachlor + cyanazine (2.24 + 1.68 kg/ha).
DE: varietal reactions\weeds\chemical control\herbicide mixtures\herbicide resistance\herbicide resistant weeds\damage\herbicides\weed control\maize\Zea mays\wheat\Triticum aestivum\imazethapyr\triazine herbicides\fallow\hybrids\application date\metolachlor\cyanazine\Kochia scoparia\phytotoxicity
GL: USA\Nebraska


TI: ALS-inhibiting herbicide seed treatments control Striga hermonthica in ALS-modified corn (Zea mays).
AU: Berner, D. K.\ Ikie, F. O.\ Green, J. M.
JN: Weed Technology
YR: 1997
VL: 11
NO: 4
PP: 704-707
LA: En
MS: 15 ref.
AA: International Institute of Tropical Agriculture, PMB 5320, Oyo Road, Ibadan, Nigeria.
AB: Field and pot experiments were carried out during 1994-95 in Nigeria to investigate corn [maize] seed (hybrids 8322-13, Pioneer P3180IR, Pioneer P3180 and Ciba 4393IMR) treatments with nicosulfuron and imazaquin to control Striga hermonthica. The XA-17 gene in the acetolactate synthase (ALS)-modified P3180IR hybrid strongly reduced injuries to maize from herbicide seed treatments. Combining seed treatment of ALS-inhibiting herbicides and ALS-modified maize with the XA-17 gene may offer a practical means for African growers to control S. hermonthica.
DE: seed treatment\parasitic weeds\Striga hermonthica\Zea mays\maize\weed control\chemical control\nicosulfuron\imazaquin\acetolactate synthase\herbicides\hybrids\herbicide
resistance\varietal
reactions
GL: Nigeria


TI: Control of volunteer sethoxydim-resistant corn (Zea mays) in soybean (Glycine max).
AU: Young, B. G.\ Hart, S. E.
JN: Weed Technology
YR: 1997
VL: 11
NO: 4
PP: 649-655
LA: En
MS: 12 ref.
AA: Crop Sciences Department, University of Illinois, Urbana, IL 61801, USA.
AB: Field and laboratory studies were carried out during 1995-96 in Illinois, USA, to determine the potential for herbicides to control volunteer sethoxydim-resistant (SR) corn [maize] (susceptible hybrid 7877 and resistant hybrid 7877 src) in soyabeans (cv. Pioneer Brand). Greenhouse studies showed that hybrid 7877 src tolerated 181 times more sethoxydim than hybrid 7877. The src hybrid also tolerated other acetyl CoA carboxylase (ACCase) inhibitors, including fluazifop-P, quizalofop-P and clethodim with 30-, 27-, and 7-fold tolerance, respectively, than the hybrid 7877. The src hybrid exhibited the least tolerance to clethodim (28 g/ha), with a control rating of 50%. Field studies showed that quizalofop-P, fluazifop-P and fluazifop-P + fenoxaprop at 62, 140 and 140 + 47 g/ha, respectively, controlled < or = 22% of the F² of the src hybrid after 30 days. Clethodim (105, 140 and 210 g/ha) suppressed 23-70% of the src hybrid. Dry weight reductions after 60 days showed the same general trend as visual field estimates. In 1996, only AC-299263 [imazamox] (45 g/ha) and imazethapyr + imazaquin (71 + 71 g/ha) suppressed the src hybrid and prevented soyabean yield losses. However, no system completely controlled the volunteer hybrid src.
DE: maize\Zea mays\soyabeans\Glycine max\crop plants as weeds\volunteer plants\weed control\herbicides\
chemical control\herbicide resistance\herbicide resistant weeds\hybrids\sethoxydim\fluazifop-P\fenoxaprop\
quizalofop-P\clethod im\imazamox\imazethapyr\imazaquin\yield losses\crop yield\herbicide mixtures
GL: USA\Illinois


TI: Simazine and other triazines.
AU: Piper, T.
JN: Journal of Agriculture, Western Australia
YR: 1997
VL: 38
NO: 1
PP: 24-27
LA: En
AB: The chemistry and action of triazine herbicides are described in relation to their use in Western Australia. Soil moisture requirements and method of entry into the plant are outlined. Plant tolerance is discussed in relation to the mode of action of the herbicides and the ability of some species to inactivate the compounds. Mechanisms of resistance in herbicide resistant crops and weeds, and in triazine tolerant, genetically modified rape are also described. The importance of the development of simazine as a herbicide for lupins [Lupinus spp.] for the Western Australian lupin industry is discussed, and the control strategy using simazine is outlined. The significance of developing triazine resistant rape lines for areas where there are serious problems with weedy Brassica spp. is noted, and future strategies for triazine use in this crop are outlined. The environmental fate of triazine herbicides in soil under Australian conditions is described, and a system for assessing the risk of residues and dealing with them where found is described.
DE: chemistry\chemical properties\mode of action\triazine herbicides\herbicides\soil water\uptake\tolerance\herbicide resistance\crops\weeds\herbicide resistant weeds\rape\Brassica napus var. oleifera\transgenic plants\simazine\Lupinus\soil\herbicide residues
GL: Australia\Western Australia


TI: Giant foxtail (Setaria faberi) control in sethoxydim-resistant corn (Zea mays).
AU: Young, B. G.\ Hart, S. E.
JN: Weed Science
YR: 1997
VL: 45
NO: 6
PP: 771-776
LA: En
MS: 21 ref.
AA: Crop Sciences Department, University of Illinois, Urbana, IL 61801, USA.
AB: Field studies were conducted during 1995-96 at 2 sites in Illinois, USA, to evaluate sethoxydim (0.21 kg/ha) for the control of Setaria faberi in sethoxydim-resistant corn [maize]. Other treatments included were atrazine + cyanazine (0.96 + 3.0 kg/ha), atrazine + metolachlor (1.8 + 2.2 kg/ha), metolachlor/atrazine + dicamba (2.5/1.0 + 0.54 kg/ha), atrazine + dicamba + sethoxydim (1.0 + 0.54 + 0.21 kg/ha), halosulfuron + dicamba + sethoxydim (0.035 + 0.14 + 0.21 kg/ha), and a hand-weeded treatment. Flumetsulam (0.07 kg/ha) + clopyralid (0.18 kg/ha) were always used in combination with sethoxydim (0.21 kg/ha), sethoxydim + dimethenamid (0.105 + 1.1 kg/ha), metolachlor (2.5 kg/ha), and nicosulfuron (0.035 kg/ha). Metolachlor + atrazine and metolachlor + dicamba + atrazine resulted in > or = 88% weed control. Metolachlor (+ flumetsulam + clopyralid) provided > or = 90% weed control, except at one site in 1995 (only 75% control), due to heavy S. faberi infestation. Flumetsulam + clopyralid + sethoxydim or nicosulfuron provided the same level of weed control as metolachlor, except at one site in 1995 (72% control for sethoxydim and nicosulfuron). Sequential applications of sethoxydim increased weed control compared to a single sethoxydim application. Sethoxydim applied alone resulted in 8% more weed control than nicosulfuron at one site in 1996. Post-emergence sethoxydim resulted in > or = 87% weed control. Sethoxydim (+ flumetsulam + clopyralid) performance was consistent when applied with 2,4-D, halosulfuron + dicamba (0.035 + 0.14 kg/ha), and bromoxynil (0.28 kg/ha). The efficacy of sethoxydim was reduced in combination with dicamba + atrazine (0.54 + 1.03 kg/ha) in 3 out of 4 trials, and reduced in all trials in combination with bentazone + atrazine (0.58 + 0.58 kg/ha), and primisulfuron + prosulfuron (0.02 + 0.02 kg/ha). Sethoxydim resulted in better control than nicosulfuron + bromoxynil (0.035 + 0.28 kg/ha) at one site.
DE: herbicides\weeds\weed control\chemical control\Setaria faberi\Zea mays\maize\herbicide resistance\sethoxydim\atrazine\cyanazine\metolachlor\dicamba\flumets ulam\clopyralid\nicosulfuron\2,4-D\halosulfuron\bromoxynil\bentazone\primisulfuron\prosulfuron\herbicide mixtures\Setaria (Poaceae)
GL: Illinois\USA
AN: 0W04701509


TI: Occasional loss of expression of phosphinothricin tolerance in sexual offspring of transgenic oilseed rape
(Brassica napus L.).
AU: Metz, P. L. J.\ Jacobsen, E.\ Stiekema, W. J.
JN: Euphytica
YR: 1997
VL: 98
NO: 3
PP: 189-196
LA: En
MS: 30 ref.
AA: DLO-Centre for Plant Breeding and Reproduction Research (CPRO-DLO), Department of Molecular Biology, PO Box 16, 6700 AA Wageningen, Netherlands.
AB: The commercial and economic value of genetically modified crops is determined by consistent and stable transmission and expression of transgenes in successive generations. No gene inactivation is expected after selfings or crosses with non-transformed plants of homozygous transgenic oilseed rape plants if the expression of the transgene in the homozygous or hemizygous state in such plants is stable. Segregation ratios of phosphinothricin [glufosinate] (PPT) tolerance in successive generations of selfings and mutual crosses of a few independent transgenic PPT-tolerant oilseed rape plants indicated dominant, monogenic inheritance. In within-variety and between-variety crosses no transgene inactivation was observed. However, after selfings and backcrosses with non-transgenic oilseed rape, infrequent loss of the expression of the PPT tolerance transgene was observed independent of its homozygous or hemizygous state. Molecular analysis of PPT-susceptible plants showed that loss of expression was due to gene inactivation and not to absence of the transgene. Methylation and co-suppression are mechanisms that might cause reduced or even loss of transgene expression in later generations. Implications of these observations for seed multiplication of varieties and breeding activities with transgenic oilseed rape are discussed.
DE: herbicides\gene expression\outcrossing\selfing\transgenic plants\rape\glufosinate\Brassicanapus\
genetics\inheritance\segregation\co-suppression\DNA methylation\genetic transformation\herbicide
resistance\dominance


TI: Transgenic cotton resistant to herbicide bialaphos.
AU: Keller, G.\ Spatola, L.\ McCabe, D.\ Martinell, B.\ Swain, W.\ John, M. E.
JN: Transgenic Research
YR: 1997
VL: 6
NO: 6
PP: 385-392
LA: En
MS: 21 ref.
AA: Agracetus, Monsanto, 8520 University Green, Middleton, WI 53562, USA.
AB: Resistance to bialaphos [bilanafos], a non-selective herbicide, was introduced into cotton by genetic engineering. A gene encoding phosphinothricin acetyltransferase (bar) from Streptomyces hygroscopicus was inserted into elite varieties of cotton by particle bombardment. Based on expression of marker gene gus [uidA], transgenic plants of varieties Pima (Gossypium barbadense), DP50 (G. hirsutum), Coker 312 (G. hirsutum) and El Dorado (G. hirsutum) were recovered. Integration of bar into genomic DNA was confirmed by Southern blot analysis, and gene expression was confirmed by northern blot and enzyme assays. Herbicide (Basta®) tolerance up to 15000 p.p.m. was demonstrated in greenhouse trials. The herbicide tolerance trait was inherited in a Mendelian fashion in the progenies of germline transformants.
DE: herbicides\bilanafos\genetic transformation\cotton\herbicide resistance\Streptomyces hygroscopicus\barnase\reporter genes\Gossypium barbadense\Gossypium hirsutum\transgenic plants\biolistics\genes\beta-glucuronidase


TI: Frequency of 2,4-D resistant gene flow of transgenic cotton.
AU: Zhang ChangQing\ Lu QunYan\ Wang ZhiXing\ Jia ShiRong
JN: Scientia Agricultura Sinica
YR: 1997
VL: 30
NO: 1
PP: 92-93
LA: Ch
LS: en
MS: 5 ref.
AA: Biotechnology Research Center, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
AB: Pollen dispersal frequencies of transgenic cotton (Gossypium hirsutum) were evaluated using a selectable marker gene (tfdA) for resistance to the herbicide 2,4-D. In 1995, seeds of non-transgenic cotton plants, grown around a 4 × 6 m plot of transgenic cotton, were collected at different distances in 8 directions. In 1996, seedlings from these seeds were sprayed with 200 × 10­6 2,4-D at the 9-10 leaf stage and number of resistant plants scored. Pollen dispersal frequency was estimated from the results to be 11.2% at 1 m distance, decreasing to 0.61, 0.16, 0.09, and 0.03% at 5, 10, 20 and 50 m, respectively.
DE: pollen\transgenic plants\cotton\Gossypium hirsutum\genetic markers\2, 4-D\herbicides\herbicide resistance\outcrossing\gene flow\biosafety\genetic transformation
GL: China
AN: 0P06803206\0W04701433


TI: Canadian commercial production of herbicide tolerant canola.
AU: Downey, R. K.
JN: OCL - Oleagineux, Corps Gras, Lipides
YR: 1997
VL: 4
NO: 2
PP: 123-124
LA: En
AA: Agriculture and Agri-Food Canada, Research Centre and NRC, Plant Biotechnology Institute,
Saskatoon, SK, Canada.
AB: This article describes contract growing of herbicide tolerant oilseed canola [rape] in Canada and regulations to ensure postharvest segregation of genetically modified seed. Production from the limited acreage grown in 1995 and 1996 was only delivered to domestic oil extraction facilities and not allowed for export.
DE: release\food industry\Brassica napus\rape\legislation\transgenic plants\herbicide resistance\genetic
transformation
GL: Canada
AN: 0W04701432


TI: The impact of transgenic rape in cultivation systems: a study of gene flow.
FT: Impact du colza transgenique dans les systemes de culture: etude du flux de genes.
AU: Champolivier, J.\ Messean, A.
JN: OCL - Oleagineux, Corps Gras, Lipides
YR: 1997
VL: 4
NO: 2
PP: 111-113
LA: Fr
MS: 2 ref.
AA: CETIOM, 174 Avenue Victor Hugo, 75784 Paris Cedex 16, France.
AB: Preliminary results are provided of an experiment into gene flow among transgenic herbicide-resistant rape and black mustard [Brassica nigra], white mustard [Sinapis alba] and wild radish [Raphanus raphanistrum], started in 1995 at Toulouse, Dijon and Chalons, France. Three separate treatments of either glyphosate, glufosinate or an oxynil herbicide were applied to randomized plots. The Toulouse site was characterized by large numbers of cruciferous weeds [Brassicaceae] both inside and outside of the rape plots, whilst at the other sites, cultivated plots were generally weed free. Seeds of weedy relatives collected both from within and outside rape plots are currently being tested for their resistance to the 3 groups of herbicides.
DE: Sinapis alba\herbicides\rape\Brassica napus\Brassica nigra\Raphanus raphanistrum\wild relatives\glyphosate\glufosinate\nitrile herbicides\gene flow\transgenic plants\herbicide resistance\biosafety\genetic transformation\weeds
GL: France
AN: 0P06803102\0W04701291


TI: Achievements of the DeKalb Genetics Corporation in maize breeding.
FT: Dostignuca DeKalb Genetics Corporation u oplemenjivanju kukuruza.
AU: Matotan, S.
JN: Sjemenarstvo
YR: 1997
VL: 14
NO: 1/2
PP: 65-68
LA: Hr
LS: en
MS: 5 ref.
AA: Podravka d.d., Istrazivanja i razvoj, Koprivnica, Croatia.
AB: DeKalb has been working in biotechnology research for maize breeding for more than 20 years. In 1995, the first DeKalb genetically engineered insect- and herbicide- (sethoxydim, glufosinate and glyphosate) resistant maize hybrids were registered in Croatia and commercialized in the USA. In 1996, 4 more hybrids passed official tests and are expected to become registered varieties.
DE: biotechnology\maize\herbicides\hybrids\Zea mays\genetic engineering\herbicide resistance\pest resistance\plant
pests\sethoxydim\glufosinate\glyphosate
GL: Croatia
AN: 6P01400562\0P06802561\0W04701430


TI: Paymaster's picker type transgenic cotton varieties for 1997.
CT: 1997 Proceedings Beltwide Cotton Conferences, New Orleans, LA, USA, January 6-10, 1997: Volume 1.
AU: Williams, C.\ Mitchell, J.\ Swindle, M.\ Albers, D.
YR: 1997
PP: 40-41
LA: En
AA: Paymaster Technology Corp., Stuttgart, Arkansas, USA.
AB: Paymaster Technology Corp. has released five new picker type Roundup Ready® glyphosate resistant] cotton varieties, PM 1215 RR, PM 1220 RR, PM 1244 RR, PM 1330 RR, and PM 1560 RR; five new picker type Bollgard® cotton varieties, PM 1215 BG, PM 1220 BG, PM 1244 BG, PM 1330 BG and PM 1560 BG; and four new picker type Bollgard® and Roundup Ready® cotton varieties, PM 1220 BG/RR, PM 1244 BG/RR, PM 1330 BG/RR and PM 1560 BG/RR. The Roundup Ready® (RR) varieties contain the EPSPS gene developed by Monsanto that gives tolerance to the herbicide Roundup Ultra®. The Bollgard® (BG) varieties contain the Bollgard gene from Bacillus thuringiensis (Bt) also developed by Monsanto. Each of these varieties was bred by transferring the Roundup Ready® and/or Bollgard® genes from transformed Coker 312 cotton by backcrossing to the early maturing recurrent parents H 1215, H 1220, H 1244 and H 1330 and to the medium maturing variety H 1560. Performance tests by Paymaster in 1996 indicated that these transgenic varieties have outstanding yield potential, excellent fibre properties and plant morphology similar to the recurrent parent. Area of adaptation appears to be the same as that of the recurrent parents. The varieties list above are the first with both Roundup Ready® and Bollgard® in the same variety.
DE: cotton\cultivars\herbicide resistance\glyphosate\transgenics\conferences
GL: USA
AN: 0Q05102638\0W04701429


TI: Response of sethoxydim-resistant corn (Zea mays) hybrids to postemergence graminicides.
AU: Vangessel, M. J.\ Johnson, Q.\ Isaacs, M.
JN: Weed Technology
YR: 1997
VL: 11
NO: 3
PP: 598-601
LA: En
MS: 4 ref.
AA: Department of Plant and Soil Science, University of Delaware, Georgetown, DE 19947, USA.
AB: Field studies were conducted at Georgetown, Delaware, to determine if sethoxydim-resistant corn [maize] hybrids exhibited levels of cross-resistance to other acetyl-coenzyme A carboxylase (ACCase)-inhibiting herbicides. Three sethoxydim-resistant hybrids were tested in 1995 and four in 1996. The hybrids were treated with the 1× (labelled use rate for annual grass control) and 4× the rate of clethodim, fenoxaprop-P + fluazifop-P, fluazifop-P, quizalofop-P, and sethoxydim. At the 1× rate, similar levels of maize safety were observed in both years with sethoxydim, quizalofop-P (except Asgrow RX620SR in 1995), and in 1996, fenoxaprop-P + fluazifop-P. Maize treated with the 4× rate of sethoxydim did not exhibit injury, while all other ACCase-inhibiting herbicides caused > or = 50% maize injury. Sethoxydim-resistant maize hybrids did not consistently exhibit acceptable levels of cross-resistance to other ACCase-inhibiting herbicides. It was concluded that the use of clethodim will control volunteer sethoxydim-resistant maize in rotational crops.
DE: maize\as weeds\USA\Delaware\herbicides\herbicide resistance\sethoxydim\control\acetyl coenzyme
A\hybrids\clethodim\fenoxaprop\fluazifop\quizalofop\cross resistance\weeds\weed control\chemical control\
rotations\phytotoxicity\herbicide mixtures
GL: USA\Delaware
AN: 0W04700480\6P01400715


TI: Weed management in no-tillage bromoxynil-tolerant cotton (Gossypium hirsutum).
AU: Culpepper, A. S.\ York, A. C.
JN: Weed Technology
YR: 1997
VL: 11
NO: 2
PP: 335-345
LA: En
MS: 27 ref.
AA: Crop Science Department, North Carolina State University, Raleigh, NC 27695-7620, USA.
AB: An experiment was conducted at four locations in North Carolina during 1994 and 1995 to evaluate weed control, cotton yield, fibre quality and net returns in no-tillage bromoxynil-tolerant cotton. The experiment focused on using bromoxynil or pyrithiobac sodium applied early post-em. (POST) over-the-top as alternatives to fluometuron plus MSMA applied early POST directed. Fluometuron plus MSMA was more effective than bromoxynil or pyrithiobac sodium on tall morningglory (Ipomoea purpurea [Pharbitis purpurea]), large crabgrass (Digitaria sanguinalis), goosegrass (Eleusine indica) and broadleaf signalgrass (Brachiaria platyphylla). Bromoxynil and fluometuron plus MSMA were similarly effective on common lambsquarters (Chenopodium album), common ragweed (Ambrosia artemisiifolia) and eclipta (Eclipta prostrata) and more effective than pyrithiobac sodium. Pyrithiobac sodium and fluometuron plus MSMA were similarly effective on smooth pigweed (Amaranthus hybridus) and Palmer amaranth (Amaranthus palmeri) and more effective than bromoxynil. Prickly sida (Sida spinosa) control by bromoxynil and pyrithiobac sodium was equal to or greater than control by fluometuron plus MSMA. All early POST herbicides controlled pitted morningglory (Ipomoea lacunosa) similarly. Regardless of the early POST herbicides used, fluometuron applied pre-em. (PRE) and cyanazine plus MSMA applied late POST directed increased control of most weeds and increased cotton yield and net returns. Bromoxynil and pyrithiobac sodium effectively substituted for fluometuron plus MSMA only in systems that included fluometuron applied PRE and cyanazine plus MSMA applied late POST directed. Effects of herbicide systems on cotton fibre quality were minor.
DE: fluometuron\msma\amaranthus hybridus\amaranthus palmeri\ambrosia\brachiaria platyphylla\chenopodium album\digitaria sanguinalis\eclipta prostrata\eleusine indica\ipomoea lacunosa\sida spinosa\amapa\pharbitis purpurea\gossypium hirsutum\management\no-tillage\cotton\herbicide resistance\gossypium hirsutum\crop plants as weeds\volunteer plants\Ambrosia artemisiifolia\USA\North Carolina\weeds\fibre plants\weeds\chemicalcontrol\cyanazine\bromoxynil\pyrithiobac\control\tolerance\herbicide s\crop yield\control
GL: USA\North Carolina
AN: 0W04604920


TI: Potential impact of herbicide-resistant crops on specialty and minor crops.
CT: Proceedings of the fifty-first annual meeting of the Northeastern Weed Science Society, Newport, RI, USA,
6-9 January 1997 [edited by Glenn, S.].
AU: Gianessi, L. P.
YR: 1997
PP: 169-172
LA: En
MS: 4 ref.
AA: National Center for Food and Agricultural Policy, 1616 P Street, NW, Washington, DC 20036, USA.
AB: Reasons why there have been few developments of herbicide-resistant speciality and minor crops (mostly vegetables) are discussed. They centre around the huge costs of developing and registering new herbicides and of the transformation process, which can only be justified commercially by crops grown on a very large scale, such as corn [maize] and soyabeans. Two herbicide-resistant vegetable cultivars that have been developed, however, are South Bay head lettuce (tolerant of glyphosate) and Lemhi Russet potatoes (tolerant to bromoxynil). Additional constraints associated with vegetable-growing are the complex rotations in use and the tendency for certain vegetables to become weeds in following crops.
DE: lactuca sativa\solanum tuberosum\conferences\Northeastern Weed Science Society\vegetables\herbicides\herbicide resistance\glyphosate\lettuces\leafy vegetables\potatoes\bromoxynil\root vegetables\economics\registration\new products\plant breeding\tolerance
AN: 0W04604343\0P06711141\7K02201442\0C06800359


TI: Potential impact of herbicide-resistant crops on specialty and minor crops.
CT: Proceedings of the fifty-first annual meeting of the Northeastern Weed Science Society, Newport, RI, USA,
6-9 January 1997 [edited by Glenn, S.].
AU: Gianessi, L. P.
YR: 1997
PP: 169-172
LA: En
MS: 4 ref.
AA: National Center for Food and Agricultural Policy, 1616 P Street, NW, Washington, DC 20036, USA.
AB: Reasons why there have been few developments of herbicide-resistant speciality and minor crops (mostly vegetables) are discussed. They centre around the huge costs of developing and registering new herbicides and of the transformation process, which can only be justified commercially by crops grown on a very large scale, such as corn [maize] and soyabeans. Two herbicide-resistant vegetable cultivars that have been developed, however, are South Bay head lettuce (tolerant of glyphosate) and Lemhi Russet potatoes (tolerant to bromoxynil). Additional constraints associated with vegetable-growing are the complex rotations in use and the tendency for certain vegetables to become weeds in following crops.
DE: lactuca sativa\solanum tuberosum\conferences\Northeastern Weed Science Society\vegetables\herbicides\herbicide resistance\glyphosate\lettuces\leafy vegetables\potatoes\bromoxynil\root vegetables\economics\registration\new products\plant breeding\tolerance
AN: 0W04604343\0P06711141\7K02201442\0C06800359


TI: Impact of herbicide resistant germplasm on row-crop variety development.
CT: Proceedings of the fifty-first annual meeting of the Northeastern Weed Science Society, Newport, RI, USA,
6-9 January 1997 [edited by Glenn, S.].
AU: Walker, A. K.
YR: 1997
PP: 154-168
LA: En
AA: Asgrow Seed Company, 5926 Highway 14 East, Janesville, WI 53546, USA.
AB: Asgrow Seed Company's progress in the development and sales of herbicide-tolerant crops is reviewed, with data presented from the company's research stations and Concept Farms, and also from cooperative university trials. STD soyabeans, IMI maize and Poast Compatible maize [maize tolerant of sethoxydim] were first introduced in 1993, 1994 and 1996, respectively, and are mutagenesis products; Roundup Ready soyabeans [soyabeans tolerant of glyphosate] and Liberty Link maize and soyabeans were or will be introduced in 1996, 1997 and 1998, as products of transformation. There has been rapid adoption of these new varieties and hybrids.
DE: glyphosate\zea mays\glycine max\conferences\Northeastern Weed Science Society\maize\soyabeans\herbicides\herbicide resistance\sethoxydim\cereals\grain legumes\transgenic plants\resistance\breeding\mutations\resistance
AN: 0W04604342\6P01302989\0P06711222\7N02001574


TI: Discussion of genetically modified organisms.
FT: Le point sur les organismes genetiquement modifies.
AU: Liegeois, E.
JN: Agricontact
YR: 1997
NO: No. 291
PP: 29-32
LA: Fr
AB: The legal framework devised by the European Union to deal with modern biotechnology is outlined and the safeguards devised for testing and planting/sowing transgenic plants are described. Biosafety issues are discussed in relation to glyphosate-tolerant soyabeans; the environmental effects of a genetically modified plant on the environment, the envionmental impact of glyphosate applications and the impact of glyphosate residues on human health are all considered. The implications of pyralid- and herbicide-tolerant maize are also dealt with; the effects of both its insecticidal properties, through the expression of Bacillus thuringiensis gene Cry-1A, and its tolerance of glufosinate-ammonium are considered. Transgenic characteristics of genetically modified maize, chicory, spring and autumn rape, sugarbeet, cauliflower and broccoli, potato, tobacco, lucerne and poplar [Populus] that have been tested in Belgium are listed.
DE: biotechnology\transgenic plants\genetic engineering\biosafety\herbicide resistance\Glycine max\environmental impact\herbicide residues\toxicity\Pyralidae\plant pests\insect pests\pest resistance\Zea mays\Bacillus thuringiensis\chicory\Cichorium intybus\rape\Brassica napus var. oleifera\sugarbeet\Beta vulgaris var. saccharifera\cauliflowers\Brassica oleracea var. botrytis\broccoli\Brassica oleracea var. italica\potatoes\Solanum tuberosum\tobacco\Nicotiana tabacum\lucerne\Medicago sativa\Populus\forest trees\Belgium\legislation\herbicides\genetic transformation\European Union\glyphosate\soyabeans\tolerance\grain legumes\residues\nontarget effects\environment\man\glufosinate\maize\cereals\residues\environme nt\resistance\resistance
GL: Belgium\Europe
AN: 7K02201020\0W04604426\6P01302972\7N02001617\0E08511636


TI: Preemergence broadleaf weed control and crop tolerance in imidazolinone-resistant and -susceptible corn
(Zea mays).
AU: Sprague, C. L.\ Stoller, E. W.\ Hart, S. E.
JN: Weed Technology
YR: 1997
VL: 11
NO: 1
PP: 118-122
LA: En
MS: 21 ref.
AA: Department of Crop Science, University of Illinois, 1102 South Goodwin Avenue, Urbana, IL 61801, USA.
AB: Field studies were conducted in 1994 and 1995 at Dekalb and Urbana, Illinois, to evaluate preemergence broadleaf weed control and crop tolerance in imidazolinone-resistant (IR) and -susceptible (non-IR) corn [maize] using atrazine, imazethapyr, AC 263,222 ((+)-2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1 H-imidazol-2-yl]-5-methy l-3-pyridinecarboxylic acid), CGA-152005 [prosulfuron], MON 12000 [halosulfuron] with and without MON 13900 (a safener), and flumetsulam + clopyralid. When sufficient rainfall occurred within 28 d of application to insure herbicide absorption, the IR corn variety was more tolerant than the susceptible variety to imazethapyr, AC 263,222, CGA-152005 at 40 and 80 g/ha, and MON 12000 with and without MON 13900. Overall crop tolerance of IR corn was equal to that of corn treated with atrazine for all herbicide treatments except CGA-152005, which injured IR corn. Control of velvetleaf (Abutilon theophrasti), common lambsquarters   (Chenopodium album), Pennsylvania smartweed (Polygonum pensylvanicum), tall morningglory (Ipomoea purpurea [Pharbitis purpurea]) and jimsonweed (Datura stramonium) by all herbicide treatments was equal or superior to that of atrazine at 1.7 kg/ha. However, control of common cocklebur (Xanthium strumarium) was significantly greater with atrazine compared to imazethapyr and the low rate of CGA-152005.
DE: imazethapyr\weed control\zea mays\crop\tolerance\herbicide mixtures\Xanthium strumarium\Chenopodium album\Datura stramonium\Polygonum pensylvanicum\Pharbitis purpurea\Abutilon the ophrasti\maize\USA\Illinois\weeds\cereals\chemicalcontrol\flumetsulam\clopyralid\atrazine\
prosulfuron\halosulfuron\control\AC 263,222\interactions\herbicide safeners\herbicides\imidazolinone herbicides\herbicide resistance\phytotoxicity\nontargeteffects\control\control\control\carboxylic acid, (<+->)-2-[4,5-dihydro-4-methyl-4-(1-methylethyl)
-5-oxo-1H-imidazol-2-yl]-5-methy l-3-pyridine-
GL: USA\Illinois
AN: 0W04604016\6P01302988


TI: Performance of imazethapyr-resistant corn (Zea mays) compared with susceptible near-isogenic and
commercial hybrids.
AU: Boerboom, C. M.\ Lauer, J. G.
JN: Weed Technology
YR: 1997
VL: 11
NO: 1
PP: 110-117
LA: En
MS: 22 ref.
AA: Department of Agronomy, University of Wisconsin, Madison, WI 53706, USA.
AB: First-generation imazethapyr-resistant corn [maize] hybrids evaluated at the University of Wisconsin yielded less than other commercial hybrids. To determine if this resistance trait affected yield or agronomic traits, 10 near-isogenic pairs of imazethapyr-resistant and -susceptible corn hybrids were compared. Whether treated with imazethapyr or not, imazethapyr-resistant hybrids yielded the same when averaged across hybrids, although yield varied among a few individual hybrids within single experiments. Seven of the imazethapyr-resistant hybrids yielded the same, two yielded more, and one yielded less than their susceptible near-isogenic counterpart during eight site-years. Grain moisture was not affected, but imazethapyr-resistant hybrids had fewer broken stalks than did susceptible hybrids. The imazethapyr resistance trait does not appear to affect yield potential, but the backcrossing procedure may have caused early resistant hybrids to lag behind in yield compared to other new hybrids.
DE: zea mays\commercial hybrids\performance\backcrossing\plant breeding\maize\weeds\USA\Wisconsin\cereals\imazethapyr\herbicide resistance\crop yield\herbicides
GL: USA\Wisconsin
AN: 0W04604015\6P01302956\0P06711373


TI: Biodegradation and plant protection from the herbicide 2,4-D by plant-microbial associations in cotton production systems.
AU: Feng, L.\ Kennedy, I. R.
JN: Biotechnology and Bioengineering
YR: 1997
VL: 54
NO: 6
PP: 513-519
LA: En
MS: 24 ref.
AA: Cooperative Research Centre for Sustainable Cotton Production, Department of Agricultural Chemistry and Soil Science, University of Sydney, NSW 2006, Australia.
AB: A significant 'biosafening' protection of plants from the effect of 2,4-D in plant-microbial associations was demonstrated. The 2,4-D degrading plasmid, pJP4, was transferred into Rhizobium sp. CB1024, which nodulates Dolichos lablab [Lablab purpureus], and Azospirillum brasilense Sp7 carrying a nifA-lacZ gene marker, which can colonize cotton roots. Both transconjugants degraded 2,4-D in pure culture via co-metabolism up to 50 µg ml(­1). When the transconjugants were inoculated onto L. purpureus and cotton, respectively, plants were resistant to this herbicide when the nutrient solution was treated with 2,4-D up to 10 µg ml(­1) for L. purpureus, and 0.5 µg ml(­1) for cotton. Plants inoculated with wild-type strains were dead (L. purpureus) or dying (cotton). Because cotton is more sensitive to herbicides, only incomplete protection of plants was achieved with the transconjugant. Improving the effect of colonization of A. brasilense on cotton roots may be critical for complete degradation and plant protection. The transconjugant of Rhizobium sp. CB1024 was still able to nodulate L. purpureus, and N²-fixing activity was only slightly affected. Other pesticide-degrading capacities may also be inserted into those plant-associated bacterial strains for the degradation of these chemicals by plant-microbial associations. Whether such systems will be successful when applied in the field with competition from other bacteria remains to be determined.
DE: plasmids\Rhizobium\Azospirillum brasilense\markers\metabolism\Gossypium hirsutum\herbicide resistance\phytotoxicity\roots\nodules\nitrogen fixation\2,4-D\Lablab purpureus\cotton\biodegradation\tolerance\herbicides\field crops
AN: 0W04603956


TI: Inheritance of glyphosate tolerance among maize somaclones.
AU: Racchi, M. L.\ Forlani, G.\ Stefanini, F.\ Camussi, A.
JN: Maydica
YR: 1997
VL: 42
NO: 3
PP: 275-280
LA: En
MS: 28 ref.
AA: Laboratorio di Genetica, Ist. di Selvicoltura, via S. Bonaventura 13, I-50145 Firenze, Italy.
AB: Two families derived from a maize somaclone previously found tolerant of exposure to 2.4 mM (0.2 kg a.i. in 400 litres/ha of water) glyphosate were evaluated genetically for herbicide tolerance. The lines were self-crossed and crossed with three inbred genotypes showing significant variation in tolerance of the herbicide. Seedlings of the families obtained were evaluated in a growth chamber following a treatment with 2.4 mM glyphosate at the three-leaf stage. Visual injury rating, dry weight, shoot height and carbon-exchange rate were scored two weeks after the application of the herbicide. General combining ability effects were significant, suggesting that additive gene action is important in conferring tolerance of glyphosate. The results strengthen the possibility that additional factors, not related to the properties of the main target of herbicide action, the activity of the shikimate pathway enzyme 5-enol-pyruvyl-shikimate-3-phosphate synthase [3-phosphoshikimate 1-carboxyvinyltransferase], may provide the basis for increased tolerance of glyphosate.
DE: inheritance\glyphosate\tolerance\maize\Zea mays\inbred lines\mode of action\herbicides\herbicide resistance\combining ability\somaclonal variation\inbred lines\3-phosphoshikimate 1-carboxyvinyltransferase
AN: 0P06801536\0W04701004\6P01400515


TI: Gene flow from transgenic crops.
AU: Chevre, A. M.\ Eber, F.\ Baranger, A.\ Renard, M.
JN: Nature (London)
YR: 1997
VL: 389
NO: 6654
PP: 924
LA: En
MS: 6 ref.
AA: Station d'Amelioration des Plantes, INRA, BP29, F-35653 Le Rheu Cedex, France.
AB: To study genetic mechanisms involved in gene flow from crops to related species, an intergeneric model of gene flow from transgenic oilseed rape (Brassica napus; 2n = 38) containing 1 copy of the bar gene, which confers resistance to the herbicide Basta (glufosinate), to wild radish (Raphanus raphanistrum; 2n = 18), was developed. Oilseed rape × wild radish F(1) interspecific hybrids were obtained and studied for 4 successive generations in the field, surrounded by wild radish plants. Chromosome numbers generally decreased over the 4 generations, with 89.5% of F(4) plants having less than 27 chromosomes. Basta resistance in F(1) hybrids displayed Mendelian segregation, namely a 1 : 1 ratio of resistant and susceptible plants, as oilseed rape female parents were heterozygous for the bar transgene. However, because of unreduced gametes, bar transmission was high in F(1) to F(2) plants. bar transmission was dependent on the chromosome number of the female parent and decreased in successive generations, resulting in 23.5% resistant plants among F(4) hybrids. It is concluded that intergeneric gene flow would be slow within weed genomes under natural conditions, as 4 generations were needed to produce herbicide resistant plants with a chromosome number and morphology close to that of the natural weed.
DE: genes\transgenic plants\genetic transformation\Brassica napus\release\rape\radishes\herbicide resistance\glufosinate\genes\wild relatives\weeds\transgenic plants\hybrids\chromosome number\unreduced gametes\Brassica napus (rape)\Raphanus raphanistrum\intergeneric hybridization\herbicides\gene flow
AN: 0P06800872\0W04700850\7B01001002


TI: The impact on biosafety of the phosphinothricin-tolerance transgene in inter-specific B. rapa × B.
napus hybrids and their successive backcrosses.
AU: Metz, P. L. J.\ Jacobsen, E.\ Nap, J. P.\ Pereira, A.\ Stiekema, W. J.
JN: Theoretical and Applied Genetics
YR: 1997
VL: 95
NO: 3
PP: 442-450
LA: En
MS: 44 ref.
AA: Department of Molecular Biology, CPRO-DLO, P.O. Box 16, 6700 AA Wageningen, Netherlands.
AB: There is strong evidence indicating that gene flow from transgenic Brassica napus into weedy wild relatives is inevitable following commercial release. Research should now focus on the transmission, stability, and impact of transgene expression after the initial hybridization event. The present study investigated the transfer of a phosphinothricin [glufosinate] tolerance transgene by interspecific hybridization between B. rapa [B. campestris] and two transgenic B. napus lines. The expression of the transgene was monitored in the F(1) hybrids and in subsequent backcross generations. The transgene was transmitted relatively easily into the F(1) hybrids and retained activity. Large differences in the transmission frequency of the transgene were noted between offspring of the two transgenic lines during backcrossing. The most plausible explanation of these results is that the line showing least transmission during backcrossing contains a transgene integrated into a C-genome chromosome. Approximately 10% of offspring retained the tolerant trait in the BC(3) and BC(4) generations. The implications of these findings for the stable introgression of transgenes carried on one of the chromosomes of the C-genome from B. napus and into B. rapa are briefly discussed.
DE: biosafety\brassica campestris\hybrids\gene flow\backcrossing\rape\transgenic plants\herbicide resistance\herbicides\Brassica napus\genetic transformation\gene expression\glufosinate\interspecific hybridization
AN: 0P06712722\0W04700437


TI: QTLs associated with chlorimuron ethyl sensitivity in soybean: effects on seed yield and related traits.
AU: Mian, M. A. R.\ Shipe, E. R.\ Alvernaz, J.\ Mueller, J. D.\ Ashley, D. A.\ Boerma, H. R.
JN: Theoretical and Applied Genetics
YR: 1997
VL: 94
NO: 8
PP: 971-974
LA: En
MS: 10 ref.
AA: Department of Crop and Soil Sciences, University of Georgia, Athens, GA 30602-7272, USA.
AB: Soyabean (Glycine max) genotypes are known to differ in chlorimuron ethyl sensitivity (CS). Earlier two putatively independent marker loci were reported linked to two quantitative trait loci (QTLs) controlling CS in a soyabean population derived from a cross of PI97100 (sensitive to chlorimuron ethyl) and Coker 237 (tolerant of chlorimuron ethyl). The objective of the present study was to quantify the association of the two marker loci with seed yield and related traits in this soyabean population following application of chlorimuron ethyl. Phenotypic data were collected for 111 F(2)-derived lines of the cross grown in replicated plots at Athens, Georgia, in 1994 and 1995, and at Blackville, South Carolina, in 1995. The two CS marker loci explained as much as 50% of the genetic variation in seed yield and seed number m(­2), but had no association with seed weight, plant height, lodging, seed protein, or seed oil. There were no epistatic interactions between the two marker loci for any of the traits. The marker locus (cr168-1 on USDA linkage group E) linked to the major CS QTL explained between 13 and 23% of the variation in seed yield. The Coker 237 allele at this locus was associated with decreased CS and increased seed yield. The marker locus (Blt015-2 on an unknown linkage group) linked to the minor CS QTL accounted for a maximum of 11% of the variation in seed yield. The Coker 237 allele at this locus was associated with an increase in CS and a decrease in seed yield. The association of the two marker loci with seed number m(­2) strongly resembled their association with seed yield. Seed yield had a strong positive correlation (r = 0.74-0.94) with seed number m(­2), and the effect of chlorimuron ethyl on seed yield was due mainly to its effect on seed number m(­2) rather than seed weight.
DE: glycine max\restriction fragment length polymorphism\chlorimuron\effects\traits\plant height\lodging\herbicide resistance\linkage\soyabeans\gene mapping\herbicides\quantitative traits\genetics\resistance\yields\resistance\seed production\crop yield\grain legumes
GL: Georgia\USA\South Carolina
AN: 0P06711546\0W04604811\7N02001594\7B01000262