国外转基因抗除草剂甜菜研究

对国外抗除草剂甜菜的创制原理、方法以及在修饰基因、除草效果、经济效益、食品安全评价和抗性基因漂移研究方面进行了综述。     

Ten-year response of bird communities to an operational herbicide-shelterwood treatment in a northern hardwood forest

Use of herbicides in forestry to direct successional trajectories has raised concerns over possible direct or indirect effects on non-target organisms. We studied the response of forest birds to an operational application of glyphosate and sulfometuron methyl herbicides, using a randomized block design in which half of each 8 ha block received herbicide and the other acted as a control, on shelterwood seed-cut Allegheny hardwood stands in northwestern Pennsylvania. We monitored birds using 50 m radius point counts in two pretreatment years and for 10 years post-treatment (1992-2004). Fences were erected six years after herbicide treatment in response to increased deer browsing at a subset of sites. Avian responses to herbicide treatment varied by nesting guild: we detected no response by cavity-nesters, but documented declines in the shrub-, ground- and canopy-nesting guilds. Responses were short-lived (2-4 years post-treatment), but shrub-nesters did not recover until fencing provided regenerating vegetation respite from browsing. Thus, apparent responses of birds to herbicide were confounded with deer browsing in this study. High species turnover, even within control plots, suggests that avian communities may be assessed more appropriately assessed at larger spatial scales than those used in this study (6.5-8 ha).     

Experimental bases for a chemical control of Coquillettidia mosquito populations

Coquillettidia mosquitoes are not efficiently controlled by the conventional chemical practices which are known to be satisfactory against the larvae of other mosquito species. A research project was undertaken to conceive a new management strategy using plants as pesticide vectors to reach the Coquillettidia aquatic larvae. Therefore, larval mortality was measured in the presence of plants treated with phloem-translocated pesticides. The herbicide glyphosate at sub-lethal concentrations induced root epidermal cell lyses in maize plantlets cultivated in aqueous media, which clearly decreased larval fixation. Therefore, such herbicide strategy might operate through disturbing the larval physiological activities depending on fixation. The dimethoate insecticide did not affect root viability but at low concentrations seemed to disturb the plant–insect interactions. Larvae showed a lower attraction for roots and a considerable decrease in the root fixation rate. These larval behavior modifications were sufficient to induce mortality, probably due to a lack of fixation on plant roots. The effectiveness of plant foliar treatment with glyphosate or dimethoate under laboratory conditions suggested that it might be the basis for an efficient control strategy for Coquillettidia larvae and mosquitoes having the same living conditions in ponds and for which fixation on macrophyte roots is an absolute requirement (e.g.Mansonia, Mimomyia).     

利用除草剂草甘膦防治桑椹菌核病的初步试验

桑椹菌核病是一类真菌病害,病原菌以菌核的形式在土壤里长期存活,因而探讨利用除草剂草甘膦对病原真菌的抑制作用防治桑椹菌核病。分别配制95%草甘膦与对照药剂70%甲基硫菌灵的不同浓度稀释液,在发病桑园土表对肥大性、小粒性和缩小性3种桑椹菌核病菌的子实体和子囊盘进行喷洒。施用95%草甘膦500倍稀释药液和70%甲基硫菌灵620倍稀释药液1 d后明显可见桑椹肥大性、小粒性菌核病菌的子实体和子囊盘开始萎蔫干枯,子囊盘向上卷起,对桑椹缩小性菌核病菌子实体和子囊盘的杀灭作用更为明显,施药4 d后,3种类型桑椹菌核病菌子囊盘完全腐烂失活。另将3种桑椹菌核病菌的子囊孢子置于含有草甘膦或甲基硫菌灵的液体培养基内振荡培养48 h后,检测药液对病菌子囊孢子萌发的抑制作用,结果95%草甘膦375、500、625倍稀释药液对3种类型病原菌子囊孢子的萌发均具有较好抑制效果,其EC50值均小于对照70%甲基硫菌灵的EC50值。试验结果初步表明,95%草甘膦对桑椹菌核病3种类型病原菌的子实体和子囊盘有较好的杀灭作用,能有效抑制病菌子囊孢子的萌发。建议发病桑园于2月中旬至4月上旬以95%草甘膦375、500、625倍稀释药液喷洒土表,能起到对桑椹菌核病的防治作用。     

Recovery of Faba Bean (Vicia faba L.) Plants as Affected by Glyphosate

Two field experiments were carried out during 1982/83 and 1983/84 seasons at Experimental Farm of National Research Centre at Shalakan, Kalubia Governorate, Egypt, to study the reversal effect of glyphosate induced phytotoxicity on growth and yield and its components of faba bean by the application of growth factors, i.e., growth regulators, amino acids and nutrient elements at different concentrations. A split plot design with four replications was used in both seasons. The obtained results indicated clearly that: Glyphosate at the two higher doses exhibited varying degrees of phytotoxic symptoms and reduced all the faba bean plant characters except the number of branches/plant. GA₃ alone or in a mixture with cytokinin reversed the phytotoxic effect of the glyphosate herbicide on decreasing the plant height. Cytokinin at 4/1000, phenylalanine and tryptophan at both levels, as well as GA₃ at 50 ppm, reversed the phytotoxic effect of the glyphosate herbicide on decreasing the dry weight/plant cytokinin at 4/1000, tryptophan at both concentrations, as well as, phenylalanine at 500 ppm, reversed the phytotoxic effect of the glyphosate herbicide on decreasing the number and dry weight of pods, seed yield per plant and per ha.     

刚察县哈尔盖乡甘肃棘豆调查与灭治

哈尔盖乡冬春草场上，甘肃棘豆平均密度为８０．８株丛／ｍ￣２，平均盖度为６１．３％，空间分布为集群型（Ｓ￣２＞ｍ），其株丛平均直径与根直径呈显著的正相关（Ｐ＜０．０５），根直径、营养枝数量、生殖枝数量和株丛平均直径与根长之间呈极显著的正相关（Ｐ＜０．０１）。利用草甘膦灭除１６７５ｈｍ￣２，平均灭效达９５．３％，取得了显著的生态和经济效益。     

Spatial variability of glyphosate mineralization and soil microbial characteristics in two Norwegian sandy loam soils as affected by surface topographical features

The aim of this study was to investigate the possible influence of surface topographical features on the spatial variability of glyphosate degradation and some microbial characteristics in sandy loam soil. Soil samples were taken from the ploughed layer across an agricultural field after seedbed preparation for grain (Grue site), and down to 1 m depth under a ridge tilled field (Målselv site), both sites having similar soil textural characteristics (sandy loam soil). Laboratory experiments were performed looking at glyphosate mineralization and soil microbial activity at the Grue site, as well as microbial biomass, activity and substrate utilization patterns at the Målselv site. Microbial biomass and activity decreased, and substrate utilization patterns changed with increasing soil depth, reflecting naturally occurring changes in quantity and quality of soil organic carbon. Further, our results show that considerable spatial heterogeneity in the degradation rate of glyphosate and general carbon utilization exists even across small areas within a single agricultural field. This horizontal variability was observed over several spatial scales, and could not be clearly explained. It evidently arose from differences in environmental factors affecting microbial activity and growth, and topographical features controlling redistribution of water and matter flow patterns were correlated to the investigated soil microbial variables.     

Response of wheat (Tritium aestivum) to low rates of glyphosate and glufosinate

Field studies were conducted in 2007 and 2008 at Hamilton Farms near Lonoke, Arkansas, USA to evaluate the potential impact of sub-lethal doses of glyphosate and glufosinate on winter wheat (Tritium aestivum). Three wheat cultivars were seeded, and glyphosate and glufosinate were applied at 1/10 and 1/20 times the labeled dose at the 3- to 4-leaf, panicle initiation, and boot stages. Both herbicides caused significant injury to wheat; however, wheat response to both herbicides was different. Glufosinate injury occurred rapidly and consisted of mainly leaf necrosis. Glyphosate injury to wheat was minimal and manifested in the form of leaf yellowing. Glyphosate caused shortened flag leaf when applied at PI and reduced canopy height when applied at boot. Injury was minimal to wheat across all treatments, with the highest level of injury being 34% following glufosinate applied at boot. Conversely, wheat was most sensitive to glyphosate at the 3- to 4-leaf stage. Flag leaf length was reduced the greatest by glyphosate at PI, whereas glufosinate reduced flag leaf length minimally. Even though glyphosate injury was lower than that of glufosinate, yield was reduced more by glyphosate. Wheat seed weight and germination were not affected by either herbicide. Wheat appears to be slightly more sensitive to glyphosate with respect to yield; however, it is slightly more sensitive to glufosinate with respect to foliar injury.     

草甘膦铵盐可溶性粒剂防治非耕地杂草药效试验

对草甘膦铵盐可溶性粒剂防治非耕地杂草的效果进行了试验研究,结果表明,74．7％草甘膦铵盐可溶性粒剂可有效防除反枝苋、地肤、旱稗、小藜、狗尾草等杂草。74．7％草甘膦胺盐可溶性粒剂是一种苗后茎叶喷雾除草剂,适用于非耕地防除多种杂草,施药时期为杂草出苗后,适宜剂量为2060．0g a．i．／hm^2,药液量750．0L／hm^2。     

大豆体细胞胚的诱导及对草甘膦耐性的研究

以大豆未成熟子叶为外植体,研究合丰25、吉林35、吉育91对未成熟子叶体细胞胚诱导率的影响,并探讨3种基因型大豆未成熟子叶对草甘膦的耐性。结果表明:3种基因型的愈伤组织诱导率均为100%,体细胞胚诱导率为53.95%～72.12%,平均胚数吉育91高于其它2种基因型。3种基因型的体细胞胚诱导率在草甘膦浓度间存在差异,在大豆以未成熟子叶为受体转基因时,诱导体细胞胚胎发生的草甘膦筛选浓度为2.5～5.0 mg.L-1。