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1.
The weed species, prickly sida (Sida spinosa L.) and sicklepod (Senna obtusifolia L.), were treated with 14C-glyphosate alone and formulated with different polyethlylane oxide (PEO) surfactants in tallow amine ethoxylate and non-ionic alkoxylate series to determine the amount of 14C-glyphosate absorption and translocation. The surface tension, contact angle, and 14C-glyphosate distribution were significantly affected by both the presence of different waxes on the plants and by the addition of surfactants to the glyphosate. The surface and contact angle values of the surfactants, with and without glyphosate, showed a significant increase as the PEO number increased in both surfactant series. A higher absorption of the 14C-glyphosate was recorded for S. spinosa compared with S. obtusifolia. The absorption and translocation of the 14C-glyphosate increased with the increase in the PEO number of tallow amine ethoxylate. In the case of the non-ionic alkoxylate surfactant series, an increase in the absorption of 14C-glyphosate was recorded when the surface tension and contact angle values decreased. There was no significant difference in the translocation values obtained in the two species after the addition of the surfactants. The amount of 14C-glyphosate absorbed by the treated leaf was significantly higher in the case of S. spinosa compared with S. obtusifolia. A linear relationship was observed with the physical properties, 14C absorption, and the efficacy of glyphosate with the addition of the non-ionic alkoxylate surfactant series. The percentage control was higher with the higher PEO surfactant in the tallow amine ethoxylate surfactant series and with the lower PEO surfactant in the non-ionic alkoxylate surfactant series as the two series are chemically different. 相似文献
2.
Low rates of picloram in mixture with glyphosate provided a rapid enhancement of the onset of injury to the shoots of Cirsium arvense (Canada thistle or creeping thistle) under field (0.07+1.0 and 0.07+1.5 kg ha?1) and greenhouse (0.035+0.42 and 0.07+0.84 kg ha?1) conditions. Picloram slightly reduced the amount of 14C-glyphosate absorbed at 24 and 48 but not 72 h after treatment. Movement of 14C-glyphosate from the treated leaves to the shoot apex, remainder of the shoot and roots was reduced in the presence of picloram. Necrosis of the treated leaves above the treated spots was evident, presumably indicating acropetal movement of either or both herbicides. With the picloram + glyphosate mixtures there was increased shoot regrowth over glyphosate alone at 1 year after treatment under field, and with certain mixtures at 18 days and 4 weeks after treatment under greenhouse conditions. Following application of the mixtures, accumulation of glyphosate in the shoots may be responsible for the enhanced onset of shoot injury while failure of enough glyphosate to translocate to, and cause death of, the roots may be responsible for the increased shoot regrowth over glyphosate alone. 相似文献
3.
Surfactant and salt affect glyphosate retention and absorption 总被引：1，自引：0，他引：1
The influence of nonylphenoxy surfactants and glyphosate salt formulation on spray retention, phytotoxicity and [14C]glyphosate uptake was investigated in wheat (Triticum aestivum L). and Kochia scoparia L. The amount of spray retained, and uptake of [14C]glyphosate increased with increasing hydrophilic-lipophilic balance (HLB) value of surfactants. The volume of spray delivered to the plant treatment area and retained by wheat and K. scoparia plants increased with increasing surfactant HLB values, but this only partly accounted for the higher spray retention. Spray retention by leaves of plants was not affected by calcium chloride, either alone or with ammonium sulphate in the glyphosate spray solution. [14C]Glyphosate absorption by wheat and K. scoparia was reduced by calcium chloride alone, but not in mixtures with ammonium sulphate, regardless of surfactant. Phytotoxicity and uptake of glyphosate salt formulations for wheat was: isopropylamine > ammonium > sodium > calcium; these results indicate that the surfactant selected is important to maintain glyphosate efficacy and that sodium and calcium cations antagonize glyphosate by forming salts that are absorbed less than commercial isopropylamine formulations. 相似文献
4.
Differential phytotoxicity of glyphosate in maize seedlings following applications to roots or shoot
The transport and differential phytotoxicity of glyphosate was investigated in maize seedlings following application of the herbicide to either roots or shoots. One-leaf maize seedlings (Zea mays L.) were maintained in graduated cylinders (250 mL) containing nutrient solution. Half of the test plants were placed in cylinders (100 mL) containing different 14C-glyphosate concentrations; the remainder received foliar appliation of 14C-glyphosate. After 26 h, the roots and the treated leaves were washed with distilled water, and the plants placed again in cylinders (250 mL) containing fresh nutrient solution for 5 days. Plants were weighed, and split into root, seed, cotyledon, coleoptile, mesocotyl, first leaf and apex. The recovery of 14C-glyphosate was over 86%. For both application treatments, the shoot apex was the major sink of the mobilized glyphosate (47.9 ± 2.93% for root absorption and 45.8 ± 2.91% for foliar absorption). Expressed on a tissue fresh weight basis, approximately 0.26 μg a.e. g−1 of glyphosate in the apex produced a 50% reduction of plant fresh weight (ED50) when the herbicide was applied to the root. However, the ED50 following foliar absorption was only 0.042 μg a.e. g−1 in the apex, thus maize seedlings were much more sensitive to foliar application of the herbicide. 相似文献
5.
Uptake, translocation, metabolism and selectivity of glyphosate in Canada thistle and leafy spurge 总被引：1，自引：0，他引：1
The uptake, translocation and metabolism of glyphosate [N-(phosphonomethyl) glycine] by Canada thistle (Cirsium arvense (L.) Scop.) (susceptible) and leafy spurge (Euphorbia esula (L.)) (resistant) were examined in an attempt to elucidate the nature of the differential sensitivity. The pattern of uptake and translocation was similar in both species. Glyphosate moved readily in the apoplast and the symplast. High humidity and/or surfactant greatly increased the amount of 14C-glyphosate absorbed and translocated over that in low humidity and/or without surfactant. No 14Cmetabolites were detected in either species 1 week after treatment with 14C-glyphosate. More of a glyphosate spray solution containing a fluorescent dye was received and retained on Canada thistle by virtue of its growth habit than on leafy spurge. More glyphosate should therefore be available for uptake by Canada thistle and this may account for the differential sensitivity of these two species. 相似文献
6.
Growth analysis, absorption and translocation studies were conducted to compare a 1-aminomethanamide dihydrogen tetraoxosulfate (GLY-A) formulation of glyphosate with two isopropylamine (GLY-IPA-1, GLY-IPA-2) formulations of glyphosate on velvetleaf. The two isopropylamine formulations differed by the presence of a surfactant in the formulation, GLY-IPA-1 containing surfactant whereas GLY-IPA-2 did not. Four- to six-leaf velvetleaf was treated with GLY-A and GLY-IPA-1 and GLY-IPA-2 (0, 50, 67, 89, 119, 158, 280, 420, 560 and 840 g AE ha(-1)) with and without ammonium sulfate (AMS; 20 g L(-1)). GLY-A and GLY-IPA-2 included a non-ionic surfactant (2.5 mL L(-1)) in the spray solution at all herbicide concentrations. No additional surfactant was added to GLY-IPA-1. The IC50 value for GLY-A was 88 g AE ha(-1) compared with 346 and 376 g AE ha(-1) for GLY-IPA-1 and GLY-IPA-2 respectively in the absence of AMS. When AMS (20 g L(-1)) was added to the spray solution, the estimated IC50 values were 143, 76 and 60 g AE ha(-1) for GLY-IPA-1, GLY-IPA-2 and GLY-A respectively. Absorption of 14C-glyphosate into the third leaf of five- to six-leaf velvetleaf was three- to sixfold greater 72 h after treatment (HAT) when applied as GLY-A compared with GLY-IPA-1 and GLY-IPA-2 respectively in the absence of AMS. AMS (20 g L(-1)) increased absorption of 14C-glyphosate in all glyphosate formulations two- to threefold, but differences among the formulations remained. Approximately three- and sixfold more 14C-glyphosate applied as GLY-A had translocated out of the treated leaf compared with GLY-IPA-1 and GLY-IPA-2 respectively by 72 HAT. Adding AMS (20 g L(-1)) increased translocation of 14C-glyphosate out of the treated leaf approximately 2.5-fold for all three formulations. The increased efficacy of GLY-A versus GLY-IPA-1 and GLY-IPA-2 on velvetleaf is due to the greater rate of absorption and subsequent translocation of glyphosate out of the treated leaf. AMS increased the efficacy of all three formulations by increasing absorption and translocation of glyphosate in the plant. 相似文献
7.
在人工气候室培养空心莲子草,植株经草甘膦与乙烯利混合处理后,测定对植株的抑制作用和草甘膦的吸收与传导量。结果表明,加入乙烯利(100mg·L~(-1))后草甘膦(300mg·L~(-1))对地下根茎抑制率比对照提高了13.6个百分点。植株经乙烯利喷雾处理后,基芽、地下茎和根系中~(14)C-草甘膦含量分别是对照的3.56、1.75和2.35倍。放射性成像图显示,植株地下茎与根系中~(14)C-草甘膦传导量明显高于对照。 相似文献
8.
Summary. Retention of the spray solution was shown to be a major factor in the selectivity of ioxynil. Retention was high on mustard plants with or without surfactant(Tween 20). Very little ioxynil was retained by barley and pea plants when no surfactant was included in the spray hut inclusion of 0.1 or 1.0% Tween 20 increased retention. With 1.0% the retention on pea plants approached that on mustard, and there was then little differential toxicity. With no surfactant in the spray, mustard plants retained twenty-six times more ioxynil than barley plants. Addition of 01 or 1.0% surfactant increased retention by barley and reduced the differential to eleven times and eight times respectively. By varying the angle of barley leaves to the spray it was shown that the normal upright position results in reduced interception of a vertical spray and reflection of the drops without surfactant. It was concluded that for a given species growth reduction by ioxynil is largely conditioned by the amount retained and that apart from influencing retention, Tween 20 has no major independent action. At equivalent retention levels barley was much less susceptible than mustard or pea. Plants of mustard, pea and barley were treated either on the leaves only or over the whole exposed surface of the plant lo assess the influence of morphology on the response to ioxynil. There was no difference in the response of barley, but treatment by dipping aerial shoots of mustard and pea produced an effect twice that from treatment of the leaves alone at the same level of retention. The increased response of mustard and pea to whole shoot treatment is considered to be due primarily to the exposed stem and bud tissues of these species. Les bases de la toxicilé différentielle du 4-hydroxy-3,5-di-iodobenzomtrite I. Infiuence de la rétention de la bouillie et de la morphologie de la plante 相似文献
9.
为明确助剂3%卵磷脂·维生素E (商品名为安融乐?,AnnGro?)对草甘膦的增效作用及其在植物体内的吸收与传导的影响,以空心莲子草Alternanthera philoxeroides为试验材料,通过生物测定计算了安融乐?分别与2种草甘膦异丙胺盐水剂(商品名分别为“发达”和“农达”)混用后的ED50值和ED90值,以及药液表面张力和药液与叶面的接触角;利用同位素示踪技术测定了14C-草甘膦在空心莲子草体内的吸收与传导。结果表明:与草甘膦异丙胺盐水剂单用相比,安融乐?与2种草甘膦异丙胺盐水剂混用后空心莲子草的死亡时间均提前1 d;ED50值和ED90值分别降低34.9%、21.4%和35.9%、23.3%;药液表面张力和药液与叶面的接触角均显著降低。处理4 d后,14C-草甘膦+安融乐?处理的空心莲子草体内的14C-草甘膦总吸收量、在植物体内总传导... 相似文献
10.
The effects of several formulations on foliar uptake of glyphosate, and on the morphology of glyphosate deposits on leaves, were examined in Tartary buckwheat (Fagopyrum tataricum (L.) Gaertn.). [14C]glyphosate, in the form of the free acid or the isopropylamine salt (IPAS), was applied to foliage alone or with various adjuvants. Uptake of all glyphosate IPAS formulations was greater than that of the corresponding acid formulation. Addition of ‘Tween 20’ enhanced the uptake of glyphosate IPAS compared to glyphosate alone, but had no effect on the uptake of glyphosate acid. Ammonium sulfate and the ‘Roundup’ formulation blank increased the uptake of glyphosate acid and IPAS to 2-3 times that of herbicide alone. Surface deposits, as observed by scanning electron microscopy, varied with the formulation of the herbicide, although there were no differences between the acid and IPAS formulations. Glyphosate alone initially formed a deposit with both crystalline and smooth, amorphous areas. Later in the treatment period (48 and 72 h after application), the deposit was almost entirely crystalline. The addition of ‘Tween 20’ or of formulation blank resulted in the formation of a more amorphous, non-crystalline deposit. Herbicide solutions containing ammonium sulfate dried to form a highly crystalline deposit. However, crystals similar to those of glyphosate alone were not visible in these deposits. The ability of these adjuvants to prevent or delay crystal formation may play a role in their enhancement of herbicide uptake. 相似文献
11.
Absorption, translocation and distribution of 14C-glyphosate were examined in Agropyron repens (L.) Beauv. plants growing under field conditions in the autumn. Glyphosate absorption did not increase beyond 3 days after application, whereas translocation to the rhizomes continued up to 7 days after application. The translocated glyphosate accumulated more in new rhizomes than in older parts of the rhizomes. Ten per cent of the glyphosate translocated out of the treated shoot was recovered in younger shoots 7 days after application. Plants harvested the following spring contained less than 20% of the glyphosate originally applied. Although a growth cabinet experiment indicated that 34% of the glyphosate in the rhizomes of treated plants could be remobi-lized into new aerial shoots, considerably less was recovered in new, aerial shoots in the spring in the field-grown plants. Freezing experiments showed that glyphosate translocation to the rhizomes was only prevented when cold treatment caused visible damage to A. repens foliage. 相似文献
12.
The differential tolerance of resislant creeping red fescue (Fes- tuca rubra L, var, rutra) and susceptibie reed canarygrass (Pha- laris arundinacea L.) seedlings to glyphosate [N-(phosphono- meihyDglycine) was confirmed under growth chamber condilions. The absorption, transiocation and metabolism of 14C-glyphosate was examined in both species to determine if differences in these processes could account for the observed selectivity, Creepmg red fescue actually absorbed more glyphosate than did t-eed canarygrass, and both species rapidly translocated the herbicide throughout their respective tissues. No metabolism of glyphosate was detected in either species. Differential interception and retention of the glyphosate spray can probably be eliminated as possible selectivity mechanisms. The relative tolerance of creeping red fescue to glyphosale appears to be related to its ability lo regenerate roots and shoots from the crown of the plant, but the mechanism of resistance remains obscure. 相似文献
13.
Structure-concentration–foliar uptake enhancement relationships between commercial polyoxyethylene primary aliphatic alcohol (A), nonylphenol (NP), primary aliphatic amine (AM) surfactants and the herbicide glyphosatemono(isopropylammonium) were studied in experiments with wheat (Triticum aestivum L.) and field bean (Vicia faba L.) plants growing under controlled-environment conditions. Candidate surfactants had mean molar ethylene oxide (EO) contents ranging from 5 to 20 and were added at concentrations varying from 0·2 to 10 g litre?-1 to [14C]glyphosate formulations in acetone–water. Rates and total amounts of herbicide uptake from c. 0·2–μl droplet applications of formulations to leaves were influenced by surfactant EO content, surfactant hydrophobe composition, surfactant concentration, glyphosate concentration and plant species, in a complex manner. Surfactant effects were most pronounced at 0·5 g acid equivalent (a.e.) glyphosate litre?-1 where, for both target species, surfactants of high EO content (15–20) were most effective at enhancing herbicide uptake: surfactants of lower EO content (5–10) frequently reduced, or failed to improve, glyphosate absorption. Whereas, at optimal EO content, AM surfactants caused greatest uptake enhancement on wheat, A surfactants gave the best overall performance on field bean; NP surfactants were generally the least efficient class of adjuvants on both species. Threshold concentrations of surfactants needed to increase glyphosate uptake were much higher in field bean than wheat (c. 2 g litre?-1 and < 1 g litre?-1, respectively); less herbicide was taken up by both species at high AM surfactant concentrations. At 5 and 10 g a.e. glyphosate litre?-1, there were substantial increases in herbicide absorption and surfactant addition could cause effects on uptake that were different from those observed at lower herbicide doses. In particular, the influence of EO content on glyphosate uptake was now much less marked in both species, especially with AM surfactants. The fundamental importance of glyphosate concentration for its uptake was further emphasised by experiments using formulations with constant a.i./surfactant weight ratios. Any increased foliar penetration resulting from inclusion of surfactants in 0·5 g litre?-1 [14C]glyphosate formulations gave concomitant increases in the amounts of radiolabel that were translocated away from the site of application. At these low herbicide doses, translocation of absorbed [14C]glyphosate in wheat was c. twice that in field bean; surfactant addition to the formulation did not increase the proportion transported in wheat but substantially enhanced it in field bean. 相似文献
14.
14C-glyphosate (N-(phosphonomethyl)glycine) uptake by germinating maize (Zea mays L. ‘PAG SX56’) or soybean (Glycine max (L.) Merr. ‘Williams’) seeds from sterile quartz sand was minimal on a weight basis until the radicle became functional. Uptake in soybean seedlings was ten times greater (on a weight basis) than in maize. Germination of either species was not affected by glyphosate concentrations up to 10?3m , but seedling axis elongation was inhibited in soybeans at 10?4m and in maize at [0?3m When 14C-glyphosate was applied to the fully expanded first trifoliolate soybean leaf (assimilate-exporting), movement into root and shoot assimilate sinks occurred. About 7% of the total 14C-glyphosate applied was absorbed and translocated into other parts of the plant by 48 h. Of the total 14C accumulated by 48 h in the roots and apical meristem, nearly 50% was present by 12 h. Minor phytotoxicity resulted from 10 nmoles of glyphosate in the plant. Absorption et migration du 14 C-glyphosate chez le maïs (Zea mays) en germination et chez les semences et les plantes de soja (Glycine max) L'absorption du 14C-glyphosate (N-(phosphonométhyle) glycine)par du maïs en germination (Zea mays L.,‘PAG SX56′)ou par des semences de soja (Glycine max (L.) Merr.,‘Williams’) a partir de sable de quartz stérile a été minimale (sur la base du poids) jusquà ce que la racine devienne fonctionnelle. L'absorption par des plantules de soja a été, sur la base due poids, 10 fois plus grande que chez le maïs. La germination de ces deux espèn n'a pas été affectée par des concentrations de glyphosate allant jusquà 10?3m , maïs l'élongation des plantules a été inhibée chez le soja á 10?4m et chez le maïs à 10?3m . Lorsque le 14C-glyphosate a été appliqué sur la première feuille trifoliée de soja pleinement dévdoppé (en état d'exporter des métabolites). une diminution du mouvemem des métabolites vers les jeunes pousses et vers les racines s'est manifestée. Eaviron 7% du 14C-glyphosate total appliqué a été absorbé et a migré dans d'autres parties de la plume en 48 heures. Près de 50% du 14C total accumulé dans les racines et le méristème apical y était présent en 12 heures. Une faible toxicité a réulté de b présence de 10 nmoles de glyphosate dans la plante. 14 C-glyphosat-Aufnahme und -Translokation bei keimenden Samen von Mais (Zea mays) und Sojabohnen (Glycine max) und bei Sojabohnenpflanzen Die Aufnahme von 14C-Glyphosat (N-(Phosphonomethyl)glycin) aus sterilem Quarszsand durch keimende Samen von Mais (Zea mays L.‘PAG SX56′) und Sojabohnen (glycine max (L.) Merr.‘Williams’) war, bezogen auf das Pflanzengewicht, bis zur Funktionsaufnahme der Keimwurzel, gering. Die Aufnahme war bei den Sojabohnenkeimlingen zehnmal grösser (Gewichts-basis) als bei Mais. Die Keimung wurde bei beiden Arten durch Glyphosat bis zu 10?3m nicht beeinflusst. Das Streckungswachstum des Stengels wurde aber bei der Sojabohne bei 10?4m und beim Mais bei 10?3m gehemmt. Wenn 14C-Glyphosat auf das erste vollstándig entwickelte dreibláttrige Sojabohnenblatt (Assimilate exportierend) appliziert wurde, konnte ein Transport in die Assimilatesinks der Wurzel und des Sprosses beobachtet werden. Nach 48 h waren etwa 7% des applizierten 14C-Glyphosats aufgenommen und in andere Teile der Pflanze transloziert. Vom gesamten nach 48 h in den Wurzeln und im apikalen Meristem akkumulierten 14C waren fast 50% bereits nach 12 h vorhanden. 10 nmol Glyphosat in den Pflanzen waren nur geringfügig phytntoxisch. 相似文献
15.
The rate of aerobic evolution of 14CO2 from 14C-glyphosate labelled in the methylphosphonyl carbon, varied 100-fold within a group of five Hawaiian sugarcane soils. The rate depended inversely on the degree of soil binding, probably associated with the phosphonic acid moiety, and to a less certain extent on soil pH and soil organic matter. After an initial rapid degradation, the rate of 14CO2 evolution in three soils reached a constant at 16–21 days which continued to the 60-day termination. The other two soils showed a continually decreasing rate throughout. Two soils released over 50% of the labelled carbon in 60 days, a third released 35%, while the remaining soils released 1.2 and 0.8% respectively. Labelled carbon in the soils after 60 days consisted of glyphosate and one metabolite, aminomethyl-phosphonic acid, with glyphosate predominating in high fixing soils. The 14C could be extracted almost completely with NaOH solution, and remained mainly in solution after acidification. 相似文献
16.
The pattern and extent of 14C-glyphosate [N-(phosphonomethyl)glycine] translocation from the treated leaf and metabolism of 14C-glyphosate were studied in field bindweed (Convolvulus arvensis L.), hedge bindweed (Convolvulus sepium L.). Canada thistle [Cirsium arvense (L.) Scop.] tall morning glory [lpomoea purpurea (L.) Roth.] and wild buckwheat (Polygonum convolvulus L.). 14C was translocated throughout the plants within 3 days with accumulation in the meristematic tips of the roots and shoots evident. Cross and longitudinal sections of stems and roots showed that the 14C was localized in the phloem. Field bindweed translocated 3–5% of the applied 14C from the treated leaf, hedge bindweed 21.6%, Canada thistle 7.8%, tall morningglory 6.5%, and wild buckwheat 5%. Field bindweed, Canada thistle, and tall morningglory metabolized the parent glyphosate to aminomethylphosphonic acid to a limited extent. This metabolite made up less than 15% of the total 14C. Of the total 14C applied to excised leaves, 50% had disappeared within 25 days. 相似文献
17.
Rhizome segments from Alternanthera philoxeroides were shaken in solutions of 14C-glyphosate for 24 h to establish a range of internal tissue concentrations. Rhizomes were killed at concentrations of 16 μg g?1 dry weight and above and survived at concentrations of 8 μg g?1 dry weight and below. Plants grown in the field for 10 weeks in declining photoperiod were used to investigate the uptake and translocation of 14C-glyphosate after application of a constant dosage in either 1.0-or 0.2-μl droplets corresponding to concentrations of 1.06 and 5.3 g 1?1, of glyphosate acid, respectively. Use of smaller droplets of higher concentration increased absorption of 14C, but did not improve translocation. Uptake by treated leaves was 25 and 41% of the applied glyphosate for the large and small droplets respectively, but translocation to underground parts of the plant was about 7% of applied 14C-activity. Radiolabel accumulated in new rhizomes was equivalent to about 0.5 μg g?1 dry weight of glyphosate, at least 30 times below the concentration required for tissue death. Absorption et transport de glyphosate C14 chez Alternanthera philoxeroides (Mart.) Griseb. I.Concentrations dans les rhizomes nécéssaires pour l'inhibition Des fragments de rhizome d'Alternanthera philoxeroides ont été trempés dans des solutions de glyphosate C14 pour aboutir à un éventail de concentrations internes des tissus, Les rhizomes ont été tués à des concentrations de 16 μg g?1 PS et plus, et ont survécu à des concentrations de 8 μg g?1 PS et en-dessous. Des plantes cultivées en plein champ pendant 10 jours en photopériode décroissante ont été utilisées pour étudier l'absorption et le transport du glyphosate C14 après l'application d'une dose constante dans des gouttelettes de 1 ou 0,2 μl correspondant à des concentrations de 1,06 et 5,3 g l?1 de glyphosate C14 acide respectivement, L'utilisation de gouttelettes plus petites de concentrations plus é1evées a augmenté l'absorption du C14, mais n'en a pas amélioré le transport. L'absorption par les feuilles traitées était de 25 et 41% du glyphosate appliqué pour les grandes et les petites gouttelettes respectivement, mais le transport vers les parties souterraines de la plante était d'environ 7% du C14 appliqué. Le radio-marqueur dans les nouveaux rhizomes était équivalent à environ 0,5 μg g?1 PS de glyphosate, soit au moins 30 fois en-dessous de la concentration nécessaire à la mort des tissus. Aufnahme und Translokation von 14C-Glyphosat in Alternanthera philoxeroides (Mart.) Griseb. I. Für die Hemmung erforderliche Konzentration im Rhizom Rhizomteile von Alternanthera philoxeroides wurden 24 Stunden lang in 14C-Glyphosat-Lösungen geschüttelt, um eine Reihe von Konzentrationen in den inneren Geweben einzustellen. Die Rhizome wurden bei Konzen-trationen von 16 und mehr μg g?1 TM abgetötet und überlebten bei Konzentrationen von 8 μg g?1 TM und weniger. Die Aufnahme und Translokation von 14C-Glyphosat nach der Applikation einer konstanten Dosis in 1,0-oder 0,2-μl-Tröpfchen, entsprechend Konzentrationen von 1,06 und 5,3 g l?1 Glyphosat-Säure, wurden an Pflanzen untersucht, die im Freiland 10 Wochen lang bei abnehmender Photoperiode gewachsen waren. Der Gebrauch kleinerer Tropfen höherer Konzentration führte zu mehr Absorption von 14C, förderte aber nicht die Translokation. Das Glyphosat wurde von den behandelten Blättern zu 25 bzw. 41% aus den großen Oder den kleinen Tröpfchen aufgenommen, aber die Translokation in die unterirdischen Pflanzenteile war etwa 7% der ausgebrachten 14C-Aktivität. Die in neuen Rhizomen akkumlierte Radioaktivität entsprach 0,5 μg g?1 TM Glyphosat, mindestens 30mal weniger als für die Abtötung von Gewebe erforderlich. 相似文献
18.
Calcium ion in hydroponic solution with glyphosate [N-phosphonomethyl (glycine)] did not significantly influence the efficacy of the herbicide in reducing growth of soybean (Glycine max) seedlings. Data from atomic absorption spectroscopy studies revealed that glyphosate reduced Ca2+ uptake and translocation, whether supplied alone or with other metal ions. Results with radiolabelled 45Ca2+ indicated that glyphosate severely retards translocation of Ca2+ from the roots to the leaves and cotyledons but the effect is not detectable until 24 h after exposure to glyphosate. Influence du glyphosate sur l'absorption el le mourement de I'ion calcium dans des plantules de soja. L'ion calcium présent dans une solution hydroponique contenant du glyphosate (N-phosphono-methyl (glycine) ne modifie pas dc facon significative I'efficacité de I'herbicide dans son action sur la réduction de croissance de plantules de soya. Des données fournies par la spectroscopie d'absorption atomique montrent que le glyphosate reduit l'absorption et le mouvement des ions Ca2+ seuls ou en présence d'ionsd'autresmétaux. Les résultats obtenus avec des ions marqués 45Ca2+ révèlent que le glyphosate retarde notablement le mouvement des ions Ca2+ entre les racines et les feuilles ou les cotylédons mais cet effct n'est pas détectable avant une péríode de 24h suivant l'exposition au glyphosate. 相似文献
19.
Vila-Aiub MM Balbi MC Distéfano AJ Fernández L Hopp E Yu Q Powles SB 《Pest management science》2012,68(3):430-436
BACKGROUND: In a large cropping area of northern Argentina, Sorghum halepense (Johnsongrass) has evolved towards glyphosate resistance. This study aimed to determine the molecular and biochemical basis conferring glyphosate resistance in this species. Experiments were conducted to assess target EPSPS gene sequences and 14C‐glyphosate leaf absorption and translocation to meristematic tissues. RESULTS: Individuals of all resistant (R) accessions exhibited significantly less glyphosate translocation to root (11% versus 29%) and stem (9% versus 26%) meristems when compared with susceptible (S) plants. A notably higher proportion of the applied glyphosate remained in the treated leaves of R plants (63%) than in the treated leaves of S plants (27%). In addition, individuals of S. halepense accession R2 consistently showed lower glyphosate absorption rates in both adaxial (10–20%) and abaxial (20–25%) leaf surfaces compared with S plants. No glyphosate resistance endowing mutations in the EPSPS gene at Pro‐101–106 residues were found in any of the evaluated R accessions. CONCLUSION: The results of the present investigation indicate that reduced glyphosate translocation to meristems is the primary mechanism endowing glyphosate resistance in S. halepense from cropping fields in Argentina. To a lesser extent, reduced glyphosate leaf uptake has also been shown to be involved in glyphosate‐resistant S. halepense . Copyright © 2011 Society of Chemical Industry 相似文献
20.
Summary. Entry of ioxynil-14C into portions of leaves was greater with mustard than with barley or pea and was unrelated to stomatal density. Measurement of ioxynil content of sprayed plants showed that by increasing the concentration of ioxynil and adding a surfactant, almost as much ioxynil could be made to enter barley as entered mustard from a lower concentration without surfactant. Auto radiographs showed that a limited amount of 14C was translocated to a small extent in plants following localized application of ioxynil-14C. An experiment comparing leaf removal by cutting with destruction of equivalent leaf areas by ioxynil treatment suggested a greater translocated effect of ioxynil with mustard than with pea or barley. Les principes de la phytotoxicité différentielle du 4-hydroxy-3,5-di-iodobetZonitrile II. Absorption et migration 相似文献