草甘膦对龙葵苗期生理指标的影响

选取生长势一致的龙葵幼苗进行5个施药剂量梯度的处理,测定其叶片中叶绿素、可溶性糖、丙二醛含量.结果表明,随着草甘膦剂量的加大龙葵幼苗叶绿素a含量、叶绿素b含量和叶绿素总量与对照相比均显著减少;在施药后第4天,750 g/667m2剂量下处理的幼苗可溶性糖含量比对照增加了244%,低剂量草甘膦(15 g/667m2)处理龙葵幼苗,可溶性糖含量变化不显著;经高剂量草甘膦处理后的幼苗丙二醛含量也显著增加.因此,农业生产中推荐使用750 g/667m2剂量的草甘膦防治龙葵.     

农杆菌介导的抗草甘膦基因(sxglr-11)的玉米遗传转化

利用根瘤农杆菌(Agrobacterium tumefaciens)介导法将抗草甘膦基因(sxglr-11)导入优良玉米再生系HiII,共转化幼胚1 673个,分化出再生苗67株,其中,28株移栽成活,经PCR检测13株为阳性植株,阳性率为46.4%。采用草甘膦浓度梯度筛选,确定了未转基因的对照植株的致死浓度范围为1%～2%。利用2%的草甘膦对T0转基因植株6～8叶龄苗的叶片进行涂抹,结果表明,阳性植株均具有草甘膦抗性。T1植株经2%草甘膦抗性筛选,转基因植株表现出3∶1的孟德尔分离方式。     

草甘膦防除肇东苜蓿田菟丝子试验研究

试验选用不同剂量的草甘膦对肇东苜蓿田的杂草菟丝子进行化学防除,旨在筛选草甘膦除草剂的经济合适的剂量和使用方法。研究表明,从防除效果和安全性考虑,草甘膦水剂400mg／kg和800mg／kg的剂量处理可以有效防治肇东苜蓿田的恶性杂草菟丝子。     

Herbicide tolerant canola systems and their impact on winter crop rotations

Canola is widely grown in Australia to provide diversity within winter crop rotations. Its production is heavily reliant on triazine tolerant varieties but Clearfield^® and conventional varieties are also significant components of the industry. Glyphosate tolerant varieties have been introduced, thereby providing an alternative technology to be incorporated into the farming systems. To evaluate the potential impact of the relative herbicide technologies, a comparison of herbicide tolerant canola weed management systems was undertaken at Wagga Wagga, Australia over a 5-year rotation. Near isogenic lines of conventional, glyphosate tolerant and triazine tolerant varieties were evaluated for their abilities to control annual ryegrass (Lolium rigidum), the most challenging weed of temperate crops in Australia. Glyphosate tolerant and triazine tolerant canola achieved high levels of ryegrass control and attained higher yields than the conventional system. Glyphosate tolerant canola provided extra control of broadleaf weeds and also achieved better seed oil levels when compared with the other canola systems. There were positive flow-on weed management benefits for the remainder of the crop sequence from the weed control achieved in the initial crop, particularly following glyphosate tolerant canola. Subsequent control of volunteer canola in all treatments was readily achieved by using paraquat/diquat. The glyphosate tolerant weed management system was more profitable than the triazine tolerant system, although no allowance was made for technology costs as they were not known at the time of study. These outcomes demonstrate the potential value of herbicide tolerant canola to Australian farmers.     

酵母菌S-2对草甘膦除草剂的降解特性

[目的]从福建三农集团污水处理池的活性污泥中分离草甘膦降解菌株,研究其降解特性。[方法]采用富集驯化和选择性培养,分离能以草甘膦为唯一碳源、氮源的酵母菌S-2,对其降解特性进行了研究。[结果]适宜菌株S-2生长和获得最佳降解率的条件为：接种量4%、pH值7.0、温度30℃、转速130～160r/min。[结论]该研究为草甘膦的生物降解与污染土壤的生物修复提供必要的参考。     

Distribution and frequency of resistance to four herbicide modes of action in Lolium rigidum Gaud. accessions randomly collected in winter cereal fields in Spain

Lolium rigidum is the most prevalent and damaging grass weed of winter cereals in Spain. L. rigidum infestations are frequently treated with herbicides and, consequently, populations have evolved resistance. The objective of this study was to determine the extent and frequency of herbicide resistance in L. rigidum populations in Spain to the selective herbicides chlortoluron, diclofop-methyl and chlorsulfuron, commonly used for its control in-crop, and to glyphosate. The response to these herbicides was evaluated on 123 accessions surveyed randomly across cereal cropping areas of the regions of Castile and León, Catalonia and Andalusia. The fresh weight and the frequency of undamaged plants were calculated for each accession and herbicide. At the regional level, higher frequencies of accessions displaying resistance occurred in Catalonia, an intensively cropped region with a greater herbicide selection pressure. Of concern is that in this region the 60% of the accessions displayed some level of resistance to the ALS-inhibiting herbicide chlorsulfuron. The 6.9% of the accessions found in Castile and León with some resistance to glyphosate could also indicate an incipient problem of resistance to this herbicide. For the other herbicides and regions the majority of the accessions remained susceptible. The possible mechanisms of herbicide resistance development in L. rigidum accessions (target-site versus non-target-site resistance) and their variation among regions was discussed. This study can be used to generate herbicide resistance-management schemes for farmers, based upon the herbicide the site and the potential for resistance development.     

Differential tolerance of weedy red rice (Oryza sativa L.) from Arkansas, USA to glyphosate

Red rice (Oryza sativa L.), a weedy relative of cultivated rice (O. sativa), is a troublesome weed in rice in the southern United States. It is also very problematic in other world regions where rice is grown. There are many types of red rice. Some have white pericarp. In this paper, the term ‘red rice’ will be used to refer to the weedy types that occur in this region of the southern USA. Because of the great diversity in morphology and phenology of red rice populations in the USA, we hypothesized that these have differential tolerance to glyphosate. Red rice is subjected to selection pressure by glyphosate, which is the principal herbicide used in glyphosate-resistant soybean planted after rice. Two hundred-fifteen red rice accessions were collected in Arkansas, USA between 2002 and 2003 and evaluated for glyphosate tolerance between 2003 and 2006. The commercial dose of glyphosate controlled red rice accessions 81-100% regardless of application timing, by 30 d after treatment. The number of survivors that produced seeds and the seeds produced per survivor differed between accessions. Application of the full dose at the tillering stage was more effective than at the 3- to 4-leaf stages. At half the field dose, 40 to 54% of survivors produced seed, with germination capacity of 30-100%. The lowest dose of glyphosate, 225 g a.e. ha⁻¹, resulted in the widest range of control ratings from 30 to 100%. The red rice accessions differentiated into six tolerance categories. A tolerance map was generated and will be used in educating growers about the proper use of glyphosate for red rice management.     

Pre-harvest glyphosate application effects on properties of β-glucan from oat groats

Pre-harvest glyphosate is applied to cereal grains to control weed growth. However, it has been claimed that oat (Avena sativa L.) composition is affected by pre-harvest glyphosate application. The research was conducted to evaluate differences in properties of β-glucan in grains of pre-harvest glyphosate treated versus untreated oat plants. Two oat cultivars (Rockford and Souris) were grown at Minot and Prosper, ND, in 2015, and glyphosate was sprayed during the soft dough stage, hard dough stage, or not applied. β-glucan viscosity was not significantly (p > 0.05) affected by treatment at soft dough (1082 cP) or mature (1166 cP) stages compared with untreated (1150 cP) controls. Applying glyphosate at the soft dough stage significantly (p < 0.05) reduced the content and solubility of the β-glucan versus untreated samples. β-glucan content and solubility in oat treated at soft dough were 4.35% and 52.1%, respectively, while in untreated samples were 4.65% and 60.6%, respectively. Treatment at soft dough and hard dough stages significantly (p < 0.05) increased weight average molecular weight (M_w) of the high molecular weight fraction of soluble β-glucan (4.4 × 10⁶ and 3.8 × 10⁶, respectively), compared with untreated controls (3.5 × 10⁶). The M_w of the low molecular weight fraction of soluble β-glucan fraction significantly (p < 0.05) increased at soft and hard dough treatments (5.5 × 10⁵ and 3.3 × 10⁵, respectively), versus untreated samples (3.0 × 10⁵). Therefore, glyphosate can be applied when the grain has reached physiological maturity or thereafter.     

草甘膦除草剂在山地核桃园的除草试验

在核桃园杂草生长高峰期6-7月，喷施浓度为3．0～3．5g／L的草甘膦防除效果明显，达93．3％～100％。草甘膦不仅能防除1年杂草，而且可控制杂草2—3年内不蔓延，起到免耕作用。在除草后的地块撒播绿肥，出苗快、保存率较高、生长快。     

铜和草甘膦对蚯蚓的毒性效应研究

污染物的交互作用及其生态毒理效应已成为环境科学研究的主要方向。含铜杀菌剂与除草剂草甘膦[N-(膦酸甲基)甘氨酸]是农业生产中常见的农药,其在土壤中共存可能造成复合污染。草甘膦中含有羧基、氨基、磷酸基等配位基团对重金属阳离子和有机阳离子有很强的络合能力,草甘膦可以影响重金属的生物有效性、毒性以及重金属在生物体内的积累。本文以赤子爱胜蚓(Eisenia fetida)为例,采用室内模拟试验,单一试验设置5个铜浓度25 mg·kg-1、50 mg·kg-1、100 mg·kg-1、200 mg·kg-1和400 mg·kg-1,5个草甘膦浓度25mg·kg-1、50 mg·kg-1、100 mg·kg-1、200 mg·kg-1和500 mg·kg-1,并以去离子水做空白对照;复合试验设置2个铜浓度(低铜浓度25 mg·kg-1和高铜浓度200 mg·kg-1)分别与5个草甘膦浓度(0、25 mg·kg-1、50 mg·kg-1、100 mg·kg-1和200 mg·kg-1)复合;每个处理3次重复,试验期为35 d。研究了铜和草甘膦的单一及复合施用对蚯蚓的亚急性毒性效应。单一毒性试验结果表明,蚯蚓对低浓度铜的响应不敏感,而较高浓度铜使蚯蚓生物量的相对增长率受到显著抑制(α=0.01,r2=0.570),且未出现死亡,并且随着铜浓度的增加蚯蚓体内铜含量显著增加(α=0.01,r2=0.905)。与对照相比草甘膦的添加对蚯蚓的生长无显著影响。复合毒性试验结果表明,草甘膦和铜复合可以降低蚯蚓对铜的吸收,特别是当铜浓度较高时即200 mg·kg-1,草甘膦和铜复合可显著降低蚯蚓对铜的吸收,并且草甘膦能够减轻铜对蚯蚓生物量相对增长率的抑制,但差异并不显著。以上结果表明,铜比草甘膦的毒性大很多,铜与草甘膦复合能够减少蚯蚓对铜的吸收,缓解铜的毒性。因此本研究认为,在草甘膦和重金属共存的污染土壤中,草甘膦能够控制重金属的生物有效性和毒性。