生防菌Alternaria amaranthi-3对反枝苋的防治效果

反枝苋Amaranthus retroflexus是一种世界性恶性杂草。为了确定微生物除草剂候选菌Alternaria amaranthi-3防除反枝苋的潜力,通过盆栽试验研究了接种浓度、露期和水乳剂型对A.ama-ranthi-3菌株致病力的影响。结果显示,接种浓度显著影响菌株的致病力,在48h露期条件下,接种孢子浓度为105个/mL时,菌株水剂对反枝苋幼苗生长抑制率为35.55%;浓度为107个/mL时,生长抑制率达到75.25%。露期对该菌株的致病力也有较大影响,在不保湿条件下,菌株水剂对反枝苋的生长抑制率为26.43%,而保湿48h处理的生长抑制率达到77.96%。Span80∶Tween80=1∶3的复配乳化剂和大豆油制备的水乳剂可显著降低露期对菌株防效的影响和提高菌株的致病力,无露期时,菌株水乳剂对反枝苋的生长抑制率达到88.35%,显著高于水剂;48h露期条件下,菌株水乳剂处理的生长抑制率为90.59%,而菌株水剂处理为77.96%。表明通过剂型的改进菌株Alternaria amaranthi-3能有效防除反枝苋。     

绿磺隆残留的生测方法研究

作者从指示植物的选用,玉米种子的前处理,培养器皿,加药方式,培养期间的光照处理,培养时间等诸方面对绿磺隆玉米主根长土培生测法进行了研究。结果表明,以玉米掖单４号为生测指示植物,２５℃下浸种１２ｈ后立即播种,以一次性塑料口杯为培养器皿,采用一次性加药方式,不见光培养６ｄ即可获得满意的生测结果。回归分析表明,绿磺隆浓度与玉米主根长抑制率之间回归模型为Ｙ＝ａＸ＾ｂ,相关性极好（ｒ〉０．９０）,该方法有很     

广西灵川等4地刺苋和反枝苋对草甘膦的敏感性

刺苋和反枝苋在广西各地农田均有分布,综合运用培养皿种子检测法、整株生物测定法对广西4个不同地点的刺苋和反枝苋种群进行草甘膦敏感性测定。结果表明,桂林灵川的刺苋和桂林兴安的反枝苋对草甘膦表现出敏感性下降的情况。同时,使用生化指标测定法检测的植株体内莽草酸含量变化情况与其敏感性变化趋势基本一致。     

反枝苋对烤烟农艺性状及产值的影响

为了明确烟田主要杂草反枝苋对贵州烤烟农艺性状、产量、产值的影响,反枝苋按0~25株/m~2的密度栽种,共设置13个处理,在烤烟成熟期记录株高、茎粗、叶片数、叶长、叶宽、叶鲜质量、地上植株鲜质量、茎秆鲜质量、叶干质量、产值等一系列指标参数,通过11种曲线方程进行拟合、回归分析。结果发现三次方程(y=b_0+b_1×x+b_2×x~2+b_3×x~3)具有最高的拟合度和实用性,建议生产上可以用该三次方程预测反枝苋对烟草农艺性状、产量、产值的影响。     

小麦提取物对反枝苋,繁缕生长的化感效应研究

接受抽穗期小麦提取物进行化感效应测定的１０种作物和杂草中，反枝苋和繁缕的生长受到显著影响：提取物浓度５００ｍｇ／ｋｇ时，反枝苋种子发芽率为１４％。用小麦提取物５０ｍｇ／ｍ２进行土壤处理，２个月后反枝苋干重抑制率达８２％，用同样剂量对繁缕进行了茎叶处理，３０天后有７６％～８５％的繁缕死亡     

两种喷雾助剂对氟磺胺草醚在反枝苋上的吸收和药效的影响

采用14C-氟磺胺草醚同位素标记法研究了喷雾助剂JFC 和ABS(十二烷基苯磺酸钠)对14C-氟磺胺草醚在反枝苋上的吸收和药效的影响。结果表明,在药液中添加2 g/L的JFC ,反枝苋对14C-氟磺胺草醚的吸收面积可增加1.4倍,吸收量增加3.2倍,药效提高28.5%;添加2 g/L的ABS ,反枝苋对14C-氟磺胺草醚的吸收面积增加1.3倍,吸收量增加1.0倍,药效提高19.2%。JFC不但具有促进药液在反枝苋叶面扩展的能力,还具有促进药剂渗透的能力,当添加2 g/L的JFC 时,反枝苋单位面积吸收强度增加75.7%;ABS基本上不能增加反枝苋单位面积的吸收强度,只具有促进药液扩展的能力。     

25%胺苯磺隆WP防除油菜田杂草的效果

为了阐明新一代除草剂25％胺苯磺隆WP对看麦娘、牛繁缕、碎米荠的防治效果，进行了油菜田间防效试验。施用25％胺苯磺隆WP有效成分15—37．5g。结果表明，其防除看麦娘、牛繁缕、碎米荠的效果很好、是一种安全、高效的油菜田除草剂。     

玉米田反枝苋对烟嘧磺隆的抗性水平及靶标抗性分子机理

为明确玉米田主要杂草反枝苋对烟嘧磺隆的抗性水平及靶标抗性分子机理,采用整株水平测定法检测了黑龙江省玉米田反枝苋对烟嘧磺隆的抗性水平,通过靶标酶离体活性测定,分析了抗性和敏感种群反枝苋乙酰乳酸合成酶 (ALS) 对烟嘧磺隆的敏感性,并通过靶标ALS基因克隆测序进行了序列比对分析。结果显示:黑龙江省反枝苋疑似抗性种群 (HLJ-R) 对烟嘧磺隆已产生较高水平抗性,其抗性倍数达13.7;酶活性测定结果表明:烟嘧磺隆对HLJ-R种群ALS活性的抑制中浓度 (IC₅₀) 值是对敏感种群 (TA-S) IC₅₀值的43.9倍;与TA-S种群相比,HLJ-R种群ALS基因205位丙氨酸突变为缬氨酸,574位色氨酸突变为亮氨酸。研究表明,黑龙江省玉米田反枝苋对烟嘧磺隆已产生较高水平抗性,且靶标ALS基因的突变可能是其抗性产生的主要原因之一。     

113种植物的乙醇提取物对反枝苋和马唐种子萌发及生长的抑制活性

筛选和评价植物资源的除草活性可为新型植物源除草剂的研发提供候选材料和理论依据。本研究用种子萌发法和平皿法,评价了56科113种植物提取物对反枝苋和马唐种子萌发和生长的抑制活性。结果表明,在125 mg DW/mL的供试浓度下,大黄、牡丹皮、大叶三升麻、木香、佩兰、楸树、安息香树、泡桐、短叶罗汉松和杜衡提取物对马唐种子萌发和生长的抑制作用最为明显;牡丹皮、佩兰、木香、鹿藿和短叶罗汉松提取物对反枝苋种子萌发和生长的抑制活性最为明显。毒力测定表明,楸树、木香、杜衡、泡桐、佩兰、安息香树和大叶三升麻提取物对马唐幼根的抑制中浓度（IC50）分别为39.30、5.93、13.93、28.69、8.72、19.19和15.19 mg DW/mL;对马唐幼芽的IC50分别为48.22、8.13、15.28、42.12、22.39、7.78、23.43和12.92 mg DW/mL。木香、牡丹皮、短叶罗汉松、鹿藿、佩兰和紫背浮萍对反枝苋幼根的IC50分别为2.46、2.85、2.59、1.03、2.24和2.79 mg DW/mL;对反枝苋幼芽的IC50分别为7.05、31.21、24.17、4.52和...     

50％嘧苯胺磺隆水分散粒剂防除移栽稻田杂草效果及对后茬作物的影响

50％嘧苯胺磺隆水分散粒剂对水稻田禾本科杂草稗草、部分阔叶草及莎草均有较理想的防效,对移栽水稻安全,增产效果较明显。50％嘧苯胺磺隆水分散粒剂对水稻田后茬作物小麦、油菜、萝卜的安全性好。     

The ecological fitness of ALS-resistant Amaranthus retroflexus and multiple-resistant Amaranthus blitoides

Summary Field studies were conducted to evaluate the ecological fitness of Amaranthus spp. biotypes that evolved resistance to either acetolactate synthase (ALS) inhibitors ( A. retroflexus , SuR), to triazine herbicides ( A. blitoides , SuS/TR), or to both ( A. blitoides , SuR/TR), and estimate their ecological fitness under competitive conditions. The plants were grown in monoculture and in replacement series experiments. The examined mixtures were 100%S, 75%S/25%R, 50%S/50%R, 25%S/75%R and 100%R, at a constant stand of 400 plants m⁻². The SuR and SuS A. retroflexus biotypes attained similar shoot dry biomass per plant, biomass per plot and relative yield total (RYT) = 1. In monoculture, the final shoot biomass of A. blitoides biotypes SuS/TS plants was higher than that of SuR/TR and SuS/TR. A negative effect of association was observed, amensalism, when SuS/TS was grown in mixture with SuR/TR, in favour of the wild type. However, SuR/TR and SuS/TR biomass was not influenced by the presence of the competitor. These data support the hypothesis that the ALS-resistance trait in A. retroflexus and A. blitoides is not associated with growth penalty and did not incur ecological cost in the field. We suggest that the cause of the observed reduction in growth rendering the SuS/TR and SuR/TR less fit than the wild type is due to the triazine resistance, and may facilitate their dissipation.     

Invasion process and potential spread of Amaranthus retroflexus in China

Amaranthus retroflexus, a troublesome agricultural weed native to North America, has expanded its distribution in large areas of China since its introduction around 1905. Geographical interpretation of changes in their distribution ranges could provide valuable insights on its spatiotemporal invasion patterns and could be used to predict the extent of its future spread. Based on compiled historical distribution occurrences of A. retroflexus in North American and Chinese ranges, invaded ecological niche models for three hypothetical invasion stages were developed. Native models on the basis of all available records within the North American range were also generated for reciprocal comparison with the invaded model. Climate similarity between native and invasive ranges was also investigated. Amaranthus retroflexus has exhibited a rapid and large range expansion after about a 50‐year lag, especially in central and western China. It established a relative stable distribution in the 1960s and has been undergoing a more continuous westward expansion since then. Presently A. retroflexus has not yet reached full occupancy of suitable habitats in China. The results highlight prioritising habitats in south‐western China for monitoring and control to prevent its further spread.     

反技苋的生物学特性及防治

反枝苋是世界性分布的一种恶性杂草,了解其生物学特性将有助于对其进行有效防治.本文从反枝苋的分布与危害、生长发育和繁殖等几个方面,详细综述了反枝苋的的生物学特性和防除措施,包括物理防治、化学防治及生物防治,并对综合治理反枝苋提出了几点建议.     

反枝苋的生物学特性及防治

反枝苋是世界性分布的一种恶性杂草．了解其生物学特性将有助于对其进行有效防治。本文从反枝苋的分布与危害、生长发育和繁殖等几个方面，详细综述了反枝苋的的生物学特性和防除措施，包括物理防治、化学防治及生物防治，并对综合治理反枝苋提出了几点建议。     

Mapping of atrazine resistance for Amaranthus retroflexus L. in Hungary

The study extending over all sixteen counties of Hungary has shown atrazine resistant biotypes of Amaranthus retroflexus L. to grow not only in and around maize monocultures but also in rotationally grown maize and even along highways and ruderal areas. In the present study made in 1983 resistant A. retroflexus was found in five counties (Bács-Kiskun, Csongrád, Hajdu-Bihar, Nógrád and Szabolcs-Szatmár) where Hartmann recorded it as absent in 1976. In addition, resistant populations were also found in the counties of Szolnok and Veszprém. The area in which populations of A. retroflexus have developed resistance to atrazine therefore appears to be extending.     

反枝苋种子休眠解除方法研究

研究了光照和黑暗两种条件下氢氧化钠（NaoH）、盐酸（HC l）、赤霉素（GA3）和乙烯利（ETH）处理对反枝苋种子萌发的影响。结果表明,氢氧化钠、盐酸、赤霉素和乙烯利浸泡处理均可以明显提高反枝苋种子的发芽率,且随着试剂浓度的提高,发芽率表现出单峰变化曲线,浓度过低或过高均不利于种子的萌发。其中,赤霉素对解除反枝苋种子休眠最有效,且以200 mg/L浸泡处理24 h效果最好,发芽率可达90.8%,比对照提高了52.5百分点。其次为4%NaOH和6%HC l处理1 h,与800 mg/L ETH处理24 h的效果相当,发芽率在70%~75%之间。黑暗条件不利于反枝苋种子的萌发,发芽率略低于光照条件。     

黑龙江省大豆田反枝苋对氟磺胺草醚的抗药性机制研究

为明确反枝苋抗性种群对氟磺胺草醚的抗性机制,分别测定了氟磺胺草醚对反枝苋抗性和敏感种群体内原卟啉原氧化酶(PPO)、谷胱甘肽S-转移酶(GSTs)、超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性的影响。结果表明:氟磺胺草醚处理后,抗性和敏感反枝苋种群PPO活性均受到一定程度的抑制,但抗性种群活性受到抑制后能逐渐恢复,而敏感种群则不能恢复;施用氟磺胺草醚后,抗性和敏感反枝苋种群GSTs和SOD活性变化无明显差异,抗性和敏感反枝苋种群POD和CAT活性均受到一定程度的抑制,但抗性种群活性受到抑制后能逐渐恢复,而敏感种群则不能恢复。研究表明,反枝苋抗性种群体内PPO对氟磺胺草醚敏感性降低是其产生抗药性的原因之一,反枝苋POD和CAT对活性氧的抵御能力差异也可能与反枝苋对氟磺胺草醚的抗性有关。     

Competitive effects of redroot pigweed (Amaranthus retroflexus) on the growth indices and yield of corn

The mutual effects of redroot pigweed ( Amaranthus retroflexus ) on corn ( Zea mays ) were evaluated in an experiment conducted in 2005 at the Iranian Plant Protection Research Institute at Qazvin, considering the different densities of redroot pigweed against four different corn densities. Redroot pigweed, at 0, 35, 50, 65, and 80 plants m⁻¹ row⁻¹, was arranged factorially with corn at four, five, six, and seven plants m⁻¹ row⁻¹ in a randomized complete block design. Crop–weed competition resulted in a reduction in the total dry matter, Leaf Area Index, and crop growth rate of corn. Furthermore, an increasing weed density ≤65 plants m⁻¹ row⁻¹ reduced the corn grain yield and biological yield. Overall, six corn plants m⁻¹ row⁻¹ was suggested as the optimum density of this crop in competition with redroot pigweed.