外来入侵杂草——五爪金龙

五爪金龙抗逆性强,生长繁茂,是一种较难防除、严重危害其他植物生长、影响景观自然性和完整性的外来杂草.因此,了解其生物生态学特性,进行必要的监控与防除及科学利用非常重要.文章归纳了外来杂草五爪金龙的形态特征、生活史、分布、生境类型及其对经济、生态的影响,介绍了利用、预防、控制和管理措施等.     

外来入侵杂草长芒苋

长芒苋(Amaranthus palmeri S.Watson)是20世纪80年代中期传人我国的一种新植物,为中国苋属异株亚属一新归化物种.近年来长芒苋在北京市不断扩展蔓延.本文对长芒苋的形态特征、生物学特性、分布、危害及其防除作一简要介绍.     

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。     

马唐和反枝苋在棉田中的竞争试验初报

利用二次通用旋转组合设计进行马唐、反枝苋竞争试验,得出两种杂草竞争的数学模型,分析了杂草的种内竞争相种间竞争的天系,并对杂草竞争试验的研究方法进行了探讨。     

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。     

外来杂草假臭草的特征特性

假臭草为菊科泽兰属一年生草本植物,原产南美,现散布于东半球热带地区.假臭草于20世纪80年代传人我国,在香港、福建厦门、广东南部、澳门、海南和台湾均有分布.假臭草繁殖速度快,对土壤肥力吸收能力强,能释放化感物质抑制其他植物生长,对入侵地农林业生产与生物多样性带来极大的危害.本文在调查研究及查阅大量文献的基础上,归纳了外来杂草假臭草的形态特征、生活史、起源、入侵途径、生境类型、营养和环境条件、在我国的分布、可能扩散的区域、经济和生态影响、预防控制和管理措施等.     

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.     

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。     

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。     

稔平半岛外来杂草入侵现状及防控措施

通过野外调查与查阅文献资料,首次对惠州稔平半岛的外来杂草种类、分布和危害现状做了调查研究,并分析了外来杂草的来源和入侵途径,针对稔平半岛外来杂草入侵现状提出防除和管理建议。     

外来入侵性杂草——大爪草

大爪草（Spergula arvensisL．）为石竹科一年生旱地杂草，广泛分布于日本、印度、俄罗斯及其他一些欧洲国家，北美、非洲等地区也有分布。我国黑龙江、西藏局部地区的荒漠、河谷也有发生。主要危害麦类、油菜、玉米、蚕豆、蔬菜等多种作物。     

外来入侵杂草刺萼龙葵

2003年北京首次发现外来入侵杂草刺萼龙葵(Solanum rostratumDunal.)。2005年在北京顺义区试验地进行了刺萼龙葵生育期观察,并在北京延庆县野外自然群落中随机取样带回室内测定。本文对其形态特征、生物学特性、分布及危害进行了叙述。     

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.     

反枝苋对咪唑乙烟酸抗性水平及分子机制

为初步明确大豆田反枝苋对咪唑乙烟酸的抗药性水平,并从分子角度对抗药性机制进行解释,以我国四川成都和黑龙江嫩江采集的反枝苋种子为材料,通过琼脂法检测了反枝苋对咪唑乙烟酸的抗药性水平,并分别对R(嫩江抗性种群)和S(成都敏感种群)的乙酰乳酸合成酶(ALS)部分序列进行扩增和测序。皿内生测结果表明,成都种群的GI50为11.20,嫩江种群的GI50为52.26,其抗药性指数RI为4.67。分子检测结果表明,与S种群相比,R种群反枝苋ALS位于高度保守区Domain B编码574位氨基酸的基因发生突变,TGG突变为TTG,导致色氨酸被亮氨酸取代。ALS保守区域氨基酸的替换可能是嫩江反枝苋种群对咪唑乙烟酸产生抗性的重要原因之一。     

外来入侵杂草意大利苍耳

意大利苍耳(Xanthium italicum Moretti.)为菊科苍耳属一年生草本植物,原产美洲。本文对意大利苍耳的形态特征、生物学特性、分布及危害进行了叙述。     

Interference of Chenopodium suecicum J. Murr, and Amaranthus retroflexus L. in maize

Competitive interactions among Chenopodium suecicum, Amaranthus retroflexus and maize were investigated in a series of variously arranged plot and pot experiments. In the initial phase of growth, C. suecicum occupied the available space more rapidly than A. retroflexus. In later stages of growth, the competitive influence of A. retroflexus on C. suecicum became greater than that of C. suecicum on A. retroflexus. The competitive ratio between C. suecicum and A. retroflexus was dependent on the total density of the stand. At low densities, A. retroflexus was more competitive than C. suecicum, while at high densities the opposite was true. According to the indices of competition, maize yields were affected more by C. suecicum than by A. retroflexus. Reciprocal yield models demonstrated that one A. retroflexus and one C. suecicum plant were competitively equivalent to 0.26 and 1.05 maize plants, respectively, as measured by the effects on maize biomass, while one maize plant was approximately equivalent to 5.5 weed plants, as measured by the effects on weed biomass. In the replacement series of the weeds, the presence of maize reduced the competitive ability of A. retroflexus against C. suecicum. Yield losses of maize increased as the proportion of C. suecicum plants in the mixture increased. C. suecicum plants which were seeded before the crop and those which were not removed until later than 32 days after crop emergence significantly lowered the maize yield. Interaction de Chenopodium suecicum J. Murr, et de Amaranthus retroflexus L. chez le maïs Les interactions compétitives entre Chenopodium suecicum, Amaranthus retroflexus et le maïs ont étéétudiées dans plusieurs expériences au champ et en pots. Lors de la phase initiale de croissance, C. suecicum occupait l'espace disponible plus rapidement que A retroflexus. Dans les phases ultérieures de croissance, l'effet compétitif de A. retroflexus sur C. suecicum devenait supérieur à celui de C. suecicum sur A. retroflexus. Le rapport de compétition entre C. suecicum et A. retroflexus dépendait de la densité globale de l'implantation. A faibles densités, A retroflexus était plus compétitif que C. suecicum, alors qu'à hautes densités l'inverse était vrai. Selon les indices de compétition, les rendements de mais étaient plus affectés par C. suecicum que par A. retroflexus. Des modèles de rendement réciproque ont montré que, du point de vue de l'aptitude è la compétition mesurée par les effets sur la biomasse du maïs, une plante de A. retroflexus et une plante de C. suecicumétaient respectivement équivalentes à 0.26 et 1.05 plantes de maïs. Une plante de maïs était approximativement équivalente à 5.5 mauvaises herbes, son aptitude à la compétition étant mesurée par son effet sur la biomasse des mauvaises herbes. Dans des séries de remplacement des mauvaises herbes, la présence du maïs réduisait l'aptitude à la compétition de A. retroflexusà l'égard de C. suecicum. Les pertes de rendement du maïs augmentaient en même temps que la proportion de C. suecicum dans la culture mélangée. Les plantes de C. suecicum qui étaient semées avant la culture et celles qui n'étaient pas enlevées dans les 32 jours qui suivaient la Ievée de la culture réduisaient de manière significative le rendement du maïs. Konkurrenz von Chenopodium suecicum Murr. und Amaranthus retroflexus L. mit Mais In verschiedenen Freiland- und Topfversuchen über Konkurrenzbeziehungen zwischen Chenopodium suecicum, Amaranthus retroflexus und Mais nahm Chenopodium suecicum in der frühen Wachstumsphase den verfügbaren Raum schneller ein als A. retroflexus. Später wurde die Konkurrenzkraft von Amaranthus retroflexus gegenüber C. suecicum größer als die von C. suecicum gegenüber Amaranthus retroflexus. Das Konkurenzverhältnis der beiden Arten hing von der Bestandesdichte ab. Bei geringer Dichte war A. retroflexus konkurrenzstärker, bei hoher C. suecicum. Entsprechend den Konkurrenzindices wurde der Maisertrag von C. suecicum stärker als von Amaranthus retroflexus beeinträchtigt. Auf der Grundlage der Mais- bzw. Unkraut-Biomassebildung wurde ein reziprokes Ertragsmodell entwickelt, nach dem das Konkurrenzäquivalent von 1 Pflanze Amaranthus retroflexus oder von 1 Pflanze Chenopodium suecicum 0–26 oder 1–05 Maispflanzen bzw. von 1 Maispflanze 5.5 Unkrautpflanzen entsprach. In Unkraut-Substitutionsversuchen setzte der Mais die Konkurrenzkraft von Amaranthus retroflexus gegenüber Chenopodium suecicum herab. Die Maisertragsverluste nahmen mit steigendem Chenopodium-Anteil zu. Vor dem Mais gesäte und erst 32 Tage nach dem Auflaufen des Maises gejätete Chenopodiumsuecicum-Pflanzen minderten den Maisertrag.     

外来入侵性杂草--胜红蓟

胜红蓟属于菊科藿香蓟属，在我国主要分布于华南和西南地区，入侵农田后造成农作物减产，属于区域性恶性杂草。胜红蓟也是一种具有强烈化感作用的植物，可对生态、环境和人体健康带来危害，是一种有毒生物污染物。本文对胜红蓟的生物学特征及分布、异株克生作用、主要危害、防除措施及利用价值等进行了介绍。     

Comportement germinatif des graines d'Amaranthus retroflexus L. recoltées dans les conditions naturelles

Germination behaviour of seeds of Amaranthus retroflexus L, harvested under natural conditions The influence of time of emergence of seed-bearing plants and of the climate at the time of dissemination on dormancy of seeds of Amaranthus retroflexus L. formed solely on the main inflorescence was studied. Under conditions favourable to germination (30 C) the seeds harvested latest (November) are at shedding the least dormant and those produced very early (August) the most dormant. But after dry storage for 60 days, the seeds had a germinative capacity near 100% whatever their origin. Under conditions less favourable to germination (20 C) the seeds harvested from the plants which had developed very late (June-July) germinated better than those developed on plants which appeared very early (March April). These differences were not overcome by dry storage. In the light of these facts, the authors discuss the elTects of interactions between climatic factors and the physiological state of the plants on the germinability of naturally-disseminated seeds.     

Alien invasive species in Siberia:current status and problem

Although alien and invasive plant species have been researched extensively in the European part of Russia,the situation in Siberia is another matter.Hitherto,alien and invasive species in Siberia have not received much attention because this problem was not especially acute in Siberia.The lack of attention on alien and invasive species in Siberia is attributed to three major reasons:1) Low vegetative productivity and sparse human populations in the Siberian territory have limited botanical research interest in the area.2) Severe Siberian climate likely prevents many alien and invasive species from increasing their distribution into Siberia.3) Most Siberian plant communities have not been human-transformed and thus may be resistant to newcomers.Nevertheless,recent increased economic activities have resulted in increasing plant migration to Siberia,and this process should be monitored.Furthermore,global environmental changes may also have made Siberia more favorable for more alien and invasive species.Currently,research on alien and invasive species has begun in the Altai-Sayan region(Western Siberia) and the Magadan region(Northeastern Asia).     

Physiological effects of buthidazole on Zea mays L., Amaratithus retroflexus L., Medicago sativa L. and Agropyron repens(L.) Beauv.*

Buthidazole (3-[5-(1,1-dimethylethyl)-1,3.4-thiadiazol-2-yl]-4-hydroxy-l-methyl-2-imidazolidinone) at concentrations of 10^?6-10^?4M did not affect germination of corn (Zea mays L.,‘Pioneer 3780’), redroot pigweed (Amaranlhus retroflexus L.), alfalfa (Medicago saliva L., ‘Vernal’), and quackgrass (Agropyron repens(L.) Beauv.) seeds. Stressing the seeds obtained from mature corn plants treated either pre-emergence or pre- plant incorporated with buthidazole at several rates by accelerated ageing and cold treatments further indicated that this herbicide did not affect germination. Total photosynthesis and dark respiration of corn plants 12 days after pre-emergence application and of redroot pigweed, alfalfa, and quackgrass plants after postemergence application of buthidazole at several rates were measured with an infrared CO₂ analyser. The results suggested that buthidazole was a rapid inhibitor of photosynthesis of the sensitive redroot pigweed and quackgrass plants, with less effect on corn and alfalfa. Buthidazole did not affect respiration of the examined species except for a transitory increase in corn and alfalfa 12 days after pre-emergence or 4 h after postemergence treatment with buthidazole at 0.56 or 1.12 and 2.24 kg/ha, respectively. A long-term inhibition of quackgrass respiration 96 h after treatment with buthidazole at 1.12 and 224 kg/ha was also evident.