江苏省外来归化植物新记录

报道了江苏省外来归化植物新记录5种,隶属4科5属,分别是粉绿狐尾藻[Myriophyllum aquaticum(Vellozo)Verdc.]、阔叶丰花草(Spermacoce alata Aubl.)、绣球小冠花(Coronilla varia L.)、野牛草[Buchloe dactyloides(Nutt.)Engelm.]和水草(Phalaris aquatica L.)。     

新疆玉米田间杂草组成及群落结构分析

为明确新疆玉米种植区田间杂草的组成以及群落结构特征,对新疆3个玉米主产区田间杂草群落组成进行系统调查及对杂草群落结构进行分析。结果表明,新疆灌溉玉米产区共有杂草38种,隶属17科34属,其中,以禾本科稗[Echinochloa crusgalli(L.) Beauv.]、狗尾草[Setaria viridis(L.) Beauv.],藜科灰绿藜(Chenopodium glaucum L.),锦葵科野西瓜苗(Hibiscus trionum L.)和苘麻(Abutilon theophrasti Medicus)以及苋科凹头苋(Amaranthus lividus L.)为该地区优势杂草。不同地区的重要杂草种类和群落结构组成存在差异,喀什春播玉米田杂草的种类最丰富,乌鲁木齐地区杂草次之,伊犁地区杂草的危害时期最为集中。生态位宽度的分析结果进一步验证了各地区重要杂草的优势性。乌鲁木齐地区马齿苋、稗,伊犁地区狗尾草、苘麻和田旋花,喀什春播玉米田的田旋花和龙葵以及喀什复播玉米田中苘麻和灰绿藜等主要杂草与地区重要杂草的生态位重叠值较高,在防治重要杂草时应谨防上述地区的主要杂草上升为重要杂草。     

厦门市发现九里香白粉病

九里香[Murraya paniculata(L.) Jacks.]属芸香科,又名七里香,是华南地区极重要的绿化小灌木,其造型优美,气味芬香,极少受病虫害为害。国内仅台湾报道有煤烟病[Meliola tenella Pat.;Triposporiospsis spingera(Hohn.) Yamam.],疫病(Phytophthora murrayae Saw.)和灰斑病(Hendersonia sp.)。     

利用植物竞争防除恶性杂草银胶菊

4个昆士兰当地禾本科牧草品种昆士兰蓝草(Dichanthium sericeum R. Br.)、黑茅草[Heteropogon contortus (L.) Roem. & Schult.]、卷曲米切尔草[Astrebla lappacea (Lindl.) Domin]和高风车草[Chloris ventricosa (R. Br.)],1个当地豆科牧草品种笔花豆(Stylosanthes scabra Vogel)及1个引进改良禾本科牧草品种蒺藜草(Cenchrus ciliaris L.)用于温室试验,以确定这6种牧草与恶性杂草银胶菊(Parthenium hysterophorus L.)的竞争能力,为银胶菊的生物防除开发新途径.试验结果表明,笔花豆、蒺藜草、昆士兰蓝草、高风车草都比银胶菊有较强的竞争能力,其竞争系数分别为3.6、3.4、1.7和1.2.卷曲米切尔草的竞争能力低于银胶菊,黑茅草的竞争能力最差.     

重庆市低中海拔稻作区不同种植制度下稻田杂草种类与优势种群分析

以水稻-冬闲-水稻和水稻-油菜-水稻2种种植制度下的稻田杂草为研究对象,采用五点取样法,监测了重庆市低中海拔稻作区的杂草种类,并分析了其优势种群。结果表明,水稻-冬闲-水稻种植制度下,监测区域内稻田杂草种类主要有8科10属11种;优势杂草为稗草[Echinochloa crusgalli(L.) Beauv.]和鸭舌草[Monochoria vaginalis(Burm. f.) Preslex Kunth.];水稻-油菜-水稻种植制度下,监测区域内稻田杂草种类主要有8科12属12种;优势杂草为空心莲子草[Alternanthera philoxeroides(Mart.)Griseb.]和看麦娘(Alopecurus aequalis Sobol.)。     

不同耕作模式下麦田杂草发生规律

为明确不同耕作模式下小麦田杂草发生规律及其危害,通过田间实地调查,初步探讨了耕翻秸秆还田、耕翻无秸秆还田、浅旋秸秆还田、浅旋无秸秆还田、免耕秸秆还田等5种耕作方式下小麦田杂草群落组成。结果表明,当前小麦田杂草发生种类有27种,分属于14科24属,其中,双子叶植物13科24种,单子叶植物1科3种。频度最高杂草主要有看麦娘(Alopecurus aequalis Sobol.)、硬草[Sclerochloa dura (L.) Beauv.]、早熟禾(Poa annua L.)、繁缕[Stellaria media (L.) Villars]、猪殃殃[Galium aparine L. var. tenerum (Gren. et Godr.)Rchb.]、荠菜[Capsella bursa-pastoris (L.) Medic]等,但不同耕作方式下杂草优势群落有所不同,5种耕作方式分别以硬草+看麦娘+繁缕+猪殃殃、猪殃殃+繁缕+硬草+荠菜、硬草+荠菜+繁缕+猪殃殃+看麦娘、猪殃殃+繁缕+硬草+荠菜+早熟禾、硬草+猪殃殃+看麦娘+荠菜+繁缕为优势杂草群落,其中硬草+猪殃殃+繁缕为群落基本结构。不同播种方式对杂草的发生没有影响,而水旱轮作、秸秆还田对杂草具有一定的控制作用。     

广东省裁培药用植物上弯孢类型炭疽菌的鉴定

 作者按照Sutton的分类系统,把标准培养特性、致病力和寄主范围等作为分种的主要特征,对广东省15种栽培药用植物上的弯孢型炭疽菌进行研究,共鉴定出3个种,即辣椒刺盘孢(Colletoptrichum capsici)、百合刺盘孢(C.liliacearum)和束状刺盘孢(C.dematium]报道了辣椒刺盘孢的7种新寄主,即:良姜(Alpinia officinarum Hance)何首乌(Polygo-hum multiflorum Thunb.)五叶参[Pentapanax leschenaultii (Wight&Arn.) Seem].龙利叶(Sauropus spatulifolius Beille)、穿心莲[Andrographis paniculata (Burmf).Nee.]佛手(Citrus medica L.)、山柰(Kaempferia galanga L.)辣椒刺盘孢在广东分布普遍,致使淮山、何首乌和佛手等遭受重大损失。     

甘肃省临夏州小麦脚腐病病原鉴定

对甘肃省临夏州小麦脚腐病病原进行了分离鉴定,从3块病田的37株罹病小麦上分离得到56个真菌菌株,分别被鉴定为雪腐镰刀菌[Fusarium nivale(Fr.)Ces.]、燕麦镰刀菌[Fusarium avenaceum(Corda et Fr.)Sacc.]、麦斑点附球霉[Epicoccum triticiP.Henn.]、小壳色单隔孢菌[Diplodiellasp.]、交链孢菌[Alternariaspp.]、芽枝霉[Cladosporiumsp.]、黑孢霉[Nigrosporasp.]。其中,雪腐镰刀菌致病性最强,燕麦镰刀菌致病性中强,麦斑点附球霉致病性弱,其余菌不致病。     

甘肃渭源蒙古黄芪根腐病病原菌的分离与鉴定

黄芪是豆科黄芪属蒙古黄芪[Astragalus membranaceus(Fisch.)Bge.var.mongholicus(Bge.)Hsiao]或膜荚黄芪[A.membranceus(Fisch.)Bge.]的干燥根,主要成分有皂苷类、黄酮类、多糖及其它成分。具有补气固表、利尿托毒、排脓、敛疮生肌之功效。黄芪为多年生药用植物,野生资     

丙嗪嘧磺隆与氰氟草酯桶混1次用药防控水稻机插秧田草害效果及安全性

通过田间小区试验与大田示范验证9. 5%丙嗪嘧磺隆SC与20%氰氟草酯OD桶混一次施药防控机插秧水稻(Oryza sativa L.)全生育期杂草的效果和安全性。结果表明:机插秧水稻移栽后12 d,9. 5%丙嗪嘧磺隆SC 60 mL/667 m2与20%氰氟草酯OD 75 mL/667 m2桶混一次用药对稗属杂草(Echinochloa spp.)、千金子[Leptochloa chinensis (L.) Nees]、鸭舌草[Monochoria vaginalis (Burm. f.) Presl.]、多花水苋(Ammannia multiflora Roxb.)、鳢肠[Eclipta prostrata (L) L.]的株防效和鲜质量防效均达93%以上,与常规两封一杀(插秧前3 d施用50%苯噻·苄WP 1 050 g/hm2,插秧后10 d施用35%丙草·苄WP 1 500 g/hm2结合插秧后25 d施用6%五氟·氰氟OD 1 800 mL/hm23次用药)的防效相当,且对水稻安全。与常规两封一杀化除方案相比较,9. 5%丙嗪嘧磺隆SC与20%氰氟草酯OD桶混1次用药控草技术减少了2次用药,有效控制了机插秧水稻全生育期草害,降低了稻田除草剂用量,节省了用工成本,有较好的推广应用价值。     

辽宁省大豆田杂草发生与危害

采用倒置"W"九点取样法调查辽宁省大豆田杂草,明确了辽宁省大豆田杂草有19科35种,其中阔叶杂草占74.29%,禾本科杂草占14.29%,其他杂草占25.71%;一年生杂草占54.29%,多年生杂草占31.43%。相对多度达10%以上的杂草依次为藜、鸭跖草、稗草、苘麻、反枝苋、红蓼、马唐、铁苋菜、马齿苋和山苦菜。其中藜和鸭跖草相对多度在30%以上,为辽宁省大豆田杂草优势种群。     

渭北旱塬保护性耕作春玉米田杂草发生及防除

通过田间调查和药效试验,对渭北旱塬一年一熟区春玉米田保护性耕作条件下杂草发生规律及化学除草效果进行了初步研究.结果表明:倒秆免耕秸秆全程覆盖春玉米田杂草种类与传统翻耕田差别不明显,优势种均为田旋花、反枝苋和灰绿藜,主要差别在于保护性耕作农田杂草生物量大.96%金都尔乳油900 mL/hm2和70%乙草胺乳油900 mL/hm2土壤封闭处理对保护性耕作春玉米田杂草均具有一定的防效,且对玉米出苗无影响,而96%金都尔乳油播后封闭处理明显优于70%乙草胺乳油,其50d的鲜重防效仍高达87.4%;20%克无踪水剂1 500 mL/ hm2和40%莠去津悬浮剂2 250mL/hm2定向喷雾处理也可有效控制春玉米田杂草,但20%克无踪水剂明显优于40%莠去津悬浮剂,其23 d的株防效仍高达88.4%;4种药剂的3种防治方法均具有保产作用,其中20%克无踪水剂处理后保产效果最好.可见,在黄土高原保护性耕作玉米田杂草防治中,可优先考虑以96%金都尔乳油进行播后土壤封闭处理,其次可选用20%克无踪水剂于苗期进行定向喷雾处理.     

乌桕不同器官除草活性研究

在10 g/L的浓度下,乌桕不同器官粉末对生菜和小麦幼苗的生长均有较高的抑制活性,且以叶器官活性最高,果实最低。而叶在0.1～10.0 g/L的不同浓度下对夏至草、反枝苋、生菜、荠菜、小麦和黄瓜幼苗的生长具有不同程度的抑制作用,且抑制活性随浓度的增加而提高,其中以夏至草的敏感性最高,而黄瓜最低。     

Evolved glyphosate-resistant weeds around the world: lessons to be learnt

Glyphosate is the world's most important herbicide, with many uses that deliver effective and sustained control of a wide spectrum of unwanted (weedy) plant species. Until recently there were relatively few reports of weedy plant species evolving resistance to glyphosate. Since 1996, the advent and subsequent high adoption of transgenic glyphosate-resistant crops in the Americas has meant unprecedented and often exclusive use of glyphosate for weed control over very large areas. Consequently, in regions of the USA where transgenic glyphosate-resistant crops dominate, there are now evolved glyphosate-resistant populations of the economically damaging weed species Ambrosia artemissifolia L., Ambrosia trifida L., Amaranthus palmeri S Watson, Amaranthus rudis JD Sauer, Amaranthus tuberculatus (Moq) JD Sauer and various Conyza and Lolium spp. Likewise, in areas of transgenic glyphosate-resistant crops in Argentina and Brazil, there are now evolved glyphosate-resistant populations of Sorghum halepense (L.) Pers and Euphorbia heterophylla L. respectively. As transgenic glyphosate-resistant crops will remain very popular with producers, it is anticipated that glyphosate-resistant biotypes of other prominent weed species will evolve over the next few years. Therefore, evolved glyphosate-resistant weeds are a major risk for the continued success of glyphosate and transgenic glyphosate-resistant crops. However, glyphosate-resistant weeds are not yet a problem in many parts of the world, and lessons can be learnt and actions taken to achieve glyphosate sustainability. A major lesson is that maintenance of diversity in weed management systems is crucial for glyphosate to be sustainable. Glyphosate is essential for present and future world food production, and action to secure its sustainability for future generations is a global imperative.     

西农No.24菌株发酵产物对反枝苋的除草活性初步研究

西农No.24菌株是从陕西秦岭山区采集的200份土壤中分离得到的一株放线菌,经初步鉴定为链霉菌属(Streptomyces)。采用微量小杯法,通过发酵、洗脱和高效液相色谱(HPLC)分离,测定西农No.24菌株发酵液对反枝苋Amaranthus retroflexus L.的除草活性。结果表明,该菌株的发酵产物对反枝苋有较强的抑制生长作用。其发酵液对反枝苋种子萌发抑制率为26.7%,主根生长抑制率为80.6%,主茎生长抑制率为66.5%;离子交换液对反枝苋的种子萌发抑制率为42.9%,主根生长抑制率为93.1%,主茎生长抑制率为86.2%。经HPLC分离后得到8个馏份,其中馏份4的除草活性最强,对反枝苋的种子萌发抑制率为86.36%,主根生长抑制率为95.84%,主茎生长抑制率为93.76%。     

12-(取代苯氧异丁酰氧亚氨基)-1,15-十五内酯的合成及除草活性

通过取代苯氧异丁酸与12-(羟基亚氨基)十五内酯的反应,合成了取代苯氧异丁酰氧亚氨基十五内酯,并测定了其对苋菜的除草活性。所有化合物均经过1H NMR、13C NMR和元素分析确证。初步的生物活性测定结果表明,目标化合物 Ⅲa~Ⅲd 的EC50值分别为34.570、46.492、55.385、50.114 mg/L,其活性比对照药剂2,4-D(117.325 mg/L)高,而比苯磺隆(22.381 mg/L)低。     

N-硝基二苯基脲衍生物的除草活性研究

测定了6个N-硝基二苯基脲衍生物( Ⅰ )在500 mg/L浓度下对稗草Echinochloa crusgalli和绿苋Amaranthus viridis的除草活性,从中筛选出两个化合物 Ⅰ b 、 Ⅰ e 做系列浓度试验。结果表明,它们对稗草、绿苋均表现出一定的抑制活性,且随着浓度增加,抑制活性增强。     

寄主植物对甜菜夜蛾酯酶活性及杀虫剂敏感性的影响

寄主植物对甜菜夜蛾的生长发育、羧酸酯酶活性及杀虫剂的敏感性有显著影响。取食甜菜、苋菜、甘蓝、青菜的甜菜夜蛾幼虫历期渐次增加 ,蛹重依次降低 ,而酯酶活性依次增大。 4种不同寄主喂养的甜菜夜蛾对功夫菊酯的敏感性与酯酶活性呈明显负相关性。     

Pyrimidinyl-substituted amides and thioureas: syntheses, crystal structure and herbicidal activities

BACKGROUND: The high herbicidal activities of [1,2,4]triazolo[1,5-c]pyrimidine and 2H-1,2,4-thiadiazolo[2,3-a]pyrimidine derivatives suggested the development of new fused heterocyclic compounds for application as herbicides. RESULTS: Three series of pyrimidinyl-substituted thioureas (4) and amides (5, 6) were synthesized, and the typical crystal structure of a 2H-1,2,4-thiadiazolo[2,3-a]pyrimidine derivative (5a) was determined by X-ray diffraction. All the compounds were tested for herbicidal activity against selected weeds. CONCLUSION: The series of fused heterocyclic amides 5a to 5d exhibited high herbicidal activities both against monocotyledonous weeds (Echinochloa crus-galli L., Sorghum bicolor (L.) M?nch., Digitaria sanguinalis (L.) Scop) and against dicotyledonous weeds (Amaranthus retroflexus L. and Brassica campestris L.) in pre-emergence treatments. In particular, compound 5b at low concentration still showed high inhibitory activity against A. retroflexus in pre-emergence treatment. Different substituents at the meta positions of the pyrimidine ring were found to affect the herbicidal activity.