曲阜市麦田杂草调查及其对小麦的他感作用研究

报道了曲阜市麦田杂草的种类和发生规律．结果表明，曲阜市麦田杂草有16科45种，以越冬发生型和早春发生型杂草为主．主要优势种杂草有麦瓶草Silene conoidea、播娘蒿Descurainia sophia、荠菜Capsella bursa-pastoris、宝盖草Lamium amplexicaule、野燕麦Atena fatua、看麦娘Alpecurus aequalis、猪殃殃Galium aparine var．tenerum、牛繁缕Mdachium aquaticum、波斯婆婆纳Veronica persica、麦家公Lithospermum arvense、田旋花Calystegia arvensis等．同时研究了7种优势杂草对小麦的他感作用，结果表明，播娘蒿的水提液能明显抑制小麦种子的萌发和幼苗生长，宝盖草、麦瓶草和荠菜的水提液也具有较强的抑制作用。     

乌鲁木齐市外来杂草的调查与分析

实地调查表明,乌鲁木齐市目前共有21种外来杂草,隶属9科17属.在此基础上,对这些外来杂草的引入途径、生活史特征、植物区系地理成分和传播特点等进行了初步研究.     

金华市郊外来杂草的区系地理及植物学性状分析

金华市郊外来杂草计有24科54属73种,优势科现象明显,其中菊科(Compositae)17属21种最多,其次是禾本科(Gramineae)5属7种、豆科(Legum inosae)5属7种、苋科(Amaranthaceae)2属7种、大戟科(Euphorbiaceae)2属4种、旋花科(Convolvulaceae)2属4种.其中,裂叶月见草(Oenothera laciniata Hill.)是浙江中部的新记录外来杂草,毒莴苣(Lactuca serriola L.)是我国东部地区的新外来检疫杂草.该区域外来杂草属的地理成分包括泛热带分布(39.47%)、热带亚洲-热带美洲间断分布(18.42%)、北温带分布(21.05%)、旧世界温带分布(13.16%)、热带亚洲与热带非洲间断分布(5.26%)、东亚和北美间断分布(2.63%).与金华北山种子植物区系比较,金华地区外来杂草热带分布属居多,尤其应加强热带亚洲-热带美洲间断分布类型种类的管理.金华市郊外来杂草的原产地主要为南美和中美洲(33%)、北美(26%)和欧洲(22%).分析表明,在干扰生境下有利于外来杂草种群定居传播的性状有:生活周期短、植株耐践踏、有毒、种子或果实小而量大、传播方式多样、具有特殊的附属结构等,这些特征可作为外来种杂草化风险评估时的参考.     

Gene flow from transgenic oilseed rape (Brassica napus L.) to cruciferous weeds under mentor pollen inducement

The alien gene flow between genetically modified glyphosate-resistant rapeseed variety Q3 (Brassica napus L.) and four cruciferous weeds was studied under mentor pollen inducement. The results showed that when Thlaspi arvense L., Capsella bursa-pastoris (L.) Medic, Cardamine hirsute L. and Rorippa palustris (L.) Besser were pollinated with mentor pollen, the mixed Q3 and the weed, pollen grains aggregated largely and germinated quickly, and the numbers of pollen tubes penetrating into the style and the ovary were greatly increased as compared with corresponding self-pollination groups. Twenty four to forty eight hours after pollination, several pollen tubes were observed to penetrate into the ovule via micropyle in each mentor combination. However, when the mentor progenies were analyzed by PCR, all of them showed negative for the Q3 herbicide-resistant gene. Collectively, these results indicated that crossing between T. arvense, C. bursa-pastoris, C. hirsuta, R. palustris (as female) and Q3 (as male) was highly incompatible and the herbicide-resistant gene could not flow from Q3 to these four weeds.     

青海春油菜田杂草化学防除技术

对青海春油菜田防除野燕麦（Avena fatuaL.)先后使用的氟乐灵，高效盖草能，禾草克等，防除阔叶杂草使用的菜王星，高特克等除划剂的使用技术和防除效果进行了阐述，并对我省农科院初步研究的油草净土壤和茎叶处理系列复配剂技术进行了介绍。     

沈阳地区常见草坪杂草调查

经过 2年时间对沈阳地区的草坪杂草进行的调查统计鉴定 ,确定了沈阳地区草坪杂草种类及发生规律 .结果表明 ,常见杂草有 2 4个科 ,4 8种 ,其中蒙古蒲公英 (Taraxacummon golicum)、苦菜 (Ixerisdenticulata)、蓄 (Polygonumaviculare)、刺儿菜 (Cephalonoplossegetum)、车前 (Plantagoasiatlca)、荠菜 (Capsellabursa pastoris)、小蓬草 (Erigoroncanadensis)、附地菜(Trigontispeduncularis)、风花菜 (Rorippaislandica)最为常见 .春季 (4～ 5月份 )是草坪杂草高发季节 ,一年生、二年生、多年生杂草都有 ,杂草种类多 ,数量大 ,危害严重 .立秋以后以二年生或多年生杂草为主 .并对草坪杂草的综合防除进行了讨论 .     

秦皇岛市农田杂草的种类与生育期

实地考察了秦皇岛市下辖的三区四县 (北戴河区、山海关区、海港区、昌黎县、抚宁县、卢龙县、青龙县 )农田杂草的种类、分布、危害及主要杂草的生育期。秦皇岛市有农田杂草 5 3科 15 8属 2 4 4种 ,其中恶性杂草 6科 11属 12种 ;寄生性杂草 1科 1属 4种 ;普通性杂草 4 6科 14 1属 2 2 8种。列出了秦皇岛市农田杂草名录。     

OSMAC Strategy Integrated with Molecular Networking for Accessing Griseofulvin Derivatives from Endophytic Fungi of Moquiniastrum polymorphum (Asteraceae)

Three endophytic fungi isolated from Moquiniastrum polymorphum (Less.) G. Sancho (Asteraceae) were cultivated using the one strain many compounds (OSMAC) strategy to evaluate the production of griseofulvin derivatives. Extracts obtained were analyzed by HPLC–MS/MS and the chromatographic and spectrometric data used to elaborate a feature-based molecular network (FBMN) through the GNPS platform. This approach allowed the observation of differences such as medium-specific and strain-specific production of griseofulvin derivatives and variations of cytotoxic activity in most extracts. To evaluate the efficiency of the OSMAC approach allied with FBMN analysis in the prospection of compounds of biotechnological interest, griseofulvin and 7-dechlorogriseofulvin were isolated, and the relative concentrations were estimated in all culture media using HPLC–UV, allowing for the inference of the best strain–medium combinations to maximize its production. Malt extract-peptone broth and Wickerham broth media produced the highest concentrations of both secondary metabolites.     

Separation and determination of coumarins from Cacalia tangutica by capillary zone electrophoresis

Capillary zone electrophoresis (CZE), using a 20 mmol/L borate buffer at pH 10.5, was developed for the identification and determination of three coumarins--7-hydroxy-coumarin (HC), 7-hydroxy-8-methoxy-coumarin (HMC) and 7-O-beta-D-glucosyl-coumarin (GC)--in the extracts of the flower of Cacalia tangutica. Regression equations revealed linear relationships (correlation coefficient 0.9986-0.9990) between the corrected peak area (the ratio of peak area to migration time) of each constituent and its concentration. The relative standard deviations (RSD) of the migration time and peak area were 1.45-1.52 and 2.60-3.84% (intra-day), and 1.75-2.22 and 2.90-4.04% (inter-day), respectively. The recoveries of three constituents ranged between 94.5 and 105.6%. The effects of pH value, buffer concentration and applied voltage on the migration behavior of HC, HMC and GC were investigated. The contents of the three active constituents in the flower of Cacalia tangutica were successfully determined within 6 min under the optimum conditions chosen. Moreover, the dissociation constants for three coumarins were also determined by CE.     

Abstracts

Abstract

Uptake of weed-borne nitrogen by maize was tested with ¹⁵N in field experiments on silty loam (haplic phaeozem) after common growth of maize and Chenopodium album L. and incorporating the weeds at the 4- to 6-leaf stage of maize. Maize took up 22–23% of the weed-borne N in the year of incorporating and residual 7–32% in the following year. Uptake of weed-borne N was higher in comparable pot experiments. Different soil humidity after different water supply was mainly reasonable for these differences. Weed-borne nitrogen contributed 7–16% to total N of maize in the year of incorporating and 4–11% in the following year. Yield and N uptake between weeded and unweeded maize differed partly significant.