长期连作对大豆根际土壤镰孢菌种群的影响

利用中国科学院海伦农业生态试验站大豆连作长期定位试验区,进行了大豆根际土壤镰孢菌分离鉴定及大豆根腐病致病力检测,结合核酸序列和限制性片段长度多态性(RFLP)的系统发育分析,研究了长期连作(20年)较短期连作(3年)对大豆根际土壤镰孢菌种群密度和结构、致病力及遗传多样性的影响.结果表明： 3年连作大豆根际土壤镰孢菌种群密度为6.0×10⁴ CFU·g^-1,且以强致病力的尖镰孢菌、禾谷镰孢菌、轮枝镰孢菌及中等致病力的腐皮镰孢菌为优势种;连作20年大豆根际土壤镰孢菌种群密度和优势菌的优势度均显著低于3年连作,其中尖镰孢菌、禾谷镰孢菌和腐皮镰孢菌的种群密度仅为3年连作的36%、32%和22%,没有分离到致病力最高的轮枝镰孢菌,而种群多样性和均匀度显著高于3年连作;仅分离自20年连作土壤的三线镰孢菌、砖红镰孢菌及燕麦镰孢菌均为非致病菌种,且与强致病力镰孢菌种在基于转录间隔区(ITS)和转录延长因子(EF-1α)序列的聚类分析中显示了系统进化亲缘关系的差异性.因此,大豆20年连作会导致根际土壤镰孢菌种群生长受抑制、使其种群结构和遗传多样性发生改变,同时降低大豆根腐病菌种群致病力.     

三江平原地区大豆根腐病病株上镰孢菌的分离鉴定

为了明确引起三江平原地区大豆根腐病的镰孢菌(Fusarium)种类及优势种群,对该地区大豆根腐病样本进行了采集。通过组织分离和形态学鉴定,共鉴定出6种镰孢菌,分别为木贼镰孢(F.equiseti)、尖孢镰孢(F.oxysporum)、芬芳镰孢(F.redolens)、半裸镰孢(F.semitectum)、腐皮镰孢(F.solani)和拟轮枝镰孢(F.verticillioides)。其中尖孢镰孢(F.oxysporum)的分离频率最高,达16.67%。对6种镰孢菌的形态学特征进行了描述。     

滁菊连作土壤中尖孢镰刀菌的分离、鉴定及变化特征

采用传统平板培养法及尖孢镰刀菌专性培养基对滁菊连作土壤的真菌和尖孢镰刀菌进行分析测定,结果表明,在滁菊连作条件下,土壤中真菌和尖孢镰刀菌的数量显著增加,平均分别达到8.71×105 cfu/g干土和3.12×104cfu/g干土,各自是对照土壤的2.24倍和5.57倍。土壤中尖孢镰刀菌数量显著增加可能是导致滁菊连作障碍的重要因素。     

孢悬液浓度和宿主体型大小对球孢白僵菌对松墨天牛幼虫的致病力的影响

【目的】球孢白僵菌Beauveria bassiana是一种被广泛用于害虫生物防治的生防菌。本研究探讨了孢悬液浓度和宿主体型大小对球孢白僵菌对松墨天牛Monochamus alternatus 幼虫的致病力的影响,旨在为松墨天牛的生物防治提供科学基础。【方法】分别用0.5% 吐温-80(CK)以及1×10⁵, 1×10⁶, 1×10⁷, 1×10⁸和1×10⁹孢子/mL的球孢白僵菌孢悬液接种松墨天牛4龄幼虫,统计接种后15 d内幼虫死亡率和染菌率。同时用最佳浓度(1×10⁹孢子/mL)的球孢白僵菌孢悬液接种体型大小分别为100~150, 200~220, 300~320, 400~420, 500~520和600~650 mg/头的松墨天牛幼虫,测定接种后20 d内幼虫的死亡率和染菌率。【结果】接种1×10⁵~1×10⁹孢子/mL的球孢白僵菌后,松墨天牛4龄幼虫起初活动自如,后在头部出现烧灼状伤并且体色逐渐变红,最后周身长满菌丝。不同浓度下,随球孢白僵菌孢子浓度升高,松墨天牛4龄幼虫校正死亡率和校正染菌率增加。接种1×10⁶~1×10⁹孢子/mL球孢白僵菌孢悬液15 d的松墨天牛4龄幼虫累计校正死亡率均可达到100%,1×10⁷, 1×10⁸和1×10⁹孢子/mL浓度下,松墨天牛达到100%校正死亡率所需时间最少。接种0 (CK), 1×10⁵, 1×10⁶, 1×10⁷, 1×10⁸和1×10⁹孢子/mL球孢白僵菌孢悬液的松墨天牛4龄幼虫校正染菌率在第15天分别为0, 20.00%, 86.67%, 90.00%, 96.67%和100.00%,表现为白僵菌孢子浓度越高,染菌率越高。1×10⁹孢子/mL的接种浓度下,松墨天牛幼虫个体越大,天牛幼虫死亡率和染菌率越高。表现在第20天时,体型大小为100~150, 200~220, 300~320, 400~420, 500~520和600~650 mg/头的幼虫的死亡率分别为76.67%, 76.67%, 66.67%, 93.33%, 100.00%和100.00%,染菌率分别为60.00%, 63.33%, 60.00%, 86.67%, 96.67%和100.00%。【结论】球孢白僵菌悬浮液浓度对松墨天牛幼虫的死亡和侵染有显著影响,表现为随孢子浓度的增加而增加;同时,松墨天牛幼虫个体越大,死亡率和染菌率越高。研究结果对开展利用球孢白僵菌防治松墨天牛具重要借鉴和指导意义。     

香蕉植株根区土壤的真菌多样性分析

尖孢镰孢菌古巴专化型(Fusarium oxysporum f.sp.cubense)是香蕉枯萎病的病原菌,该菌是一种土壤习居菌,了解香蕉根区土壤中真菌多样性及镰孢菌属(Fusarium)真菌所占比例,对如何减少土壤中的病原菌、预防香蕉枯萎病的发生有重要的指导意义。该文通过采集不同宿根年限的香蕉健康植株和枯萎病植株的根区土壤,利用高通量测序技术测定土壤样品中的真菌种群。结果表明:(1)同一宿根年限的香蕉植株中,健康植株根区土壤中所获的reads及OTUs数量均高于枯萎病植株,说明健康植株根区土壤的真菌多样性丰富于枯萎病植株。(2)除了一年生香蕉枯萎病植株以担子菌门(Basidiomycota)为主外,其他土壤样品中均以子囊菌门(Ascomycota)为主,其中的丛赤壳科最高相对丰度来自三年生健康植株的根区土壤(26.02%),其次是五年生的枯萎病植株根区土壤(15.56%)。(3)在丛赤壳科中,镰孢菌属在三年生健康植株土壤中的相对丰度最高(2.54%),在其他样品中的相对丰度在0.1%～0.65%之间;在镰孢菌属中,腐皮镰孢菌(Fusarium solani)的相对丰度(0～1.59%之间)高于尖孢镰孢菌(F.oxysporum),尖孢镰孢菌仅占很小的比例(相对丰度0～0.08%之间)。可见,在不同香蕉植株的根区土壤中,健康植株的根区土壤真菌多样性高于枯萎病植株,无论是健康植株还是枯萎病植株的根区土壤中,作为香蕉枯萎病病原菌的镰孢菌属或尖孢镰孢菌的群体均不占主导地位。     

一株花椒根腐病拮抗菌的筛选、发酵条件及其抑菌物质的初步分析

【背景】腐皮镰孢(Fusarium solani)是陇南花椒根腐病的主要病原物,是危害花椒生产的重要原因之一。【目的】筛选拮抗腐皮镰孢的生防菌株,为开发防治花椒根腐病的微生物农药提供新的生物资源。【方法】采用平板对峙法结合16S rRNA基因序列分析等方法从花椒根围中分离具有较强抑菌效果的细菌并进行筛选鉴定;通过Box-Benhnken中心组合设计试验探究该菌最佳发酵条件;采用液质联用(LC-MS)方法对该菌发酵液的有机溶剂提取相进行非靶向代谢组学分析及KEGG、Lipidmaps数据库注释。【结果】分离筛选出一株拮抗菌株贝莱斯芽胞杆菌(Bacillus velezensis) W-1,该菌株对腐皮镰孢的抑菌率为89%,对藤仓赤霉(Gibberella fujikuroi)、禾谷镰孢(Fusarium graminearum)、梅毒镰孢(Fusarium syphilis)、层生镰孢(Fusarium proliferatum)和松针刺盘孢(Colletotrichum fioriniae)的抑制率为57%-90%。优化后W-1的最佳发酵条件为pH值6.5、温度30℃、接种量5%、转速...     

甘肃大葱贮藏期镰孢菌腐烂病病原鉴定

【目的】大葱在贮藏期频繁发生镰孢菌腐烂病,损失严重。明确该病害病原种类对病害防治具有重要意义。【方法】利用组织分离法对采集自甘肃省兰州市(区)蔬菜市场的16份大葱贮藏期镰孢菌腐烂病病样进行病原物的分离、纯化培养,经单孢分离后根据形态学特征,再结合r DNA-ITS、EF-1a(tef)基因序列分析的方法进行鉴定。【结果】共分离得到80株镰孢菌,经鉴定分属3个种,即层出镰孢菌(Fusarium proliferatum)、尖孢镰孢菌(F.oxysporum)和燕麦镰孢菌(F.avenaceum),其中层出镰孢菌为大葱镰孢菌腐烂病的优势致病菌,分离频率为52.50%。对兰州白葱不同部位进行致病性测定,结果表明层出镰孢菌对大葱鳞茎的致病力最强,而燕麦镰孢菌对大葱鳞茎的致病力最弱。【结论】3种镰孢菌作为该病害的病原,属国内首次报道。     

寄主为蚧的层束梗孢一新记录种

在贵州茂兰国家自然保护区发现寄生蚧壳虫的层束梗孢属真菌gzuifr-hym201307jk。主要特征为孢梗束灰白色单生,14¹7 mm×0.9 mm,产孢细胞柱状向上收缩变尖,顶部具有117 mm×0.9 mm,产孢细胞柱状向上收缩变尖,顶部具有1³个叉状的产孢小颈,大小10.83个叉状的产孢小颈,大小10.8¹4.0×4.314.0×4.3⁵.4μm;分生孢子梭形,7.65.4μm;分生孢子梭形,7.6¹0.8×4.310.8×4.3⁵.4μm。经鉴定该真菌为中国新记录种——Hymenostilbe furcata。     

甜瓜根系分泌物中酚酸物质对尖孢镰孢菌的化感效应

采用HPLC法对甜瓜根系分泌物进行分离鉴定,检测到甜瓜根系分泌物中含有没食子酸、邻苯二甲酸、丁香酸、水杨酸、阿魏酸、苯甲酸和肉桂酸7种酚酸物质,通过外源添加法研究该类物质对尖孢镰孢菌的化感效应.室内试验结果表明: 阿魏酸、苯甲酸、肉桂酸在0.1、0.25 mmol·L^-1处理浓度下能够显著促进尖孢镰孢菌的孢子萌发,水杨酸则对孢子萌发具有一定的抑制作用;丁香酸、阿魏酸在菌丝培养后期表现出较强的促进作用.盆栽结果显示,在0.05、0.1和0.5 mmol·L^-1处理浓度下肉桂酸、阿魏酸、苯甲酸可显著促进甜瓜枯萎病病情.
     

我国东北地区玉米穗腐镰孢菌的种类及其分离频率

从辽宁、吉林、黑龙江三省采集的43份玉米病穗上共分离获得327株镰孢菌,根据形态特征鉴定属于7个种,其分离频率分别为半裸镰孢菌(Fusarium semitecturrt)37.77%,尖孢镰孢菌(F.oxysporum)3.51%,拟轮枝镰孢菌(F.verticillioides)3.57%,克鲁克威尔镰孢菌(F.c...     

Augmentation of Soil with Sporangia of Actinoplanes spp. for Biological Control of Pythium Damping-off

A method was developed for applying strains of Actinoplanes spp. that are hyper-parasites of oospores of Pythium ultimum to soil for reducing Pythium damping-off of plants. The method is based on the augmentation of soil with sporangia of a strain of Actinoplanes spp. borne on clay granules. In vitro sporulation of strains K30, W57, W257 and 25844 was: (1) greater for most strains on dilute Czapek-Dox agar than on four other agar media; (2) inhibited by continuous exposure to fluorescent light of intensity 4-150 μEm^-2s^-1, but not by exposure to 1 μEm^-2s^-1 or darkness; (3) greater at 20-307deg;C than at 10°C;and (4) greater at pH 6-7 than at pH 5 or 8. On solid carriers treated with dilute Czapek-Dox broth (pH 7) and incubated in the dark at 30°C for 3 weeks, strains sporulated poorly or not at all on vermiculite, perlite and rice hulls, but sporulated abundantly (10⁷-10⁹ colony-forming units (CFU) g^-1 of granules) on montmorillonite clay granules. When strains 25844, W57 and W257 were applied as granules (4 10⁷ - 4 × 10⁸ CFU g^-1) at 5% (w/w) to field plots infested with 750-1000 oospores of P. ultimum g^-1 of soil, only strain 25844 consistently increased emergence and reduced root rot of table beets 8- 1 at 24-28 days after planting compared with controls. Strain 25844 (10⁸ CFU g^-1 of granules) at 1% (w/w) also increased the emergence of bush beans at 28 days after planting in P. ultimum-infested plots, but lower rates were ineffective. The inoculum viability of strain 25844 on clay granules declined 100-fold during 2 months of storage at 5-35°C, but thereafter remained stable for another 4 months. Strain 25844 on 6-month-old granules retained a high degree of hyper-parasitic activity toward oospores of P. ultimum. Augmentation of field soil with sporangia of Actinoplanes spp. is a valid approach to the biological control of pythium damping-off.     

茄病镰刀菌单克隆抗体的制备及胶体金免疫层析试纸条的研发*

Objective: The cell lines secreting specific monoclonal antibodies (McAbs) were prepared by using Fusarium solani, one of the pathogenic fungi causing root rot of Fritillaria thunbergii, and the colloidal gold immunochromatographic test strip based on McAbs was developed to provide scientific basis for detecting root rot of F. thunbergii. Methods: Hybridoma technology was used to obtain cell lines that could secrete specific McAbs against F. solani using the whole protein extract of F. solani as the antigen. The specificity, titer, sensitivity and binding protein of McAbs were detected by indirect ELISA and Western blot. Colloidal gold particles were prepared by trisodium citrate reduction method and McAbs were labeled to prepare colloidal gold immunochromatographic strip. Results: Three cell lines secreting specific McAbs against F. solani were obtained, which were named as FsA3, FsG6 and FsD4. The detection sensitivity of FsA3 was 24.41 ng / mL, and that of both FsG6 and FsD4 was 12.21 ng / mL. FsA3, FsG6 and FsD4 had strong reactions to F. solani, and had no cross-reaction to Alternaria tenuissima, A. alternata, Botrytis cinerea, F. equiseti, F. incarnatum, F. oxysporum, Phoma sp., and Phomopsis oblonga. The colloidal gold immunochromatographic strip based on FsG6 showed only a quality control line when detecting the tissue culture seedlings of F. thunbergii. When 100 ng F. solani antigen or the samples of F. thunbergii infested with root rot disease were detected, there were visible quality control lines and test lines. Conclusion: The specificity and sensitivity of the McAbs and test strip are sufficient to detect F. solani isolated from diseased strains of F. thunbergii, which provides the technical support for the rapid detection of root rot of F. thunbergii in the field.     

Combined application of Pseudomonas fluorescens strain LRB3W1 with a low dosage of benomyl for control of cabbage yellows caused by Fusarium oxysporum f. sp. conglutinans

An antagonistic bacterium, Pseudomonas fluorescens strain LRB3W1, inhibited the fungal growth of Fusarium oxysporum f. sp. conglutinans in vitro and suppressed cabbage yellows caused by F. oxysporum f. sp. conglutinans. Under glasshouse conditions, the bacterium survived at ca. 10⁶-10⁷ CFU g^-1 in the cabbage rhizosphere for 4 weeks after the initial application. The chemical fungicide, benomyl, did not suppress the disease severity at low concentration (1 or 10 µg mL^-1). However, the disease severity was decreased by the combined application of a low dosage of benomyl with strain LRB3W1. Combined application of a low dosage of benomyl with strain LRB3W1 was more effective than treatment with the bacterium alone. The survival of strain LRB3W1 was not influenced by the presence of benomyl. This combined use of the biocontrol agent, strain LRB3W1, and a fungicide, benomyl, should be an attractive approach for suppressing cabbage yellows in sustainable agriculture because of the reduced chemical dosages needed for disease management.     

Production of a Mixed Inoculum of Fusarium oxysporum Fo47 and Pseudomonas fluorescens C7 to Control Fusarium Diseases

Strains of non-pathogenic Fusarium oxysporum and Pseudomonas fluorescens are effective biocontrol agents against Fusarium diseases. Use of strain Fo47 of F. oxysporum in combination with strain C7 of P. fluorescens improves disease control in comparison to application of Fo47 alone. To develop a product based on a combination of these two strains, it would be beneficial to produce and formulate both organisms together. When an irradiated peat was inoculated with these strains either alone or in combination, they grew actively and reached similar maximum population densities irrespective of the initial inoculum concentration (1×10³ and 1×10⁶ g^-1 of peat) and mode of inoculation. These populations survived well with only a slight decrease in population densities after 11 months storage at 25°C. A bioassay was performed to evaluate peat and microbial suspension inocula of C7 and Fo47 alone or in combination against the flax pathogen, F. oxysporum f. sp. lini. Biocontrol activity of the peat-produced inocula was as effective as the suspensions. There was no dose-response relationship for C7, and when C7 was used as a mixed inoculum with Fo47, the biocontrol activity was always greater than that provided by Fo47 alone. This process could be used to produce an effective mixed inoculum with a shelf life of one year or more.     

Potential of Serratia marcescens strain B2 for biological control of rice sheath blight

Serratia marcescens strain B2 inhibited mycelial growth of the rice sheath blight pathogen Rhizoctonia solani AG-1 IA. Rice plants were treated with bacterial suspension and then challenge inoculated with the pathogen. Application of S. marcescens effectively reduced the incidence of sheath blight. S. marcescens survived in soil under glasshouse conditions at ca. 10⁸ colony forming units g^-1 of soil for 4 weeks after application. These results suggest that S. marcescens has potential as an effective and persistent biological control agent for rice sheath blight.     

内生枯草芽孢杆菌JL4在葡萄叶上的定殖及其对葡萄霜霉病的防治

为了明确枯草芽孢杆菌JL4在葡萄叶表面和内部的定殖情况,研究定殖与防治效果的关系,采用电击转化的方法将含有GFP基因的质粒pGFP78导入枯草芽孢杆菌JL4中,并得到成功表达GFP 的生防菌JL4-gfp,测试了标记菌株的稳定性及其对葡萄霜霉病菌的抑制作用.采用叶片喷雾法接种,用抗生素平板稀释分离回收,检测生防菌JL4-gfp在葡萄叶片的定殖情况,并将采回的叶片在室内接种葡萄霜霉菌孢子囊悬浮液进行生防测定.结果表明: 标记菌株在经过10次传代培养后,仍具有良好的发光表型,能稳定表达GFP蛋白,并且标记菌株JL4-gfp对葡萄霜霉菌保持了原有的抑菌作用;用抗生素平板稀释分离回收,检测到JL4-gfp菌株在葡萄叶片表面的定殖量在接种后的0、3和7 d分别为3.6×10⁵、2.7×10⁵和3.1×10³ CFU·g^-1;叶片内部的定殖在接种3 d后达到最大(9.6×10⁴ CFU·g^-1),然后下降,14 d后已经检测不到接种菌株;室内生防测定结果显示,喷雾后3 d对葡萄霜霉病的防治效果达88.0%以上,但7 d后则无明显防效.JL4-gfp的定殖量与其防治葡萄霜霉病的效果呈正相关,其有效定殖量临界值为10⁵ CFU·g^-1.     

Determination of (-)-threo-chlorocitric acid in human plasma by gas chromatography—positive chemical-ionization mass spectrometry

A method is described for measuring (-)-threo-chlorocitric acid in human plasma. Plasma is acidified to pH 1 to minimize lactonization and a¹³C analogue of (-)-threo-chlorocitric acid is added as internal standard. The acidified plasma is then extracted with ethyl acetate containing 10% methanol. The ethyl acetate—methanol extract is back-extracted with acetate buffer (pH 5). This extract, following adjustment to pH 1, is reextracted with ethyl acetate. The residue after removal of the ethyl acetate is treated with ethereal diazomethane. The wet residue is reconstituted in ethyl acetate and a portion of this solution is analyzed by gas chromatography—chemical ionization mass spectrometry. The mass spectrometer is set to monitorm/z269 [MH⁺ of trimethylated (-)-threo-chlorocitric acid] andm/z270 [MH⁺ of trimethylated (-)-threo-[¹³C]chlorocitric acid] in the gas chromatographic effluent. Them/z/269 tom/z270 ion ratio in a sample containing an unknown amount of (-)-threo-chlorocitric acid is converted to an amount of compound using a calibration curve. The calibration curve is generated by analyzing control plasma spiked with various known amounts of (-)-threo-chlorocitric acid and a fixed amount of (-)-threo-[¹³C]chlorocitric acid. The limit of quantitation is 0.1–0.6 μg ml⁻¹, depending on the characteristics of the calibration curve generated with each set of samples. The precision (relative standard deviation) at a concentration of 2 μg ml⁻¹ is 3.3%.     

塔里木河干流胡杨径向生长对地表径流变化的响应

以塔里木河干流荒漠河岸胡杨(Populuseuphratica)为研究对象,在塔里木河干流河道上游和中游选择帕满水库和坎白尔吾斯坦2个断面,分析胡杨径向生长的特点。根据不同断面的河道径流数据,采用小波分析和相关性分析方法研究塔里木河胡杨径向生长随径流动态变化的响应。结果表明,帕满水库-新其满断面,胡杨基部断面生长增量(BAI)与径流在15–24年时间尺度上都发生震荡,且径流震荡年份要早于基部断面生长增量震荡年份。坎白尔吾斯坦-英巴扎断面,胡杨BAI与径流在10–20年时间尺度上都发生震荡,BAI震荡周期出现时间较晚。在塔里木河干流沿岸,径流是胡杨径向生长的主要限制因素之一。上游帕满水库断面,胡杨BAI与前一年11月至当年3月的径流量呈显著相关;中游坎白尔吾斯坦断面,胡杨BAI与前一年12月至当年3月的径流量呈显著相关。塔里木河不同河段胡杨BAI对径流变化响应的敏感度存在差异。研究表明,塔里木河上游采样区胡杨生长良好,所对应的最佳径流达1.3340×10~8 m~3;塔里木河中游采样区胡杨径向生长的最合理径流量的范围为0.380 3×10~8–1.205 6×10~8 m~3。     

大气CO2浓度缓增对稻田硝酸盐型甲烷厌氧氧化过程的影响

硝酸盐型甲烷厌氧氧化(AOM)是控制稻田甲烷排放的一种新途径,大气CO₂浓度升高会对稻田甲烷排放产生重要影响,但有关其对硝酸盐型AOM过程的影响知之甚少。本研究依托开顶式气室组成的CO₂浓度自动调控平台,采用¹³CH₄稳定性同位素示踪技术,从甲烷氧化活性、相关功能微生物Candidatus Methanoperedens nitroreducens (M. nitroreducens)-like古菌丰度与群落组成等方面,系统研究了稻田土壤中硝酸盐型AOM过程对大气CO₂浓度缓增的响应。试验设置背景CO₂浓度和CO₂浓度缓增处理(背景CO₂浓度基础上每年增加40 μL·L^-1,直至增幅达160 μL·L^-1)。结果表明: 稻田土壤硝酸盐型AOM速率为0.7～11.3 nmol CO₂·g^-1·d^-1;定量PCR结果显示,M. nitroreducens-like古菌mcrA基因丰度为2.2×10⁶～8.5×10⁶ copies·g^-1。与对照相比,CO₂浓度缓增处理使土壤中硝酸盐型AOM速率和M. nitroreducens-like古菌mcrA基因丰度均有一定幅度提高,特别是在5～10 cm深度下两者均显著提高。CO₂浓度缓增处理未显著改变M. nitroreducens-like古菌群落结构,但使其多样性显著降低。相关性分析表明,土壤有机碳含量可能是影响硝酸盐型AOM过程的重要因子。综上,大气CO₂浓度缓增在一定程度上促进了硝酸盐型AOM反应,暗示在未来气候变化背景下其在控制稻田甲烷排放中具有积极作用。     

北京土石山区水分在土壤-植物-大气连续体(SPAC)中的稳定同位素特征

氢氧稳定同位素是广泛存在于自然界水体中的环境同位素,其在不同水体中组成特征的差异可以指示水分循环过程及植物用水机制.本研究在北京山区选取了两种主要的绿化树种——常绿针叶林侧柏和落叶阔叶林栓皮栎为研究对象,通过对降水、土壤水、泉水、植物茎干水和叶片水同位素的变化特征进行分析,讨论了水分在大气-土壤-植物连续体中的运动过程.结果表明: 研究区大气降水线方程为δD=7.17δ¹⁸O+1.45(R²=0.93), 土壤蒸发线方程为δD=3.85δ¹⁸O-38.02(R²=0.76), 降水入渗补给土壤水的过程中存在一定程度的蒸发分馏.在不同季节,降水、土壤水和泉水δD和δ¹⁸O值变化规律不同;雨季,δD和δ¹⁸O平均值大小为降水>地下水>土壤水,降水和土壤水共同补充地下水;旱季,δD和δ¹⁸O值大小排序为降水> 土壤水>地下水,降水和地下水都对土壤水有贡献.侧柏和栓皮栎年内茎干水分δD和δ¹⁸O的拟合线性方程分别为δD=5.03δ¹⁸O-30.78 和δD=3.0δ¹⁸O-48.92,栓皮栎利用的土壤水分相对于侧柏更加富集,其水分来源深度更浅.栓皮栎叶片水分同位素变化特征相对于侧柏对大气微环境的反应更加敏感,且其叶片水分蒸发和同位素动力分馏程度更强,但是它们对环境条件的变化反应一致.