采用BSLB(Brine Shrimp Letality Bioassay)法对元宝枫 (Acer truncatum Bunge .)及同属植物活性部位的筛选(英文)

本文通过BSLB法对元宝枫及同属植物不同部位的水提物进行了活性试验 ,得知 :元宝枫的幼技、种皮的水提物具一定的生物致死活性 ;同属植物青榨槭叶和种子 ,秦岭槭、杈叶槭果翅的水提物也具一定的生物致死活性。

Cloning of Atr MYB Transcription Factor Gene from Acer truncatum

[Objective] Cloning of the AtrMYB transcription factor gene from Acer truncatum was conducted to further explore the red leaf development mechanism and breed cultivars of colored-leaf maple. [Method] The Acer truncatum ‘Luhong No.1＇ cultivar was used as the material for cloning the MYB gene by mean of RTPCR and RACE-PCR. [Results] Sequence analysis showed that the fragment contained a full coding region of 831 bp encoding 276 amino acid residues with a molecular weight of 32.17 kD and a molecular formula C_（1430）H_（14052）N_（2247）O_（406）S_（14）. The gene was named as AtrMYB with a Gen Bank accession number of 1825712. This coded protein had apI of 9.44. The results showed that the AtrMYB exhibited typical features of the R2R3-MYB domain. The AtrMYB was highly homologous with the MYB of other species at nucleotide and amino acid levels. The AtrMYB had no signal peptide, but a nuclear localization signal. The phylogenetic tree showed that the AtrMYB was at the same clade as the MYB from Citrus sinensis. [Conclusion] The AtrMYB was cloned from Acer truncatum ‘Luhong No.1＇ cultivar. These results have provided a foundation for further purification and identification of target protein and function study of the AtrMYB.

Cloning and Sequence Analysis of CHS Gene Fragment from Acer truncatum

[Objective] This study aimed to clone and analyze the sequence of CHS gene from Acer truncatum leaves. [Method] Using A. truncatum cultivars No.1-6 as experimental materials, total RNA was extracted from A. truncatum leaves with the modified CTAB method. CHS gene sequences were downloaded from the NCBI and aligned by BLAST. Degenerate primers were designed by DNAMAN and Primer- premier5 to amplify the target band. CHS gene fragment was amplified by RT-PCR and ligated to pMD18-T vector. The identified positive colonies were sequenced. [Result] A 1 365 bp fragment was amplified. Sequence analysis suggested that the obtained fragment encoded 365 amino acids and shared above 90% homology to nucleotide sequence of CHS gene from A. palmatum and A. [Conclusion] In this study, CHS gene was successfully cloned from A. truncatum for the first time, which laid the foundation for efficient utilization of CHS gene.

Volatiles from <i>Acer truncatum</i>Flowers

Plant volatile organic compounds (Biogenic Volatile Organic compounds, referred BVOCs) have a significant impact on the atmospheric environment, air quality and human health. This experiment takes Acer truncatum flowers as the research object, uses solid-phase micro-extraction combine GC-MS (SPME-GC-MS) to detect the main component of volatiles released by the flowers from 10 individual trees of Acer truncatum (Acer truncatum Bunge). The results showed that 37 kinds of volatiles were detected and they are belonged to four types organic compouds, such as terpenoids, alcohols, ketones, esters. According to the analysis of the main components of Acer truncatum flower volatiles includes Fluorene, 4,8 -Dimethyl-1,3 (E), 7-Nonene, (cis, trans)-2,6-Dimethyl-2,4,6-triene-Partenkirchen, Myrcene, Basil hexene, 3-Carene, (E)-Basil, Camphene, Caryophyllene, Linalool, α-Terpinolene, O-cymene, 3-Vinyl-1,2-dimethyl-1, Eucalyptus alcohols and Alcohol vinegar-12. However, there were no significant differences between individual trees in terms of obscure material O-cymene, Eucalyptus alcohols, Alcohol vinegar-12, as well as the significant differences in terms of remaining volatiles.

DNA Fingerprinting of Acer truncatum Clones Using SRAP Markers

[ Objective] This study aimed to establish DNA fingerprints of 23 Acer truncatum clones, thus providing the theoretical basis for selection, classification and identification of A. truncatum varieties. [Method] Sixteen pairs of SRAP primers with rich polymorphism and high specificity were used to establish DNA fin-gerprints. [Result] A total of 223 bands were amplified with 16 primer pairs, including 197 polymorphic bands. Averagely 13.9 loci and 12.3 polymorphic loci were amplified with each primer pair. The average percentage of polymorphic loci reached 88. 34% . [ Conclusion] The classification result drawn by cluster analy-sis is consistent with that obtained based on main characteristics and genetic relationships of A. truncatum, clones. By using DNA fingerprints established with prim-er pairs ME1-EM4 and ME2-EM1, 23 A. truncatum clones can be effectively distinguished, and the confidence probability is greater than 99.99%.

Enrichment of nervonic acid in Acer truncatum Bunge oil by combination of two-stage molecular distillation,one-stage urea complexation and five-stage solvent crystallization

Nervonic acid is the world’s first and only potent substance that can repair damaged nerve fibers and promote nerve cell regeneration with high nutritional value.The wide variety of fatty acids in plant oils and fats with similar structures makes the large-scale separation and purification of high-purity nervonic acid very difficult.A new combined process of molecular distillation,urea inclusion and solvent crystallization was established to prepare high-purity nervonic acid with the mixed fatty acids obtained after saponification and acidification of Acer truncatum Bunge oil as raw materials.First,according to the difference in the mean free path of fatty acids,molecular distillation was used to separate and remove C16 saturated fatty acid of palmitic acid and four C18-C20 fatty acids of stearic,oleic,linoleic,and linolenic acids.The content of C16-C20 fatty acids decreased from 72.92% to 19.22% after two-stage molecular distillation processes,in which the contents of saturated fatty acid of palmitic acid decreased to about 0.5%.Then,according to the difference in carbon chain length and saturation of fatty acid,the contents of C22-C24 saturated fatty acids of tetracosanoic and docosanoic acids decreased to 0.21% and 0.07% by urea inclusion with urea/free fatty acid preparation by saponification(SPOMFs)ratio as 0.6.In addition,all saturated fatty acids were basically separated.Finally,according to the difference in the solubility of fatty acids in solvents,the C18-C20 unsaturated fatty acids of oleic,linoleic,and linolenic acids and C22 unsaturated fatty acid of erucic acid were removed by solvent crystallization.The content of C18-C20 unsaturated fatty acids decreased to less than 5% with pentanol as the solvent after the first stage solvent crystallization.The content of erucic acid decreased to 3.47% with anhydrous ethanol as the solvent after the second to fifth stage solvent crystallization.The combined process of molecular distillation,urea inclusion and low temperature crystallization innovatively adopted an efficient,simple and easy-toindustrial solvent crystallization method to separate erucic and nervonic acids,obtaining nervonic acid with purity of 96.53% and final yield of 47.99%.

A Comparative Study on Extraction Methods of Total RNA from Leaves of Acer truncatum ‘Luhong No.1’

Leaves of Acer truncatum ＇ Luhong No. 1 ＇ contain large amounts of polysaccharides and polyphenols, which seriously affect extraction yield and quality of total RNA. In order to explore the appropriate total RNA extraction method, total RNA was extracted from leaves of A. truncatum ＇ Luhong No. 1 ＇ with three methods, including kit method, Trizol method and modified CTAB method. The results showed that ODE6o/OD2so and OD^o/OD2ao ratios of total RNA extracted from leaves of A. truncatum ＇ Luhong No. 1 ＇ with kit method were higher than 1.8, with a general yield and certain level of DNA contamination ; OD^o/OD~ and OD^o/OD^o ratios of total RNA extracted with Trizol method were about 1.5, with the lowest yield; OD260/OD280 and OD260/OD230 ratios of total RNA extracted with modified CTAB method were about 2.0, with the highest yield and distinct eleetrophoresis patterns. The results demonstrated that total RNA extracted with modified CTAB method exhibited high yield and purity, which could meet the demands of subsequent molecular biology research. Thus, modified CTAB method is the appro- oriate method for extracting total RNA from leaves of A. truncatum ＇ Luhong No. 1 ＇

亚临界萃取和膜技术精制元宝枫籽油的工艺优化

为了提高元宝枫籽油(ASO)的质量特性和储藏稳定性,对亚临界萃取得到的元宝枫籽油进行精制,以去除磷脂、过氧化物和游离脂肪酸。本文对亚临界萃取ASO的提取工艺进行优化,并对得到的原油利用膜分离技术进行脱胶精制,以膜通量,脱胶率、碘值、过氧化值、酸价为指标,对不同孔径的陶瓷膜和不同截留分子量的聚醚砜膜进行筛选。考察膜截留分子量、温度和压力对膜通量的影响;通过响应面法,确定ASO精制的最佳工艺参数。同时采用气相色谱-质谱法比较精制前后脂肪酸的含量。结果表明,当粒径为30目、萃取温度50℃,固液比为1:4 g/mL,聚醚砜膜分子量为100 kD,温度44℃,压力1.9 MPa,ASO得油率均值为35.92%,脱胶率为86.73%,通量为12.51 L/m2·h,碘值为116.93 g/100 g,过氧化值为0.06 g/100 g,酸价为3.66 g/100 g,与原油相比脂肪酸含量无明显损失。研究结果显示,用膜分离法脱胶是一种提高油脂品质的有效手段,本研究可为优质元宝枫籽油的生产提供技术支持。

元宝枫组织培养与快速繁殖技术

【目的】元宝枫是我国特有的木本油料植物,非常适合开发利用,但其组培离体繁殖生根非常困难,建立合理的完整组培离体再生体系,在短时期内获得大量种苗和当年生带芽茎段,为该树种优良种苗规模化生产提供新途径,为选育元宝枫良种、种质资源保存与推广等提供研究基础。【方法】以元宝枫当年生带芽茎段和种子为试材,通过正交设计筛选法和单因素筛选法对其灭菌方式及腋芽诱导、继代增殖、生根培养基进行设计筛选。在MS、1/2MS和NN69基础培养基中分别添加不同质量浓度的6-BA、NAA和TDZ激素,通过不同配比找出元宝枫各阶段的最适培养基。【结果】全年中4月份为带芽茎段最佳采集时间,经洗衣粉溶液轻刷表面并冲洗半小时后,以75%酒精30 s+0.1%HgCl_(2) 10 min浸泡处理的灭菌效果最佳。再生体系各阶段最适培养基均为MS基础培养基,在其基础上再添加不同质量浓度的激素可以诱导嫩芽分化成不同器官。启动培养阶段,6-BA对腋芽诱导影响最大,最适培养基诱导率可达73.33%;继代增殖阶段,TDZ对不定芽分化影响最大,增殖系数最高可达4.31;生根阶段,采用单因素筛选法,发现添加0.2 mg·L^(-1) IBA元宝枫生根率和生根条数均为最高,达93.33%和4.3。【结论】元宝枫最适培养基为:1)启动培养:MS+0.06 mg·L^(-1) 6-BA和0.06 mg·L^(-1) NAA,诱导率为73.33%;2)增殖培养:MS+0.30 mg·L^(-1) TDZ和0.05 mg·L^(-1) NAA;3)生根培养:MS+0.2 mg·L^(-1) IBA。

6个元宝枫种仁含油率及脂肪酸组分分析

为了对山东油用元宝枫种质资源进行筛选和评价,本研究以泰安市6个元宝枫无性系种子为试验材料,使用脉冲核磁共振仪和气相色谱仪对元宝枫种子含油率及脂肪酸组分进行定量测定。结果表明:元宝枫种仁含油率存在一定差异,平均含油率为51.7%,含油率最高为6号(53.48%),最低为4号(49.84%);饱和脂肪酸含量排序为:棕榈酸(4.35%)>硬脂酸(2.30%)>山嵛酸(0.75%);不饱和脂肪酸含量排序为:亚油酸(34.07%)>油酸(24.87%)>芥酸(16.18%)>花生一烯酸(8.08%)>神经酸(6.04%)>α-亚麻酸(1.71%)>γ-亚麻酸(0.71%)。其中,γ-亚麻酸含量0.36%(3号)~1.33%(5号),变异系数大(51.08%);种子含油率为49.84%(4号)~53.48%(6号),变异系数最低(2.84%);总体上,饱和脂肪酸和不饱和脂肪酸的变异程度均不大,变异系数分别为4.28%和0.38%。相关性分析表明,含油率与脂肪酸含量之间并无显著相关性。亚油酸与油酸、γ-亚麻酸与棕榈酸均呈显著负相关;α-亚麻酸与硬脂酸在极显著正相关);芥酸和山嵛酸呈现显著正相关,其他脂肪酸含量之间无显著相关性。

科尔沁沙地不同种源元宝枫功能性状变异及其环境驱动因子研究

【目的】研究不同种源地木本油料植物功能性状变异及其环境驱动因子,对其核心育种群体构建和良种选育具有重要的意义。【方法】以分布于科尔沁沙地周围的乌旦塔拉、松树山、代钦塔拉3个中国现存最大的元宝枫天然林为研究对象,测定其叶片和种子功能性状、土壤理化性质,同时结合气候数据,采用方差分析、相关性分析、RDA排序分析以及构建PLS-SEM模型等方法,研究科尔沁地区不同种源地元宝枫功能性状的变异程度以及性状与环境之间的相关性,探究元宝枫功能性状与环境因子之间的关系。【结果】(1)3地元宝枫各个功能性状的差异性明显,各性状的变异系数表现为比叶面积(SLA)>油酸含量(OA)>种子长宽比(ZC∶ZK)>碳氮比(C∶N)>神经酸含量(NA)>种子油脂含量(OC)>亚油酸含量(LOA)>叶片碳含量(LCC),种源间变异系数范围为3.81%~19.51%,种源内变异系数范围为3.60%~14.64%,种源间变异大于种源内变异;(2)3个种源地中,代钦塔拉地区油脂、亚油酸含量最高,乌旦塔拉地区的神经酸含量最高;(3)相关性结果显示,元宝枫功能性状与环境因子间存在显著的相关关系;(4)RDA分析结果显示,环境因子可以解释24.1%的元宝枫功能性状变异,土壤有机质(SOM)和气温季节性变异系数(BIO-4)为主导生态因子,气象和土壤共同决定元宝枫功能性状的变异,且气象因子起主导作用;(5)PLS-SEM模型显示,元宝枫叶片及种子性状与油脂指标之间的路径系数较小,协同作用不显著,年均温是元宝枫油脂相关指标的主要影响因子,且与其油脂相关性表现出负相关,即较低的温度有利于元宝枫种子油脂的积累。【结论】气象是驱动元宝枫功能性状变异的主导环境因子,且气温是决定元宝枫种子油脂含量的关键因子,该研究结果可为油用元宝枫定向培育提供理论基础。

丛枝菌根真菌对元宝枫生长及其根系形态的影响

【目的】阐明丛枝菌根(arbuscular mycorrhizal,AM)真菌对元宝枫生长状况及根系形态特性的影响,探讨元宝枫根系形态与其生长发育的关系。【方法】在元宝枫幼苗生长基质中接种摩西斗管囊霉(Funneliformis mosseae)和根内根孢囊霉(Rhizophagus intraradices)2种AM真菌,以不接种AM真菌为对照,通过盆栽试验,培养90 d后,测定元宝枫的生长状况、根系活力及根系形态指标,利用单因素方差分析和多重比较方法,分析接菌与不接菌处理之间的差异,采用envfit()函数、冗余度分析和变差分解分析元宝枫生长状况与其他指标间的关系。【结果】①接种2种AM真菌后,元宝枫株高、地径、茎干质量和根系活力较对照显著提高,根冠比下降。根内根孢囊霉对元宝枫的促生作用比摩西斗管囊霉显著。②与对照相比,接种2种AM真菌后,元宝枫根表面积和根体积显著增大,粗根根长占总根长的比例增加,细根根长占总根长的比例显著降低。根内根孢囊霉对元宝枫根系形态的影响比摩西斗管囊霉显著。③元宝枫生长状况与其根系活力和根系形态密切相关。【结论】接种AM真菌有助于增强元宝枫的根系活力,改善其根系形态,促使其汲取更多养分,进而提高其生物量。

元宝枫油对衰老果蝇生理指标及肠道菌群的影响

探究元宝枫油对衰老果蝇生理指标及肠道菌群的影响。在基础培养基中分别添加10、20 g/kg和40 g/kg的元宝枫油对野生黑腹果蝇进行干预,观察果蝇寿命、爬行能力、嗅觉记忆能力和热耐受能力等行为学变化情况;检测超氧化物歧化酶(superoxide dismutase,SOD)活力和谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)活力;收集果蝇中肠,进行16S rRNA基因扩增子测序,检测肠道微生物组的变化。结果表明,与对照组相比,不同含量的元宝枫油干预均能显著延长果蝇的寿命(P<0.000 1),其中,20 g/kg元宝枫籽油抗衰老效果最佳,平均延长寿命31%。另外,20 g/kg元宝枫油干预可明显改善衰老果蝇的爬行能力、嗅觉记忆能力和热耐受能力,提高SOD和GSH-Px活力。衰老改变了果蝇肠道微生物的组成和结构,线性判别分析结果显示衰老果蝇中Enterobacteriaceae、Gluconobacter和Morganella morganii 3类细菌相对丰度增加,而元宝枫油抑制了衰老过程中以上3类细菌相对丰度的增加。综上,元宝枫油具有抗衰老作用,可改善果蝇的生理功能衰退,延长寿命,其机制可能与改变衰老果蝇肠道微生物的丰富度、均匀度和菌群结构,从而调节肠道菌群和提高抗氧化能力有关。

元宝枫种仁多糖提取纯化、结构表征以及降糖活性研究

对元宝枫(Acer truncatum Bunge)种仁多糖进行提取纯化,探究其理化性质和降糖活性。采用水提醇沉法提取元宝枫种仁多糖,并通过响应面法优化元宝枫种仁多糖提取工艺。通过Sevage法脱蛋白和柱层析对元宝枫种仁多糖进行纯化,通过红外光谱、热重分析及离子色谱法对其进行单糖组成和结构表征,并进一步通过建立肝癌细胞胰岛素抵抗模型(IR-HepG2),考察纯化后元宝枫种仁多糖体外降糖活性。结果表明,在提取1次、液固比为30:1 mL/g、提取温度为80℃、提取时间为3.5 h条件下,多糖(PATM)得率为18.17%。经Sevage法脱蛋白,DEAE-DE纤维素52层析柱和SephadexG-100凝胶层析柱分离纯化,得到纯化多糖(PATM-3-1)。PATM-3-1具有多糖组分红外光谱特征峰,其单糖组成为D-半乳糖醛酸、L-阿拉伯糖、D-半乳糖、L-鼠李糖、D-葡萄糖、D-木糖、D-甘露糖、D-葡萄糖醛酸、L-岩藻糖、D-核糖和D-氨基葡萄糖。体外降糖活性实验的结果表明,PATM-3-1具有较强的α-淀粉酶抑制活性,能显著(P<0.05)提高胰岛素诱导的HepG2细胞中葡萄糖消耗量、糖原含量、己糖激酶、丙酮酸激酶含量,展现出优异的降糖活性。本研究为元宝枫种仁多糖的开发和应用提供参考和数据支撑。

元宝枫凋落叶浸提液对3种中草药化感作用的研究

本研究以甘草、黄芩和桔梗为化感受体,探究不同浓度的元宝枫凋落叶浸提液对3种中草药种子萌发和幼苗生长的影响,以期为北京元宝枫林下中草药的种植提供理论依据。结果表明:元宝枫凋落叶浸提液对甘草和黄芩的种子萌发表现出“低促高抑”效应,而对桔梗表现为抑制作用。元宝枫凋落叶浸提液对3种中草药种子萌发和幼苗生长的化感效应为桔梗>黄芩>甘草。3种中草药幼苗叶片的叶绿素含量在不同浓度处理下均低于对照。元宝枫凋落叶浸提液处理使黄芩幼苗叶片的超氧化物歧化酶(SOD)活性升高,黄芩、甘草幼苗叶片的过氧化氢酶(CAT)活性随浸提液浓度的升高先升后降,3种中草药幼苗叶片的丙二醛含量随浸提液浓度的升高呈先增加后减少的趋势。综上,元宝枫林下应避免种植桔梗,适宜种植甘草和黄芩。

不同种类生物炭对元宝枫育苗基质养分及酶活性的影响

为探究添加不同种类、不同用量生物炭对元宝枫育苗基质养分及酶活性的影响,筛选出其育苗基质最优施炭量,为元宝枫育苗基质科学施用生物炭提供理论参考。以元宝枫幼苗为试验对象,采用盆栽法并设置不同生物炭种类(竹炭、橡胶木炭、稻壳炭)与不同施用量(3%、5%、7%)的基质施炭试验,1年后测定基质养分及酶活性,采用相关性分析与通径分析探讨基质养分与酶活性之间的关系、聚类分析探讨最优施炭量。结果显示:(1)添加生物炭能在一定程度上提升基质的养分含量及酶活性,pH值范围为6.89~7.21,全氮、全磷、全钾含量分别提高了6.25%~76.38%、4.08%~414.29%、41.86%~111.81%,水解性氮、有效磷、速效钾含量分别提高了8.56%~56.66%、33.67%~576.53%、26.11%~58.16%,且基质养分及酶活性之间存在显著相关关系。(2)施用稻壳炭对基质的pH、有机碳、全氮、水解性氮和脲酶、过氧化氢酶、蔗糖酶活性提升效果优于竹炭和橡胶木炭。(3)水解性氮和pH为酶活性影响较大的养分因子;速效钾和全氮是对脲酶影响较大的养分因子;全氮和pH是对过氧化氢酶影响较大的养分因子;全钾和水解性氮是对蔗糖酶影响较大的养分因子。(4)DK7%处理(添加7%稻壳炭)对基质养分含量和酶活性的提升效果显著,属于高等肥力水平。总体来看,添加生物炭短期内对元宝枫育苗基质养分及酶活性具有促进效果,建议在元宝枫育苗基质添加生物炭时优先选择7%稻壳炭。

寄生元宝枫种子和食叶害虫的希姬小蜂属Hyssopus一新种(膜翅目:姬小蜂科)

本文报道在内蒙古和北京发现的一个寄生蜂新种——元宝枫希姬小蜂Hyssopus truncatumi Yang,Liu et Cao(膜翅目:姬小蜂科Eulophidae)。该姬小蜂寄生杨凌冠麦蛾Bagdadia yanglingensis幼虫(为害元宝枫种子)和元宝枫花细蛾Caloptilia dentata幼虫(取食元宝枫叶片),对杨凌冠麦蛾幼虫的寄生率达34.4%。目前,杨凌冠麦蛾对元宝枫种子危害严重,种子受害率达40%,同时,元宝枫花细蛾也是元宝枫的重要食叶害虫,因此,利用元宝枫希姬小蜂开展这两种害虫的生物防治具有重要的应用潜力和价值。本文详细描述了元宝枫希姬小蜂的形态特征,并附彩色形态特征图;同时,与希姬小蜂属的两个近似种进行了鉴别特征比较。

丛枝菌根真菌对元宝枫枯叶分解及其生长的影响

【目的】探究丛枝菌根(arbuscular mycorrhizal,AM)真菌对元宝枫生长以及枯叶分解的影响,明确其与元宝枫生长状况间的关系。【方法】以元宝枫(Acer truncatum)幼苗为试验材料,采用盆栽试验,设置接种AM真菌(AMF)和不接菌(CK)2个处理,其中AMF处理灭菌基质中加入根内根孢囊霉(Rhizophagus intraradices,Ri),CK中加入灭菌Ri和菌剂过滤液,同时在2个处理供试的花盆中放置2个装有元宝枫枯叶的分解盒,待元宝枫幼苗生长180 d后,测定元宝枫幼苗生长指标、养分含量以及枯叶中的养分含量,计算元宝枫枯叶的分解量以及不同粒径剩余枯叶质量,并采用冗余分析研究元宝枫生长状况、养分含量与枯叶养分间的相关性。【结果】(1)与CK相比,AMF处理元宝枫的地上部、地下部鲜质量和干质量以及根全氮、全磷、全钾和叶全磷含量显著增加,但二者的株高、地径和叶全氮含量无显著差异,叶全钾含量显著降低。(2)与CK相比,AMF处理元宝枫枯叶总分解量显著增加,粒径>0.15 mm枯叶质量显著降低,粒径0.25μm~0.15 mm枯叶质量显著增加。(3)与CK相比,AMF处理促进了枯叶中多酚的释放,降低了枯叶全氮积累,但对枯叶单宁、纤维素、全磷、全钾和有机碳含量无显著影响。(4)相关性分析发现,枯叶全氮累积系数与叶全钾含量呈显著正相关,与元宝枫生物量以及根和叶养分含量呈负相关;而枯叶多酚累积系数的表现则与之相反。【结论】接种AM真菌促进了元宝枫枯叶的分解,影响了元宝枫枯叶中有效养分的含量,从而促进了元宝枫的生长发育。

寄生和捕食元宝枫种子瘿蚊的重要天敌——毛链金小蜂属一新种(膜翅目:金小蜂科)

【目的】元宝枫是我国珍贵经济林树种,其籽油中含有丰富的神经酸等物质,在预防和治疗人类神经系统疾病上具有重要价值。然而,近年来作者发现元宝枫种子受到一种元宝枫瘿蚊(Acumyia sp.)幼虫的严重侵害。为了无公害防治该害虫,本研究旨在调查并鉴定元宝枫瘿蚊的天敌。【方法】通过在北京和内蒙古的实地调查,发现了寄生和捕食元宝枫瘿蚊幼虫和蛹的一种小蜂。通过分类研究,确定其为小蜂总科金小蜂科毛链金小蜂属Systasis的一个新种——元宝枫瘿蚊毛链金小蜂Systasis aceri Yang,Liu et Cao sp.nov.。本文详细描述了该寄生蜂的形态特征,并附有彩色形态特征图。同时,还记述了该小蜂的生物学,也和毛链金小蜂属我国的二个相近种进行了比较,提供了鉴别特征。【结果】该新种与中国的一种寄生刺槐叶瘿蚊的小蜂——叶瘿蚊毛链金小蜂Systasis obolodiplosis Yao et Yang相似,但可以通过以下特征进行区分:新种体呈金绿色,雌性体长3.4~3.6 mm,雄性1.8~2.4 mm(而后者体呈蓝色,带有紫色金属光泽;雌性体长2.1 mm,雄性1.3 mm);唇基略呈方形,宽为高的1.4倍(后者的唇基更宽,宽度是其高度的2.0倍);腹部较长,长为宽的2.7倍(后者的腹部较短,长为宽的1.8倍)。Xiao&Huang修订了中国毛链金小蜂属的种类,并提供了9个种的分类检索表。使用此检索表,新种最初被归为Systasis procerula Xiao et Huang。然而,本新种雌性在其他特征上存在差异:痣后脉长度是痣脉的1.4倍(后者的痣后脉短于痣脉);触角较短,梗节加鞭节的长度是头宽的1.15倍(后者是头宽的1.4倍);本种腹部更长,长为宽的2.7倍(后者腹部较短,长为宽的1.5倍)。此外,还描述了新种的生物学特性。元宝枫瘿蚊毛链金小蜂对元宝枫瘿蚊幼虫和蛹具有较高的寄生率,达到34%。其1~2龄幼虫为寄生性,而3龄以后则转为捕食性,能将单个种子中的52~125头瘿蚊幼虫(或蛹)捕食殆尽。该小蜂一年发生2~3代,是元宝枫瘿蚊的主要天敌。【结论】本天敌的发现为无公害生物防治元宝枫瘿蚊提供了一种优秀天敌。这一发现对于保护元宝枫这一珍贵树种及其籽油资源具有重要意义,并为未来种实害虫提供了新的生物防治技术。

元宝槭幼苗光合生理的水氮耦合效应研究

研究元宝槭幼苗光合生理的水氮耦合效应可以为元宝槭苗木水肥管理提供科学依据,有利于元宝槭产业发展。以1 a生元宝槭实生苗为材料,设置田间持水量(FC)的10%~20%(W1)、40%~50%(W2)、70%~80%(W3)3个水分梯度,施氮0 g/株(N0)、2 g/株(N1)、4 g/株(N2)和6 g/株(N3)4个氮肥梯度的二因素完全随机盆栽实验,通过测定不同水氮处理下元宝槭幼苗的光合参数、叶绿素含量、叶绿素荧光参数,分析其变化规律,揭示水氮耦合对元宝槭苗期光合生理的影响机制。结果表明,水氮耦合对元宝槭的光合生理有显著影响:(1)元宝槭幼苗的Pn、Gs、Ci、Tr等4个光合参数总体变化趋势表现为随着土壤含水量的增加而增加,而iWUE、LS则与之相反;施氮对元宝槭光合参数的影响较复杂,W2N2处理Pn最高,为8.84μmol/(m^(2)·s)。(2)水氮对元宝槭幼苗的光系统II的实际光化学效率(ΦPSII)、非光化学猝灭系数(qN)影响较大,而对光系统II的最大光化学效率(Fv/Fm)、光化学猝灭系数(qP)无明显影响。(3)水分是元宝槭叶绿素含量的主要影响因素,随土壤水分含量升高,元宝槭总叶绿素含量提高,叶绿素a/b值下降,叶绿素b的比例显著增大。(4)元宝槭Pn与Ci、Gs、Tr、Fv/Fm、Chl显著正相关,与iWUE、LS则呈现出显著负相关性。综上所述,提高土壤含水量能显著提高元宝槭幼苗的光合作用,土壤含水量较低时,水分是影响元宝槭光合生理的主导因素,土壤含水量为中、高水平时,其光合生理由水氮共同决定,该结论可为元宝槭苗期水肥管理体系建立提供理论参考。