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1.
通过将沙棘(Hippophae rhamnoides L.)与3种杨树品种(小黑杨(Populus cv.“Xiaohei”)昭林6号杨(P.cv.“Zhaolin06”)和欧美杨64号(P.euramericane cv.“N3016”))的人工林分别按株混两种方式进行混交实验,研究了固氮植物沙棘对亚湿润干旱区的杨树人工林生长和生产力的影响。研究结果表明:无论哪一种杨树品种或混交方式,沙棘与杨树  相似文献   

2.
通过将沙棘(Hippophae rhamnoides L.)与3种杨树品种(小黑杨(Populus cv.“Xiaohei”),昭林6号杨(P.cv.“Zhaolin06”)和欧美杨64号(P.euramericane cv.“N3016”))的人工林分别按株混和行混两种方式进行混交实验,研究了固氮植物沙棘对亚湿润干旱区的杨树人工林生长和生产力的影响。研究结果表明:无论哪一种杨树品种或混交方式,沙棘与杨树混交后能显著地增加杨树人工林的生长量,林分平均胸径增加6%~38%,林分平均高增加8%~23%。在株混方式中,杨树地上部生物量大于杨树纯林的地上部生物量。但是在行混方式中,呈现相反的规律,这是由于行混方式中单位面积的杨树株数少。无论哪一种杨树品种或混交方式,杨树与沙棘混交林的地上部净生产力大于杨树纯林的地上部生产力。在株混和行混两种方式中,沙棘占总地上部净生产力的比例分别为20%和41%,但草本植物所占的比重很小。  相似文献   

3.
袁自清  赵震宇 《真菌学报》1994,13(3):173-177
本文报道了新疆腔菌纲座囊菌目刺球座属(Lasiobotrys)、穴壳属(Dothiora)和普氏腔孢属(Plowrightia)的六种子囊菌,即:忍冬刺球座菌(L.lonicerae)、花揪穴壳菌(D.sorbi)及其无性阶段花揪疡壳孢(Dothichiza sorbi)、茶Biao子普氏腔孢菌(P.ribesia)、小檗普氏腔孢菌(P.berberidis)、沙棘普氏腔孢菌(P.hippopha  相似文献   

4.
脐橙与柠檬种间细胞电融合再生杂种植株   总被引:2,自引:0,他引:2  
‘纽荷尔’脐橙(Citrussinensis(L.)Osbeck)胚性细胞悬浮原生质体与‘尤力克’柠檬(Citruslimon(L.)Burm.f)叶肉原生质体经电场诱导融合,培养8个月,首批再生了1棵植株,形态学观察,染色体计数及RAPD分析证明异源四倍体体细胞杂种,该杂种的获得为三倍体无籽柠檬品种培育提供了杂交亲本。  相似文献   

5.
王耀 《古生物学报》1996,35(6):702-713
描述了豆海百合类2属7种,它们是:Pisocrinus(P.)pilula,P.(G.)kosovensis,P.(G.)bohemicus,Pampisocrinusollula,P.Sphericus,以及Pisocrinus(G.)brevissp.nov.和Parapisocrinuspateriformissp.nov.;并首次发现了P.(G.)bohemicus萼杯内腔的内部钙质骨胳构造。同时,还就波希米亚豆海百合种内变异和豆海百合类的对称性进行了研究。  相似文献   

6.
辽西半干旱区几种人工林生态系统涵养水源功能研究   总被引:23,自引:4,他引:19  
从森林生态系统树冠截留降雨、枯落物持水及土壤蓄水3个层次对辽西半干旱区5种人工林生态系统的涵养水源功能进行了定量研究.结果表明,各人工林生态系统树冠对降雨的平均截留率为14.58%~37.19%,依次为沙棘林>油松沙棘混交林>杨树沙棘混交林>油松纯林>杨树纯林;枯落物层厚度为1.6~4.1cm,枯落物贮量为1890.4~6425.2kg·hm^-2,枯落物层厚度和贮量均为沙棘林>油松沙棘混交林>杨树沙棘混交林>油松纯林>杨树纯林,枯落物最大持水量取决于枯落物贮量及其最大持水率,枯落物最大持水量为5957.7~19332.9kg·hm^-2,依次为沙棘林>油松沙棘混交林>杨树沙棘混交林>油松纯林>杨树纯林;各人工林生态系统0~40cm土壤层非毛管蓄水量为23.70~37.85mm,依次为沙棘林>杨树沙棘混交林>油松沙棘混交林>杨树纯林>油松纯林.在5种人工林生态系统中,沙棘林的涵养水源功能最好,混交林较油松和杨树纯林有更好的涵养水源功能.  相似文献   

7.
杨树刺槐混交林及纯林枯落叶分解   总被引:17,自引:0,他引:17  
研究了杨树(Populusspp.)、刺槐(Robiniapseudoacacia)纯林及混交林枯落叶一年中的分解及养分动态变化规律.结果表明,杨树枯落叶分解速度较慢,刺槐较快,而混交林则较杨树有较大提高.在分解过程中,杨树枯落叶N、P释放困难,需经过长达10个月的养分富积过程;刺槐枯落叶N、P元素释放较为容易;混交林枯落叶养分富积时间缩短、幅度下降,分解速度加快,说明杨树和刺槐混交有利于枯落叶分解和N、P循环.  相似文献   

8.
研究了2种栽培烟草(普通烟草Nicotiana tabacum L.和黄花烟草N.rustica L.)的六大栽培类型10个品种的核型。结果表明:所有供试材料均为双二倍体。黄花烟草的‘黄花烟’品种的核型公式为:2n=4x=48=44m(2SAT)+4sm。普通烟草9个品种的核型可简式为:‘白花铁杆’2n=4x=48=34m+10sm(2SAT)+4st;‘柳叶尖’2n=4x=48=34m+10+s  相似文献   

9.
杨树刺槐混交林有纯林枯落叶分解   总被引:6,自引:3,他引:3  
研究了杨树(Populus spp.)、刺槐(Robinia pseudoacacia)纯林及混交林枯落叶一年中的分解及养分动态变化规律。结果表明,杨树枯落叶分解速度较慢,刺槐较快,而混交林则较杨树有较大提高。在分解过程中,杨树苦落叶N、P释放困难,需经过长在10个月养分富积过程;刺槐枯落叶N、P元素释放较为容易;混交林枯落养分富积时间缩短、幅度下降,分解速度加快,说明杨树和刺槐混交有利于枯落叶分  相似文献   

10.
农业系统生产力(ASP)的量化及其现状分析   总被引:6,自引:0,他引:6  
农业系统生产力(ASP)的量化及其现状分析卢进登,韩纯儒(北京农业大学农学系,100094)QuantificationofAgrosystemProductivity(ASP)andAnalysisonitsCurrentSituationinCbina¥.LuJin-deng;HanChunru(BeijingAgriculturalUniversityfBeijing100094).ChineseJournalofEcology,1993,12(2):21-22.BasedonabriefanalysisontheformationprocessofASP,itsconceptisdescribedandanintegratedindi-catorforitsquantification—ASP2isputforwards.Fromthose,theASPlevelsinvariousregionsofChinaareanalyzedand8levelsaredividedbyusing.Hierarchicclusteringmethod.It’s:clarifiedthatAS-PIisamore  相似文献   

11.
通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.  相似文献   

12.
The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.  相似文献   

13.
14.
龙胆科药用植物化学成分的研究现状   总被引:16,自引:0,他引:16  
龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。  相似文献   

15.
Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l−1 glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l−1) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.  相似文献   

16.
The review deals with study of enzymologic properties of a novel highly specific acetylcholinesterase substrate, N-(β-acetoxyethyl) piperidinium iodomethylate (“piperidylcholine”), and its 30 derivatives that were tested as effectors of cholinesterases of mammals and various species of Pacific squids. It was proven for the first time that responsible for specificity of action was structure of cyclic ammonium grouping of the alcohol part of molecule of the ester substrate. Analysis of specificity is performed based on enzymatic hydrolysis parameters—activity of catalytic center of cholinesterases and bimolecular constant of the reaction rate that are determined at optimal and low substrate concentrations. Among the specially synthesized group of thioester compounds there is revealed one more highly specific acetylcholinesterase substrate—N-(β-acetoxyethyl) piperidinium.  相似文献   

17.
18.
真菌类遗传学分析的知识结构教学   总被引:5,自引:2,他引:3  
罗桂花 《遗传》2002,24(3):349-350
本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.  相似文献   

19.
目的 针对医疗机构的合理用药水平进行评价研究。方法 根据医疗机构合理用药的具体要求,构建医疗机构合理用药评价指标体系,采用基于模糊群决策的方法和多指标评价分析法构建医疗机构合理用药评价模型。结果 构建了基于模糊群决策的医疗机构合理用药评价模型,并通过实例分析证明了评价模型的可行性。结论 建立的基于模糊群决策的医疗机构合理用药评价模型能够对医疗机构的合理用药水平进行科学评价,为提高医疗机构合理用药水平奠定基础。  相似文献   

20.
Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m−2 s−1. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to Pfr.  相似文献   

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