3种同域分布的杓兰属植物的种子及杂交种子特征分析

杂交种子研究在一定程度上能说明是否存在杂种不活机制,在植物生殖隔离研究中具有重要意义。通过对同域分布的西藏杓兰(Cypripedium tibeticum)、黄花杓兰(C.flavum)和褐花杓兰(C.calcicola)的自交、异交、杂交种子的形态特征及活性进行分析,发现3种杓兰属植物两两之间均可产生杂交种子,且杂交种子活性较高,杂交种子与其他处理所得种子的外观、表面纹饰无显著性差异;种子宽度、种子长度、有胚率、着色率并没有比自交或异交种子显著低。这一结果表明这3种同域杓兰属植物种与种之间具有相当高的亲和性,它们之间不存在明显的杂种不活机制。黄花杓兰与西藏杓兰或褐花杓兰间的传粉者大小明显不同,黄花杓兰由丽蝇和熊蜂工蜂传粉,而西藏杓兰和褐花杓兰由体形较大的熊蜂蜂王传粉,传粉者隔离已使得它们之间的物种界限比较清晰,因此已经没有必要再产生杂种不活等其他隔离机制。而西藏杓兰与褐花杓兰的传粉者相同,又没有明显的杂种不活隔离机制,暗示它们之间有其他合子后隔离机制或应将其合并为一个种。     

黄花杓兰的花芽发育

对黄花杓兰（Cypripedium flavum P.F.Hunt et Summerh.）成年植株做了一个生长季的研究,提出了一年芽、二年芽和多年休眠芽的概念。指出由芽形成到植株开花需两年时间,其具体发育路线是：第一年6－7月份,根状茎顶端二年芽基部外侧有两个新的小芽产生,即“一年芽”,至9－10月份发育出7－9片幼叶,然后随气温下降停止生长;第2年4月份复苏,即为“二年芽”,二年芽在本生长季内发育成混合芽,但一般情况下只有一个充分发育,另一个未能充分发育并且一般将来也不再有发育的机会,被称为“多年休眠芽”;第3年5月份充分发育的二年芽长出地面,形成植株,迅速开花、结果,至9月底植株枯萎。本文还讨论了黄花杓兰发育过程与环境的关系。     

中国特有兰科植物褐花杓兰的繁殖生物学特征及其与西藏杓兰的生殖隔离研究

作为被子植物中最进化的类群, 兰科植物通常依靠种内特化的传粉者而形成种间物种隔离。褐花杓兰(Cypripedium smithii)与西藏杓兰(C. tibeticum)是杓兰属大花亚组中的两个近缘种类, 二者形态特征相似, 分布区也存在明显重叠。在西藏杓兰繁殖生物学特征已知的基础上, 本文对褐花杓兰的繁殖生物学特征进行了研究, 并对褐花杓兰与西藏杓兰进行了外部形态比较。结果表明, 4个居群中普遍存在西藏杓兰和褐花杓兰间的一系列形态过渡类型, 两个物种并没有明确的形态差异。褐花杓兰与西藏杓兰杂交亲和, 传粉观察也表明褐花杓兰由熊蜂(Bombus)蜂王传粉, 具有与西藏杓兰相同的传粉系统。因此, 在自然条件下, 西藏杓兰与褐花杓兰之间可能会存在较频繁的基因流, 从而产生一系列中间过渡类型。将它们分为两个独立的物种并不是最好的选择, 建议将其合并为一个种。     

花舞者——扇脉杓兰

正杓兰属植物是兰科(Orchidaceae)杓兰亚科(Cypripedioideae)的一个保育研究的热点类群,全属植物约50种(含变种),中国是该属植物的分布中心,我国产32种、1变种,其中24种为特有种[1]。扇脉杓兰(Cypripedium japonicum)是一种珍稀的多年生地生兰,隶属于兰科(Orchidaceae)杓兰亚科(Cypripedioideae)杓兰属(Cypripedium),具极高观赏价值。扇脉杓兰中药名为扇子七,全株可入药,《陕西中草药志》记有:扇     

黄花杓兰云南中甸居群遗传结构及克隆多样性的分析

采用AFLP分子标记方法对云南中甸的6个黄花杓兰( Cypripedium flavum )居群进行了遗传多样性水平、遗传结构及克隆多样性研究,其中两个居群用样方取样法分析其克隆空间结构.POPGENE软件分析结果表明:两组引物共产生104个位点,其中86个为多态位点,多态位点百分率为82.69%.黄花杓兰具有丰富的遗传变异(物种水平上, He=0.2884, Ho=0.4312;居群水平上,P=64.59%, He=0.2449, Ho=0.3606),黄花杓兰居群的遗传分化不大( Gst=0.154),居群间基因交流较为频繁( Nm=2.7460).居群的克隆多样性水平高( D=0.9638-0.9960,G/N=0.83-0.96),同一克隆的分株相邻,克隆生长延伸范围狭窄.黄花杓兰居群之所以保持较高水平的遗传多样性,可能与其既能通过实生幼苗增加基因的杂合度,又能通过无性分株把杂合体固定下来有关.     

花舞者——扇脉杓兰

<正>杓兰属植物是兰科(Orchidaceae)杓兰亚科(Cypripedioideae)的一个保育研究的热点类群,全属植物约50种(含变种),中国是该属植物的分布中心,我国产32种、1变种,其中24种为特有种[1]。扇脉杓兰(Cypripedium japonicum)是一种珍稀的多年生地生兰,隶属于兰科(Orchidaceae)杓兰亚科(Cypripedioideae)杓兰属(Cypripedium),具极高观赏价值。扇脉杓兰中药名为扇子七,全株可入药,《陕西中草药志》记有:扇     

不同海拔的三种杓兰属植物与菌根真菌群落组成相关性

本研究采集了四川黄龙沟沿海拔梯度3 170-3 400m上4个不同杓兰居群中3种杓兰植物根,利用克隆文库方法获得菌根真菌ITS序列,研究同一栖息地（黄龙沟）不同海拔梯度和不同杓兰对菌根真菌多样性和群落结构的影响。共得到18个可操作分类单元（OTU）,其中14个OTU隶属胶膜菌科Tulasnellaceae,为优势类群（99.6%）;2个OTU隶属腊壳菌科Sebacinaceae,2个OTU隶属亡革菌科Thelephoraceae。随着海拔升高,西藏杓兰菌根真菌多样性减少,而黄花杓兰和无苞杓兰没有明显变化;海拔对3种杓兰菌根真菌群落结构均无显著影响。3种杓兰之间菌根真菌群落结构差异显著且指示物种互不相同,说明在同一栖息地,杓兰对菌根真菌的偏好性显著影响其菌根真菌群落结构。这些研究结果利于了解环境变化对杓兰属植物菌根真菌区系组成的影响,为进一步探索菌根真菌与杓兰属植物的互作机制奠定基础。     

杓兰属(兰科)中一个国产种类的新等级

丽江杓兰大围山变种(Cypripedium lichiangense vat．daweishanense)被提升为种的等级：大围山杓兰(Cypripedium daweishanense)。此种的特征是：中萼片浅黄绿色,上面疏被栗色斑点;花瓣较短,近等长于或略长于唇瓣。而丽江杓兰(Cypripedium lichiangense)的中萼片为紫肝色;花瓣要长得多,大约为唇瓣长的2倍。它们均属于三棱组(Cypripedium sect．Trigonopedium)。该组共含11种,均为中国特有种。文中提供了一个该组的分种检索表。     

甘肃省杓兰属植物资源调查及2新记录种

通过对甘肃省杓兰属植物进行系统的调查和资料整理,共发现甘肃省杓兰属植物15种,占中国杓兰属植物种类的39.47%,其中9种为中国特有种。调查发现2种甘肃省杓兰属植物分布新记录种——巴郎山杓兰(Cypripedium palangshanense T.Tang et F.T.Wang)和离萼杓兰(Cypripedium plectrochilum Franch.)。通过整理重新编制了甘肃省杓兰属植物的分种检索表。     

三种杓兰根相关真菌多样性和生态功能

【背景】除了菌根真菌(Orchid mycorrhizal fungi,OrMF)外,兰科植物根中还有其它内生真菌,称为根相关真菌(Root-associated fungi,RAF)。【目的】采用分离培养的方法获得同一栖息地针叶林和灌木林两种不同生境西藏杓兰、黄花杓兰和无苞杓兰的RAF菌株,研究其真菌谱系、多样性和生态功能结构。【方法】从杓兰根碎屑中分离RAF,通过总DNA提取、PCR扩增及测序得到ITS(Internaltranscribedspacer)序列;进行系统发育和多样性分析,并通过NCBI数据库比对得到相似性最高序列的注释信息来分析RAF生态学特性。【结果】共分离得到278株RAF,25种OTU类型,包括23个子囊菌门OTU,2个毛霉菌门OTU。RAF物种丰富度分析发现西藏杓兰的较黄花杓兰高,不同生境没有显著差异;不同杓兰物种较不同生境的RAF群落分化程度高。生态功能分析显示25个OTU包括共生型、腐生型和致病型3种营养型,以及外生菌根菌群、植物病原菌群、内生真菌群、动物病原菌群、真菌寄生菌群、杜鹃花类菌根群、未定义的腐生菌群和不确定型8种共位群。【结论】阐明不同生境采集的不同杓兰中RAF的分布特点和生态功能,为未来研究RAF与杓兰属植物的共生关系奠定基础。     

心脑血管疾病大额住院消费统计分析

通过对医院2004-2006年心脑血管疾病大额住院消费(消费大于50000元,以下简称大额消费)病例发病率高的前五种疾病的构成情况、药费、材料费消耗情况进行分析,认为加强大额病例中发病率高的病种的重点管理,是降低医疗费用的有效途径。建议制定常见病大额病种预定额付费方案和审查报销制度;采用适宜技术;控制药费,防止过度医疗,有效地遏制医疗费用的过快增长。     

Evidence that the C-terminus of OprM is involved in the assembly of the VceAB-OprM efflux pump

Although the architecture of tripartite multiple drug resistance (MDR) efflux pumps of Gram-negative bacteria has been well characterized, the means by which the components recognize each other and assemble into a functional pump remains obscure. In this study we present evidence that the C-terminal domain of the Pseudomonas aeruginosa OprM and the α-helical hairpin domain of Vibrio cholerae VceA play an important role in the recognition/specificity/recruitment step in the assembly of a functional, VceAB-OprM chimeric efflux pump. To our knowledge, this is the first evidence directly linking the C-terminal domain of an outer membrane efflux protein to its recruitment during the assembly of a tripartite efflux pump.     

两个猪苓菌株生长速度及酯酶同工酶比较研究

对不同地理分布的猪苓纯培养菌株进行了种性和酯酶同工酶的比较研究,结果表明,鸡爪苓（Z）纯培养菌株和猪屎苓（ZJ）纯培养菌株的种性有很大不同,两个纯培养菌株的酯酶同工酶酶带类型差异较大,亲缘关系较远。     

Synthesis of modified fragments of fibrinogen and their effect on the activity of proteolytic enzymes

New analogues of the Gly-Pro-Arg and Arg-Gly-Asp fragments of fibrinogen were synthesized: Gly-Pro-Arg-Pro (I), Gly-Pro-Arg-Pro-Met-OMe (II), Gly-Pro-Arg-Pro-Phe (III), Gly-Pro-Arg-Pro-Asp (IV), Gly-Pro-Arg-Pro-Glu (V), and Arg-Asn-Trp-Asp (VI). Their effect on the activity of proteases of various types was studied with the method of lysis of fibrin plates. All the peptides were found to inhibit plasmin activity (by 60–85%) and the γ-subunit of nerve growth factor (by 55–93%). Tetrapeptide (VI) proved to be an effective inhibitor of tissue activator of plasminogen and the γ-subunit of nerve growth factor (by 96 and 93%, respectively). The peptides exerted practically no effect on the activity of urokinase and moderately inhibited the activity of streptokinase [(III), IV), and (VI)], papain [(I), (II), IV), and (VI)], subtilisin [(V) and (VI)], α-chymotrypsin [(III), (V), and VI)], and Bacillus subtilis metalloprotease (VI). They inhibit trypsin [except for (I) and (III)] when applied on fibrin plates at a concentration of 1 × 10^?2 M, while, at the concentration of 1 × 10^?3 M, (I) and (II) induced an increase in proteolytic activity by 35 and 47%, respectively.     

Studies on the energy coupling sites of photophosphorylation IV. The relation of proton fluxes to the electron transport and ATP formation associated with Photosystem II

1. By using dibromothymoquinone as the electron acceptor, it is possible to isolate functionally that segment of the chloroplast electron transport chain which includes only Photosystem II and only one of the two energy conservation sites coupled to the complete chain (Coupling Site II, observed P/e₂ = 0.3–0.4). A light-dependent, reversible proton translocation reaction is associated with the electron transport pathway: H₂O → Photosystem II → dibromothymoquinone. We have studied the characteristics of this proton uptake reaction and its relationship to the electron transport and ATP formation associated with Coupling Site II.

2. The initial phase of H⁺ uptake, analyzed by a flash-yield technique, exhibits linear kinetics (0–3 s) with no sign of transient phenomena such as the very rapid initial uptake (“pH gush”) encountered in the overall Hill reaction with methylviologen. Thus the initial rate of H⁺ uptake obtained by the flash-yield method is in good agreement with the initial rate estimated from a pH change tracing obtained under continuous illumination.

3. Dibromothymoquinone reduction, observed as O₂ evolution by a similar flash-yield technique, is also linear for at least the first 5 s, the rate of O₂ evolution agreeing well with the steady-state rate observed under continuous illumination.

4. Such measurements of the initial rates of O₂ evolution and H⁺ uptake yield an H⁺/e⁻ ratio close to 0.5 for the Photosystem II partial reaction regardless of pH from 6 to 8. (Parallel experiments for the methylviologen Hill reaction yield an H⁺/e⁻ ratio of 1.7 at pH 7.6.)

5. When dibromothymoquinone is being reduced, concurrent phosphorylation (or arsenylation) markedly lowers the extent of H⁺ uptake (by 40–60%). These data, unlike earlier data obtained using the overall Hill reaction, lend themselves to an unequivocal interpretation since phosphorylation does not alter the rate of electron transport in the Photosystem II partial reaction. ADP, P_i and hexokinase, when added individually, have no effect on proton uptake in this system.

6. The involvement of a proton uptake reaction with an H⁺/e⁻ ratio of 0.5 in the Photosystem II partial reaction H₂O → Photosystem II → dibromothymoquinone strongly suggests that at least 50% of the protons produced by the oxidation of water are released to the inside of the thylakoid, thereby leading to an internal acidification. It is pointed out that the observed efficiencies for ATP formation (P/e₂) and proton uptake (H⁺/e⁻) associated with Coupling Site II can be most easily explained by the chemiosmotic hypothesis of energy coupling.     

林带阻力系数与透风系数关系的理论分析

根据冲量定理分析了林带对气流的阻力,首次得到了林带阻力系数的估算模式（Ｃｄ＝（１．８＋０．２α）（１－α）ｓｉｎ２ω,并利用有关文献发表的资料进行了验证．文章还对来流平行林带时林带对气流的阻力进行了讨论,指出来流平行林带时林带对气流的阻力仅为来流垂直林带时林带对气流阻力的０．７—１．１％,可以不予考虑．     

2种嵩草属植物形态特征对生境干旱化的响应

该研究于西藏自治区东南部的东达山高山草甸沿生境干旱化梯度设置10个样地,采用线性回归方法分析优势种高山嵩草(Kobresia pygmaea)和矮生嵩草(K.humilis)叶片数量与其它构件数值(分株数量、茎基直径、根系数量和根系长度)之间的关系,并采用线性回归斜率测度分株功效、叶片萌生能力、根系分生功效和根系伸长功效,以探讨嵩草的分株能力、茎基生长和根系生长对生境干旱化过程的响应机制。结果显示:(1)2种嵩草植物的叶片数量与4种构件数值均为显著线性正相关关系。(2)随着生境干旱化程度增加,高山嵩草分株数量增加,矮生嵩草分株受干旱抑制程度高,分株数量呈下降趋势;2种嵩草分株功效下降,即单株叶片数量因干旱化程度增加而减少。(3)2种嵩草的茎基直径、叶片萌生能力随着生境干旱化程度增加而下降;高山嵩草叶片萌生能力的变化与生境干旱化梯度一致,具有连续性;矮生嵩草叶片萌生能力对生境干旱化的适应性弱,干旱到一定程度发生骤降。(4)随着生境干旱化,高山嵩草的根系数量和长度均增加,矮生嵩草根系长度增加,但数量却无规律变化;2种嵩草的根系分生功效和根系伸长功效均下降。研究表明:嵩草属植物分布的最适宜生境为表面稍有积水的沼生生境。为适应生境干旱化,高山嵩草降低叶片萌生率以减少蒸腾作用,增加分株数量以增强对空间的占有能力,并增加根系数量和长度来提高对土壤水分的吸收能力,因此对干旱有较强适应性且分布范围广;矮生嵩草只通过降低叶片萌生率,增加根系长度响应干旱化生境,其分布范围较窄。     

Photoinactivation of Photosystem II in leaves

Photoinactivation of Photosystem II (PS II), the light-induced loss of ability to evolve oxygen, inevitably occurs under any light environment in nature, counteracted by repair. Under certain conditions, the extent of photoinactivation of PS II depends on the photon exposure (light dosage, x), rather than the irradiance or duration of illumination per se, thus obeying the law of reciprocity of irradiance and duration of illumination, namely, that equal photon exposure produces an equal effect. If the probability of photoinactivation (p) of PS II is directly proportional to an increment in photon exposure (p = kΔx, where k is the probability per unit photon exposure), it can be deduced that the number of active PS II complexes decreases exponentially as a function of photon exposure: N = N_oexp(−kx). Further, since a photon exposure is usually achieved by varying the illumination time (t) at constant irradiance (I), N = N_oexp(−kI t), i.e., N decreases exponentially with time, with a rate coefficient of photoinactivation kI, where the product kI is obviously directly proportional to I. Given that N = N_oexp(−kx), the quantum yield of photoinactivation of PS II can be defined as −dN/dx = kN, which varies with the number of active PS II complexes remaining. Typically, the quantum yield of photoinactivation of PS II is ca. 0.1μmol PS II per mol photons at low photon exposure when repair is inhibited. That is, when about 10⁷ photons have been received by leaf tissue, one PS II complex is inactivated. Some species such as grapevine have a much lower quantum yield of photoinactivation of PS II, even at a chilling temperature. Examination of the longer-term time course of photoinactivation of PS II in capsicum leaves reveals that the decrease in N deviates from a single-exponential decay when the majority of the PS II complexes are inactivated in the absence of repair. This can be attributed to the formation of strong quenchers in severely-photoinactivated PS II complexes, able to dissipate excitation energy efficiently and to protect the remaining active neighbours against damage by light.     

民勤绿洲边缘地下水位变化对植物种群生态位的影响

在民勤绿洲边缘,利用空间区域不同地下水位(湖区8～12m,泉山区15～17m,坝区20～23m)和时间序列(1984～1992年)民勤沙井子地区地下水位下降(7.45～11.65m)梯度,研究地下水位下降对荒漠植物种群生态位的影响。结果表明:空间区域地下水位下降,植物种群生态位宽度均减小,种群退化;时间序列地下水位下降,白刺种群在扩展,其它植物种群在退化。白刺种群生态位宽度在民勤绿洲边缘荒漠植物群落中最大,是该区的建群种。由于白刺种群在地下水位7.45～11.65m范围内扩展,民勤绿洲生态环境治理中地下水位达到该范围是一个主要目标。     

The detection of salivary enzymes of phytophagous Hemiptera: a compilation of methods

The role of Hemipteran saliva and salivary enzymes is central to an understanding of the etiology of damage that these insects cause to plants. The dilute nature of the salivary secretions and the minute quantities in which they are often obtainable have made analysis and detection of salivary components very difficult. Such investigations in this laboratory have led us to formalise the techniques involved and we believe that the compilation of these methods presented herein may be useful to other research workers in this area. Methods are described for acid and alkaline phosphatase, esterase, /S-glucosidase, carbohydrases, invertase, amylase, proteinase, pectinase, cellulase, catalase, peroxidase, catechol oxidase, superoxide dismutase and ascorbic oxidase.