神农架南坡珍稀植物独花兰的物候、繁殖及分布的群落特征

神农架南坡独花兰分布的群落一般位于坡度 1 5～ 45°的阴坡 ,海拔范围为 1 30 0～ 1 70 0 m。土壤类型主要为山地黄棕壤 ,p H值 5 .0～ 5 .6。9月中下旬独花兰地下假鳞茎萌芽出土并开始展叶 ,1 1月中下旬抽生花葶 ,次年 3月下旬开花 ,4月下旬至 5月上旬叶片逐渐枯死 ,地下部假鳞茎开始发育 ,9月中下旬假鳞茎发育成熟 ,1 0月下旬至 1 1月上旬果实成熟。独花兰的结实率两年的调查结果差异较大 ,分别为 2 .3%、9.5 %。每株独花兰每年能长出 1～ 3个假鳞茎 ,抽生 1～ 3个叶片和花葶。神农架南坡独花兰主要分布在以化香 ( Platycarya strobilacea)、四照花 ( Dendrobenthamia japonica)、华千金榆 ( Carpinuscordata var.chinen-sis)等为主的落叶阔叶林下以及以箬竹 ( Indocalamustessellatus)灌丛下 ,群落物种组成中北温带成分占绝对优势。群落遭到不同程度的人为干扰 ,随着干扰强度的递增 ,独花兰在不同群落中的个体数量有递减的趋势 ,在郁闭的森林下个体数量最大而箬竹灌丛下最小。人为干扰、结实率低、种子萌发困难是导致独花兰濒危的主要原因 ;建立保护区 ,恢复独花兰分布区的森林植被是保护独花兰的有效途径。     

独花兰野生种群研究——开花与营养体状态的关系

对安徽省天堂寨自然保护区独花兰野生种群的花果期节律和营养体状态研究表明,开花植株占观察样本的375%,个体是否开花与假鳞茎数目、地下茎总体积和叶面积呈极显著相关关系。绝大多数开花个体具有３个假鳞茎且其总体积通常达８cm３,叶面积达33 cm2。个体较大的植株开花持续期较长。花葶在花果期具有不同的生长时相：开花期中止生长,幼果期呈逻辑斯谛型生长。面对日益增长的人类采掘风险,独花兰开花与大型植株的关联可能是其生活史中影响种群生存的脆弱点之一。     

独花兰野生种群研究——开花与营养体状态的关系

对安徽省天堂寨自然保护区独花兰野生种群的花果期节律和营养体状态研究表明 ,开花植株占观察样本的 3 7 5 %,个体是否开花与假鳞茎数目、地下茎总体积和叶面积呈极显著相关关系。绝大多数开花个体具有 3个假鳞茎且其总体积通常达 8cm3,叶面积达 3 3cm2 。个体较大的植株开花持续期较长。花葶在花果期具有不同的生长时相 :开花期中止生长 ,幼果期呈逻辑斯谛型生长。面对日益增长的人类采掘风险 ,独花兰开花与大型植株的关联可能是其生活史中影响种群生存的脆弱点之一。     

西藏兰科植物1新记录属和2新记录种

该文报道了西藏兰科1个新记录属——坛花兰属(Acanthephippium) 及其新记录种——锥囊坛花兰(Acanthephippium striatum Lindl),另1西藏新记录种为夏天麻(Gastrodia flavilabella S. S. Ying)。锥囊坛花兰与同属的中华坛花兰［A. gougahense (Guillaumin) Seidenfaden］和坛花兰(A. sylhetense Lindl. Gen)相近,主要区别在于后两者唇盘肉质增厚且萼囊宽而短钝。夏天麻植株形态类似于南天麻［G. javanica (Bl.) Lindl］,后者花苞片宿存,为三角形;根状茎上不具珊瑚状根;唇盘基部爪上的胼胝体非球形。文中对新记录1属和2种兰科植物进行了描述,并附有新记录的特征照片,丰富了该区野生兰科植物本底资源。同时根据IUCN的评价标准,对其濒危等级进行了评估认定,提出了保护等级的建议。凭证标本保存于西藏高原生态研究所标本室(XZE)。     

15种独蒜兰属植物叶表皮微形态特征及分类学意义研究

为解决兰科(Orchidaceae)独蒜兰属(Pleione D. Don)植物分类学问题并探索叶片超微结构在分类学中的意义,该研究利用扫描电子显微镜,对独蒜兰属15种植物成熟叶片的细胞界限、角质层纹理、气孔器分布等15个叶表皮超微特征进行观测分析,以明确它们的分类学意义。结果表明：(1)细胞界限、表皮细胞蜡质量、角质层纹理、气孔器分布、气孔器周围蜡质、气孔器外拱盖内缘、角化现象、气孔器相对高度、表皮细胞长度、表皮细胞面积、保卫细胞长度和保卫细胞面积这9个指标对于该属分类具有重要价值和意义。(2)利用上述特征可以对春花独蒜兰组(S. Humiles)、独蒜兰组(S. Pleione)和独蒜兰复合体(P. bulbocodioides complex)的组内区分进一步细化。(3)聚类分析将15种独蒜兰属植物聚类为4个分支,与传统分类学和分子系统学分类结果基本一致。研究认为,大理独蒜兰(P. × taliensis P. J. Cribb & Butterfield)与云南独蒜兰［P. yunnanensis (Rolfe) Rolfe］、黄花独蒜兰(P. forrestii Schltr.)在多个叶片微观特征方面表现出高度的一致性,大理独蒜兰的亲本有待于进一步研究确认。     

云龙天池国家级保护区云南松种群年龄结构及动态分析

云南松是中国西南地区的特有树种。云南松林是暖温性针叶林的典型代表,主要分布于滇中高原。云南松种群是否可以自我更新,将影响滇中地区的植被动态。明晰未受干扰的云南松种群的结构和动态是研究云南松林可持续发展的重要基础。云南省云龙天池自然保护区内的云南松林是较为原始的森林。以云龙天池国家级自然保护区云南松天然种群为研究对象,分析了云南松天然种群静态生命表、存活曲线、生存函数曲线和谱分析。结果表明：云龙天池国家级自然保护区的云南松年龄结构为倒J型,种群年龄结构数量变化动态指数V_pi为28.29%,存在外部干扰时侯的种群年龄结构动态指数V''_pi为1.77%,种群动态指数V_pi和V''_pi都大于0,种群在外部环境干扰下承担的风险概率P_max为6.25%,以上结果表明云南松种群为增长型种群结构,具有一定的抗干扰能力。云南松种群的存活曲线为Deevey-Ⅱ型,生存分析发现生存率、累计死亡率、死亡密度和危险率在Ⅰ-Ⅶ龄级（胸径<35 cm）变化较大,Ⅶ-XVI龄级（胸径35-80 cm）趋于稳定;谱分析结果表明第Ⅲ龄级（胸径10-15 cm）是影响种群数量的主要阶段。以上结果说明云南松种群的低龄级个体数量波动大,个体死亡较多,高龄级衰退,建议自然保护区内的天然云南松幼龄林和中龄林可以采取抚育间伐措施来促进其种群的生长发育和更新。     

朱鹮肠道微生物多样性与产酶活性

【背景】朱鹮是我国国家一级保护动物,属于世界上最濒危的鸟类之一。对朱鹮肠道微生物的多样性和产胞外酶活性进行分析,可为朱鹮种群数量恢复提供思路。【目的】了解朱鹮肠道微生物的多样性,测定其产胞外酶活性。【方法】采用纯培养的方法获得朱鹮肠道微生物,通过革兰氏染色和生理生化鉴定,结合16S rRNA基因扩增和序列分析对细菌进行鉴定。使用水解圈法筛选产淀粉酶、蛋白酶、纤维素酶、脂肪酶的菌株。【结果】从人工喂养的朱鹮新鲜粪便中共分离到296株细菌,共计2个门11个属。变形菌门(Proteobacteria) 236株,占分离总数的79.73%,分别为：埃希氏菌属(Escherichia) 137株,占分离总数的46.28%;哈夫尼亚菌属(Hafnia) 39株,占分离总数的13.18%;变形菌属(Proteus) 28株,占分离总数的9.46%;柠檬酸杆菌属(Citrobacter) 23株,占分离总数的7.77%;气单胞菌属(Aeromonas) 6株,占分离总数的2.03%;肠杆菌属(Enterobacter) 1株,占分离总数的0.34%;志贺菌属(Shigella) 1株,占分离总数的0.34%;克雷伯菌属(Klebsiella) 1株,占分离总数的0.34%。厚壁菌门(Firmicutes) 60株,占分离总数的20.27%,分别为：肠球菌属(Enterococcus) 33株,占分离总数的11.15%;库特氏菌属(Kurthia) 14株,占分离总数的4.73%;芽孢杆菌属(Bacillus) 13株,占分离总数的4.39%。优势菌群为变形菌门(Proteobacteria)中的埃希氏菌属(Escherichia),占细菌总数的46.28%。经过生理生化鉴定,每个菌株生理生化鉴定出的种属与各自的16S rRNA基因鉴定出的种属相一致。产酶活力分析结果显示有238株产蛋白酶、25株产脂肪酶、24株产淀粉酶、15株产纤维素酶,分别占分离总数的80.41%、8.45%、8.11%和5.07%。【结论】朱鹮肠道微生物分离出的细菌可分为2门11属,优势菌群为变形菌门(Proteobacteria)中的埃希氏菌属(Escherichia),占细菌总数的46.28%;产酶活性分析显示,80.41%的菌株具有产蛋白酶能力。     

海南铜鼓岭鸭脚木种群动态特征研究

鸭脚木(Schefflera octophylla)是海南文昌铜鼓岭国家级自然保护区内滨海森林的优势种,也是海南其他地区热带森林常见伴生种。为深入了解该区滨海森林内鸭脚木种群的生存现状、更新机制以及未来发展的动态变化特点,该研究通过对海南热带滨海森林2.56 hm²样地中鸭脚木种群的调查,以径级结构代替龄级结构,编制鸭脚木种群静态生命表,并结合种群动态量化指数、生存函数、时间序列预测模型等方法定量分析鸭脚木种群结构和数量动态变化。结果表明:(1)研究区域内共记录鸭脚木数量2 814株,按照径级大小共划分为12个龄级,龄级结构呈倒J字型,属于趋向稳定型种群。(2)该区鸭脚木的存活曲线趋于Deevey-Ⅱ型,种群各径级的死亡率相接近。(3)鸭脚木种群的量化指数显示,V_pi=30.685>0,V_pi''=0.236>0,说明该种群现处增长阶段并且相对稳定。(4)据时间序列模型预测鸭脚木种群在未来的3、6、9 a内各龄级的种群个体数量整体呈现增加的趋势。综上分析认为,该区生境有利于鸭脚木种群的生长且该种群形成了良好的生存策略,其幼龄个体较多且后备资源丰富,能较好地补充各龄级个体自然死亡造成的损失,对森林的天然更新起到一定促进作用     

高寒典型草原主要物种的株高和盖度预测种群和群落地上生物量

为快速、准确、无破坏地测定草原地上生物量,在祁连山高寒典型草原植物生长旺季,观测了冬季和春秋季放牧地60个样方内各物种的株高、盖度等生长指标。以冬季牧地紫花针茅（Stipa purpurea）、醉马草（Achnatherum inebrians）、赖草（Leymus secalinus）、扁穗冰草（Agropyron cristatum）、二裂委陵菜（Potentilla bifurca）、银灰旋花（Convolvulus ammannii）6个主要物种的株高、盖度、株高和盖度的乘积为自变量,分别预测同物种、其他物种和群落地上生物量。用春秋季牧场的数据验证模型的精确性和稳定性。结果表明：主要物种的生长指标可预测其自身、其他物种和群落地上生物量。对自身种群,株高和盖度乘积的复合因子预测效果最好;4种禾草对其他物种、二裂委陵菜对菊科植物种群,株高、盖度单因子预测效果优于复合因子;6个主要物种单独或2-6个种结合均可预测群落地上生物量,但是以6个物种株高和盖度的乘积同时预测时决定系数最大,可解释群落地上生物量89.5%的变异,为高寒典型草原群落地上生物量最优预测模型。     

长白山次生杨桦林优势更新幼苗空间分布及环境解释

为了解长白山次生杨桦林中优势更新幼苗的空间分布及其与环境因子之间的关系,以5.2 hm²（200 m×260 m）固定样地更新幼苗的全面定位调查和环境因子调查本底数据为基础,对样地内个体数量排序前5的优势更新幼苗进行分析。结果表明：在中小距离尺度上,水曲柳（Fraxinus mandshurica）（0-90 m）、色木槭（Acer mono）（0-60 m）、紫椴（Tilia amurensis）（0-60 m、90-150 m）和假色槭（Acer pseudo-sieboldianums）（0-90 m）更新幼苗的空间分布关系为显著正自相关,呈聚集性分布;群落水平上,环境变量和空间变量对5种优势更新幼苗的空间分布变异解释能力为61%,其中,纯粹空间变量的解释度为56%,而纯粹环境变量的解释度不足1%;种群水平上,环境因子对更新幼苗的空间分布有一定影响,其中,水曲柳幼苗的空间分布与土壤有机质、土壤全钾和土壤水分显著相关,色木槭幼苗的空间分布与土壤有机质和土壤全磷显著相关,紫椴幼苗的空间分布与土壤全磷显著相关,假色槭幼苗的空间分布与土壤水分显著相关;簇毛槭（Acer barbinerve）幼苗的空间分布与环境因子未表现出显著的相关性。长白山次生杨桦林中优势更新幼苗多为聚集性分布,环境因子对其分布有一定影响。     

Antioxidant activity of extracts from leaves and roots of Salvia miltiorrhiza Bunge, S. przewalskii Maxim., and S. verticillata L

Three Salvia species have been studied for antioxidant activity in methanol extracts from roots and leaves. The presence of the polyphenols and tanshinones was screened by HPLC and spectrophotometric assays and related to the antioxidant potential. The antioxidant capacity of the studied species is high, but differences between species and organs have been also revealed. Salvia przewalskii leaf extract was the strongest one in all tests, followed by Salvia miltiorrhiza root and Salvia verticillata leaf. Among the roots, the most active was S. miltiorrhiza extract, followed by S. verticillata. The antioxidant activity correlates to the total polyphenol and, depending on the assay, to the hydroxycinnamic acids content. The high content of tanshinones in both S. miltiorrhiza and S. przewalskii roots is unlikely to contribute to the antioxidant activity.     

栽培高粱、甜高粱和拟高粱比较基因组原位杂交分析

用一种植物的总基因组DNA与近缘或远缘物种的染色体杂交,可以研究植物近缘或远缘物种基因组进化关系。以拟高粱总基因组DNA为探针,对栽培高粱、甜高粱基因组进行杂交,结果表明栽培高粱、甜高粱和拟高粱基因组中重复序列存在很大的同源性,基因组进化关系表现出保守性。栽培高粱与拟高粱基因组间重复序列的同源性要比甜高粱与拟高粱间重复序列的同源性高。     

互花米草、狐米草和大绳草茎秆的比较解剖观察

互花米草、狐米草和大绳草的表皮均由长细胞、短细胞(栓质细胞和硅质细胞)、盐腺和气孔器组成。它们成纵行交互排列。盐腺的结构与大米草相似,但三个种的盐腺和气孔器的数目不同,尤其以大绳草最多。它们的内部结构是由气道、不同大小的维管束、基本组织以及厚壁组织组成。然而,维管束的数目及厚壁组织的发育各不相同。狐米草和大绳草有高度木质化的厚壁组织细胞,而互花米草的厚壁组织木质化较弱。大绳草的维管束多于其他两种。     

Stylosanthes sp. aff.S. scabra: a putative diploid progenitor ofStylosanthes scabra (Fabaceae)

Stylosanthes sp. aff.S. scabra is an undescribed taxon showing affinities with the allotetraploid speciesS. scabra, but distinct in a number of attibutes. Several collections show potential as forage for clay soils in northern Australia. Twelve accessions have been analysed using STS (sequence-tagged-sites) as genetic markers, and they all displayed STS phenotypes of typical diploid species. Taking into account their morphological similarities, the STS analysis provides strong evidence thatStylosanthes sp. aff.S. scabra might be a diploid progenitor of the allotetraploidS. scabra. This speculation was supported by cytological examinations. Somatic chromosome numbers of two of these accessions were counted and both were found to be diploid (2n = 20). The level of polymorphism among the 12Stylosanthes sp. aff.S. scabra accessions, estimated using randomly amplified polymorphic DNA (RAPD) as markers, was 7.8%, and the dissimilarity value betweenStylosanthes sp. aff.S. scabra andS. viscosa (the other putative progenitor ofS. scabra) was 89%.     

滇丹参、甘西鼠尾、褐毛甘西鼠尾水提取液对鼠血栓形成及微循环的影响

目的：观察云南产甘西鼠尾属药物滇丹参、甘西鼠尾、褐毛甘西鼠尾的水提取物对鼠血栓形成及微循环的影响。方法：用电刺激法造成大鼠颈动脉血栓形成,观察血流阻塞时间(OT值);小鼠尾静脉注射血栓形成诱导剂,观察滇丹参、甘西鼠尾、褐毛甘西鼠尾对抗肺血栓形成的作用;采用活体微循环观察方法,研究滇丹参、甘西鼠尾、褐毛甘西鼠尾对去甲肾上腺素和高分子右旋糖苷所致小鼠、大鼠肠系膜微循环障碍的影响。结果：滇丹参、甘西鼠尾、褐毛甘西鼠尾2、4g/kg时,能明显延长闭塞性血栓形成时间(OT值)(P＜0．01)。20、40g/kg时,能有效抑制胶原和肾上腺素复合液所致小鼠肺血栓形成(P＜0．0l,P＜0．05)。能显著改善微动脉、微静脉痉挛和血液流态,增加毛细血管开放数,加快血流速度(P＜0．0l,P＜0．05)。结论：滇丹参、甘西鼠尾、褐毛甘西鼠尾均能防止血栓形成、改善微循环障碍。     

Morphological variation among members of theStellaria longipes complex:S. longipes,S. longifolia,andS. porsildii (Caryophyllaceae)

Morphological relationships were investigated among diploidStellaria porsildii, polyploidS. longipes, and diploidS. longifolia. Canonical discriminant analysis, based on a priori assumptions to maximize differences among groups, showed thatS. longipes clusters equally distant between the two diploid species along an axis connecting the diploids' centroids, but it differs along an axis perpendicular to this axis. The intermediacy along the former axis is evidence thatS. longipes is an amphiploid derived fromS. longifolia andS. porsildii. The divergence along the latter axis may be attributable to adaptively valuable heterotic traits which were retained following amphidiploidization. The only morphological discontinuity occurred between the two diploids, whereas the morphological range ofS. longipes overlapped the range of both diploids forming a continuum. The lack of discrete clusters is likely due to hybridization and introgression withS. longifolia on one hand, and convergence of traits betweenS. longipes var.monantha andS. porsildii on the other. High a posteriori assignments in classificatory discriminant analysis supports the separation ofS. longipes var.monantha from otherS. longipes specimens. AlthoughS. longipes var.monantha grouped close toS. porsildii, the two groups separate based on leaf shape traits. Overall results support, firstly, the hypothesis thatS. porsildii is a diploid parent species which by hybridizing withS. longifolia gave rise to polyploidS. longipes. Secondly, results suggest thatS. longipes var.monantha converged morphologically towardsS. porsildii relatively recently due to ecological specialization, and merits distinction at least as a variety ofS. longipes.     

Partial resistance to late blight (Phytophthora infestans) in hybrid progenies of four South American Solanum species crossed with diploid S. tuberosum

Resistant genotypes of the diploid tuber-bearing South American species Solarium arnezii x hondelmannii, S. berthaultii, S. leptophyes and S. microdontum were crossed with three diploid genotypes of S. tuberosum that varied in resistance and maturity type. The progenies were field tested for 2 years for resistance to a complex race of Phytophthora infestans. A wealth of genetic variation for resistance was found in most of the progenies. At least two susceptibility groups could be distinguished in some progenies of S. microdontum. This could be explained by the presence of several major resistance genes in the wild parent and, unexpectedly, in the susceptible parent SH 82-44-111. In most of the wild parents and in the susceptible parent SH 77-114-2988 there appeared to be minor resistance genes. General combining ability effects were predominant; small specific combining ability effects were detected in some crosses of S. microdontum. Gene action appeared dominant in some crosses.     

Electrofusion of protoplasts from <Emphasis Type="Italic">Solanum tuberosum</Emphasis>, <Emphasis Type="Italic">S. bulbocastanum</Emphasis> and <Emphasis Type="Italic">S. pinnatisectum</Emphasis>

This paper discusses a number of experiments performed, involving the fusion by an electric field of mesophyll protoplasts from Solanum tuberosum cv. Bintje, S. tuberosum dihaploid clones 243, 299 and the wild tuberous disease-resistant species S. bulbocastanum and S. pinnatisectum. Three fusion experiments (S. bulbocastanum + S. tuberosum dihaploid 243, S. pinnatisectum + S. tuberosum cv. Bintje and S. pinnatisectum + S. tuberosum dihaploid 299) yielded 542 calli, the 52 ones of which produced shoots. Obtained regenerants were estimated by the flow-cytometry (FC) and RAPD analysis to determine hybrid plants.The utilisation of the FC as a useful method for detecting somatic hybrids is also discussed in this paper. The combination S. bulbocastanum + S. tuberosum dihaploid 243 led to the creation of eight somatic hybrids, the combination S. pinnatisectum + S. tuberosum cv. Bintje yielded four somatic hybrids and the combination S. pinnatisectum + S. tuberosum dihaploid 299 resulted in no hybrid regenerants. Morphology in vitro, growth vigour and production of tuber-like structures were evaluated in hybrid plants. Plants were transferred in vivo for further estimation (acclimatization, habitus evaluation and tuberization ability).     

Expression of the S. aureus hysA gene in S. carnosus from a modified E. coli-staphylococcal shuttle vector

We have modified an E. coli-staphylococcal shuttle vector for use in the general cloning and expression of genes from pathogenic staphylococci in Staphylococcus carnosus. As S. carnosus is non-pathogenic, this expression system will facilitate the study of the roles of individual gene products in the disease process. To evaluate the use of this expression system, a DNA fragment containing the Staphylococcus aureus hyaluronate lyase (hysA) gene was cloned into the modified vector, pNW21, and introduced into S. carnosus. Hyaluronate lyase was both produced and secreted by S. carnosus. In addition, the secreted HysA protein was enzymatically active, as determined using a zymographic assay.