国产兜兰属植物观赏价值评价及其在华南地区的应用前景分析

以植株的生长状况、整株姿态、叶片观赏性、开花性、花形、花色和花朵观赏期为评价指标,利用灰色关联分析,对我国原产的27种兜兰属植物的观赏价值进行了综合评价并分析了它们在华南地区的应用前景。结果表明:多花长瓣型的飘带兜兰与理想种的关联度最高,达到0.7304,是最值得在华南地区栽培的兜兰种类,其次为白旗兜兰。而紫纹兜兰、汉氏兜兰;文山兜兰、格利兜兰、带叶兜兰、亨利兜兰、同色兜兰,它们的关联度系数超过0.6;紫毛兜兰、巨瓣兜兰、红旗兜兰、天伦兜兰、长瓣兜兰、根茎兜兰的关联度均超过0.5;也是值得推广兜兰种类;杏黄兜兰、硬叶兜兰、白花兜兰由于生长状况差、开花性差等原因与理想种的关联度分别只有0.1900、0.1921、0.2917,不适于华南地区栽培;其它9种兜兰的关联度虽然介于0.35~0.50之间,但其中有些种类如虎斑兜兰、麻栗坡兜兰、波瓣兜兰、德氏兜兰等由于具有独特的观赏价值和育种潜力,也是值得在华南地区栽培的兜兰种类。     

国产兜兰属植物的引种和栽培

兜兰由于独特的花朵造型、绚丽的花朵色彩、持久的观赏花期而具有极高的观赏价值,是国际上栽培最广泛的兰花之一。由于生态环境的破坏以及人们对其过度地采挖,兜兰现已成为世界上最濒危的植物物种之一,许多种类已濒临灭绝,所有兜兰野生种均被列入《濒危野生动植物种国际贸易公约》(CITES)附录I而被禁止交易。进行兜兰的迁地保护是兜兰种质资源保护最有效的措施之一。作者于2003~2008年对原产于中国的兜兰属植物进行了系统的引种,已收集到了原产于中国的所有兜兰种类,并种植于中国科学院华南植物园具有加温和水帘降温设施的科研温室中,所有种类均已成活并开花,但不同种类的生长状态和开花率表现出较大的差异。对兜兰属植物的引种方法和栽培技术也进行了探讨。     

濒危物种杏黄兜兰的保育生态学

杏黄兜兰(Paphiopedilum armeniacum)是中国特有的兰科濒危物种。自2000年4月1日至2005年10月10日,在云南省怒山的落砂坡山选取66个调查点进行杏黄兜兰保育生态学研究:对443基株共1302分株进行了繁殖式样、物候和生命周期等主要生物学特性,以及对该物种的生境要求、群落结构特征等生态学习性进行了观察研究,并在广东省深圳进行迁地保护和迁地繁殖后重返原产地的试验,研究了原产地的气候、植被和其他环境因素与杏黄兜兰之间的关系以及杏黄兜兰迁地栽培和繁殖的无性后代重返原生长地的生物学特性。研究结果表明:落砂坡山的杏黄兜兰在石灰岩上的次生灌木丛或草丛内生长良好;它兼具有性和无性繁殖,无性繁殖的目的就是实现有性繁殖和延长基株的寿命;无性繁殖有二种形式:产生分蘖或根茎;灌木丛或草丛的落叶为杏黄兜兰生长提供腐殖质,杏黄兜兰根茎繁殖是它对落叶等覆盖的一种适应;分株的开花率为7.39%±1.02%,开花分株的结果率为32.23%±12.08%;杏黄兜兰具有入侵适度破坏和正处于恢复初期的森林环境的能力,而在茂密连片的大树森林内不能生长。杏黄兜兰在深圳人工疏林下生长良好并繁殖许多无性的克隆分株,将繁殖的克隆分株重返原产地能正常开花和结实。试验结果显示,杏黄兜兰可以进行迁地保护以保存种质资源和迁地繁殖的植株回归原产地。基于杏黄兜兰濒危机制的分析,认为,杏黄兜兰生存所面临的威胁是生长空间被完全剥夺和人为灭绝性采集而不是其自身存在的生物学缺陷,为此,提出了相应的保育对策。     

贵州省野生兜兰属植物资源现状及保护成效分析

兰科(Orchidaceae)兜兰属(Paphiopedilum)植物花形奇特,研究价值和观赏价值都很高,对环境要求严格,是生物多样性保护中的“旗舰”类群。为掌握贵州省野生兜兰属植物资源现状和保护成效,该研究对野生兜兰属植物进行专项调查,对其资源量、分布格局、受威胁因素和就地保护等进行分析。结果表明:(1)共调查到8种兜兰属植物的103个分布点,分布于27个县,以南部、西南部为主要分布区,生境复杂多样,自然分布不均衡。(2)各物种分布面积从大到小的顺序为硬叶兜兰>小叶兜兰>麻栗坡兜兰>巨瓣兜兰>带叶兜兰>长瓣兜兰>白花兜兰>同色兜兰,资源丰富度从高到低的顺序为硬叶兜兰>小叶兜兰>带叶兜兰>巨瓣兜兰>麻栗坡兜兰>白花兜兰>长瓣兜兰>同色兜兰。(3)该类群受干扰因素复杂,受威胁较为严重,其中过度采挖、干旱、生境退化和破碎化是其濒危的主要原因。(4)该属“有效保护(EP)”2种,“较好保护(WP)”1种,“一般保护(GP)”2种,“较少保护(LP)”3种,未找到目标物种以致“保护状况不明(PSU)”2种。已调查到的物种保护率达100%,但分布点保护率仅29.13%,各物种分布点保护率差异显著; 建议相关部门有针对性地提升全省兜兰属植物的保护强度,进一步优化保护方式和范围,确保这些珍稀濒危的植物资源得到持续的生存发展。     

濒危植物的区系性质与迁地保护

对昆明植物园迁地保护的濒危植物的适应性进行了观察总结,并讨论了濒危植物的区系性质与其对迁地保护区适应性的关系。原产云南中部和东南部的濒危植物对迁地保护区的环境有较强的适应性。大部分种类都能正常生长、开花和结果。广布种一般比分布区狭窄种有更强的适应能力。冬季低温制约着一些濒危植物在迁地保护区的生存。而冬春季节干旱制约高山种类的生存。一些种类虽生长、开花正常,但因其传粉媒介的缺乏而不结实。因物种的生理生态特性的差异,即使具有相同区系性质的不同种类也具有不同的适应性。     

南方红豆杉迁地保护小种群适应性进化机制研究

为了解南方红豆杉迁地保护种群的适应性进化机制,以南京中山植物园内南方红豆杉迁地保护栽培种群和扩散的衍生种群为材料,以引种初始地江西野生种群为对照,对南方红豆杉群落的结构、遗传多样性及遗传结构进行分析和研究。结果表明,南方红豆杉野生种群和迁地保护种群均维持着较高水平的遗传多样性,其中野生种群遗传多样性稍高于迁地保护小种群,但迁地保护种群中南方红豆杉个体密度大于野生种群。同时,种群内的遗传变异所占比例大于种群间的。整体来看,南方红豆杉迁地保护种群还处于演替早期,存在不明显的奠基者效应,有进一步演替发展的可能。     

兜兰属宽瓣亚属（广义）的被充研究

对新种小囊兜兰Paphiopedilum globulosum与新变种扁球兜兰P.micranthum var.oblatum作了描述与绘图。两者均为采自云南东南部的栽培植物,与硬叶兜兰P.micranthum近似。但小囊兜兰具有宽得多的叶（宽2．8－3．4cm),先端多少呈钩状、宽1．1－1．2cm的辱瓣,以及与唇瓣囊口几乎同样大小的退化雄蕊,而扁球兜兰则叶宽2．2－3cm,唇瓣扁球形,囊深不超过1cm,可区别于硬叶兜兰。上述种类均属于宽瓣亚属（广义）。该亚属有16个种产中国、越南或两地共有。本文提供了分种检索表。     

野生沙葱的资源分布与保护利用

分析了野生沙葱的资源分布、生态适应性、营养价值、研究与利用现状,提出了在全国范围内进行沙葱资源的分布范围、分布类型、种源特征、遗传变异、群落特征及其演替规律的调查与确定,建立沙葱的种质资源库和数据库,全面开展不同种源沙葱的迁地保护、生态适应性、保护生物学及人工优质丰产栽培技术研究等一系列保护、利用的思路与措施。     

带叶兜兰5个野生居群表型多样性分析

以云南、广西、贵州的5个带叶兜兰主要野生居群分布区为研究对象,采用巢式方差分析、表型分化系数、主成分分析、相关分析、聚类分析等分析方法,对带叶兜兰的18个性状的表型多样性进行分析。结果显示:带叶兜兰表型性状在居群间表现出显著或极显著差异,居群内变异较少。带叶兜兰平均表型分化系数为75.18%,居群间的变异是居群多样性的主要来源;18个表型性状变异系数平均值的变化范围为6.36%～18.51%,离散程度较高。主成分分析表明,造成带叶兜兰表型变异的主要来源是株高、子房长、花茎高、最大叶长、花横径和合萼片长6个性状。Pearson相关分析表明,株高、合萼片宽和中萼片宽等与大部分性状均呈显著或极显著正相关;18个性状中只有合萼片长与地理因子极显著相关。聚类分析结果表明,5个居群大致依据地理距离聚为3个类群。本研究发现,带叶兜兰居群遗传多样性较高,居群间的变异远高于居群内的变异,因此,应尽可能保护更多的野生居群,在原地保护的基础上建立种质资源保存圃、库,进行人工繁殖和育种,以利用促保护。     

中国云南兜兰属（兰科）一新种

20 0 0年 6～ 7月间 ,我们在云南文山、昆明和广西平南等地发现 ,该地生长或栽培的所谓“紫纹兜兰”已经相继开花。而在深圳市梧桐山的紫纹兜兰野生群落每年要到 1 0～ 1 2月左右才开花 ,这就引起我们的注意 ,并对两种不同产地和不同花期的实体进行了较为深入的比较。紫纹兜兰Ｐ .ｐｕｒｐｕｒａｔｕｍ (Ｌｉｎｄｌ.)Ｓｔｅｉｎ的模式标本采自香港 ,在民间被称为“香港小姐”。据说今天在香港地区已较难觅到其芳踪了。 1 990年夏天我们在靠近香港新界的梧桐山上发现了野生的紫纹兜兰居群。它生长在以杜鹃花科、山茶科等植物占优势的乔灌木群…     

Encapsulation of moss buds: an efficient method for the in vitro conservation and regeneration of the endangered moss <Emphasis Type="Italic">Splachnum ampullaceum</Emphasis>

In vitro culture techniques are usually employed for ex situ conservation of endangered plant species. However, encapsulation to preserve threatened bryophytes is scarcely used, and only as a pretreatment prior to cryopreservation. In our study, two different methods of germplasm conservation, involving calcium-alginate encapsulation of moss material, were assessed. The plant material used was gametophyte buds (gametophores) of Splachnum ampullaceum Hedw., a rare species of moss. Moss regeneration was evaluated at different periods of time to examine the efficacy of the technique for moss germplasm conservation. The effects of encapsulation and cold storage on developmental parameters such as protonematal colony diameter, bud length, and number of buds were also studied. The results suggest that moss encapsulation with no prior treatment may be a suitable method for germplasm conservation during long periods of time. With our method survival rates as high as 50% could be reached after 2.5 years of cold storage versus 0% of 24-h cryopreserved beads. This technique together with cold storage, avoiding freezing, may be especially important in desiccation intolerant mosses.     

初论中国兜兰属植物的保护策略及其潜在资源优势

兜兰属植物是最受人们喜爱的兰科植物之一 ,中国是兜兰属植物的主要产地。与世界其他地区一样 ,我国兜兰属植物也面临持续的商业采集压力。本文回顾了世界兜兰属植物的贸易、栽培和育种的历史 ,认为有菌播种方法可以更有效地保护兜兰属植物的多样性 ,同时也能够为兜兰属植物的人工栽培和育种提供新的手段。目前我国兜兰属植物一方面仍遭受各种人为因素的干扰 ,急需采取措施加以保护 ;另一方面对我国兜兰属植物的认识还不够全面和深入 ,还不能对人为因素影响的程度和范围作出客观的评价 ,特别是有关兜兰属植物的繁育技术还很薄弱。针对这种现状 ,作者提出在较长时期内我国兜兰属植物的保护策略宜以原地保护 (insituconservation)为主 ,同时积极开展有关兜兰属植物保护生物学的基础研究 ,大力发展和完善迁地保护 (exsituconservation)技术体系。最后 ,讨论了我国兜兰属植物的潜在资源和生态等方面的优势。     

Mycorrhizal specificity, preference, and plasticity of six slipper orchids from South Western China

Mycorrhizal fungi of six endangered species, Paphiopedilum micranthum, Paphiopedilum armeniacum, Paphiopedilum dianthum, Cypripedium flavum, Cypripedium guttatum, and Cypripedium tibeticum, from two closely related genera in the Orchidaceae from Southwestern China, were characterized using the nuclear internal transcribed spacer (ITS) and part of the large subunit gene of mitochondrial rDNA (mtLSU) sequences. The most frequently detected fungi belonged to the Tulasnellaceae. These fungi were represented by 25 ITS sequence types and clustered into seven major clades in the phylogenetic analysis of 5.8S sequences. Species of Paphiopedilum and Cypripedium shared no fungal ITS sequence types in common, but their fungal taxa sometimes occurred in the same major clade of the 5.8S phylogenetic tree. Although it had several associated fungal ITS sequence types in a studied plot, each orchid species had in general only a single dominant type. The fungal sequence type spectra of different species of Paphiopedilum from similar habitats sometimes overlapped; however, the dominant sequence types differed among the species and so did the sequence-type spectra within Cypripedium. Orchids of P. micranthum and P. armeniacum transplanted from the field and grown in two greenhouses had a greater number of mycorrhizal associations than those sampled directly from the field. Root specimens from P. micranthum taken from the greenhouses were preferably associated with mycobionts of the Tulasnella calospora complex, while those from the field had mycorrhizal associations of other tulasnelloid taxa. Such plasticity in mycorrhizal associations makes ex situ conservation or even propagation by means of mycorrhization of axenically grown seedlings possible.     

Preservation of plant genetic resources in the biotechnology era

Thousands of years ago humans began domesticating crops as a food source. Among the wild germplasm available, they selected those that were best adapted for cultivation and utilization. Although wild ancestors have continued to persist in regions where domestication took place, there is a permanent risk of loss of the genetic variability of cultivated plants and their wild relatives in response to changing environmental conditions and cultural practices. Recognizing this danger, plant ex situ genebank collections were created since the beginning of the last century. World-wide, more than 6 million accessions have been accumulated including the German ex situ genebank in Gatersleben, one of the four largest global collections, housing 150,000 accessions belonging to 890 genera and 3032 species. This review summarizes the ex situ plant genetic resources conservation behavior with a special emphasis on German activities. Strategies for maintenance and management of germplasm collections are reviewed, considering modern biotechnologies (in vitro and cryo preservation). General aspects on genetic diversity and integrity are discussed.     

Genetic diversity and genetic structure of different populations of the endangered species Davidia involucrata in China detected by inter-simple sequence repeat analysis

Dove tree (Davidia involucrate) is a Tertiary relic species endemic to China and is reputed to be a ‘living fossil’ in the plant kingdom. Genetic diversity and genetic structure of this species were analyzed for its conservation and management, using inter-simple sequence repeat (ISSR) data obtained from eight populations distributed throughout seven provinces of China. A relatively high level of genetic diversity, at both population and species levels, was detected using the POPGENE software. Analysis of molecular variance (AMOVA) revealed a moderate level of among-population variation (i.e., 33.21%). The genetic structure of dove tree was closely consistent with their isolated topographical distribution region based on the results of the STRUCTURE, POPGENE-UPGMA and PCA analysis. It is postulated that the relatively high level of genetic diversity has been maintained because of: (a) the original wild geographical distribution, (b) propagation through outcrossing seeds or root suckers, (c) the longevity of individuals and (d) the relatively little human disturbance. Genetic drift and restricted gene are important factors affecting genetic differentiation. There was no significant correlation between geographical distances and a pairwise comparison with genetic distances, as analyzed by the Mantel test, but the clustering result of genetic diversity was consistent with their isolated topographical distribution regions. Thus, maintaining the stable special habitats associated with this species is recommended for the in situ conservation. Furthermore, it is important to develop an effective seed germination system for the maintenance of an ex situ conservation pool of the germplasm resources.     

High genetic diversity of in situ and ex situ populations of Madagascan coffee species: further implications for the management of coffee genetic resources

The genetic diversity of endemic Madagascan Coffea species has not received any considerable attention, despite the high extinction threat facing most of the species on the island. In order to address this shortfall, we assessed and compared the genetic diversity and allelic richness of ex situ and in situ populations for four selected species, and 18 ex situ populations maintained at the Kianjavato Coffee Research Station. We also investigated the possibility of in situ and ex situ hybridization events for Madagascan coffee, both within and between species. For these purposes, we used 18 nuclear microsatellite markers, on a total of 37 Coffea populations (4 in situ and 33 ex situ) representing a total of 398 genotypes (96 in situ and 302 ex situ) for 23 species. Our study showed (1) strong differentiation between Madagascan Coffea species; (2) good differentiation between all the populations studied, including those from the same locality (even when the area of the locality was restricted); (3) good evidence for both in situ and ex situ hybridization, although in situ hybridization appeared to be limited; (4) much higher genetic diversity within in situ collections compared to ex situ collections; and (5) that, despite limitations, the Kianjavato Coffee Research Station collection is an extremely valuable resource of Madagascan coffee germplasm. Recommendations for in situ and ex situ germplasm conservation are discussed.     

High throughput measure of diversity in cytoplasmic and nuclear traits for unravelling geographic distribution of rosemary

In the present work, variability of both cytoplasmic and nuclear microsatellite traits was investigated with the aim of characterizing a set of rosemary germplasm resources (Salvia rosmarinus). Most of the materials were collected in Italy and France. High‐resolution melting curves were compared each other computing their Euclidean distances and estimating the differences within their principal component as a measure of genetic diversity. Mantel correlation results combined to linear discriminant analysis allowed examined populations to be divided in four principal groups corresponding to four geographic areas, with few interesting and discussed exceptions. As rosemary propagates by seeds coming from insect mediated pollination, steady wild populations can be expected to be in panmictic equilibrium. Gained results confirmed and extended precedent characterization of rosemary genotypes and are compatible with the distribution of other Mediterranean species, as well as with the presence of a glacial refugium in the north‐east area of Sardinia previously described. As the officinal use of this aromatic shrub is spreading, characterization and conservation of wild Mediterranean germplasm is gaining strategic importance. A core collection of 100 genotypes was pointed out as suitable for a cheaper biodiversity ex situ preservation as well as for subsequent metabolic and linkage disequilibrium analyses.