濒危植物南川升麻生殖特性的研究

研究了南川升麻的生殖生物学特性,并探讨了其致濒的原因。南川升麻只分布在中国四川省金佛山地区,仅１个居群,个体总数６０００￣８０００株,其中开花植株约占１９％左右;花序圆锥状,花期８月中至１０月初,１１月中下旬果实成熟。南川升麻雌雄异熟,表现为大约花谢７ｄ后柱头才发育成熟;自然条件下可正常受精,但频率低,结籽率平均仅为５．８％￣７．０％,可授期内人工异株授粉,结籽率可提高到２８．０％;胚乳核型,种子     

濒危植物南川升麻传粉生物学的研究

南川升麻（ＣｉｍｉｃｉｆｕｇａｎａｎｃｈｕａｎｅｎｓｉｓＨｓｉｓｏ）的繁育系统以异交为主,传粉昆虫主要为蝇类,盛花时的访花频率平均每花每天１１次,雄蕊脱落后约０６次;单穗升麻（Ｃ．ｓｉｍｐｌｅｘＷｏｒｍｓｋ）以虫媒为主,风也可以帮助其花粉在近距离传播。单穗升麻的传粉昆虫有蝇类和蜂类,盛花时的访花频率蝇类为１．４次,蜂类为１．２次。南川升麻和单穗升麻都是靠大的花序和气味来吸引传粉昆虫,报酬是退化雄蕊基部分泌的蜜液。自然条件下南川升麻每个柱头上平均有４枚花粉,结籽率平均为６４％,而单穗升麻每个柱头上平均有１７枚花粉,结籽率平均为４５９％。南川升麻有性生殖中传粉的限制是其致濒的重要因素之一。     

Pollination Biology in Cimicifuga nanchuanensis,an Endangered Species (Ranunculaceae)

The pollination biology of Cimicifuga nanchuanensis Hsiso, an endangered species and C. siraplex Wormsk, a widespread species as a control, has been studied. Protandry occurs in both species, the former goes further than the latter. The breeding system of C. nanchuanensis is dominantly xenogamous. The average visitation rate of flies as the main pollinators is 1.1 and 0.6 per flower per day at anthesis and after stamen shedding respectively. C. simplex is mainly an entomophilous plant. However, wind pollination could occur within a short distance. Moreover, a certain ratio of self pollination exists also in this species. The mean visitation rates of flies and bees, the main pollinators of C. simplex, are 1.4 and 1.2 respectively at anthesis. The pollinating insects of both plant species are attracted by their big inflorescences and the fragrant odor. Nectar, the reward for pollinators, produces in the secretory cells at the base of the spoonform staminode. In natural conditions, an average of 17 pollen grains are found on the surface of a stigma resulting in a mean seed set rate of 45.9 %. Pollination limitation (very few pollinators and their low efficiency of pollination) in C. nanchuanensis is one of the weak links in its life cycle and one of the reasons for the endangerment of this species.     

泰山白首乌塑料大棚弥雾蔓插育苗技术

利用塑料大棚弥雾进行泰山白首乌蔓茎扦插育苗,加快了白首乌的繁殖速度。实验证明：6月中旬选用IBA 1000mg/kg处理扦插生根率为72％,8月20日进行大田移栽,移植成活率达95％。     

Studies on the Structure,Afterripening and Cytochemistry of Seeds in Eleutherococcus brachypus Harms

Seeds of Eleutherococcus brachypus Harms were flat-kidney-shaped and their seed coats were only composed of one layer of cells. Embryos with abundant protein in their cells were just at the heart-shaped stage and were capped by sacs formed from degenerating endosperm cells when seeds shed from their maternal plants. A large amount of stored protein grains and lipids existed in endosperm cells but no polysaccharide grains were present either in endosperm cells or in embryo cells. Viable seeds were only 9.27% of the total. The plump seeds germinated in the cultivated field after 18～19 months and their germinating rate was 1.67%. Besides, the content of protein decreased gradually and a few polysaccharide grains were stored in embryo cells during the process. The afterripening process of seeds stratified at different temperatures ended after 6 months and the cytochemistry features of the seeds were that the content of protein decreased gradually and numerous polysaccharide grains had been stored in embryo cells at the late heart-shaped embryo stage and retained till the mature embryo stage. The structure, afterripening and cytochemistry of seeds were compared between Eleutherococcus brachypus and Eleutherococcus senticosus. The poor quality of the seeds, longer time of afterripening in a natural state and much lower germination rate of E. brachypus are considered to be important reasons for the endangerment of this species. Somemeasures are suggested for its conservation based on the above facts.     

湖北赛武当自然保护区野生珍稀植物优先保护定量研究

通过对湖北赛武当国家级自然保护区内的野生珍稀植物资源进行调查,运用濒危系数、遗传价值系数和物种价值系数,计算出物种优先保护值,以确定物种濒危等级和优先保护等级。结果显示：（1）该区内共有珍稀保护植物33种,隶属于26科33属,其中易危15种、近危11种、安全种7种;（2）该区珍稀植物优先保护值的范围为0.2631~0.6985,据此得出33种珍稀植物的优先保护等级为：Ⅰ级6种、Ⅱ级13种、Ⅲ级12种、Ⅳ级2种。（3）本研究结果与相关珍稀保护植物名录的濒危等级和优先保护级别存在较大差异,这可能是由于生境破碎化和人为干扰导致大部分植物在本区受威胁程度加重,因此应强化管理。     

银杉花粉生命力及其变异

中国特有植物银杉(Cathay argyrophylla)是最濒危的松杉类植物之一。研究表明,受精前胚珠的高败育率是银杉生殖效率低的重要原因之一,但迄今对银杉花粉活力及其变异仍不得而知。由于花粉活力对授粉、受精、种子产量和质量以及后代适合度都有直接影响,该研究采用TTC染色和体外萌发法测定了来自大瑶山(Dayaoshan, DYS)和花坪(Huaping, HP)两个地区7个种群16个个体52份银杉花粉样品的生活力。结果表明银杉花粉的活力水平(93.3%)与其它裸子植物相当,干燥低温条件下银杉的花粉活力比较稳定,体外萌发的适宜蔗糖浓度在13%左右。ANOVA分析揭示种群内个体间的花粉活力差异不大(p>0.05),而地区内的种群间及地区间的花粉活力有显著差异(p<0.05)。银杉花粉活力与其生殖成功没有相关性。在上述基础上,从控制授粉的角度讨论了银杉的保护策略和复壮的可能性。     

基于DNA条形码评估西双版纳国家级自然保护区对樟科植物进化历史的保护

为评估西双版纳国家级自然保护区对樟科这一重要植物类群进化潜力的保护情况, 揭示将物种进化历史纳入生物多样性保护评估的重要性, 本研究通过对西双版纳地区长期的野外调查并查阅标本记录与文献资料, 整理出该地区樟科13属121种物种的具体分布信息, 以植物条形码ITS序列作为分子标记构建了反映整个西双版纳地区樟科植物系统发育关系的系统发育树。我们以此为基础, 从物种层面分析了各物种的进化特异性(evolutionary distinctiveness, ED), 从区域层面分析了自然保护区内、外以及32个行政乡镇的系统发育多样性(phylogenetic diversity, PD), 并结合物种丰富度(species richness, SR)与物种濒危等级, 综合探讨了西双版纳国家级自然保护区对樟科植物进化历史的保护情况。研究发现, 西双版纳国家级自然保护区仅拥有整个西双版纳地区54.5%的樟科物种数, 却保护了该地区樟科植物约88.8%的进化历史, 没有被列入保护范围但却拥有高系统发育多样性的区域有打洛镇、易武乡等。就物种而言, 进化特异性相对较高的19个物种中, 有5种(26.3%)在自然保护区内没有分布; 濒危等级高的54个物种中, 有20种(37.0%)在自然保护区没有分布, 同时拥有高进化特异性和濒危等级的物种仅有1种不在保护区内分布。结果表明, 虽然西双版纳国家级自然保护区对樟科这一植物类群的系统发育多样性以及高保护价值物种的保护较好, 但仍有部分重要樟科植物的进化历史没有涵盖在现有自然保护区范围内; 按照传统方法设定的自然保护区虽能在一定程度上保护樟科物种的进化历史, 但仍然存在与标准化系统发育多样性保护策略相矛盾的地方。因此, 今后在建立自然保护区时, 应将系统发育多样性考虑在内, 以保护生物多样性应对环境变化的潜力。     

Seed Dormancy and Germination in Cimicifuga nanchuanensis

Seed anatomy, dormancy breakage, the temperature effect to seed germination and seed life-span of Cimicifuga nanchuanensis Hsiao were studied and the endangerment of this plant in association to these biological characteristics was explored. The embryos were at the globular stage at the time of seed shedding in late November. Low temperature and humid conditions or treatment with exogenous GA3 stimulated the development of embryos and sped up the process of seed germination. The optimum temperature of germination was 20 ℃, but the seeds almost lost their viability after 9 months of storage. Nevertheless, in its natural habitation, the seeds could not acquire enough environmental humidity to accomplish their after-ripening during the dry and cold winter from late November to the following March; after then the temperature in the spring (averaged 10.1 ℃ in April and May) was much lower than 20 ℃ or so which is favorable for seed germination. Moreover, the testa could not provide adequate protection for the embryos and the short life-span of the seeds prevents their survival until the next germination. Therefore it seems reasonable to infer that the unfavorable environmental condition during the process of after-ripening until seed maturation is involved in the cause of endangerment of this plant species.     

物种濒危状态等级评价概述

濒危等级是确定物种优先保护顺序和制订濒危物种保育策略的重要依据,《生物多样性公约》、相关国际组织和一些国家都把物种濒危状态的评价作为生物多样性保护工作中的一个重要步骤。本文对IUCN和美国、加拿大等国在物种濒危状态评价中有关等级标准、评价程序、数据信息采集管理及网络应用方面的问题进行了分析。国际上物种濒危状态评价工作呈现出以下几个方面的发展趋势：(1)物种濒危等级评价标准由定性指标向定量指标发展;(2)物种濒危状况评价程序逐步规范严格,评价过程透明,公众积极参与;(3)数据信息的采集逐步标准化,储存与管理更新采用计算机及网络技术;(4)物种濒危等级的公布与更新逐步以网络形式为主;(5)全球对物种濒危状态评价工作日益重视,物种濒危等级信息在物种资源利用、保护及其他方面的应用愈加广泛。在此基础上,作者提出了我国在物种濒危状况评价中急需加强的3个方面的工作：(1)建立我国的物种濒危等级评价标准;(2)建立完善的物种濒危等级评价程序并制定相关的指导性文件;(3)加强濒危物种评价中数据信息的规范采集、网络管理和数据共享。     

濒危植物南川升麻种群数量动态的分析

运用种群静态生命表、生殖力表和Leslie矩阵模型,研究了中国特有的濒危植物南川升麻种群数量动态过程。结果表明,南川升麻种群为衰退型种群,种群的净增殖率、内禀增长率和周限增长率较低,种群世代周期偏长,在25a内种群幼苗数量和总数量呈现出持续下降的趋势。南川升麻种群经历了两次死亡高峰期,受到了环境筛的强烈过滤作用。     

云南省小黑山自然保护区兰科植物多样性及保护评价

云南省小黑山自然保护区孕育了丰富的兰科植物。据调查,保护区有兰科植物43属、134种,约占云南省135属、780种的31.9%和17.2%,是保护区种子植物种类最多的科。兰科植物在保护区的各个生态类型中均有出现。保护区134种兰科植物以附生兰占优势,占67.16%(90种);其次,地生兰占31.34%(42种),腐生兰为1.50%(2种)。保护区兰科植物起源于新、旧世界的热带和温带,热带属占70.0%(28),温带属占27.5%(11)。鉴于兰科植物重要的保护价值,应加强保护区兰科植物的保护。首先应加强保护区的建设和管理,还应加强社区经济发展,加强科学研究,实施社区共管以及加大保护宣传力度。     

云南种子植物分布新记录

报道了云南新记录种子植物10种7变种1变型,隶属于9科16属,即柔毛泡花树、山青木、白毛四照花、缙云四照花、沙梾、小叶臭味新耳草、纤枝兔儿风、小苦荬、兔儿风蟹甲草、华合耳菊、纤细半蒴苣苔、尾叶黄芩、长唇筒冠花、南川鼠尾草、短叶虾脊兰、带唇兰、类头状花序藨草和细杆筇竹等。     

雅鲁藏布江下游地区兰科植物濒危程度和优先保护序列研究

在对雅鲁藏布江下游地区兰科（Orchidaceae）植物资源进行调查的基础上,结合资料收集和标本查阅,利用多个评价指标定量计算各濒危植物的优先保护值,确定该区域珍稀濒危兰科植物的濒危等级和优先保护序列。结果表明：对雅鲁藏布江下游地区的60属156种濒危兰科植物濒危等级进行评价,其中处于极危（CR）状态的有15种,处于濒危（EN）状态的有46种,处于易危（VU）状态的有78种,处于近危（NT）状态的有17种;优先保护范围值为0.853 9～0.416 8,其中被划分为Ⅰ级保护植物有45种,Ⅱ级保护植物有72种,Ⅲ级保护植物有39种。该研究结果与各种保护植物名录的濒危程度和优先保护级别存在较大差异,大部分兰科植物在该区受威胁程度加强,与这些兰科植物在雅鲁藏布江下游地区现实生存状态基本保持一致,对该区域兰科植物的保护迫在眉睫,应引起足够重视。     

Dynamics of novel forests of Castilla elastica in Puerto Rico: from species to ecosystems

Novel forests (NFs)—forests that contain a combination of introduced and native species—are a consequence of intense anthropogenic disturbances and the natural resilience of disturbed ecosystems. The extent to which NFs have similar forest function as comparable native secondary forests is a matter of debate in the scientific community. Little is known about the performance of individual species in those forests. This study focuses on the functional attributes of Castilla elastica NFs in Puerto Rico and on the differences between introduced and native species growing side by side in these forests. Rates of processes measured here were later compared with data from literature about NSFs. I hypothesize that juvenile plants of C. elastica in NFs have higher survival rate than those of native species and that C. elastica trees have faster biomass fluxes than native trees. To test the hypotheses, I measured survival rates of juvenile plants and tree growth and characterized the aboveground litter fluxes and storage. Although juvenile plants of native species displayed higher survival rates than those of C. elastica (53% vs. 28%), the latter was dominant in the understory (96%). Stand biomass growth rate was 2.0 ± 0.4 (average ± one standard deviation) Mg·ha⁻¹·year⁻¹ for the whole forest, and Guarea guidonia, a native species, exhibited the highest tree growth. Total litter fall was 9.6 ± 0.5 Mg·ha⁻¹·year⁻¹, and mean litter standing stock was 4.4 ± 0.1 Mg·ha⁻¹. Castilla elastica litter fall decomposed twice as fast as that of native species (5.8 ± 1.1 vs. 3.03 ± 1 k·year⁻¹). Literature comparisons show that the present NFs differ in some rates of processes from NSFs. This study brings unique and detailed supporting data about the ecological dynamics under mature novel forest stands. Further comprehensive studies about NFs are important to strengthen the body of knowledge about the wide range of variation of emerging tropical ecosystems. Due to the large increase in the area covered by NFs, greater attention is needed to understand their functioning, delivery of ecological services and management requirements.     

Seeds of alpine plants are short lived: implications for long-term conservation

Background and Aims

Alpine plants are considered one of the groups of species most sensitive to the direct and indirect threats to ecosystems caused by land use and climate change. Collecting and banking seeds of plant species is recognized as an effective tool for providing propagating material to re-establish wild plant populations and for habitat repair. However, seeds from cold wet environments have been shown to be relatively short lived in storage, and therefore successful long-term seed conservation for alpine plants may be difficult. Here, the life spans of 69 seed lots representing 63 related species from alpine and lowland locations from northern Italy are compared.

Methods

Seeds were placed into experimental storage at 45 °C and 60 % relative humidity (RH) and regularly sampled for germination. The time taken in storage for viability to fall to 50 % (p₅₀) was determined using probit analysis and used as a measure of relative seed longevity between seed lots.

Key Results

Across species, p₅₀ at 45 °C and 60 % RH varied from 4·7 to 95·5 d. Seed lots from alpine populations/species had significantly lower p₅₀ values compared with those from lowland populations/species; the lowland seed lots showed a slower rate of loss of germinability, higher initial seed viability, or both. Seeds were progressively longer lived with increased temperature and decreased rainfall at the collecting site.

Conclusions

Seeds of alpine plants are short lived in storage compared with those from lowland populations/related taxa. The lower resistance to ageing in seeds of alpine plants may arise from low selection pressure for seed resistance to ageing and/or damage incurred during seed development due to the cool wet conditions of the alpine climate. Long-term seed conservation of several alpine species using conventional seed banking methods will be problematic.     

Compositional and Thermal Properties of Thylakoid Polar Lipids of Nerium oleander L. in Relation to Chilling Sensitivity

The polar lipid classes from thylakoids of Nerium oleander L. were studied with the aim of relating changes in their composition and thermal behavior with reported changes in the transition temperature of their polar lipids and chilling sensitivity of their leaves. With an increase in growth temperature, the transition temperature of phosphatidylglycerol increased from 16°C to 26°C, and for sulfoquinovosyldiacylglycerol from 19°C to 24°C. Transitions in the other lipid classes were below −10°C for plants grown at both growth temperature. The major changes in the molecular species of phosphatidylglycerol, with increasing growth temperature, were an increase in 1-oleoyl-2-palmitoyl phosphatidylglycerol from 21 to 39% and a decrease in 1-oleoyl-2-trans-3-hexadecanoic phosphatidylglycerol from 51 to 25%. Although the disaturated species increased from 8 to 23%, the maximum was less than that reported for chilling-sensitive plants. There was no change in the sum of the palmitic, hexadeca-trans-3-enoic and stearic acids. Dipalmitoyl sulfoquinovosyldiacylglycerol increased from 12 to 20% and 1-linolenoyl-2-palmitoyl sulfoquinovosyldiacylglycerol decreased from 40 to 30%. It is concluded that the increase in the transition temperature of the polar lipids and the sensitivity of acclimated oleander plants to chilling could not be predicted by the absolute sum of the saturated fatty acids or disaturated molecular species in phosphatidylglycerol. The polar lipid transition appears to be a product of mixing of both high and low melting-point lipids.     

兰科盆距兰属（Gastrochilus）植物的修订

本文对盆距兰属（Ｇａｓｔｒｏｃｈｉｌｕｓ）植物作了修订,共分３个组,含４６种和１变种,其中１个组（Ｓｅｃｔ．Ｃａｅｓｐｉｔｏｓｉ）和８个种（Ｇ．ｃａｒｎｓｕｓ,Ｇ．ｇａｒｈｗａｌｅｎｓｉｓ,Ｇ．ｌｉｎｅａｒｉｆｏｌｉｕｓ,Ｇ．ｇｕａｎｇｔｕｎｇｅｎｓｉｓ,Ｇ．ｓｕｂｐａｐｉｌｌｏｓｕｓ,Ｇ．ｎａｎｃｈｕａｎｅｎｓｉｓ,Ｇ．ｓａｃｃａｔｕｓａｎｄＧ．ｇｏｎｇｓｈａｎｅｎｓｉｓ）为新的,首次在本文作了描述报导。本属属的形态特征,研究历史和订正后属下的分类群检索表,种的文献引证、简短的特征记要和地理分布以及在属中被排除的分类单位索引均提供在本文。     

Natural history, biogeography, and endangerment of Hawaiian dry forest trees

We describe the floristic composition of Hawaiian dry forest trees and identify natural history characteristics and biogeographic variables that are associated with risk of endangerment. Hawaiian dry forests are comprised of 109 tree species in 29 families, with 90% of all species endemic, 10% indigenous, and 37% single-island endemics. Forty-five percent of Hawaiian dry forest taxa are at risk of endangerment. Dry forest taxa at risk have a significantly larger range size compared to taxa from other Hawaiian forest types. Dispersal mechanism was a significant predictor of a species occurrence in dry forest compared to other forest types based on logistic regressions clustered by lineage. Among dry forest taxa, hermaphroditic breeding systems, autochorous dispersal mechanisms, conspicuous flowers, and dry fruit were all more likely to be at risk of endangerment. When analyses were clustered by lineage using logistic regressions, only dispersal mechanism and flower size were significant predictors of risk and taxa with autochorous dispersal and conspicuous flowers were more likely to be at risk. The Big Island, Maui, Oahu, and Kauai all have remarkably similar numbers of dry forest taxa (63–65 species) and dry forest taxa at risk of endangerment. However, Big Island and Kauai have the highest number and percentage of single-island endemics. These results demonstrate patterns of endangerment specific to Hawaiian dry forests, the high levels of endangerment in this forest type, and the importance of prioritizing conservation in dry forest regions.     

香木莲有性生殖特性与其濒危机制的研究

针对香木莲（Manglietia aromatica Dandy)结籽率低以及野外实生苗稀少的现象。本文研究了香木莲雌配子体发育过程,花粉萌发力,开花生物学特性与种子结构的观察。结果表明,在雌配子体发育阶段存在以下退化现象：1）从大孢子母细胞开始减数分裂到功能大孢子形成阶段,在此过程中珠心内的功能结构发生退化,功能大孢子未能正常形成,仅残留有退化痕迹,退化率为27．9％;2）胚囊成熟时,受精前卵器细胞发生退化,退化率为80％,花粉萌发实验结果表明,在人工培养条件下具有正常萌发能力的花粉不足0．01％,这些都是香木莲结籽率低的重要原因,同时,香木莲的开花生物学特性限制了传粉的顺利进行。调查和研究的结果显示,人为的砍伐是造成香木莲种群急剧减少的直接原因;有性生殖障碍和生境破坏是制约香木莲种群更近的最主要因素,由此提出了对香木莲的拯救和保护对策,就地保护;研究并推广繁育技术,进行种群重建;进行迁地保护,保存尽可能多的种质资源。