重唇石斛地上部分化学成分及其生物活性研究

为了解重唇石斛(Dendrobium hercoglossum)的化学成分,利用硅胶、Sephadex LH-20柱色谱和半制备高效液相色谱等方法,从其地上部分分离了14个化合物,经波谱分析,其结构分别鉴定为：3,4,5-三甲氧基苯酚(1)、3-hydroxy-1-(4-hydroxy-3,5-dimethoxyphenyl)-propan-1-one (2)、methyl 3-(p-hydroxyphenyl) propionate (3)、justiciresinol (4)、榕醛(5)、异落叶松脂素(6)、threo-2,3-bis-(4-hydroxy-3-methoxyphenyl)-3-methoxypropanol (7)、(+)-松脂素(8)、aloifolⅠ(9)、dendrocandin T (10)、3-甲氧基-4-羟基苯丙酮(11)、1,3,5-三甲氧基苯酚(12)、香草醇(13)和丁香脂素(14),其中化合物1～12,14均为首次从重唇石斛中分离得到,化合物7、10和14为首次从石斛属植物中分离得到。化合物4、8和10具有显著的酪氨酸酶抑制活性,IC_...     

兜唇石斛多糖的研究

从兜唇石斛（Ｄｅｎｄｒｏｂｉｕｍａｐｈｙｌｌｕｍ）的茎中提取到３种多糖：ＡＰ－１,Ａｐ一２,Ａｐ一３,玻璃纤维纸电泳、超速离心和凝胶层析证明：三者都为单一均匀成分。３种多糖的特性粘数（［ｎ］）分别为４２６．９６,４１６．９６,２３４．０３;分子量（Ｍｗ）分别为８６３００,６１５００,４３１００;旋光度（）分别为－３０．０００,－３３．０００,１７．０００。经化学方法和光谱分析证明：ＡＰ为Ｂ（１→４）连接的、含Ｏ一乙酰基的、吡喃型的直链Ｄ一葡萄甘露聚糖。动物体内试验表明：ＡＰ有免疫增强作用。     

梳唇石斛组织培养(简报)

以梳唇石斛当年生茎段为材料,在MS 6-BA 0.1mg/L(单位下同) NAA 0.01培养基上进行不定芽诱导培养;在MS 6-BA 2.5 NAA 0.05 AC(活性碳)1g/L培养基上进行丛生芽诱导与增殖培养;50d为一个继代周期,繁殖系数为4～5;在1/2MS 6-BA 0.5 NAA 0.05 椰汁100g/L AC 1g/L培养基上进行壮苗培养;在1/2 MS IBA 1.0 AC 1g/L培养基上进行生根培养;最后移栽到小颗粒碳化树皮中,成活率可达90%。     

厚唇裸重唇鱼胚胎发育的形态学观察

采用体视显微镜对厚唇裸重唇鱼的胚胎发育过程进行连续观察和描述。结果表明,受精卵呈卵圆形,卵径较大,吸水膨胀后为(4.41±0.13)mm。在水温为9℃条件下,授精后9h进入卵裂期,23h 30min进入囊胚期,33h进入原肠期,71h进入神经胚期,74h 30min进入器官分化期,210h开始破膜而出,初孵仔鱼全长9.35mm。破膜后16d仔鱼开始上浮。对厚唇裸重唇鱼的胚胎发育特点与其近缘种的差异进行了讨论。     

梳唇石斛试管开花诱导和离体保存

对珍稀濒危药用植物梳唇石斛（Dendrobidium strongylanthum Rchb. f.）离体开花诱导和保存进行试验、观察和分析,研究基本培养基和植物生长调节剂对诱导离体开花的影响以及培养条件对离体保存的影响。结果显示,试管丛芽培养在MS＋6-BA 2 mg/L＋NAA 0.2 mg/L的培养基上,培养20 d试管开花的诱导率高达96%以上。试管丛芽接种在花宝1号3 g/L＋NAA 1 mg/L＋活性炭0.5 g/L培养基上,在12 ℃和HR 60%条件下保存,继代周期可延长至2年。该物种快速繁殖方法和保存技术的成功,为濒危植物梳唇石斛持续利用提供了技术支持。     

基于高通量测序的厚唇裸重唇鱼微卫星分子标记筛选

本研究对厚唇裸重唇鱼(Gymnodiptychus pachycheilus)基因组进行Illumina HiSeq高通量测序,共获得85 905条序列,包含567 200个微卫星位点,从中筛选出15个微卫星位点,采用雅砻江新龙种群和黄河渭河种群对其多态性进行了验证。新龙种群中,15个位点的平均等位基因数为6.9(3 ~ 13),观测杂合度(Ho)为0.712 4,多态信息含量(PIC)为0.630 3,有8个位点显著偏离哈迪-温伯格平衡,1对位点表现出连锁。渭河种群中,15个位点的平均等位基因数为8.4(4 ~ 16),观测杂合度(Ho)为0.719 5,多态信息含量(PIC)为0.680 7,有7个位点显著偏离了哈迪-温伯格平衡,4对位点表现出连锁。筛选获得的15个微卫星位点多态性较高,适合用于厚唇裸重唇鱼种群遗传学研究。     

桂林唇柱苣苔传粉生物学及生殖配置研究

对桂林唇柱苣苔在不同生境下（YZ居群,半野生,林下裸露岩石上;DB居群,洞穴岩石上）的生殖生态学进行了比较研究。结果表明：（1）桂林唇柱苣苔的花期为2月下旬至4月中旬,受环境因素的影响,单花期在DB居群（16~24 d）明显长于YZ居群（10~17 d）;（2）两个居群的P/O比差异显著,花粉量比胚珠量有更明显的变化,这可能与其生境有关;（3）桂林唇柱苣苔属于兼性异交系统,不存在无融合生殖现象;(4)传粉和种子后熟阶段均存在限制,致使各种处理的结实率均处在较低的水平（<45％）;（5）白颊尤垫蜂与小蜂类(DB居群)或蜜蜂(YZ居群)为桂林唇柱苣苔较为稳定的传粉者;（6）桂林唇柱苣苔植株个体越大,花期繁殖投入就越高,繁殖分配越低;（7）与DB居群相比,YZ居群可利用资源较为丰富、植株生物量较大,因此其花期投入繁殖也较高,而DB居群将更多的资源分配给营养器官,从而提高了对资源获取能力。     

雅砻江中游厚唇裸重唇鱼种群结构与生长特性

于2020年10月至2021年3月在四川省甘孜藏族自治州雅砻江江段（雅江县至新龙县）采集厚唇裸重唇鱼（Gymnodiptychus pachycheilus）样本189尾,用以研究雅砻江中游厚唇裸重唇鱼的种群结构与生长特性,分析其野生资源现状、影响因素及保护对策。结果显示雅砻江中游厚唇裸重唇鱼调查种群由3-9龄组成,其中优势年龄组为4-6龄,占样本总数的87.83%;种群平均体长和体重分别为264.1 mm和250.5 g,雌雄性比为1.48：1,雌性和雄性最小性成熟个体年龄均为4龄,对应体长分别为202.0 mm和220.0 mm,对应体重分别为105.0 g和133.0 g;种群的平均肥满度为1.22,体长（L）与体重（W）关系式为W=5.00×10^-6L^3.146（R²=0.948,n=189）,属于匀速生长类型;种群体长和体重的Von Bertalanffy生长方程分别为L_t=727.5[1-e^{-0.097（t-0.508）}],W_t=5224.9[1-e^{-0.097（t-0.508）}]^3.146;生长拐点年龄为12.4龄,对应的体长和体重分别为505.2 mm和1568.3 g。研究表明目前雅砻江中游厚唇裸重唇鱼表现出年龄结构趋于低龄化,体型趋于小型化的种群结构特点,且具有自然寿命较长、生长缓慢、渐近体长较大等生长特性,加之雅砻江饵料基础和水文条件较差等因素,推测雅砻江中游厚唇裸重唇鱼所具备的种群增长潜力较低,其野生资源的自然恢复面临挑战。因此,应尽快开展雅砻江流域厚唇裸重唇鱼野生资源的保护工作。     

基于线粒体控制区序列的黄河上游厚唇裸重唇鱼种群遗传结构

采集黄河上游厚唇裸重唇鱼(Gymnodiptychus pachycheilus)甘肃玛曲群体,测定其线粒体DNA控制区序列,并从GenBank中下载青海玛多和贵德等3地2个群体的同源序列,分析该物种的遗传多样性、遗传结构及其演化历史.从81条729 bp序列中,检测到26个变异位点(占3.57％),碱基序列总的单倍型多样性为0.844,核苷酸多样性为0.0054,界定了34个单倍型,有1个广布单倍型H2,占所有样品的38.27％.单倍型网络图图显示单倍型没有明显的亲缘地理格局,H2处于中心,呈星状发散,系统发育分析没有显示出单倍型与地理位置的对应关系.AMOVA分析显示变异主要来自地理区内群体间,歧点分布和中性检测显示厚唇裸重唇鱼近期经历了种群扩张.分析表明黄河上游3地种厚唇裸重唇鱼种群未出现分化,建议应作为一个整体进行保护.     

珍稀濒危植物小花木兰传粉生物学研究

基于定株观测,对小花木兰（Magnolia sieboldii）野生种群和人工栽培种的开花物候进行了研究。结果表明,小花木兰花期为5月中下旬至6月中下旬,花期20d左右,单花花期一般为5～7d,盛花期为6月1～5日;开花过程中花部表型变化明显,花粉在花开时不成熟,但雌蕊已经成熟,花开后雌蕊柄伸长,约20h后下柱头依然湿润,上柱头已萎缩变褐色,再过约40h下柱头也萎缩失去活力．此时花粉成熟,花药裂开;花的柱头接受到的花粉量由下往上依次减少。检测花粉活力、萌发率发现,小花木兰花粉在散发6d后基本失去活力和萌发能力。重力玻片法观测表明,小花木兰为虫媒传粉;花柱的授粉率不高,为65％;柱头上平均花粉量为3．5个;自然状态下结实率低,为13．5％,人工栽培为20．1％;外轮花被片全部去掉,结果率下降至11．3％;去掉雄蕊,结实率下降至10．7％;再辅以人工授粉,结果率上升至25．0％。小花木兰的访花昆虫种类较少,访花频率低,其中蜜蜂和一种蚜科（Aphididae）小昆虫对其传粉影响较大。同花期灯台附（Cornus controversa）等植物对其传粉产生昆虫竞争作用。环境因素如光照、温度、阴雨、海拔等均对其传粉产生一定影响。     

Pollination Biology of the Endangered Herbal Medicines <i>Dendrobium chrysotoxum</i> (Orchidaceae)

Pollination biology studies of the endangered herbal medicines Dendrobium chrysotoxum were conducted in natural pollination conditions using flower observation, pollinator observation and artificial pollination experiments. Populations of D. chrysotoxum with fragrance and nectar were pollinated by Ctenoplectra davidi Valhalla (Hymenoptera: Apidae) species. The floral structure of D. chrysotoxum adapted precisely to its pollinators. Flowers had a low capsule setting (0.17%) under natural conditions. However, compared to open pollination, artificial pollination experiments showed a significant increase in capsule setting, and D. chrysotoxum was cross-compatible and self-compatible, but there was pollinator limitation also. This study will provide important information for the preservation of this endangered species.     

球花石斛多糖免疫调节作用的研究

本研究目的为评价球花石斛多糖对正常小鼠免疫功能的影响。球花石斛采用碱提醇沉法得到球花石斛多糖,分别以400、600、800mg/kg小鼠灌胃给药连续10d。通过免疫器官重量检测,碳廓清试验,脾脏T、B淋巴细胞转化试验来观察其对免疫功能的影响。结果显示低、中剂量组的脾脏指数与对照组比较有显著性差异(P<0.01),中、高剂量组的吞噬指数、校正吞噬指数和B淋巴细胞增殖能力与对照组比较有显著性差异(P<0.01,P<0.05),表明球花石斛多糖可显著增加脾脏重量,增强巨噬细胞的碳廓清能力和B淋巴细胞的增殖能力。提示球花石斛多糖具有免疫增强作用,是一种良好的免疫调节剂。     

Pollination limitation,costs of capsule production and the capsule-to-flower ratio in Dendrobium monophyllum F. Muell. (Orchidaceae)

Abstract In perennial plants, life-history theory suggests that natural selection should result in the optimization of fruit-to-flower ratios within the limits imposed by the trade-offs between resource allocation for present reproduction and future growth and reproduction. The tropical orchid Dendrobium monophyllum F. Muell., an epiphyte or lithophyte, offers no nectar rewards, is self-incompatible and has a capsule-to-flower ratio of about 1:14. The influence of pollination limitation and the costs of capsule production on capsule-to-flower ratios were assessed using experimental and field studies in which individual plants were observed for 3 years. Pollinators visited about 80% of flowers, and capsule production was significantly related to inflorescence size and pollinaria removal. About nine pollinator visits occurred per capsule. Pollinator visitation and capsule production did not vary significantly between years. The inflorescence size classes most successful in capsule production were also the most frequent in natural populations. The experimental supplementation of outcross pollen to flowers increased capsule set over controls by 45% within a year, but was limited to about 53%. A capsule-to-flower ratio of 1:2 in experimental plants significantly decreased the subsequent growth and flowering of individuals relative to controls. A capsule-to-flower ratio above 1:10 in naturally pollinated plants decreased flowering in the subsequent year. Thus, it is suggested than an increase in capsule production above 10% would not necessarily correlate with greater reproductive fitness because of the increased cost of capsule production. The capsule-to-flower ratio recorded in this study could be evolutionarily stable because of trade-offs between selection for pollinator attraction and the cost of capsule production. The production of surplus flowers appears to function in pollinator attraction and increases fitness through male function.     

美花石斛菌根真菌接菌方式与接种效应初步研究

自然条件下,兰科菌根真菌的共生对于兰科植物种子萌芽和植株生长是必不可少的。为探讨有益共生真菌对兰科植物生长的促进作用,特别是在实验室环境下接菌方式的改变与接种效应直接的联系,本研究从野生美花石斛(Dendrobium loddigesii Rolfe.)新鲜营养根中分离、筛选出3种菌根真菌（M1、M2和M3）,采用单一接菌和混合接菌的接种方式,分析3个菌株及其不同接种方式对美花石斛生长的影响。研究得到优势菌株M1和M3,并证实混合接菌对美花石斛的生物量增长具有较好的正效应,两两混合接种方式M1-M2、M2-M3及3个混合接种方式M1-M2-M3均能较好的促进美花石斛生物量的积累。充分发挥混合接菌对兰科植物生长发育所产生的效能,提高生产效率,具有较强的现实意义。     

香豆素类成分在球花石斛(Dendrobium thyrsiflorum Rchb.f.)根中的分布和相对含量

利用激光共聚焦显微技术(laser scanning confoeal microscopy,ISCM)观测了香豆素类成分(coumarins)在球花石斛(Dendrobium thyrsiflorum Rchb.f.)根中的分布及相对含量,为合理利用药用石斛提供科学的理论依据。观察结果显示香豆素类成分主要分布于球花石斛根的细胞壁,尤以细胞的角隅处为多;自发荧光强度以外皮层的最高,根被的最低。     

Comparative account of nectary structure in Hexisea imbricata (Lindl.) Rchb.f. (Orchidaceae)

• Background and Aims Despite the number of orchid speciesthat are thought to be pollinated by hummingbirds, our knowledgeof the nectaries of these orchids is based solely on a singlespecies, Maxillaria coccinea (Jacq.) L.O. Williams ex Hodge.Nevertheless, it is predicted that such nectaries are likelyto be very diverse and the purpose of this paper is to comparethe nectary and the process of nectar secretion in Hexisea imbricata(Lindl.) Rchb.f. with that of Maxillaria coccinea so as to beginto characterize the nectaries of presumed ornithophilous Neotropicalorchids. • Methods Light microscopy, transmission electronmicroscopyand histochemistry were used to examine the histology and chemicalcomposition of nectary tissue and the process of nectar secretionin H. imbricata. • Key Results and Conclusions The nectary of H. imbricatahas a vascular supply, is bound by a single-layered epidermiswith few stomata and comprises two or three layers of subepidermalsecretory cells beneath which lie several layers of palisade-likeparenchymatous cells, some of which contain raphides or mucilage.The secretory cells are collenchymatous and their walls havenumerous pits with associated plasmodesmata. They contain thefull complement of organelles characteristic of secretory cellsas well as intravacuolar protein bodies but some of the secretoryepidermal cells, following secretion, collapse and their anticlinalwalls seem to fold. Nectar secretion is thought to be granulocrineand, following starch depletion, lipid droplets collect withinthe plastids. The nectar accumulates beneath the cuticle whichsubsequently forms swellings. Finally, nectar collects in thesaccate nectary spur formed by the fusion of the margins ofthe labellum and the base of the column-foot. Thus, althoughthe nectary of H. imbricata and M. coccinea have many featuresin common, they nevertheless display a number of important differences.     

文卉石斛，福建石斛属(兰科)一新变种

记载了在福建省发现的兰科石斛属植物一新变种——文卉石斛Dendrobium luoi var. wenhuii W. L. Yang,并描述其与原变种罗氏石斛D. luoi L. J. Chen et W. H. Rao和近缘种D. zhenghuoense S. P. Chen, L. Ma & M. H. Li的形态特征区别。     

Floral longevity and nectar secretion of Platanthera chlorantha (Custer) Rchb. (Orchidaceae)

Flowering and nectar secretion were studied in Platanthera chlorantha in two years. Nectar was secreted and accumulated in this orchid's spur, originating from part of the labellum. The nectary spur was, on average, 32 mm long. It produced 6.86 micro l nectar in 1999 and 7.84 micro l in 2000. The number of flowers per inflorescence and the volume of nectar secreted per flower were not correlated. Nectar secretion and flower longevity differed depending on pollination and flower position in the inflorescence. Among pairs of pollinated and unpollinated flowers there was no difference in the volume of nectar produced; however, the life span of pollinated flowers was shorter than that of unpollinated ones. Within an inflorescence, the lowest-positioned flowers had the largest nectar production and the longest life compared with flowers positioned higher up.     

束花石斛种子超低温保存的研究

以濒危兰科物种野生束花石斛（Dendrobium chrysanthum）的成熟种子为材料,研究了PVS2植物玻璃化液对其萌发的作用,以及快速冷冻法和玻璃化法对种子超低温保存的影响。结果表明,种子的萌发率随着PVS2处理时间的延长而下降。PVS2预处理能明显地增加种子的超低温耐性。当预处理时间为15～45min时,种子的超低温耐性随预处理时间的延长而增加;当预处理时间长于60min后,种子的超低温耐性随预处理时间的延长而下降。经液氮保存后,存活的种子能萌发成为正常的幼苗。结论是经PVS2预处理45min后,成熟的束花石斛种子能成功地进行超低温保存。