Morphology of Laurencia clavata and L. elata (Ceramiales,Rhodophyta) in relation to generic circumscription in the Laurencia complex

Laurencia Lamouroux (Rhodophyta) was recently separated into three genera–Laurencia, Chondrophycus (Tokida et Saito) Garbary et Harper and Osmundea Stackhouse – each of which was newly defined based on vegetative and reproductive structures. In this study, the previously unknown vegetative and reproductive morphology of two Australian endemic species of Laurencia, L. clavata Sonder and L. elata (C. Agardh) Harvey, was studied, particularly in the context of the revised generic delineation. These species exhibit vegetative axes with four pericentral cells and trichoblast-type spermatangial development. Tetrasporangia are abaxially produced from the existing third and fourth pericentral cells. L. clavata has terete thalli with distinctive verticillate branching and is similar to Chondria C. Agardh, rather than to Laurencia, in having an unusually marked constriction at the base of the branches and starch accumulation in subcortical and medullary cells. Compared to Laurencia, apical cells of this species exhibit a less oblique division ; the resulting recognizable axial cell rows extend somewhat below the branches, and particularly at a young stage they are also clear throughout branchlets. However, other vegetative and spermatangial structures show that L. clavata is more closely allied to Laurencia than to Chondria, and it is placed in Laurencia. By contrast, L. elata exhibits morphology typical of Laurencia and is characterized by large, robust, compressed thalli with fastigiately distichous branching and an extensive secondary cortex. Furthermore, it appears to be distinct from similar species in sometimes having a parasitic species of Janczewskia Solms-Laubach (Rhodophyta). Taxonomy of Laurencia is discussed on the basis of these and previous studies.     

不同菌材对天麻(Gastrodia elata)产量的影响

以速生树种亮叶桦（Betula luminifera Winkler）和响叶杨（Populus adenopoda Maxim）、经济树种核桃（Juglans regia Linn）为菌材,壳斗科菌材白栎（Quercus fabri Hance）为对照,分别设置不同的菌材用量和麻种用量水平,仿野生栽培红杆天麻（Gastrodia elata Bl.f.elat）和乌杆天麻（Gastrodia elata Bl.f.glauca S.Chow）,分析不同菌材对天麻产量的影响,筛选出高产的菌材种类、用量和天麻变型及麻种用量的组合,探讨亮叶桦、响叶杨和核桃代替壳斗科植物栽培天麻的可行性。结果表明：不同菌材对红杆天麻和乌杆天麻产量的影响有差异。两种天麻变型对菌材的偏好不同,红杆天麻在白栎和亮叶桦菌材处理下的平均产量高于响叶杨和核桃菌材处理下的产量,而乌杆天麻在亮叶桦和核桃菌材处理下的产量高于响叶杨和白栎菌材处理下的产量。两种天麻变型的最高产量的组合均出现在亮叶桦菌材伴栽的处理中。响叶杨伴栽天麻,效果不及亮叶桦和核桃。4种菌材对天麻的折干率影响不明显。在实际生产中,以亮叶桦、核桃和响叶杨作为替代菌材是完全可行的。从72个处理中筛选出高产的组合,单位面积菌材和麻种用量分别如下：12 kg亮叶桦菌材搭配0.8 kg红杆天麻麻种,12 kg核桃菌材搭配0.6 kg红杆天麻麻种,14 kg响叶杨菌材搭配0.8 kg红杆天麻麻种;14 kg亮叶桦菌材搭配0.6 kg乌杆天麻麻种,12 kg亮叶桦菌材搭配0.6 kg乌杆天麻麻种,10 kg核桃菌材搭配0.8 kg乌杆天麻麻种。     

云南的复叶耳蕨属(ArachniodesBl.)植物

对云南产复叶耳蕨属植物进行了再次的分类订正研究,确认云南有该属植物20个种类,其中,华南复叶耳蕨Arachniodesfestina(Hance)Ching和齿头复叶耳蕨A.aristata(Forst.)Tindale为云南分布新记录;将《中国植物志》等资料中的Acrorumohradissecta、Arachniodesailaoshanensis、A.australis、A.austro-yunnanensis、A.caudata、A.chinensisvar.cornopteris、A.chinensisvar.jinpingensis、A.chingii、A.dayaoensis、A.futeshanen-sis、A.gongshanensis、A.guangtongensis、A.lushuiensis、A.pianmaensis、A.pseudo-aristata、A.pseudo-assa-mica、A.shuangbaiensis、A.sinoaristata、A.sporadosora和A.triangularis等20个名称作为新异名处理。还列出了云南产该属植物的分种检索表、名称的处理及分类讨论、地理分布等。     

野生天麻DNA导入马铃薯实现遗传转化的研究

采用浸苗法将野生天麻总DNA导入马铃薯试管苗,对筛选得到的转化植株进行蛋白及药用成份的分析。结果显示:(1)在200株转化的马铃薯中有21株的紫外扫描图谱与正常对照组有显著差异,且在220nm有明显吸收峰。(2)5株经PCR扩增出野生天麻抗真菌蛋白(GAFP)基因。(3)转基因马铃薯与正常马铃薯的蛋白表达有明显差异,并且在转基因马铃薯中有一条与野生天麻抗真菌蛋白(GAFP)相同的条带。而正常马铃薯中无此条带。(4)通过薄层层析法检测出3株转基因马铃薯表达野生天麻的有效药用成份天麻素。说明采用浸苗法进行外源总DNA导入是可行的。     

天麻3种变型开花生物学特性的研究

在天麻开花时,对略阳红秆、绿秆、乌秆天麻3种变型的花果期,花茎、花被筒及子房的长度,果实、种子及胚的长度、宽度等进行了观察研究,结果发现：天麻的这3种变型在每个方面都有一定的差异,乌秆天麻花茎最高,果实和种子最长,开花、结果日期最晚;红秆天麻花序轴、每株结果数、果实重量和种子直径最大,开花、结果日期最早;绿秆天麻花、果期最短,而胚的长度和直径却最大。     

天麻糖复合物抗衰老作用的实验研究

天麻糖复合物是从兰科植物天麻的根茎中提取的水溶性物质,经柱色谱将其分为两个组分,分别命名为：Con.1,Con.2;考察灌胃后两个组分对小鼠血清中超氧化物岐化酶活性和过氧化脂质含量的影响,同时探讨两个组分对小鼠和果蝇的抗衰老作用及其机制.结果Con.1 0.1g/kg.d能明显提高小鼠血清中T-SOD活性,降低血清中过氧化脂质降解产物（MDA）含量;Con.1可延长果蝇的平均寿命和最高寿命,因此Con.1具有明显的抗衰老作用。但Con.2影响结果不明量.     

天麻特异DNA序列的克隆及其在天麻鉴定中的应用

应用改进的RAPD方法测定了名贵中药材天麻基因组DNA指纹图谱;通过选择和回收各种天麻种群共有和优良种群特有的DNA片段,加以克隆、测序和生物信息学分析,证明其中5个DNA序列是未报道的,已被美国基因数据库收录,并运用高效液相色谱技术测定了天麻样本的有效成分天麻素含量。运用PCR技术研究了这些DNA序列在9个天麻种群中的分布及其与天麻素含量的关系。结果表明这5个DNA序列在这些天麻种群中的分布各不相同,其中DNA序列1是所研究的全部天麻种群共有、而其伪品没有的特异DNA分子标记;DNA序列2可能与天麻的天麻素含量高有关。这些DNA标记序列可用于天麻的真伪鉴别、品种鉴定和优选优育等。     

天麻及其5种伪品红外指纹图谱鉴别研究

采用傅立叶变换红外光谱法对天麻及其伪品(马铃薯、红薯、芋头、黄精、菊芋等)的材料粉末和提取物粉末进行了光谱特征比较研究.结果表明,天麻与其5种伪品的红外图谱之间在指纹区分别存在明显差异;红外指纹图谱差异程度依次为醇提物>水提物>原粉末,与伪品的主要差异集中在1 750~950 cm-1区,该区是天麻有效成分的重要特征区.研究表明,利用红外光谱法可以简便直观地将天麻粉末、天麻提取物粉末与其相应的伪品区分开来,为天麻中药材生产及提取物的质量控制提供了重要依据.     

基于HPLC-MS的西藏天麻的化学成分分析与品质鉴定

目的:天麻具有许多药理作用和重要开发价值,通过探索天麻的未知化学成分和鉴定西藏天麻种群的品质,为深入研究、开发和利用西藏优良天麻种群提供科学技术支持。方法:本研究采用HLPC-MS(液质联用)技术测定西藏天麻的化学成分;采用高效液相色谱技术测定西藏6个天麻种群的生化指纹图谱,利用天麻素峰面积、数学公式和SPSS软件,计算和比较西藏6个天麻种群的平均天麻素含量和各种化学成分分离峰的总面。结果:从天麻块茎中发现了33个未报道的化学物质;西藏天麻的生化指纹图谱具有7个较大的共有特征分离峰,分别位于1.854、2.759、7.279、7.591、8.500、9.557、10.753min;根据生化指纹图谱特征可将它们分为三个主要类型;凡是带有一型生化指纹图谱的天麻个体和种群往往含有更高的天麻素和更大的分离峰总面积,品质更优良。结论:西藏天麻种群3和种群6以一型生化指纹图谱为主,其天麻素含量最高,分离峰总面积最大,品质最优良,具有重要研究、开发和保护价值。本研究成果对于天麻的化学成分分析与鉴定、天麻种群和品质鉴定与评价以及西藏天麻的品种选优、资源保护与利用具有重要指导意义和科学价值。     

A chromosome-scale Gastrodia elata genome and large-scale comparative genomic analysis indicate convergent evolution by gene loss in mycoheterotrophic and parasitic plants

Mycoheterotrophic and parasitic plants are heterotrophic and parasitize on fungi and plants, respectively, to obtain nutrients. Large-scale comparative genomics analysis has not been conducted in mycoheterotrophic or parasitic plants or between these two groups of parasites. We assembled a chromosome-level genome of the fully mycoheterotrophic plant Gastrodia elata (Orchidaceae) and performed comparative genomic analyses on the genomes of G. elata and four orchids (initial mycoheterotrophs), three parasitic plants (Cuscuta australis, Striga asiatica, and Sapria himalayana), and 36 autotrophs from various angiosperm lineages. It was found that while in the hemiparasite S. asiatica and initial mycoheterotrophic orchids, approximately 4–5% of the conserved orthogroups were lost, the fully heterotrophic G. elata and C. australis both lost approximately 10% of the conserved orthogroups, indicating that increased heterotrophy is positively associated with gene loss. Importantly, many genes that are essential for autotrophs, including those involved in photosynthesis, the circadian clock, flowering time regulation, immunity, nutrient uptake, and root and leaf development, were convergently lost in both G. elata and C. australis. The high-quality genome of G. elata will facilitate future studies on the physiology, ecology, and evolution of mycoheterotrophic plants, and our findings highlight the critical role of gene loss in the evolution of plants with heterotrophic lifestyles.