A new species of the extinct genus Austrohamia (Cupressaceae s.i.) in the Daohugou Jurassic flora of China and its phytogeographical implications

A new conifer,Austrohamia acanthobractea,sp.nov.,is described from the Jurassic Daohugou flora,Inner Mongolia Autonomous Region,China.The material consists of impressions represented by well-preserved ...     

从叶绿体DNA trnL-F序列论双参属的归属问题

双参属Triplostegia Wall．ex DC．由分布于东南亚地区的2个种组成,为多年生草本植物。它的归属一直存在争议,有时置于川续断科Dipsacaceae或败酱科Valerianaceae,有时单立一科,即双参科Triplostegiaceae。本研究对广义川续断目Dipsacales s．l．的21种植物(分别来自于败酱科、川续断科、双参属、刺参属Morina、广义忍冬科Caprifoliaceae s. l．、五福花科 Adoxaceae)和外类群人参Panax schin-seng Nees．的叶绿体 DNA trnL-F区进行了测序,并建立系统发育树状图。结果显示,败酱科、川续断科、双参属、刺参属和广义忍冬科的4个属(双盾木属Dipelta、虫胃实属Kolkwitzia、六道木属Abelia和北极花属Linnaea)形成了一个单系群并得到了很强的支持(100％ bootstrap);双参属与川续断科有更近的关系,建议作为一个亚科置于川续断科;广义忍冬科为一多系类群;而刺参属与其他广义川续断目类群之间的关系尚不能确定。     

广义柏科主要分类群起源时间的推测

通过构建分子钟对广义柏科主要分类群的起源时间进行探讨。采用相对速率检验法分析广义柏科mat K、rbc L进化速率的稳定性,结果显示rbc L的非同义替代速率只在Pinaceae与Taxodiaceae的分类群及柏科北半球的支系(Cupressoideae)之间通过相对速率检验,而Pinaceae与柏科南半球分支(Callitrodeae)之间没有通过相对速率检验。mar K基因的非同义替代速率在Pinaceae与广义柏科的所有分类群之间通过相对速率检验。根据通过相对速率检验的分类群之间的遗传距离和基因进化速率,计算它们发生分歧的时间。据此推测,杉科的主要分类群Taiwanioideae、Athrotaxidoideae、Sequoioideae与其他分支发生分歧的时间均在侏罗纪,支持现存杉科在侏罗纪就已经建立起来的观点;Cupressaceae(s．s．)的两个支系(亚科)发生分歧的时间在124Ma之前,相当于早白垩世早期,可能由于南北古大陆的完全分离,其祖先居群被分隔成两个亚群,随后各自演化为不同的支系。Callitirodeae、Cupressoideae各属发生分歧的时间也均在白垩纪,表明Cupressaceae(s．s．)在白垩纪就已经建立起来。     

广义紫菀属(菊科紫菀族)系统学研究的现状

广义的紫菀属(Asters.l.)曾是个大包大揽的类群,产于北美和欧亚大陆.Nesom主要根据瘦果的形态和细胞学性状对Asters.l.进行了评价,将北美紫菀类植物从Aster中独立出去,使Aster成为欧亚特有类群.但是,在欧亚各国对Aster有定为一属和分为十多个属等不同的分类学处理,分歧较大.狭义紫菀属(Asters.s.)与从Asters.l.中分出的各属之间的系统学关系,以及后者中某些属与北美紫菀类和紫菀族其他亚族间的系统学关系,都存在很大疑问.过去一直认为北美是Aster的发源地,现在欧亚Asters.l.的起源与演化需要重新研究,而青藏高原是探讨Asters.l.物种多样性形成的关键地区.DNA尤其是DNA序列资料在研究Asters.l.的系统发育和分类上将发挥关键作用.     

广义飞蛾藤属(旋花科)花粉形态

对广义飞蛾藤属Porana s.l.18个分类群的花粉进行了光学显微镜和扫描电镜观察。除前人报道过的7种1变种外,其余均为首次报道。根据花粉粒的大小、形状、外壁纹饰、沟膜特征,该属花粉可细分为4个类型。研究结果不支持Staples(1993)把该属分为4个独立属的观点,而认为在属内划分为4个亚属较为合理。除毛果飞蛾藤外,花粉形态支持Staples对其它种、变种的归并。从花粉萌发孔类型上看,广义飞蛾藤属在旋花科内应处于较为原始的位置。     

A new conifer species, Mesocyparis rosanovii sp. nov. (Cupressaceae, Coniferales), and Transberingian floristic connections

A new species, Mesocyparis rosanovii sp. nov. from the Lower Paleocene of the Amur Region, Russia, is characterized by a combination of advanced and primitive features: mixed opposite-alternate branching of vegetative shoots, leafy microsporophylls, as well as a relatively high number of sporangia per microsporophyll and seeds per cone scale. The Late Cretaceous-Early Paleogene genus Mesocyparis McIver et Basinger, which obviously embraces a natural group of closely related species, was a significant component of the vegetation in the middle and high latitudes of eastern Asia and western North America. The range of the genus testifies to terrestrial Transberingian connections between the continents during the Cretaceous warming phases.     

壳斗科栎属青冈亚属的花粉形态及其系统学意义

对栎属青冈亚属17个种及炭栎花粉形态进行扫描电镜观察。结果表明:青冈亚属和炭栎花粉均为三拟孔沟,球形至长球形,(15～28.0)μm×(15.0～25.6)μm。花粉外壁纹饰可划分为3种:(1)蠕虫状(包括皱波状)、(2)聚合颗粒状、(3)棒状或小刺状。各纹饰在组间镶嵌分布。棒状及小刺状纹饰为栎属花粉较为原始式样,并为青冈亚属与高山栎组及部分巴东组(sect.Cerris)共有,推测其间具有较其它栎类更为接近的亲缘关系,可能为广义栎属中较为基础的类群,而与栎亚属sect.Quercuss.s.,Lobatae和Protobalanus关系较远。花粉形态对广义栎属系统分类价值仅适用于较高分类阶元。     

国产广义飞蛾藤属(旋花科)植物种子表面微形态及其分类学意义

首次报道用扫描电镜观察的国产广义飞蛾藤局10种1变种植物的种子表面微形态特征。该属种子表面微形态特征可分为两大类型,其中I类型又可细分为3个亚型。除模式种Porana volubilis Burm.f.外,广义飞蛾藤属的种子表面微形态特征较为一致。因此,种子表面微形态特征不支持将广义飞蛾藤属拆分为4属或5属。研究结果显示,种子表面微形态在作为属内种的分类鉴别特征具有一定价值,如种子表面微形态支持保留毛果飞蛾藤的变种等级。将种子表面微形态与该广义属的花粉形态,以及宏观形态学特征进行对比分析,结果表明,广义飞蛾藤属种子表面微形态在属下等级的划分上没有很大价值。此外,鉴于P.volubilis Burm.I.具特殊的种子表面微形态特征,该种与广义飞蛾藤属属内其余种的关系值得进一步深入研究。     

广义飞蛾藤属(旋花科)的分支系统学分析

基于33个广义的形态学性状,对广义飞蛾藤属Porana s．l．进行了分支系统学分析。经过简约性分析,得到了10个同等简约的分支树。10个同等简约树的严格一致化树表明,广义飞蛾藤属是一较为自然的分类群。与广义飞蛾藤属的孢粉学、种皮微形态学研究结果一致,分支分析的结果不支持将广义飞蛾藤属拆分为4个或5个独立的属,应在属内划分分类等级。在整个形态分支树中广义飞蛾藤属4个亚属呈并列2个分支,其中飞蛾藤亚属(subg．Porana)和白花叶亚属(subg．Poranopsis)形成姐妹群构成一分支,三翅藤亚属(subg．Tridynamia)和棒状亚属(subg．Dinetus)以姐妹群的关系构成另一支。鉴于分支分析的Bootstrap支持率不高,广义飞蛾藤属范畴的最后界定和属内等级的划分仍有待于进一步研究。     

广义金钱菌属真菌研究概况

广义金钱菌属分布广泛,物种多样性丰富,包括了许多具有食药用价值的种类,具有较高的经济、生态和科研价值,但我国对该类真菌的关注较少。本文回顾了金钱菌属的建立与发展历程,以及分子生物学研究方法应用于该类真菌后其系统学的变化过程;介绍了欧洲与北美地区对栎裸脚伞复合群物种的区分过程;总结了广义金钱菌属真菌在生物防治和药用功效及化学成分研究等方面的研究进展。同时,还发现了各地对广义金钱菌属真菌的分类学研究水平差异较大,各地区研究水平不均衡和分子系统学研究不完善等问题,所以我国亟需对该类真菌资源调查与挖掘,以期为后续研究提供参考依据。     

Human erythrocytes glucose-6-phosphate dehydrogenase: Labelling of a reactive lysyl residue by pyridoxal-5′-phosphate

Reaction of glucose-6-phosphate dehydrogenase from human erythrocytes with pyridoxal-5′-phosphate causes 80% loss of activity. The substrate glucose-6-phosphate fully protects the enzyme against this inhibition, which is reversible upon dilution, but becomes irreversible after treatment with NaBH₄. We presume that pyridoxal-5′-phosphate forms with the enzyme a Schiff base which is reduced by NaBH₄. One mole of N-?-pyridoxyl-lysine is formed per mole of enzyme subunit when the remaining activity reaches its minimal level of 20%.     

Yanliaoa, an extinct genus of Cupressaceae s. l. from the Middle Jurassic,northeastern China

Yanliaoa is a common fossil in the Middle Jurassic of western Liaoning, eastern Inner Mongolia and northern Hebei Province, China. It is an important element of the Yanliao biota. The genus was established by Pan in 1977 for fossil plants from the Middle Jurassic Haifanggou Formation in Xiasanjiaochengzi, western Liaoning Province, and in present paper, the genus Yanliaoa is studied based on new material. Pan never designated a type specimen and his fossil material cannot be located. We designate a type specimen here for Yanliaoa, so that the genus name Yanliaoa remains valid. Yanliaoa sinensis Pan emend. Tan et al., is found in the same locality and formation as the lost specimens, Y. sinensis of Pan, 1977. Yanliaoa daohugouensis n. sp., a new species with epidermal anatomy, is from the Middle Jurassic Daohugou, Inner Mongolia. A holotype is also selected from the new material for this new species. Characters of the leafy shoots and ovulate cones of Yanliaoa are emended. The epidermal anatomy of this genus is described for the first time. Compared with other extant and extinct species of Cupressaceae s. l., the current species can be distinguished from any known species both by the leafy shoot characters and its epidermal anatomy. It further indicates that Yanliaoa is an extinct and endemic conifer found in the Middle Jurassic of northeastern China.     

值得注意的中国南部植物

该文续报道胡麻科、桑寄生科等科7个分类单位。胡麻科的茶菱属和茶菱均为广东新记录。云南槲寄生、锈毛钝果寄生和枫香钝果寄生均为海南新记录。《海南植物志》第二卷记载的五蕊桑寄生(产于琼中),现订正琼中的标本应为枫香钝果寄生,海南不产五蕊寄生属植物。大戟科的子弹枫现已成为广西和广东的归化种。无患子科的雅旗是我国新引种的经济植物。     

Diterpene composition of Cupressus dupreziana and Cupressus sempervirens

The heartwood of Cupressus dupreziana and C. sempervirens were shown to contain similar mixtures of diterpenes.