宏观藻类化石及其相关的“前寒武纪谜”:对天津蓟县剖面中元古代早期高于庄组第三段中一些现象的思考

在漫长的前寒武纪,存在若干谜一样的问题,如叠层石的生长机理、臼齿状构造的成因、白云岩的形成机制和宏观藻类化石的生物学属性及其分类归属等。宏观藻类化石是指那些肉眼可见的低等植物化石,因为与现代藻类的亲缘关系尚未完全确定,它们的生物学属性及其分类位置还存在较多的争议,所以宏观藻类化石成为一个"前寒武纪谜"。发现于天津蓟县剖面高于庄组第三段非叠层石灰岩(均一石灰岩)中的可能的实体宏观藻类化石,与成因还存在争议的臼齿状构造共生,包括球状丘尔藻、椭球状寿县藻、带状塔乌藻和豆荚状荚藻等4种类型,尤其以前两种居多,组成一个丘尔藻-寿县藻组合;这些多为球状体的化石,曾经被认为是臼齿状构造的一种,称为"球状臼齿状构造",但是,由于这些宏观藻类化石具有规则的形态、较为明显的可能的细胞显微结构,与充填臼齿状构造的方解石微亮晶形成明显的区别,不属于臼齿状构造;而且以实体化石产出,与多年来所描述的碳质压型化石又存在较大的区别;同时,该球状化石的中心部位硅化而边部为钙化体,也明显区别于一般的钙质结核、燧石结核、凝灰岩结核和气泡构造等。这些球状实体化石,要比H.J.Hofmann所报道的加拿大麦肯齐山小达尔群(Little Dal Group)的臼齿状构造灰岩中的实体宏观藻类化石的形成时代要老得多,有可能是最为古老的实体宏观藻类化石。高于庄组臼齿状构造灰岩中的实体宏观藻类化石,成为思考若干前寒武纪谜的重要现象。     

THE BETAINES FROM CHINESE SEAWEEDS

Cation-exchange chromatography was selected to extract and separate betaines from marine algae. On the basis of the special chemical characteristics of the betaines and their analogues,Dragendorff‘ s reagent ( KBiI4 ) was used to test the existence of betaines and their analogues in marine algae. The total content of betaines from seven species was obtained by using the Reinkeate salt precipitation method. The results showed that the content of betaines in two species of Chlorophyta and two species of Rhodophyta were relatively high, and that the content of betaines in Enteromopha prolifera could even reach to 0.9%. The content in the three species of Phaeophyta was relatively low.     

Late Wuchiapingian (Late Dzhulfian,early Late Permian) limestone olistolites within the Tertiary flysch of Glypia Unit (Mount Parnon,central–eastern Peloponnesus,Greece)

Some olistolites reworked in a Tertiary flysch of Mount Parnon (Peloponnesus, Greece) exhibit a Late Permian assemblage, dominated by Paradunbarula (Shindella) shindensis, Hemigordiopsis cf. luquensis and Colaniella aff. minima. This association corresponds to the Late Wuchiapingian (=Late Dzhulfian), a substage whose algae and foraminifera are generally little known. Contemporaneous limestones crop out in the middle part of the Episkopi Formation in Hydra, but they are rather commonly reworked in Mesozoic and Cainozoic sequences. The palaeobiogeographical affinities shared by the foraminiferal markers of Greece, southeastern Pamir, and southern China, are very strong (up to the specific level), and are congruent with the Pangea B reconstructions. To cite this article: E. Skourtsos et al., C. R. Geoscience 334 (2002) 925–931.     

The flora and fauna associated with Himanthalia elongata (L.) S. F. Gray in relation to water current and wave action in the Lough Hyne marine nature reserve

The growth of epiphytes (plant and animal) was investigated at various stages in the development of the low littoral alga Himanthalia elongata. The vegetative thallus, or button, is very resistant to the settlement of epiphytes on its upper surface, but susceptible to extensive coverage on its lower surface and stalk, especially by Bryozoa and spirorbid worms. The receptacles or straps are invaded by a microforest of filamentous algae, which in turn provides accommondation and in many cases food for many invertebrates, including gastropods, amphipods and larval Diptera. Spirorbid worms on the underbuttons are confined to sites sheltered from strong water currents and wave action, but other epiphytes of the underbuttons show little regard for these features. Microfores and its associated fauna are restricted to sheltered sites. Perspex discs set up as imitation Himanthalia buttons were colonized by the same epiphytes as real Himanthalia buttons, but on both sides, indicating the existence of a special protective mechanism for the upper surfaces of real Himanthalia buttons.     

中国黄、渤海胶毛藻目(Chaetophorales, Chlorophyta)初探

根据编写《中国海藻志》的需要, 在我国海藻学前辈们的一些工作积累的基础上，我们结合近几十年来国际上胶毛藻目海藻研究进展及其变动情况，并查阅部分相关文献，对中国黄渤海绿藻门胶毛藻目(Chaetophorales, Chlorophyta)海藻进行了初步的分类学探讨。目前, 中国黄、渤海区此目包含1科(胶毛藻科Chaetophoraceae Greville), 3属：内枝藻属Entocladia Reinke、帕氏藻属Pringsheimiella H?hnel及笠帽藻属(新拟)Ulvella P. L. Crouan et H. M. Crouan，3种，即内枝藻Entocladia virid is Reinke、盾形帕氏藻Pringsheim iella scutata (Reinke) H?hnel ex Marchew ianka及盘形笠帽藻(新拟)Ulvella lens P. L. Crouan et H.M. Crouan，其中，第2第3种为中国的新记录种。     

甘氨酸镁对南极冰藻促生长作用研究

研究了甘氨酸镁对南极冰藻的促生长作用。甘氨酸镁已被美国和欧盟等发达国家大量用作新型无公害植物促生长剂和丰产剂。用不同浓度的甘氨酸镁 (0 ,2 5× 1 0 - 6,5 0× 1 0 - 6,1 0 0× 1 0 - 6,2 0 0× 1 0 - 6,40 0× 1 0 - 6)对国家海洋局海洋生物活性物质重点实验室保存的南极冰藻L 1绿藻 (Pyramimonassp.)和 H1硅藻 (Bacillariophyceae )进行培养。实验结果表明 ,甘氨酸镁对南极冰藻 L1绿藻和 H1硅藻有显著促生长作用 ,而且从 L1绿藻和 H1硅藻的生长曲线可以看出 ,甘氨酸镁浓度越高促生长作用越强 ,这将为海洋微藻的培养提供一种新型的生长促进剂     

Interaction Between Macrophytobenthic Groups on the Sublittoral Belt of a Greek Island

Abstract. The interrelationships between the main phytobenthic groups of Chlorophyceae, Phaeophyceae, and Rhodophyceae around Milos Island, Central Aegean Sea, were studied using standard ecological and mathematical methods. The analysis was based on seasonal sampling of 114 different macrophytobenthic species.
The employed ecological indices revealed that the sampling areas located on the north, south, and east side of Milos Island show similar annual fluctuations in abundance and species diversity. The resemblance was particularly high between all stations in October-February, between south and east stations during May, and between north and east stations during July.
Additionally, an annual cycle of group interaction with regard to species diversity and abundance exists between the Chlorophyceae, Rhodophyceae, and Phaeophyceae. The Rhodophyceae are the most abundant and dominant group throughout the year, showing percentages in the samples higher than 70% in all sampling areas.     

核酸分析技术在红藻分子系统学研究中的应用

在红藻的分子系统学研究中,核酸分子数据的获得和应用日益显得重要,因为核酸序列是进化的重要单元,通常以点突变来体现种间/种内的差异,因此能反映物种进化过程的频率.目前,在红藻分子系统学研究中,核酸标记技术有：限制性片段长度多态性（RFLP）、随即扩增多态性DNA（RAPD）、扩增片段长度多态性（AFLP） 和简单重复序列间扩增（ISSR）;相关核酸分析技术涉及到的序列有：内转录间隔区（ITS）、18S和26S rRNA,核糖体大、小亚基（LSU和SSU）,Rubisco基因及大、小亚基.其在红藻品种鉴定、种群遗传、分类和系统进化的研究中起重要的作用.     

水体内藻类的生物地球化学

藻类对水体内生命元素的转化及其分布、迁移的影响．是目前水体内藻类生物地球化学研究的重点内容。藻通过光合作用和生物矿化，控制着C、N、Si、P、S、Ca等元素在水体内的循环；驱动着C和S在水体和大气之间的交换，进而影响大气中的C和S。藻生物积累及其对环境变化的及时反馈，使藻类成为地球化学环境变化的生物指示物。本文对水体内藻类的生物地球化学进行了综述。