A phylogenetic analysis of Pisum based on morphological characters, and allozyme and RAPD markers

Cladistic analyses of 17 wild and cultivated pea taxa were performed using morphological characters, and allozyme and RAPD (random amplified polymorphic DNA) markers. Both branch-and-bound and bootstrap searches produced cladograms that confirmed the close relationships among the wild species and cultivars of Pisum proposed by a variety of systematic studies. Intraspecific rankings were supported for northern P. humile, southern P. humile, P. elatius and P. sativum, which together comprise a single-species complex. P. fulvum, while clearly the most divergent of the pea taxa, could also be assigned to the same species complex without violating the hierarchial logic of the cladogram. Its inclusion or exclusion depends on whether the level of interfertility it displays with other pea taxa or its overall morphological and chromosomal distinction are emphasized. As suggested by previous studies, northern P. humile was the most likely sister taxon to cultivated P. sativum; although, rigorous phylogenetic evaluation revealed a close genealogical affinity among P. elatius, northern P. humile and P. sativum. Despite their limited number, the 16 morphological characters and allozyme markers used precisely organized the pea taxa into established taxonomic groupings, perhaps in part reflecting the role morphology has played historically in pea classification. The RAPD data also generally supported these same groupings and provided additional information regarding the relationships among the taxa. Given that RAPDs are relatively quick and easy to use, are refractory to many environmental influences, can be generated in large numbers, and can complement traditional characters that may be limited in availability, they provide a valuable new resource for phylogenetic studies.     

Molecular biology and systematics of an extinct Lemur:Pachylemur insignis

The systematic position of the extinctPachylemur insignis has been controversial: some authors consideredPachylemur as a lemur, whereas others viewed it closer toVarecia. Its classification in the genusLemur orVarecia thus remained an open question. DNA extraction from subfossil bones, using a non-destructive method, allowed us to obtain enough material to make a Southern blot. The hybridization ofPachylemur withEulemur fulvus, Lemur catta, andVarecia variegata highly repeated DNA probes showed that only theVarecia probe gave a positive signal on hybridization on thePachylemur blot. These results indicate thatPachylemur must be considered closer to the genusVarecia than toEulemur andLemur.     

葡萄属营养器官的比较解剖学及其系统学意义

本文对国产葡萄属24个种、6个变种和4个美洲种进行了比较解剖学研究。比较观察了茎、节、 叶柄、叶片的维管系统、厚角组织、厚壁组织、毛状体、后含物、叶表皮角质等解剖学特征。并讨论了它们在系统学上的意义。     

金粟兰科的起源,演化及其分布

本文利用形态解剖,孢粉学及化石资料,讨论了金粟兰科的系统;并对其起源,演化和现代分布格局形成等问题做了合理推测,主要结果如下：（１）Ｓａｒｃａｎｄｒａ和Ｃｈｌｏｒａｎｔｈｕｓ的亲缘关系最接近,而Ａｓｃａｒｉｎａ和Ｈｅｄｙｏｓｍｕｍ的系统位置最靠近。Ｓａｒｃａｎｄｒａ是金粟兰科中最原始的属,而Ｈｅｄｙｏｓｍｕｍ则是最进化的属。（２）金粟兰科可能于白垩纪最早期起源于木质部无导管的,具简单两性虫媒花的祖     

16S rDNA analysis reveals phylogenetic diversity among the polysaccharolytic clostridia

Abstract Small subunit rDNA sequences were determined for 13 mesophilic, polysaccharolytic, mainly cellulolytic species of the genus Clostridium and one cellulolytic Eubacterium specues. Sequences were compared to those of 36 representatives of mesophilic and thermophilic clostridia, including those of nine thermophilic polysaccharolytic species published previously. The majority of strains group with 23S rRNA clusters I and III, while the others group with the thermophilic polysaccharolytic clostridia, i.e. C. stercorarium, C. thermolacticum and C. thermocellum . Lack of close genetic relationships between the various polysaccharolytic species is unexpected and may indicate that these biotechnologically important organisms differ with respect to the enzymology of polysaccharolytic degradation as well.     

Catapyrenium (Verrucariaceae) species from South America

13 species of the lichen genusCatapyrenium are reported from South America. Five species (C. analogicum, C. andicolum, C. exaratum, C. lachneoides, andC. podolepis) are described as new. A key to the species known from South America is presented. Remarks on taxonomy, ecology and distribution of the species are given.Studies on the lichen genusCatapyrenium (Verrucariaceae) III. For second part seeBreuss (1991).     

A reconsideration of the genusRabdosiella (Lamiaceae,Nepetoideae, Ocimeae)

The two generaPlectranthus andIsodon are compared and found to be very dissimilar.Isodon ist considered to be misplaced inOcimeae subtribePlectranthinae and apparently is more closely related to subtribeHyptidinae. The disjunct genusRabdosiella is compared to these two genera and regarded to be polyphyletic. The AfricanR. calycina (Benth.)Codd is returned toPlectranthus and calledP. calycinus Benth., while the AsianR. ternifolia (D. Don)Codd is placed inIsodon sect.Pyramidium and calledI. ternifolius (D. Don)Kudo.     

隆德鱼的新材料及其系统关系的初步分析——辽宁西部晚中生代地层和鱼群研究之一

依据辽宁西部三个地点的新材料和宁夏、内蒙古的标本,对罗家峡隆德鱼(Longdeichthys luojiaxiaensis Liu,1982)的形态特征作了补充描述和修订,并初步分析讨论了“薄鳞鱼类”的研究现状以及隆德鱼的系统关系。认为隆德鱼可能已是鲱头鱼派(Clupeocephala)的成员,与德国和法国基末里期的Leptolepides sprattiformis(Blainville)最为相近。     

The electrophoretic polymorphism of bacterial esterases

Abstract: The specific activities of esterases and certain other molecular properties including immunospecificity indicate that the electrophoretic variations of these enzymes in bacterial populations are the result of allelic variations at specific gene loci. The esterase polymorphism of Enterobacteriaceae and some other species isolated from man or animals demonstrates that esterases can distinguish between bacteria at the species or subspecies level, both by their biochemical properties and by their electrophoretic differences. The esterase data complement DNA hybridization studies and agree with ribosomal DNA polymorphism, especially for delineating a phylogenetically distinct group of highly pathogenic strains in Escherichia coli . A two-dimensional electrophoretic profile obtained by establishing a direct correspondence between homologous esterase bands resolved by independent runs of isoelectric focusing and standard electrophoresis considerably improves the detection of allelic variations, whereas protein titration curves (electrophoresis in pH gradient) can be used to demonstrate the real electrophoretic homogeneity of allozymes or evalue their molecular relationship in terms of apparent amino acid substitutions. This overview establishes that esterases, by their significant electrophoretic polymorphism, are reliable molecular markers for systematics and epidemiology, and are suitable enzyme systems for studying population genetics and phylogeny.     

The urgency of building global capacity for biodiversity science

The biodiversity sciences represent the disciplines of whole-organism biology, including systematics, ecology, population biology, behaviour and the fields of comparative biology. The biodiversity sciences are critically important to society because it is knowledge of whole-organisms that is essential for managing and conserving the world's species. Because of an acceleration in environmental degradation and global biodiversity loss in recent decades, the need for the biodiversity sciences has never been more urgent. Yet, biodiversity science is not well supported relative to other fields of science, and thus the need for knowledge about organisms and their environment is far outstripping biologists' ability to provide it. National and international capacity for biodiversity science must therefore be increased substantially. Each nation should establish a national biodiversity research programme coordinated across all government agencies. An international biodiversity research programme should also be established, perhaps with an organizational structure that parallels the International Geosphere-Biosphere Programme. Biodiversity scientists must assume a leadership role in educating the public and bringing about policy changes that will enhance our understanding of the world's species and their ecosystems.