Development and structure of the seed-coat of Lannea discolor (Sonder) Engl. (Anacardiaceae)

VON TEICHMAN, I., 1988. The development and structure of the seed-coat of Lannea discolor (Sonder) Engl. (Anacardiaceae). The bitegmic, anatropous ovule contains a group of nucellar cells with slightly thickened and intensively staining cell walls. Besides this hypostase sensu stricto, the nucellus cells in the chalaza become tanniniferous. This tanniniferous chalazal-nucellar tissue is intially plate-like. It is referred to as the hypostase sensu lato. The latter and the chalaza enlarge significantly. The raphe, extensive chalaza and well-developed cup-like hypostase sensu lato play an important role in the development of the seed-coat. The inner, tanniniferous epidermis of the inner integument persists in parts of the mature seed-coat. The outer, distinctly tanniniferous epidermis of the outer integument shows in the mature seed-coat a degree of secondary wall thickening. This undifferentiated type of seed-coat of L. discolor (tribe Spondieae) is remarkably similar to that of Camnosperma minor (tribe Rhoideae), both also showing tendency towards the exotestal type. In the Rhoideae the endotestal, i.e. differentiated type, of seed-coat is also present. The exalbuminous seed of L. discolor represents a derived and advanced type.     

The ontogeny and structure of the pericarp and seed-coat of Harpephyllum caffrum Bernh. ex Krauss (Anacardiaceae)

The exocarp sensu lato , which develops from the outer epidermis and adjacent parenchyma of the ovary wall, consists of collenchyma cells with a stomatous epidermis. The fleshy, parenchymatous mesocarp or sarcocarp develops after endocarp differentiation. The endocarp is partly spongy and partly woody. The spongy endocarp contains most of the vascular tissue and fills the cavities and grooves of the intricately sculptured outer woody endocarp. The inner woody endocarp and adjacent woody, endocarpal operculum develop from the inner epidermis and subepidermal parenchyma of the ovary wall. The bitegmic, anatropous ovule develops into a derived, exalbuminous seed with an undifferentiated seed-coat. An extensive chalaza, extensive hypostase sensu lato and the raphe are important in the development of the seed-coat. The pericarp and seed-coat of H. caffrum is compared with those of Sclerocarya birrea subsp. caffra and Lannea discolor . The close phylogenetic relationship of these three species of the Spondieae is reaffirmed. The marked similarities in pericarp and seed structure between H. caffrum and species of the genus Spondias are noted.     

Ontogeny of the seed-coat of Rhus lancea L. fil., and pachychalazy in the Anacardiaceae

VON TEICHMAN, I., 1991. Ontogeny of the seed-coat of Rhus lancea L. fil., and pachychalazy in the Anacardiaceae. The bitegmic, anatropous ovule develops into an exalbuminous, partially pachychalazal and endotegmic seed. In the mature seed-coat the extensive chalaza with associated tanniniferous hypostase sensu lato manifests externally as a characteristic brown patch. The walls of the cells of the hypostase are impregnated with callose and lipidic substances, which most probably represent cutin. Ultimately the outer integument and outer parts of the inner integument are more or less squashed. However, the cell walls of the inner epidermis of the inner integument show distinct secondary thickening and lignification. The pachychalazal seed with undifferentiated seed-coat characterizes not only a number of the genera of the tribe Anacardieae, but also occurs in Heeria of the tribe Rhoeae. A number of genera of the tribe Spondiadeae have a partially pachychalazal seed. The seed-coat of the latter shows varying degrees of traces of an exo-, meso- and/or endotestal lignification. The seed of certain genera of the Rhoeae, is partially pachychalazal and endotegmic, or probably only endotegmic.     

Development and structure of the seed of Ozoroa paniculosa (Anacardiaceae) and taxonomic notes

The anatropous, bitegmic and crassinucellar ovule has a nuclear endosperm development. It is further characterized by a hypostase sensu lato. This hypostase being an integral part of the chalaza undergoes a secondary extension with it. At maturity the exalbuminous seed is partially pachychalazal and therefore two anatomically distinct larger parts can be distinguished in the mature seed coat. An endotegmen typifies the integumentary seed coat, while a saddle-shaped hypostase characterizes the chalazal seed coat. This seed coat shows several characteristics of the typical anacardiaceous pachychalazal seed. The cotyledons store lipids and protein as nutrient reserveS. A well-developed cuticle, cuticular layer, cutin and callose in the hypostase cell walls, as well as tannin-like deposits in the seed coat, protect the physiologically ripe seed against dehydration.     

SYSTEMATIC SIGNIFICANCE OF SEED-SURFACE FEATURES IN ORTHOCARPUS (SCROPHULARIACEAE—SUBTRIBE CASTILLEJINAE)

Scanning electron microscope and light microscope examination of seed-coat features of 26 species of Orthocarpus have allowed recognition of many species-level differences (summarized in a key) and of three seed-coat types that parallel taxonomic subgroups but support realignments at generic and infrageneric levels. Type 1 seeds (subg. Orthocarpus, sect. Orthocarpus) have a lateral hilum, sculptured inner tangential seed-coat walls, and a tightly fitting outer seed coat. They are very similar to seeds of Cordylanthus. Seeds of Types 2 and 3 have a terminal hilum and membranous inner tangential cell walls. Type 2 seeds (subg. Orthocarpus, sects. Castillejoides and Cordylanthoides, with one exception) have a net-like, loosely fitting outer seed coat that shows close relationship to seeds of Castilleja. Inner tangential walls of Type 2 seeds normally rupture. Type 3 seeds (subg. Triphysaria, with two exceptions) have a tightly fitting outer seed coat and inner tangential walls are always retained. Seed features support evidence from floral morphology and chromosome numbers that Orthocarpus as currently recognized is not a monophyletic lineage.     

Taxonomic significance of pericarp and seed structure in Heeria argentea (Thunb.) Meisn. (Anacardiaceae) including reference to pachychalazy and recalcitrance

Heeria argentea (tribe Rhoeae), a monotypic, dioecious tree, is endemic to the core area of the Cape Floristic Region. The mature exocarp consists of a uniseriate layer of palisade-like epidermal cells, interspersed with modified stomata. The mature endocarp sensu stricto develops solely from the inner epidermis. It is essentially two-layered and resembles the state in Protorhus longifolia. This endocarp is here proposed as a distinct fourth endocarpal subtype under the so-called Anacardium -type. The large, pachychalazal, recalcitrant seed develops from the single, anatropous, bitegmic, crassinucellate ovule. This ovule is characterized by an extensive chalaza, vascularization and Anacardiaceae-type hypostase. The pachychalazal seed coat contains abundant vascular bundles and a tanniniferous hypostase. The inner epidermis of the inner integument differentiates into an endotegmen. The contribution of the integuments towards seed coat development is negligible. Concerning characters of the disc in the female flower, the meso- and endocarp, as well as seed size, degree of pachychalazy, nutrient reserves (starch) in the chlorophyllous cotyledons and hypogeal germination, Heeria shows a very close phylogenetic relationship to Protorhus longifolia. However, fruit and seed structure clearly supports the taxonomic separation of Heeria from Ozoroa. Data also support the view that Heeria is a tropical relict, and the hypothesis that pachychalazy, greater seed size, as well as recalcitrant seed viability behaviour constitute ancestral seed character states. Pachychalazy is regarded as a functional adaptation for more efficient transfer of nutrients.     

益智胚珠的珠心冠原与承珠盘细胞壁的组织化学研究

用组织化学方法研究了益智胚珠中珠心冠原与承珠盘细胞壁的组成。珠心冠原细胞壁含有纤维素、胼胝质、果胶质,但不含栓质。承珠盘细胞壁含有纤维素、木质素、果胶质,也不含栓质。讨论了珠心冠原与承珠盘细胞壁的组成及承珠盘的可能功能。     

Cellular pathway of photosynthate transport in coats of developing seed of Vicia faba L. and Phaseolus vulgaris L. II. Principal cellular site(s) of efflux

The cells responsible for the photosynthate efflux from coatsof developing seed of Vicia faba L. and Phaseolus vulgaris L.were elucidated using known properties of the efflux mechanism.Sensitivity of sucrose efflux to NEM and high potassium concentrationswas retained by seed-coat halves of Phaseolus following pectinaseremoval of the branch parenchyma cell layer. In contrast, removalof the thin-walled parenchyma transfer cell layer from Viciaseed-coat halves abolished this sensitivity. The membrane-impermeantthiol-binding fluorochrome, qBBr, selectively stained the surfaceof the thin-walled parenchyma transfer cells. This phenomenonwas inhibited by the slowly permeable sul-phydryl agent, PCMBS,indicating that the plasma membranes of these cells are enrichedin sulphydryl groups characteristic of membrance porter proteins.On the basis that carrier-mediated sucrose efflux from seedcoats appears to be proton coupled, the putative plasma membraneH+-ATPase was used as a marker for the cells responsible forcarrier-mediated photosynthate efflux. When seed-coat halveswere exposed briefly at pH 8.5 to the weak acid fluorochrome,SRG, the ground parenchyma and thin-walled parenchyma transfercell layers selectively accumulated the dye. The apparent lowpH environment in the walls of these cells that renders SRGmembrane permeant appeared to be maintained by a VAN-sensitiveproton pump. The findings with SRG were corroborated by thecyto-chemical localization of plasma membrane ATPase activityto the ground parenchyma and thin-walled parenchyma transfercells using precipitation of cerium phosphate. Together, ourobservations provide qualified support for the conclusion thatcarrier-mediated photosynthate efflux from coats of Phaseolusand Vicia seed is primarily restricted to the ground parenchymaand thin-walled parenchyma transfer cell layers, respectively. Key words: Ground parenchyma, Phaseolus vulgaris L., photosynthate efflux, seed coat, transfer cell, Vicia faba L.     

Acacia (Mimosoideae): composition and affinities of the series Pulchellae Bentham

The composition and affinities of the bipinnate Acacia series Pulchellae Bentham are examined in the light of evidence from studies of gross morphology, seedling morphology, pollen morphology and seed chemistry. Acacia mitchellii , the only non-Western Australian species, is atypical and should be relocated in section Vninervea Vassal. The remaining 27 species (the Pulchellae sensu lato ) comprise a coherent group of 21 species (the Pulchellae sensu stricto ) and six less closely related ones. These 27 species appear unrelated to series Botrycephalae Bentham. Some affinities exist with phyllodinous groups, especially series Uninerves and Continuae .     

Three groups of species in Petunia sensu Jussieu (Solanaceae) inferred from the intact seed

The intact seed surface morphology in 45 taxa of Petunia sensu Jussieu native to South America (Petunia sensu Wijsman plus Calibrachoa) was compared under scanning electron microscopy. The existence of three groups of species, differentiated in terms of seed morphology, was revealed as follows: (1) all species of Petunia sensu Wijsman, having coarse wavy middle lamellae and anticlinal walls; (2) Calibrachoa parviflora and C. pygmaea, having fine wavy middle lamellae embedded in straight anticlinal walls; and (3) the other species of Calibrachoa, having straight middle lamellae and anticlinal walls. Close relationships between seed morphology and the other characteristics observable in the groups of species are discussed.     

Detection of Lyme disease spirochetes in the skin of naturally infected wild sika deer (Cervus nippon yesoensis) by PCR.

We demonstrated the presence of Borrelia burgdorferi sensu lato DNA in the skin tissues of naturally infected wild sika deer, using PCR. The risk of transmission of B. burgdorferi sensu lato is recognized in sika deer.     

Host-Parasite Relationships of Atalodera spp. (Heteroderidae)

Atalodera ucri, Wouts and Sher, 1971, and A. lonicerae, (Wouts, 1973) Luc et al., 1978, induce similar multinucleate syncytia in roots of golden bush and honeysuckle, respectively. The syncytium is initiated in the cortex; as it expands, it includes several partially delimited syncytial units and distorts vascular tissue. Outer walls of the syncytium are relatively smooth and thickest near the feeding site of the nematode; inner walls are interrupted by perforations which enlarge as syncytial units increase in size. The cytoplasm of the syncytium is granular and includes numerous plastids, mitochondria, vacuoles, Golgi, and a complex network of membranes. Nuclei are greatly enlarged and amoeboid in shape. Although more than one nucleus sometimes occur in a given syncytial unit, no mitotic activity was observed. Syncytia induced by species of Atalodera chiefly differ from those of Heterodera sensu lato by the absence of cell wall ingrowths; wall ingrowths increase solute transport and characterize transfer cells. In syncytia of Atalodera spp., a high incidence of pits and pit fields in walls adjacent to vasctdar elements suggests that in this case plasmodesmata provide the pathway for increased entry of sohttes. The formation of a syncytium by species of Atalodera and Heterodera sensu lato, but a single uninucleate giant cell by Sarisodera and Hylonema, indicates a pattern of host responses that may be useful, with other characters, for phylogenetic inference for Heteroderidae.     

Mitogenomes provide new insights into the evolutionary history of Prodiamesinae (Diptera: Chironomidae)

Evolutionary analysis of Prodiamesinae has long been impeded by lack of information, and its phylogenetic relationship with Orthocladiinae remains questionable. Here, ten complete mitochondrial genomes (mitogenomes) of Orthocladiinae sensu lato were newly sequenced, including three Prodiamesinae species and seven Orthocladiinae species. Coupled with published mitogenomes, a total of 12 mitogenomes of Orthocladiinae sensu lato were selected for a comparative mitogenomic analysis and phylogenetic reconstruction. Mitogenomes of Orthocladiinae sensu lato are conserved in structure, and all genes arrange the same gene order as the ancestral insect mitogenome. Nucleotide composition is highly biased, and the control region displayed the highest A + T content. All protein-coding genes are under purifying selection, and the ATP8 evolves at the fastest rate. In addition, the mitogenomes of Orthocladiinae sensu lato are highly conserved, and they are practically useful for phylogenetic inference, suggesting a re-classification of Orthocladiinae by sinking Prodiamesinae as a subgroup of Orthocladiinae.     

广义竹叶青蛇属Trimeresurus (sensu lato)的分类和系统学研究进展

广义的竹叶青蛇属于Trimeresurus(sensu lato)包含有40多个物种,广泛分布在南亚和东南亚国家和地区。目前,该类群已经相继被划分为6个属：Trimeresurus(sensu stricto)、Tropidolaemus、Ovophis Protobothrops,Triceratolepidophis,Zhaoermia本文从形态、细胞以及分了系统学等方面对Trimeresurus(sensu lato)的分类和系统学研究进行综述。     

Introduced Siberian chipmunks (Tamias sibiricus barberi) harbor more-diverse Borrelia burgdorferi sensu lato genospecies than native bank voles (Myodes glareolus)

Little attention has been given in scientific literature to how introduced species may act as a new host for native infectious agents and modify the epidemiology of a disease. In this study, we investigated whether an introduced species, the Siberian chipmunk (Tamias sibiricus barberi), was a potentially new reservoir host for Borrelia burgdorferi sensu lato, the causative agent of Lyme disease. First, we ascertained whether chipmunks were infected by all of the B. burgdorferi sensu lato genospecies associated with rodents and available in their source of infection, questing nymphs. Second, we determined whether the prevalence and diversity of B. burgdorferi sensu lato in chipmunks were similar to those of a native reservoir rodent, the bank vole (Myodes glareolus). Our research took place between 2006 and 2008 in a suburban French forest, where we trapped 335 chipmunks and 671 voles and collected 743 nymphs of ticks that were questing for hosts by dragging on the vegetation. We assayed for B. burgdorferi sensu lato with ear biopsy specimens taken from the rodents and in nymphs using PCR and restriction fragment length polymorphism (RFLP). Chipmunks were infected by the three Borrelia genospecies that were present in questing nymphs and that infect rodents (B. burgdorferi sensu stricto, B. afzelii, and B. garinii). In contrast, voles hosted only B. afzelii. Furthermore, chipmunks were more infected (35%) than voles (16%). These results may be explained by the higher exposure of chipmunks, because they harbor more ticks, or by their higher tolerance of other B. burgdorferi sensu lato genospecies than of B. afzelii. If chipmunks are competent reservoir hosts for B. burgdorferi sensu lato, they may spill back B. burgdorferi sensu lato to native communities and eventually may increase the risk of Lyme disease transmission to humans.     

The Restoration of the Genus Cyclocodon ( Campanulaceae) and Its Evidence from Pollen and Seed-coat

The genus Cyclocodon Griff. was reduced by C. B. Clarke in 1881 into a section of the genus Campanumoea. Our LM and SEM observations on pollen morphology show that the pollen of all the three species in the former is 3-colporate with the exine sparsely high-spinulose, whereas that of the two species in the latter is 5～8-colpate with the exine relatively densely short-spinulose. SEM observations on seed-coat indicate that the primary ornamentation of the seed-coat of the two species in Campanumoea (s. str. ) is characterized by regular and polygonal areoles which are much larger than the radial walls in diameter and by the bead-like secondary ornamentation on the radial walls, while that of the three species in Cyclocodon is characterized by irregular-shaped areoles which are nearly equal to the radial walls in diameter and by the rope-like secondary ornamentation on the radial walls. Thus, the pollen morphology is closely correlated with the seed-coat morphology. Taking the characteristics of pollen, seed-coat and gross morphology into consideration, the genus Cyclocodon is restored, separate from Campanumoea (s. str. ). One new combination, Cyclocodon celebicus (B1.)Hong, is made in the present paper. The genus Cyclocodon is con-sidered closely related to Platycodon rather than to Campanumoa.     

Molecular Evidence for Multiple Origins of the European Spined Loaches (Teleostei,Cobitidae)

We present a phylogenetic investigation of the Northern Clade, the major monophyletic clade within the freshwater fish family Cobitidae, one of the most prominent families of freshwater fishes found in Asian and European waters. Phylogenetic reconstructions based on the cytochrome b and RAG-1 genes show the genera Microcobitis, Sabanejewia, Koreocobitis and Kichulchoia as monophyletic groups. These reconstructions also show a Cobitis sensu lato and a Misgurnus sensu lato group. The Cobitis sensu lato group includes all species of Cobitis, Iksookimia, Niwaella and Kichulchoia, while the Misgurnus sensu lato group includes Misgurnus, Paramisgurnus and Koreocobitis. Although the monophyly of both the Cobitis sensu lato and Misgurnus sensu lato groups is supported, relationships within the groups are incongruent with current generic definitions. The absence of monophyly of most genera included in the Cobitis sensu lato group (Cobitis, Iksookimia and Niwaella) or their low genetic differentiation (Kichuchoia) supports their consideration as synonyms of Cobitis. Molecular phylogenies indicate that the Asian species of Misgurnus experienced a mitochondrial introgression from a lineage of Cobitis. We also find two nuclear haplotypes in the same Cobitis species from the Adriatic area that, in the absence of morphological differentiation, may indicate molecular introgression. Most lineages within the Northern Clade consist of species found in East Asia. However, some lineages also contain species from Europe and Asia Minor. The phylogenetic relationships presented here are consistent with previous studies suggesting an East Asian origin of the Northern Clade. According to the current distributions and phylogenetic relationships of the Misgurnus sensu lato and Cobitis clade lineages, particularly of M. fossilis and C. melanoleuca, the range expansion of East Asian species into Europe was most likely via Siberia into Northern and Central Europe. Phylogenetic analyses also show that the Cobitis sensu lato group consists of two clear subgroups (I and II), each presenting geographical differences. Subgroup I is distributed exclusively in East Asian drainages with an Eastern European offshoot (C. melanoleuca), whereas Subgroup II includes species widespread throughout Europe (including the Mediterranean), Asia Minor, the Black Sea and the Caucasus, with some lineages related to species restricted to East Asia.     

Advances in Understanding Seed Dormancy at the Whole-seed Level:An Ecological, Biogeographical and Phylogenetic Perspective

Following a brief account of the early foundations of seed germination ecology sensu lato, some historical and recent developments pertaining to the ecology, biogeography and phylogeny of seed dormancy are discussed.     

广义竹叶青蛇属的系统学研究新进展

2004年以来,广义竹叶青蛇的系统学研究取得了较大的进展。本文对这近一年来的最新进展进行概括和报道。     

Advances in Understanding Seed Dormancy at the Whole-seed Level: An Ecological,Biogeographical and Phylogenetic Perspective

Following a brief account of the early foundations of seed germination ecology sensu lato , some historical and recent developments pertaining to the ecology, biogeography and phylogeny of seed dormancy are discussed .