The endotegmen tuberculae: an account of little-known structures from the seed coat of the Hydrocharitoideae (Hydrocharitaceae) and Najas (Najadaceae)

SHAFFER-FEHRE, M., 1991. The endotegmen tuberculae: an account of little-known structures from the seed coat of the Hydrocharitoideae (Hydrocharitaceae) and of Najas (Najadaceae). The sub-cellular protuberances from the inner tegmen layer have been given various names in earlier literature. Here named 'endotegmen tuberculae', they vary in shape, size and density of distribution in the endotegmen of different taxa. These characteristics make them useful for taxonomic research at both genus and species level. Their shape is a major consideration in transferring Hydrocharis dubia to the genus Limnobium. A further structure, 'exotegmen tuberculae', has been observed for the first time. This paper gives a survey of these structures and illustrates their taxonomic importance and its implications.     

Germination inhibitors in the pine seed coat

Inhibitors from (Pinus pinea L.) seed coats were separated using paper chromatography, thin layer chromatography, and a Sephadex G-10 column. The inhibitory activity was resolved into several fractions. One of these behaved similarly to abscisic acid. It has exhibed the same properties as ABA in thin-layer chromatography, paper chromatography, and Sephadex G-10 chromatography and in UV absorption and fluorescence spectra. These germination inhibitors, present in the seed coats, are involved in the regulation of P. pinea seed germination.Abbreviations ABA abscisic acid - TLC thin-layer chromatography     

Anatomical evidence and the taxonomic position of Darmera (Saxifragaceae)

GORNALL, R. J., 1989. Anatomical evidence and the taxonomic position of Darmera (Saxifragaceae). Evidence from the anatomy of nodes, petioles, trichomes, leaf crystals, ovules and seed-surfaces agrees with other published data to show that segregation of Darmera from the Saxifragaceae is unwarranted. The combined evidence indicates that the closest relatives of the genus are Astilboides, Bergenia and Mukdenia. A putative hybrid origin for this group of genera is suggested.     

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.     

Seed coat development in Leucospermum cordifolium (Knight) Fourcade (Proteaceae) and a clarification of the seed covering structures in Proteaceae

MANNING, J. C. & BRITS, G. J., 1993. Seed coat development in Leucospermum cordifolium (Knight) Fourcade (Proteaceae) and a clarification of the seed covering structures in Proteaceae . The development of the seed coat and pericarp is studied in Leucospermum cordifolium from ovule to mature seed. The ovule and seed are characterized by a tegmic pachychalaza. The pericarp is adnate to the integuments from anthesis and remains unthickened to maturity. The outer integument forms the seed coat and the seed is endotestal: the outer epidermis becomes tanniniferous and the inner epidermis develops into a crystalliferous palisade. The inner integument degenerates at an early stage. Examination of the literature reveals that the crystal palisade layer of the outer integument has been erroneously assumed to constitute an endocarp. This finding indicates that a re-interpretation of all published information on the seed coat in indehiscent Proteaceae is necessary before any speculations on the phylogenetic significance of the seed coat can be entertained.     

Effect of ovule position within the pod on the probability of seed production in Bauhinia ungulata (Fabaceae)

BACKGROUND AND AIMS: It has been claimed that ovules linearly ordered within a fruit differ in their probabilities of reaching maturity. This was investigated by studying the effect the position of an ovule within the pod has on seed abortion and seed production in Bauhinia ungulata. METHODS: Fruits collected during the dry seasons of 1999, 2000 and 2001 were opened, and the number, position and status of each ovule within the fruit were recorded. A GLM model was used to assess the effects of population, tree identity and ovule position within the pod on ovule fertilization, seed abortion, seed damage and seed maturation in two populations of B. ungulata. KEY RESULTS: Nearly 30% of the ovules were not fertilized in 1999; this percentage dropped to 5% the following two years. Seed abortion (50%) and seed damage (15%) were the same every year during the study period. Only 15% of the initial ovules developed into mature seeds in 1999; this value increased to 35% in 2000 and 2001. However, seed survivorship was dependent on the position of the ovule within the pod; non-fertilized and early aborted ovules were found more often near the basal end of the ovary. The frequency of seed damage was not affected by position. Mature seeds were found mainly in the stylar half of fruits, where ovules are likely to be fertilized by fast pollen tubes. CONCLUSIONS: The pattern of seed production in B. ungulata is non-random but is dependent upon the position of the ovule within the pod. The results suggest that the seeds produced within a fruit might differ in their vigour.     

青钱柳种皮甲醇浸提液的生物测定

通过对青钱柳[Cyclocarya paliurus (Batal.) Iljinskaja]种皮甲醇浸提液的生物测定,探讨青钱柳种子休眠与种皮内源抑制物质的关系.结果表明,青钱柳种皮不同浓度的甲醇浸提液(10%、20%、25%、30%和40%)对白菜(Brassica campestris L. ssp. chinensis)种子发芽率和种子活力以及幼苗的高生长、根生长均有抑制作用,浓度越高抑制作用越明显.用30%和40%浸提液处理, 白菜种子不能萌发;用10%、 20%和25%浸提液处理, 白菜种子的萌发率分别为98.6%、 75.0%和9.0%;苗高和根长分别比对照降低了31.6%、 48.1%、 79.7%和21.3%、 70.8%、 90.2%.表明青钱柳种子的种皮中含有抑制种子萌发和幼苗生长的成分.     

The zingiberidae,a new subclass of liliopsida (Monocotyledons)

The Zingiberidae are described as a new subclass, containing the orders Zingiberales and Bromeliales.     

The affinities of Chenopodium flabellifolium (Chenopodiaceae): Evidence from seed coat surface and flavonoid chemistry

Evidence from scanning electron microscopy of seed coat surfaces and leaf flavonoid chemistry has provided new insights into the relationships of the problematical Chenopodium flabellifolium from San Martín Island, Baja California. The seed surface of C. flabellifolium is basically smooth and thus is essentially the same as members of the subsection Lejosperma of section Chenopodium. This feature distinguishes the species from the taxon that has commonly been considered its nearest relative, namely C. neomexicanum of subsection Cellulata, which has an alveolate seed surface. Leaf flavonoid chemistry also serves to separate C. flabellifolium and C. neomexicanum. Chenopodium flabellifolium has also been viewed as conspecific with C. inamoenum (= C. hians or C. leptophyllum) of subsection Lejosperma. While the seed surface indicates that C. flabellifolium is best treated as a member of this subsection, other morphological as well as chemical data suggest that its closets affinities within the subsection lie with C. fremontii. The leaves of the two species are essentially of the same shape and collectively differ strikingly from those of C. hians and C. leptophyllum. Leaf flavonoid chemistry indicates that C. flabellifolium is closer to C. fremontii than to other taxa of subsection Lejosperma occurring in the western United States because both contain kaempferol 3-O-glycosides, which have not been detected elsewhere. The two species differ consistently in that the former has the pericarp attached to the seed whereas it is separable from the seed in the latter.     

Scanning electron microscopy of the seed coat in the genus Paulovunia (Scrophulariaceae)

A comparative study of the microscopic structures of external features of mature seeds of eight Paulownia species is presented. The external surface of the seed is made up of reticulate, apparently translucent cells, which laterally extend into wing-like structures. The laterally symmetrical wings are unequally extended in the micropylar and chalazal regions. The seed-coat ornamentation has a dorsiventral nature. Some special features of seed-coat morphology amongst the eight Paulownia species are discussed.     

Significance of the zygotic seed coat on quiescence and desiccation tolerance of Medicago sativa L. somatic embryos

Summary The influence of the zygotic seed coat on precocious germination and desiccation tolerance of somatic embryos has been studied using alfalfa (Medicago sativa L.). When cultured in contact with somatic embryos, seed coats at certain developmental stages inhibited precocious germination and induced desiccation tolerance in the somatic embryos. Germination of somatic embryos was inhibited by seed coats at the age of 16–26 days after pollination (DAP) and desiccation tolerance was induced after 20–26 DAP. Both phenomena were related to the synthesis of abscisic acid in the seed coat. The absence of a quiescent phase and desiccation tolerance in alfalfa somatic embryos may be related to the lack of developmental control by the seed coat.Abbreviations ABA Abscisic acid - DAP Days after pollination     

Systematic relevance of seed coat anatomy in the European heathers (Ericeae, Ericaceae)

The anatomy of the seed coat of the European species of tribe Ericeae (Calluna, Daboecia and Erica) of the Ericaceae family was studied, and the taxonomic importance of their characters was analyzed. The seed coat is mostly formed by a one-cell layer with thick, pitted inner walls and thin outer walls that collapse at maturity over the inner walls. The cell junctions are either raised with anticlinal walls up to four times the height of the periclinal walls or are not raised with similar values for the height of both the anticlinal and periclinal walls. Three main cell junction types were found and described. The thickness of the inner walls is variable, but there is a large overlap among the results for different species. Calluna vulgaris is the only species with no pits, and E. multiflora has a pitted pattern on its inner walls, which is distinctive from the rest of the species. Our main results agree with the external seed morphology, and valuable new data were obtained for certain groups such as the E. cinerea-E. terminalis or the E. scoparia complex. The similarities that are found in seed coat characters are not in accordance with the classical taxonomic delimitation of infrageneric groups within Erica.     

Late Quaternary records of Najas spp. (Najadaceae) from the southwestern Baltic region

Seeds of the submerged vascular plants Najas marina, Najas minor and Najas flexilis are reported from submarine Holocene deposits from the southwestern part of the Baltic Sea, and we also report on a find of Najas minor from an Eemian deposit in Jutland, which is the first record of this species from the Eemian of Denmark. The common and widespread occurrence of especially the southern extralimital N. minor is indicative of higher than present summer temperatures during the period from 10300 to 8000cal.yearsBP.     

The phylogenetic position of Anomochilidae (Reptilia: Serpentes): first evidence from DNA sequences

Previously, anilioids (Aniliidae, Anomochilidae, Cylindrophiidae and Uropeltidae) were considered the only extant, non‐macrostomatan alethinophidian snakes. Although their monophyly and intrarelationships remained poorly established, their fossoriality, small gape, and inferred phylogenetic position have been important evidence in orthodox scenarios about early snake evolution. Recent molecular studies including aniliids, cylindrophiids and uropeltids indicate anilioid polyphyly, with the latter two families comprising a clade nested within Macrostomata. We carried out the first molecular phylogenetic analysis to include the very poorly known and seemingly rare Anomochilidae. Only partial sequences of 12S and 16S rRNA mitochondrial genes could be amplified from tissue collected from a single dead specimen of Anomochilus leonardi. Amplification failed for nuclear and other mitochondrial genes, and for all the investigated genes for the holotype and paratype of A. leonardi. Analyses recovered a para‐ or polyphyletic Anilioidea. Anomochilus is recovered as most closely related to Cylindrophis maculatus (rendering Cylindrophiidae possibly paraphyletic). The relatively small amount of available data produces only moderate levels of support, but the stability of taxa and agreement across different analytical methods and with larger analyses of snake phylogeny support the abandonment of Anilioidea as a natural taxon, and the recognition of a higher category for a clade comprising Asian anilioids (Anomochilidae, Cylindrophiidae and Uropeltidae).     

A reappraisal of orders and families within the subclass Chaetothyriomycetidae (Eurotiomycetes,Ascomycota)

The subclass Chaetothyriomycetidae (Eurotiomycetes, Ascomycota) is an assemblage of ecologically diverse species, ranging from mutualistic lichenised fungi to human opportunistic pathogens. Recent contributions from molecular studies have changed our understanding of the composition of this subclass. Among others, ant-associated fungi, deep-sea fungi and bryophilous fungi were also shown to belong to this group of ascomycetes. The delimitation of orders and families within this subclass has not previously been re-assessed using a broad phylogenetic study and the phylogenetic position of some taxa such as the lichenised family Celotheliaceae or the Chaetothyrialean bryophilous fungi is still unclear. In our study, we assemble new and published sequences from 132 taxa and reconstruct phylogenetic relationships using four markers (nuLSU, nuSSU, mtSSU and RPB1). Results highlight several shortfalls in the current classification of this subclass, mainly due to un-assigned paraphyletic taxa. The family Epibryaceae is therefore described to circumscribe a previously un-assigned lineage. Celotheliales ad int. is suggested for the lineage including the lichen genus Celothelium and various plant pathogens. The delimitation of the family Trichomeriaceae is also broadened to include the genus Knufia and some anamorphic taxa. As defined here, Chaetothyriomycetidae includes four orders (Celotheliales ad int., Chaetothyriales, Pyrenulales, and Verrucariales) and ten families (Adelococcaceae, Celotheliaceae, Chaetothyriaceae, Cyphellophoraceae, Epibryaceae fam. nov., Herpotrichiellaceae, Pyrenulaceae, Requienellaceae, Trichomeriaceae, and Verrucariaceae).     

Systematic significance of seed coat morphology inSilene L. s. str. (sileneae-caryophyllaceae) from Korea

Seeds of eight species ofSilene s. str. in Korea were examined with a dissecting stereomicroscope and a scanning electron microscope (SEM) to evaluate the systematic significance of seed coat microstructure. The seeds ofSilene s. str. were characterized by triangular or reniform shape, planed or concave dorsal surface in outline, tuberculate or colliculate testa, and sinuated cell margin. Based on the degree of grooves and invagination at dorsal surface, the seeds of the examined taxa ofSilene s. str. fall into two distinct groups: (I) dorsal grooves inconspicuous, surface planed (Silene jenisseensis andS. repens), (II) dorsal grooves conspicuous, surface concave (six remaining taxa). Within each group, seeds of all species may be further distinguished based on shape, size, and testa surface sculpturing. A key to the different species or groups of species is provided, and the systematic significance between/among the taxa is also briefly discussed.     

Crystalloid formation in protochlorophyll-accumulating plastids from the inner seed coat of Cyclanthera explodens

The development of fruit, seed and plastids in the inner seed coat of Cyclanthera explodens Naud. was studied. Large amounts of protochlorophyll, in at least three different in vivo-forms, accumulated during maturation and was 14 mg/g fresh weight of the inner seed coat in mature seeds. In earlier stages plastid-membrane-lipids increased simultaneously with the pigment. This could also be seen in electron micrographs as an increased amount of membranes. During later stages the amount of pigment continued to increase without an increase in the lipids. At this stage large crystalloids were found in the plastids. The data presented led to the conclusion that the protochlorophyll form fluorescing at 691 nm is crystalline.     

The phylogenetic position of the Rhachiberothinae and the basal sister-group relationships within the Mantispidae (Neuroptera)

Abstract. The Rhachiberothinae, hitherto regarded as belonging to the Berothidae, are shown to be Mantispidae. They form the sister-group of the Symphrasinae + Drepanicinae + Calomantispinae + Mantispinae. Within the Symphrasinae, Trichoscelia is the sister-taxon of Anchieta + Plega. The raptorial fore legs of the Rhachiberothinae and the remaining Mantispidae, sometimes considered the result of convergent evolution, are one of their synapomorphies. The former inclusion of the Rhachiberothinae in the Berothidae was primarily based on symplesiomorphies; the Berothidae without the Rhachiberothinae are monophyletic.     

Floral developmental evidence for the systematic position of Batis (Bataceae)

Molecular phylogenies have associated Bataceae with Salvadoraceae and Koeberliniaceae in an expanded Brassicales. Despite a long taxonomic history, the knowledge of the flower of Batis is still fragmentary. The floral development of pistillate and staminate inflorescences of Batis maritima was investigated to understand homologies of floral structures and to discuss the phylogenetic position of Bataceae within the Brassicales. There has been considerable controversy in the past about the male flower, especially on the nature of the petals and the tubular structure enclosing the flower. Developmental evidence confirms that the male flower is built on a basic tetramerous bauplan and that the tubular structure is derived from four congenitally fused sepal lobes with the three anterior lobes highly reduced. The development of petals and stamens is unidirectional, and the androecium initiates the median stamens before the lateral stamens, suggesting the existence of two whorls. The pistillate flowers are reduced to the bare minimum with two transversal carpels enclosed by a bract. Partial inflorescences function as a swollen dispersal unit. The vestigial stipules probably represent colleters and are not homologous with true stipules. Several characters of Batis are reminiscent of the Brassicaceae, although a link with Salvadoraceae and Koeberliniaceae cannot be excluded.