玉竹的组织培养与快速繁殖

以玉竹[Polygonatum odoratum (Mill.) Druce]根状茎、叶片和茎段为外植体,于附加不同激素配比的MS培养基中诱导愈伤组织、不定芽和不定根,探讨增殖培养和植株再生的条件.结果表明,叶片和茎段外植体诱导愈伤组织和芽的分化率很低;而根状茎外植体易于培养,有较高的诱导率和增殖倍数,其愈伤组织、不定芽和不定根的诱导率分别可达87%、90%和99%以上.适宜根状茎外植体愈伤组织诱导的培养基为MS+1.0 mg/L 6-BA+0.5 mg/L NAA,有利于增殖和丛生芽分化的培养基为MS+2.0 mg/L 6-BA+0.5 mg/L IBA和MS+3.0 mg/L 6-BA+0.1 mg/L NAA,而1/2MS+3.0～5.0 mg/L NAA适宜诱导试管苗生根培养.试管苗的移栽成活率可达85%以上.     

A steroidal glycoside from Polygonatum odoratum (Mill.) Druce. improves insulin resistance but does not alter insulin secretion in 90% pancreatectomized rats

The aim of this study was to investigate the effects of three steroidal glycosides (SG-100, SG-280, and SG-460) obtained from Polygonatum odoratum (Mill.) Druce. on insulin secretion, insulin action, and relative glucose uptake in various tissues of 90% pancreatectomized male Sprague-Dawley rats. One of the compounds (30 mg/kg body weight daily) with a 40%-fat diet was orally administered to a group of such rats for 13 weeks. On the day after a hyperglycemic clamp, euglycemic hyperinsulinemic clamp with 1 microCi of [1-(14)C]2-deoxyglucose per 100 g body weight was used. Serum glucose levels were lowest in the rats receiving SG-100. Insulin secretion from pancreatic beta-cells did not change with SG administration. Whole-body glucose disposal rates increased with SG-100 administration by 39%. SG-100 increased the glycogen contents and glycogen synthase activity in the soleus muscle of pancreatectomized rats. Uptake of [1-(14)C]2-deoxyglucose into the soleus muscle was higher in such rats receiving SG-100 than in rats receiving other compounds. In conclusion, SG-100 has an antihyperglycemic effect by promoting peripheral insulin sensitivity without changing insulin secretion.     

Observations on the cytology of Bipes (Amphisbaenia) with special reference to its lampbrush chromosomes

The positions and general anatomical and histological characteristics of the gonads of Bipes biporus and B. canaliculatus are described. The amounts of DNA per haploid chromosome set have been measured in both species, the values being 1.83 and 2.0 pg for biporus and canaliculatus respectively. The karyotypes of both species are described on the basis of data from mitotic and meiotic metaphase chromosome sets and from lampbrush chromosomes. B. biporus has 10 macrochromosomes and 11 microchromosomes. B. canaliculatus has 11 macrochromosomes and 11 microchromosomes. The karyotypes of the two species differ distinctly with regard to the shapes of 3 of the macrochromosomes. Chiasma distribution is described for male meiosis in B. biporus. Studies of the lampbrush chromosomes of both species show the chiasma distribution in the female to be generally similar to that found in the male biporus. In B. canaliculatus, lampbrush chromosomes with maximally extended lateral loops are found in oocytes that are oblate spheroids measuring 0.7×1.0 mm along their short and long axes respectively, these being well before the start of the major phase of vitellogenesis. Smaller oocytes have more distinct chromomeres and shorter loops. Microchromosomes take the form of typical small lampbrush chromosomes in oocytes. There are at the most 1,000 chromomeres per haploid set of lampbrush chromosomes in B. canaliculatus. Chiasmata are described from lampbrush preparations in which the two half-bivalents are firmly attached to one another without evident association of their axes, indicating the possibility of chiasmate association between the DNA axes of lateral loops. There are remarkably few extrachromosomal nucleoli in Bipes oocytes, and its is suggested that this may indicate a level of ribosomal gene amplification that is much lower than that found in fish and Amphibia. The observations are particularly discussed in relation to current ideas concerning the structure and function of lampbrush chromosomes.     

A polyphasic study on the taxonomic position of industrial sour dough yeasts

The sour dough bread making process is extensively used to produce wholesome palatable rye bread. The process is traditionally done using a back-slopping procedure. Traditional sour doughs in Finland comprise of lactic acid bacteria and yeasts. The yeasts present in these doughs have been enriched in the doughs due to their metabolic activities, e.g. acid tolerance. We characterized the yeasts in five major sour bread bakeries in Finland. We found that most of the commercial sour doughs contained yeasts which were similar to Candida milleri on the basis of 18S rDNA and EF-3 PCR-RFLP patterns and metabolic activities. Some of the bakery yeasts exhibited extensive karyotype polymorphism. The minimum growth temperature was 8 degrees C for C. milleri and also for most of sour dough yeasts.     

A taxonomic study of thePoa macrocalyx complex,with particular reference to the populations in eastern Hokkaido

An attempt was made to investigate some populations of thePoa macrocalyx complex in eastern Hokkaido in relation to the taxonomy of this complex. Individual specimens preserved in TI, KYO and TNS were also studied. Chromosome counts of 2n=42 were obtained in the majority of a total of 84 collections, and counts of 2n=63 (incl. ca. 63), ca. 70 and 84 were also made in a few collections. High percentages of viable pollen were observed. The morphological features which were designated by previous authors to be significant in separatingPoa sachalinensis fromP. macrocalyx and in discriminating between the varieties ofP. macrocalyx were critically examined with emphasis on the observations of infra-population variation. It was confirmed that (1) the populations of thePoa macrocalyx complex in eastern Hokkaido are greatly variable morphologically and are also in a dynamic state cytogenetically, (2) plants of this complex in eastern Hokkaido belong to one and the same species,P. macrocalyx, and the varietiesfallax, scabriflora andtatewakiana may be merely morphs, and (3) some plants which are somewhat different from the plants in eastern Hokkaido with respect to glume features are distributed in Sakhalin, and northern and central Hokkaido. Some problems which should be subjected to further studies are pointed out.     

Ultrastructure of spermiogenesis of Philippia (Psilaxis) oxytropis,with special reference to the taxonomic position of the architectonicidae (Gastropoda)

Summary Spermiogenesis of the architectonicid Philippia (Psilaxis) oxytropis was studied using transmission electron microscopy. Both spermatids and mature sperm of Philippia show features comparable to sperm/spermatids of euthyneuran gastropods (opisthobranchs, pulmonates) and not mesogastropods (with which the Architectonicidae are commonly grouped). These features include: (1) Accumulation of dense material on the outer membrane of anterior of the early spermatid nucleus — this material probably incorporated into the acrosome; (2) Structure of the unattached and attached spermatid acrosome (apical vesicle, acrosomal pedestal) accompanied by curved (transient) support structures; (3) Formation of the midpiece by individual mitochondrial wrapping around the axonemal complex, and the subsequent fusion and metamorphosis of the mitochondria to form the midpiece; (4) Presence of periodically banded coarse fibres surrounding the axonemal doublets and intra-axonemal rows of granules. A glycogen piece occurs posterior to the midpiece but is a feature observed in both euspermatozoa of mesogastropods (and neogastropods) and in sperm of some euthyneurans.Despite the lack of paracrystalline material or glycogen helices within the midpiece (both usually associated with sperm of euthyneurans), the features of spermiogenesis and sperm listed indicate that the Architectonicidae may be more appropriately referable to the Euthyneura than the Prosobranchia.Abbreviations a acrosome - ap anterior region of acrosomal pedestal - as support structures of spermatid acrosome - av apical vesicle of acrosome (acrosomal vesicle of un-attached acrosome) - ax axoneme - b basal region of acrosomal pedestal - c centriole - cf coarse fibres - cr cristal derivative of midpiece - db intra-axonemal dense granules - drs dense ring structure - gg glycogen granules - gp glycogen piece - G Golgi complex - m mitochondrion - mt microtubules - n nucleus - pm plasma membrane - sGv small Golgi vesicles     

The taxonomic position of Oxystegus sinuosus (Mitt.) Hlip. in relation to the genus Barbula Hedw

Abstract

The morphology of leaves, stems and axillary hairs is compared and described in Oxystegus sinuosus and O. tenuirostris. It is suggested that O. sinuosus falls within the range of variation of Barbula as currently understood in Britain, but that O. tenuirostris is closer to Trichostomum. The morphology of the axillary hairs does not throw much light on its affinities within Barbula, but a position close to B. cylindrica is probably the most appropriate.     

A morphological and anatomical survey of Virectaria (African Rubiaceae), with a discussion of its taxonomic position

A detailed morphological and anatomical study of the tropical African genus Virectaria is presented. The observations are used to characterize the genus, to propose a key to all eight species, and to unravel the relationships between the species using cladistics. A taxonomic survey of the genus is also given. Verdcourt's infraspecific taxa based on calyx morphology in V major are adopted, but it was found that morphological distinction is correlated with ecological, habit and distributional differences. Hence, it is better to recognize Verdcourt's varieties spathulata and major as subspecies of V. major. The problematic systematic position of the genus is discussed in detail. New evidence is given for the exclusion of the genus from the Hedyotideae and Ophiorrhizeae (subfamily Rubioideae). The recently proposed position in the Sabiceeae (subfamily Ixoroideae) is not convincing either, since none of the genera included in the Sabiceeae matches Virectaria with respect to pollen, fruit, flower and growth habit. Exclusion from the Rubioideae and a position near the Sabiceeae is supported by lack of raphides, seed anatomy, placentation, stipule morphology and molecular evidence. Molecular data from a larger number of taxa are needed to confirm the position of the genus.     

The fine structure of motile cells in the generaUlvaria andMonostroma,with special reference to the taxonomic position ofMonostroma oxyspermum (Ulvophyceae,Chlorophyta)

The zoospores and isogametes ofUlvaria obscura var.blyttii, the isogametes ofMonostroma bullosum, and the anisogametes ofM. grevillei have a flagellar apparatus with counterclockwise absolute orientation and terminal caps, and therefore belong to theUlvophyceae. On the basis of the absence or presence of body scales and the morphologies of certain flagellar apparatus components,Ulvaria obscura var.blyttii is retained in theUlvales, whileM. bullosum, M. grevillei andM. oxyspermum are referred to theUlotrichales. Differences in scale morphology, certain flagellar apparatus components, and early thallus ontogeny support the transfer ofM. oxyspermum to the genusGayralia. Mating structures and their positional relationships within the cell are described from the gametes examined. A plasmalemma-associated plaque that may be a degenerate mating structure occurs in someG. oxysperma motile cells.     

A critical review of the Ralfsiales,Ralfsiaceae and the taxonomic position of Analipus japonicus (Harv.) Wynne (Phaeophyta)

A critical examination of the order Ralfsiales (Phaeophyta) is presented. It is concluded that the basis for this order is unsound and its continued use is not warranted. Characteristics of the crustose brown algae are discussed and the use of the family Ralfsiaceae (to include the Lithodermataceae) is advocated. The taxonomic position of the northern Pacific alga Analipus japonicus (Harv.) Wynne is considered and the genus is referred to the monotypic family Heterochordariaceae, Ectocarpales.     

猪笼草叶的形态解剖结构研究

对猪笼草 (N epenthes mirabilis)叶进行形态、解剖学的观察和研究 ,结果表明猪笼草的叶是一种变态的单身复叶。其基部的两个侧生小叶与总叶柄合生 ,总叶柄顶端扩大反卷为瓶状体 ,瓶状体一侧也有 2片附生小叶 ,顶生小叶与总叶柄连接处有关节 ,关节上还有 2～ 5片退化的小叶     

A cytological study of Pellia epiphylla (L.) Corda in Britain with reference to the status of Pellia borealis Lorbeer

Abstract

The history of Pellia borealis is outlined and its morphology compared with that of P. epiphylla. The techniques for preparing material for chromosome counts are described. Several gatherings of monoecious Pellia with large epidermal cells (P. borealis) were found to be haploid, n = 9. The size of the epidermal cells is shown to be valueless as a character for distinguishing the two species. It is concluded that only P. epiphylla should be retained as a species.

We wish to record our thanks to Dr S. Arnell for examining British material and for helpful correspondence; to Dr A. J. E. Smith for his valuable advice and criticism, and for the use of cytological facilities; and to all those who have contributed material of possible P. borealis.     

Banding patterns on lampbrush chromosomes of Triturus marmoratus (Amphibia Urodela) by the Giemsa stain

Lampbrush chromosome preparations from the newt species Triturus marmoratus have been submitted to a banding procedure by using a Giemsa stain technique (C-banding) as well as variants of the method. Centromeres, most of telomeres, the nucleolus organizing region and some segments along the chromosome axes appear to be differently stained. The centromere positions have been indicated on the maps of the lampbrush complement of the species. The possible relationships between banding and chromosome structure and organization are briefly discussed.