广西种子植物小资料

几年来,我所在中草药资源调查工作中,发现一些我国及广西未曾记录过的植物,现整理成文,以供有关部门参考。本文引用的标本均收藏在广西中医药研究所植物标本室(GXMI)。 山椒子水番挑(博白)番落技科Annonaceae Uvar花a grandiflora Roxb.in FI.Ind.2:665.1524;李秉滔,植物分类学报14(1):98.2976,蒋英,李秉滔,中国植物志30(2):26,图版10. 1979。 广西东南部:博白县,浪平公社,水库边1971年5月9日,王鉴均2247外北流县,隆盛公社,天堂,坡地疏林中,1977年9月26日北流调查队8一44口7。 分布:广东南部,广西东南部;印度、缅甸、泰国、越南、马来…     

Complete maps of IS1, IS2, IS3, IS4, IS5, IS30 and IS150 locations in Escherichia coli K12

Summary In this paper complete distribution maps are presented of the seven IS elements 1, 2, 3, 4, 5, 30 and 150. These maps were obtained during the construction of an almost complete restriction map of the Escherichia coli genome of K12 strain BHB2600. The positions of IS elements were correlated to this map. The distribution of integration sites of all IS types is nonrandom. Besides a large gap from 79 min to 96 min, there is a pronounced IS cluster at 6 min and another at 97 min, map locations that have low gene incidences on the classical map. One cluster coincides with a region of IS induced rearrangements. The IS distribution pattern was compared to patterns of strains W3110 and HB101.     

Why are there so many species of bumble bees at Dungeness?

WILLIAMS, P. H., 1989. Why are there so many species of bumble bees at Dungeness? Dungeness is unique in the British Isles in that it has more species of bumble bees than any other locality. Three ideas about what governs the number of species at a locality are examined by locking at patterns of flower visits at Dungeness in comparison with those at Shoreham, a species-poor locality also in Kent. The species of bumble bees that are present at Dungeness but absent from Shoreham show no association in their distributions among 2 km grid-squares in Kent with the species of food-plants that they prefer at Dungeness, nor is there any correlation between the diversity of bees and diversity of food-plants at Dungeness and Shoreham. From the information available, Dungeness is most likely to have more species of bumble bees because it has a particularly high density of the more nectar-rich flowers that bumble bees can use. Bumble bees feed most profitably from deep flowers because these contain more nectar than shallow flowers, although direct access to deeper flowers is ultimately limited by the length of each bee's proboscis. The distribution of worker proboscis lengths among species in the species-pool in Kent is clumped about a median of 7.9 mm. The best foraging conditions for the maximum number of species should be provided when flowers of similar depths are present in sufficiently large numbers for all foragers to make near-optimal flower choices. Although there is no difference in median between the distributions of the bees' proboscis lengths and the depths of the flowers they use at Dungeness, at Shoreham the flower depths used are shorter than the proboscis lengths. Among the food-plants at Dungeness, high densities of Teucrium scorodonia and Echium vulgare are likely to be especially important.     

Accumulation of cadmium and copper by the terrestrial snail Arianta arbustorum L.: kinetics and budgets

Summary Specimens of the terrestrial gastropod Arianta arbustorum were fed on cadmium- or copper-enriched agar plates with the aim of performing an input/output analysis and of studying the distribution of these metals in several organs of the snails. After a feeding period of 20 days about 45% of cadmium were lost. 36% accumulated in the hepatopancreas, where a cadmium concentration of more than 500 g/g was measured. The efficiency of cadmium assimilation decreased from about 90% at the beginning to about 55% after 20 days. Copper was distributed more evenly than cadmium, but the main site of copper storage seemed to be the foot/mantle tissues, where 49% of the ingested copper were found. The efficiency of copper assimilation always exceeded 95%. The patterns of distribution and assimilation of copper and cadmium are discussed in relation to differences in the cytological and biochemical detoxification mechanisms which exist for these metals in molluscs.     

Recovery of15N-labelled fertilizer by Coastal bermudagrass in lignite minesoil

Minesoils developed from lignite surface mining in Texas are nutrient-poor and have a high N retention capacity. A major concern of landowners and soil conservationists is the response of Coastal bermudagrass to the application of low rates of ammonium-N fertilizer on these nutrient-poor minesoils. A glasshouse study, using¹⁵N-labelled ammonium sulfate fertilizer and lignite minesoil, was conducted to measure Coastal bermudagrass biomass production and fertilizer recovery during establishment in response to clipping at 2, 4, and 8 week intervals. At N rates of 0, 40, and 80 kg N ha^–1,increases in N fertilization increased Coastal bermudagrass aboveground biomass 5-fold, but showed only small increases in belowground biomass. Recovery of ammonium-N fertilizer ranged from 54 to 63%. Roots contained approximately the same N content across all fertilizer rates suggesting that young, estabilishing, Coatal bermudagrass roots reserve N until their N requirement is met. As more N is obtained above that which was needed to maintain roots, then additional N taken up by the plant was transported to aboveground plant parts for growth. Frequent clipping intensified N transport to aboveground tissues. Reduced amounts of N were contained in roots after clipping due to reductions in root growth, biomass, and resource demand. Fertilization of Coastal bermudagrass at low N rates with different N fertilizer forms influenced the distribution of N in the plant and affected N recovery by different parts of the plant.     

Cultivar-related differences in the distribution of cell-wall-bound thionins in compatible and incompatible interactions between barley and powdery mildew

Leaf-specific thionins of barley (Hordeum vulgare L.) have been identified as a novel class of cell-wall proteins toxic to plant-pathogenic fungi and possibly involved in the defence mechanism of plants. The distribution of these polypeptides has been studied in the host-pathogen system of barley and Erisyphe graminis DC.f.sp. hordei Marchal (powdery mildew). Immunogold-labelling of thionins in several barley cultivars indicates that resistance or susceptibility may be attributed to the presence or absence of thionins at the penetration site in walls and papillae of epidermal leaf cells.All of the leaf-specific thionin genes are confined to the distal end of the short arm of chromosome 6 of barley. None of the genes for cultivarspecific resistance to powdery mildew which have previously been mapped on barley chromosomes are found close to this locus.     

The taxonomic status and distribution of Bushbabies in Malawi with emphasis on the significance of vocalizations

The debated identity of a small forest bushbaby in Malawi is resolved by a short-term field study of the animals’ behavior. Locomotor styles, calling patterns, and the structure of advertising calls confirm that the species is Galago zanzibaricusrather than G. demidoffor G. thomasi.A detailed comparison of acoustic structure between the Malawi animals and G. zanzibaricusin Kenya demonstrates a degree of between-population variation, although the calls remain conservative in those parameters expected to aid recognition of conspecifics. Distribution records extend the known geographical range of G. zanzibaricusover most of the northern half of Malawi. Further studies are required to link the animals from this region with either of the previously recognized subspecies: G. z. zanzibaricusfrom East Africa or G. z. grantifrom southern Malawi, Mozambique, and Zimbabwe.     

Thermoanaerobium lactoethylicum spec. nov. a new anaerobic bacterium from a hot spring of Kamchatka

A new anaerobic thermophilic Gram-positive, nonsporeforming bacterium strain ZE-1 was isolated from a hot spring of Kamchatka (USSR). The cells are rod-shaped, (0.5–0.8 · 2.0–20 m), non-motile. The bacterium can grow between 42 and 75°C; the optimal temperature is 65°C. The growth is possible between pH values 5.0 and 8.5; optimal pH is 7.0. The cultures grow on the media containing peptone, yeast extract, or casein hydrolysate as nitrogen sources in the presence of glucose or some other sugars, mannitol or starch. The main fermentation products of glucose are ethanol, acetate, lactate, H₂, CO₂; byproducts are propionic, butyric and isovaleric acids. Glucose is metabolized via Embden-Meyerhoff-Parnas pathway. Molecular hydrogen does not inhibit growth. The bacterium does not reduce aceton to isopropanol, but is able to form H₂S from elemental sulfur. The bacterium contains a soluble hydrogenase. This enzyme catalyzes both evolution and uptake of H₂ and is active in the presence of methyl viologen. The DNA-base composition is 34.6 mol%; the genome size 2.08x10⁹ D. The name proposed for the isolated bacterium strain ZE-1 is Thermoanaerobium lactoethylicum spec. nov.     

The importance of worm identity and life history in determining the vertical distribution of tubificids (Oligochaeta) in a riverine mud

The vertical distribution of Tubifex tubifex, Limnodrilus hoffmeisteri and L. udekemianus, in a riverine mud was studied over a year. Distribution was dependent upon species identity, season and locality. The size structure of the population, and hence species life history, was of fundamental importance in determining temporal patterns of vertical distribution. A positive correlation between worm length and depth of penetration was clearly demonstrated for all three species. However, the mid-stream populations of the three species were closer to the mud surface during the summer and autumn than were the near-bank populations, although the size structures of the populations were not significantly different. Thus, another factor, possibly the distribution of food, also influenced the vertical distribution of the worms. Cocoon distribution was similar to that of the adult worms. Cocoons of the larger species, L. udekemianus, occurred deeper in the mud than those of T. tubifex. A comparison between the vertical distributions of tubificids in cores sectioned in situ, on the stream bank, and 30 mins later, showed there to be no significant change in distribution with time.