珍稀水生植物——宽叶泽苔草的核型研究

宽叶泽苔草（Caldesia granis Samuel）。是一种珍稀濒危水生植物。它曾经一度被认为已经从中国大陆灭绝,但最近又在湖南省的一个高山沼泽中被发现。本文首次报道了依据上述新发现地点的宽叶泽苔草材料进行的细胞学研究结果。核型分析结果表明：本种染色体数目为22,其染色体组型高度不对称。结合前人对宽叶泽苔草一些近缘种的细胞学及古生物学研究结果,作者认为泽苔草属植物很可能是泽泻科中最进化的一个属。     

Effects of environmentally hazardous chemicals on the emergence and early growth of selected Australian plants

The effect of soil-incorporated copper, tri-allate, and anthracene on the emergence and early growth of three Australian native species (Banksia ericifolia, Casuarina distyla andEucalyptus eximia) and three crop species (Avena sativa, Cucumis sativus andGlycine max), was assessed using OECD Test Guideline 208. The crop species are sensitive species used in overseas phytotoxicity testing, and their responses were compared with those of the native species. Seeds were grown in pots in a glasshouse in a sandy loam soil at the chemical concentrations of 0, 10, 100, 1000 and 2000 mg kg^–1. LC50 and EC50 values were determined for each species. The most sensitive species was the monocotyledonA. sativa, while among the five dicotyledonsC. distyla was most sensitive. All three chemicals delayed emergence and affected seedling growth. The results indicate that the conditions of the OECD Test Guideline can be met under Australian conditions, but that the Guideline requires modification for use with Australian native species.     

红肉蜜柚汁胞蛋白质双向电泳体系优化研究

为建立适合红肉蜜柚发育过程中汁胞蛋白质组学的研究体系,以着色初始时期的红肉蜜柚汁胞为试材,摸索最适合的蛋白质双向电泳体系参数。结果表明,酚提取法比TCA-丙酮法更适合于红肉蜜柚汁胞总蛋白质的提取,提取得率高,双向电泳图谱清晰。采取18 cm、线性pH 3～10 和18 cm、线性pH 4～7 相结合的分析策略,可获得更为完整的蛋白质组信息,其第一向等电聚焦最佳参数（总伏小时数）分别为30 000 Vhs和43 000 Vhs。     

Characteristics of inorganic nitrogen assimilation of plants in fire-prone Mediterranean-type vegetation

A range of approaches was used to investigate how species within a fire-prone Banksia woodland in South West Australia exploited inorganic soil nitrogen sources and how this changes through the development of the fire chronosequence. Nitrate and ammonium were present in soil solution throughout the chronosequence but nitrate predominated in recently burnt sites. Mean shoot nitrate reductase activities were high for all species in recently burnt sites and showed little increase when nitrate was supplied via the transpiration stream. Nitrate reductase of shoots of most species was low at sites not burnt for several years, but following transpirational induction with nitrate, developed activities similar to those at recently burnt sites. The principal amino compounds transported in the xylem were species specific, including asparagine, glutamine and citrulline-dominated species, and changed little in relative composition across the chronosequence. Species most active in leaf nitrate reduction transported the largest amounts of nitrate in their xylem sap and proportional amounts of nitrate in xylem tended to be greatest in recently burnt sites. Most of the species examined appeared to be shoot rather than root nitrate assimilators, but marked differences were recorded in potential of leafy shoots of different species to reduce nitrate. As a general rule, shallow-rooted herbaceous, non-mycorrhizal or VAM-positive species had the highest capacity to reduce nitrate, whereas woody species with ericoid mycorrhizae or combined vesicular arbuscular/ectomycorrhizal associations exhibited little capacity to reduce nitrate in roots or shoots. It seems likely that this latter group utilize ammonium or even organic forms of nitrogen rather than nitrate. Some putative nitrogen-fixing species were active in reducing and transporting nitrate, others were virtually inactive in these respects.     

不同氮源下生长的柚树叶片光合参数对高浓度CO2驯化作用的比较

比较研究了在不同形式氮源下生长柚树叶片光合对高浓度 CO2 驯化过程中有关参数变化。植株生长在人工混成土壤中 ,分别浇灌含有 2 mmol L- 1N的 NO- 3 - N,NH+ 4 - N和 NH4 NO3- N溶液。空气 CO2 增高处理时向生长植株的开顶透明罩中通入 74.4Pa CO2 ,以空气 CO2 生长的植株为对照。利用 CI- 30 1 ( CID,Inc) CO2 气体交换系统测定叶片光合速率和通过光合作用相关响应曲线计算光合参数。结果表明 ,在 CO2分压倍增下 ,NO- 3 - N生长植株光饱和光合速率较大气 CO2 分压下的高。而生长在 NH+ 4 - N和 NH4 NO3- N的植株光合速率与大气 CO2 分压下的相近 ,表现对高 CO2 的驯化。在空气 CO2 倍增下无论供给何种形式氮源并不影响Γ* ,但可增高 Rd( P<0 .0 5 )。 CO2 分压倍增下供给 NO- 3 - N植株的 Vcmax和 Jmax较大气分压相应的植株高 ,而 NH+ 4 - N和 NH4 NO3- N植株则与大气 CO2分压的相应植株相似 ( P>0 .0 5 )。无论供给何种形式氮源 ,生长在空气 CO2 分压倍增下不改变叶片单位面积干重 ,叶绿素含量和叶片中氮在 Rubisco、生物能学组分和捕光色素复合体组分的分配系数 ;但能改变叶片中氮含量。植物对高 CO2 的驯化可能受到不同形式氮利用性的影响 ,在对高 CO2 驯化过程亦反映叶片中氮在不同光合功能组分     

Polymorphic microsatellite DNA markers for Banksia hookeriana (Proteaceae)

We developed 11 polymorphic microsatellite DNA markers for an Australian native shrub Banksia hookeriana (Proteaceae). The number of alleles per locus in 37 individuals varied from three to 17, observed and expected heterozygosities ranged from 0.297 to 0.838 and from 0.279 to 0.900, respectively. Two loci (BH‐B5 and BH‐B107) showed significant deviation from Hardy–Weinberg equilibrium (P < 0.05), and null alleles may be present at these two loci. All loci showed independent inheritance.     

濒危植物大果木莲种群格局及濒危原因分析

采用径级结构代替年龄结构以及方差均值比率法对木兰科(Magnoliaceae)木莲属(Manglietia Bl.)濒危植物大果木莲(Manglietia grandis Hu et Cheng)种群的年龄结构和种群格局进行了研究,并编制了大果木莲种群的特定时间生命表和存活曲线;结合生殖生物学特征以及遗传多样性研究结果,分析了导致大果木莲濒危的主要原因.根据株高和胸径可分别将大果木莲种群的年龄结构分为5级、高度结构分为6级;在大果木莲的5个年龄结构分级中,成年个体较多,幼年个体较少;其高度结构完整,个体高度主要在20 m以下.种群的方差均值比率为0.838 3,其空间分布格局属于随机分布.根据特定时间生命表可将大果木莲种群的发育分为3个阶段:幼树阶段(年龄级为Ⅱ～Ⅲ级)、成树阶段(年龄级为Ⅲ～Ⅳ级)、老树阶段(年龄级为Ⅳ～Ⅴ级),其中成树阶段个体死亡率最低.大果木莲种群存活曲线接近Deevey Ⅰ型,属于衰退型种群.种群自我更新能力差、种子生产力低下、有性生殖困难、生境片断化导致的基因流受限以及人为干扰是大果木莲濒危的主要原因.针对大果木莲濒危现状和致危原因,提出了相应的保护对策和建议.     

Studies on Essential Oil Composition in Leaves of Torreya grandis cv. ‘Merrillii' and Chemotaxonomy

The chemical components of different genera and species of Taxaceac have been analyzed in order to provide the data for discussion of the systematic position of this family. A characteristic component kayaflavone from the leaves of Torreya grandis cv. ‘Merrillii' has been reported in our previous paper. Recently we have obtained also a new diterpene torreyagrandate from the leaves of this species. The present paper deals with our preliminary study on essential oil composition of the leaves in the same species. 26 components have been identified. Three of them, limonene, α-pinene and δ-3-carene, are the main ones, with their contents being 44.24%, 20.75% and 4% respectively. The essential oilalso contains torreyol which is a characteristiccomponent in this species.     

Cultural and biochemical diversity of pink-pigmented bacteria isolated from paper mill slimes

A study of 25 paper mill slime deposits and one additive revealed nine pink-pigmented bacterial isolates, eight of which were different from pink-pigmented bacteria identified in the paper industry in the middle 1900s. The pink-pigmented bacteria described previously in pulp and paper included Micrococcus agilis, Bacillus subtilis, Serratia sp. and Alcaligenes viscosus. With the exception of one isolate, Micrococcus sp., these isolates possessed many cultural, biochemical and chemical properties which were different from the ones previously reported for paper mills. Eight of these bacteria were Gram-negative rods or filamentous, aerobic and positive for catalase production. Two isolates were methylotrophic, oxidizing methanol and identified as Methylobacterium zatmanii. Cellular fatty acid analysis and other characteristics showed one isolate to be Roseomonas sp. Using 16S rRNA gene sequencing, one isolate which was a Gram-negative rod was identified as Deionococcus grandis. Four bacteria had cells that were long or filamentous and these were isolated from mills with pink slime problems. The identity of one of the filamentous bacteria was determined by 16S rRNA gene sequencing to be close to Flectobacillus sp. strain MWH38. Most of the isolates were susceptible to 11 industrial biocides. Journal of Industrial Microbiology & Biotechnology (2000) 25, 74–80. Received 28 January 2000/ Accepted in revised form 09 June 2000