含金地质体表生带中主要微生物类群的研究

通过对16个含金矿区主要微生物类群的分布、生态结构的研究,发现不同类型的金矿具有不同的微生物类群.金矿矿石与金矿酸水中的自养硫细菌和异养菌分布具有明显差异,酸性水中含自养硫细菌较多,含异养菌极少;金矿氧化带中的异氧菌一般多于自氧硫细菌,其优势菌以芽孢杆菌属中蜡状芽孢杆菌为主.研究结果揭示了金矿中存在的主要微生物类群,对阐明表生金的形成、成岩和蚀变作用具有一定的意义,对发掘生物湿法冶金菌种资源具有重要作用.     

The new class 11 transposon Tn163 is plasmid-borne in two unrelated Rhizobium leguminosarum biovar viciae strains

Tn163 is a transposable element identified in Rhizobium leguminosarum bv. viciae by its high insertion rate into positive selection vectors. The 4.6 kb element was found in only one further R. leguminosarum bv. viciae strain out of 70 strains investigated. Both unrelated R. leguminosarum bv. viciae strains contained one copy of the transposable element, which was localized in plasmids native to these strains. DNA sequence analysis revealed three large open reading frames (ORFs) and 38 bp terminal inverted repeats. ORF1 encodes a putative protein of 990 amino acids displaying strong homologies to transposases of class 11 transposons. ORF2, transcribed in the opposite direction, codes for a protein of 213 amino acids which is highly homologous to DNA invertases and resolvases of class II transposons. Homology of ORF1 and ORF2 and the genetic structure of the element indicate that Tn163 can be classified as a class II transposon. It is the first example of a native transposon in the genus Rhizobium. ORF3, which was found not to be involved in the transposition process, encodes a putative protein (256 amino acids) of unknown function. During transposition Tn163 produced direct repeats of 5 bp, which is typical for transposons of the Tn3 family. However, one out of the ten insertion sites sequenced showed a 6 by duplication of the target DNA; all duplicated sequences were A/T rich. Insertion of Tn163 into the sacB gene revealed two hot spots. Chromosomes of different R. leguminosarum bv. viciae strains were found to be highly refractory to the insertion of Tn163.     

橐吾属的起源、演化与地理分布

橐吾属Ligularia Cass．是菊科千里光族款冬亚族的一个大属。在款冬亚族中本属与大吾风草属 Farfugium Lindl．亲缘关系最近,但进化程度较高。本属包括6组,11系129种。所有种类均分布在 亚洲,仅2种扩散至欧洲。在东亚地区有119种,占该属总种数的96％。高度集中在横断山区的有4组、 6系67种,其中61种为特有种,占该属总组数的66％,总系数的54．5％,总种数的52％。这个事实 表明了横断山区是该属的多度中心和多样化中心。通过性状分析,伞房组伞房系Sect．Corymbosae, Ser．Calthifoliae叶肾形,具掌状叶脉,头状花序大而少,排列呈伞房状,总苞半球形,被认为是该属的 原始类群。原始种齿叶橐吾L. dentata和鹿蹄橐吾L.hodgsonii的分布区从我国四川东部经过湖北、湖 南、安徽、福建等省至日本。这个分布格局与近缘属大吴风草属Farfugium一致。 根据共同起源原理,这两个属的祖先极有可能就发生在这一地区。因此我们推测东亚地区从中国四 川东部至日本这一地区是本属的发源地,然而根据地质历史和现代分布,作者认为中国中部(包括四川 东部)是本属的初始起源地。该属起源后,基本上沿亚洲南缘的山地扩散,少数种类向东北至亚洲东北部。本属起源时间至少不晚于中白垩纪。     

Morphometric analysis of the genusHemerocallis L. (Liliaceae) in Korea

To better understand the patterns of variability and distributions ofHemerocallis in Korea, 53 locations were visited and measurements of 19 morphological and phenological characters were taken on plants directly from their natural habitats. For morphometric analysis, 10 plants from each of 34 populations and five herbarium specimens ofH. middendorffii were used and the data from 12 quantitative characters was analyzed using univariate analysis. Except the littoral populations of Cheju, Hong, Taehuksan, and Sohuksan Islands (H. hongdoensis M. Chung & S. Kang), three peninsular KoreanHemerocallis species can be recognized mainly in South Korea:H. hakuunensis Nakai (=H. micrantha Nakai, growing on southern, central, and northwestern Korea);H. thunbergii Baker (=H. coreana Nakai, found on southeastern and central Korea); andH. middendorffii Tr. et Mey. (central and northeastern Korea). Morphological and phenological features contributing to recognition of the three groups were; color of perianth, shape of roots, shape of inflorescence, flowering time, odor, length of inflorescence, width of the lowest bracts, length of perianth tube enclosing a ovary, width of the inner perianth lobes. Natural hybridization seems to be rare in KoreanHemerocallis. It appears that the KoreanHemerocallis species are relatively well characterized by their distribution patterns, phenology, and habitats compared with the JapaneseHemerocallis species.     

罂粟科植物的分类,进化与分布

罂粟科有38属约700种,作者通过对科内各属的研究,根据其主要器官(雌蕊、雄蕊,花被、果和种子)的进化趋势,重新排列科内的分类系统,在3个亚科下,包括8个亚族。在此基础上,讨论各属可能的演化关系,分析它们的分布规律,最后探讨本科的起源。     

金粟兰科的起源,演化及其分布

本文利用形态解剖,孢粉学及化石资料,讨论了金粟兰科的系统;并对其起源,演化和现代分布格局形成等问题做了合理推测,主要结果如下：（１）Ｓａｒｃａｎｄｒａ和Ｃｈｌｏｒａｎｔｈｕｓ的亲缘关系最接近,而Ａｓｃａｒｉｎａ和Ｈｅｄｙｏｓｍｕｍ的系统位置最靠近。Ｓａｒｃａｎｄｒａ是金粟兰科中最原始的属,而Ｈｅｄｙｏｓｍｕｍ则是最进化的属。（２）金粟兰科可能于白垩纪最早期起源于木质部无导管的,具简单两性虫媒花的祖     

石灰性土壤上植物根际中Fe,Mn的形态分布及其与植物吸收的关系

研究了石灰性土壤上５种作物品种根际微生态环境中Ｆｅ、Ｍｎ的形态分布．结果表明,交换态Ｆｅ（ＥＸ－Ｆｅ）、碳酸盐结合态Ｆｅ（ＣＡＲＢ－Ｆｅ）、无定形氧化铁（ＡＯ－Ｆｅ）和交换态Ｍｎ（Ｅ－Ｍｎ）、碳酸盐结合态Ｍｎ（ＣＡＲＢ－Ｍｎ）在根际土壤中都呈现明显的累积．各品种根际中的累积量有较大差异．相关分析表明,黄潮土上植株含Ｆｅ量、吸Ｆｅ量与根际土壤ＡＯ－Ｆｅ含量呈显著正相关．根际有效态Ｆｅ累积不仅是根际ｐＨ作用的结果,与根系分泌物对难溶性Ｆｅ活化有关．根际有效态Ｍｎ累积则受到根际土壤Ｅｈ的影响．     

Interactions between C3 and C4 salt marsh plant species during four years of exposure to elevated atmospheric CO2

Elevated atmospheric CO2 is known to stimulate photosynthesis and growth of plants with the C₃ pathway but less of plants with the C₄ pathway. An increase in the CO₂ concentration can therefore be expected to change the competitive interactions between C₃ and C₄ species. The effect of long term exposure to elevated CO₂ (ambient CO₂ concentration +340 µmol CO₂ mol^-1) on a salt marsh vegetation with both C₃ and C₄ species was investigated. Elevated CO₂ increased the biomass of the C₃ sedgeScirpus olneyi growing in a pure stand, while the biomass of the C₄ grassSpartina patens in a monospecific community was not affected. In the mixed C₃/C₄ community the C₃ sedge showed a very large relative increase in biomass in elevated CO₂ while the biomass of the C₄ species declined.The C₄ grassSpartina patens dominated the higher areas of the salt marsh, while the C₃ sedgeScirpus olneyi was most abundant at the lower elevations, and the mixed community occupied intermediate elevations.Scirpus growth may have been restricted by drought and salt stress at the higher elevations, whileSpartina growth at the lower elevations may be affected by the higher frequency of flooding. Elevated CO₂ may affect the species distribution in the salt marsh if it allowsScirpus to grow at higher elevations where it in turn may affect the growth ofSpartina.     

牛蛙冬眠期及其前后的消化道嗜银细胞分布

为研究两栖类在冬眠期及其前后消化道嗜银细胞是否参与冬眠期的消化调节,本文以牛蛙(Rana catesbeiana)为实验对象,采用Grimelius银染法,对冬眠期前(n = 10)、冬眠期(n = 10)和冬眠期后(n = 10)牛蛙消化道嗜银细胞的形态及密度进行比较研究。结果表明,牛蛙消化道各部位均有嗜银细胞分布;牛蛙消化道嗜银细胞形态在冬眠期、冬眠期前及冬眠期后无差异,均为锥体型、梭型和椭圆型;牛蛙消化道各部位具有外分泌功能的锥体型和梭形嗜银细胞密度在3个时期均显著高于具有内分泌功能的椭圆型嗜银细胞密度(P < 0.01);3个时期牛蛙消化道嗜银细胞分布密度高峰均位于空肠处,但低谷有所不同,冬眠期前和冬眠期后牛蛙消化道嗜银细胞的分布密度低谷位于食管,而冬眠期其分布密度低谷位于贲门;3个时期相比,冬眠期前和冬眠期幽门处分布密度差异不显著(P > 0.05),其余部位均有差异,且食管、胃、十二指肠、空肠、回肠和直肠中嗜银细胞分布密度在冬眠期显著高于冬眠期前和冬眠期后(P < 0.05);冬眠期前和冬眠期后消化道嗜银细胞分布密度呈倒“U”型趋势,冬眠期分布密度呈现“~”型趋势。结合相关研究,推测牛蛙嗜银细胞分布密度的改变可能与机体适应不同生理状态及消化功能的调节有关。     

江西热带性植物的区系地理研究

本文通过对江西热带性植物区系成分各个分布类型的统计分析,阐述了本省热带性植物具有地理成分复杂,区系联系广泛,以泛热带和热带亚州分布型成分占优势;间断分布多样,残遗植物丰富;热带成分与温带成分交汇过渡,成为许多热带区系成分分布的北界。并初步探讨了江西植物区系地理的分界问题,笔者认为在江西境内,华东区系与华南区系的分界大致位于北纬25°(西)—25°20′(东)一线;中亚热带与北亚热带的区系分界约为北纬29°(西)—29°40′(东)一线;中亚热带两个亚热带的区系分界应在北纬27°(西)—27°40′(东)一线。此3条植物区系地理分界线由西向东有向北逐渐斜升的趋势,这是由于受太平洋湿热季风气候的影响所致。同时亦表明,某一地区植物区系的性质和特征主要是受其所处纬度(或海拔高度)的地带性气候因素长期孕育的结果。