Sex expression in Sagittaria guyanensis H.B.K. subsp. lappula (D. Don) Bojin is typically andromonoecious while the other species in the same genus are basically monoecious. The evolutionary advantages of male flowers and hermaphrodite flowers in S. guyanensis subsp. lappula were assessed by measuring sex allocation and pollen movements in two wild populations of the species. Two cultivated populations served as controls. The percentage of male flowers was very low in the two wild populations in Dongxiang, Jiangxi Province and Wuyishan, Fujian Province, viz., 2.48% and 0.96% respectively. In the two cultivated populations, male flower percentage significantly increased when the soil was of higher nutrient content. This indicates that the allocation to male versus female reproduction might change in response to environmental factors. Pollen production per male flower was 4.1 times higher than that of a hermaphrodite flower. The floral shape and size of male and hermaphrodite flowers were similar. No difference was observed between these dimorphological flowers in pollen germination rate in vitro and in the speed of pollen tube growth in vivo. Anthesis was only 4-5 h. Male flowers usually opened 0.5 h earlier than hermaphrodite flowers. An unexpected finding was that no pollen from the male flowers was found on the stigmas of the hermaphrodite flowers, in spite of the occasional visits by insects to both types of flowers in both wild and control populations. A consistent pattern of fruit development was found to exist in open pollinated flowers as well as in flowers that had been bagged. The sex ratios did not have significant influence on fruit set. Approximately 25% of the pistils in a gynoecium failed to develop into fruits because no pollen was deposited on them, indicating that the fruit set of this andromonoecious plant is mainly affected by pollen limitation rather than resource limitation. Reproduction in S. guyanensis subsp. lappula in the habitats was dependent on self-pollination in hermaphrodite flowers. The male flowers in this species might be a potential source of additional pollination and may facilitate cross-pollination. The fact that the flowers of monoecious species in Sagittaria pollinated by a wide diversity of insect visitors may contribute enormously to the diversification of sex expression in this genus.
The techniques of in situ hybridization (ISH) are widely adopted for analyzing the genetic make-up and RNA expression patterns of individual cells. There are four main criterions for evaluating this technique, including detection sensitivity, resolution, capacity and specificity. This review focuses on a number of advances made over the last years in the fluorescence in situ hybridization (FISH). These advances can be catagorized into several branches as follows: (1) Multicolor-FISH (mFISH), including conventional mFISH, combinatorial FISH, ratio labelling FISH, multicolor chromosome painting and comparative genomic hybridization (CGH); (2) Extended DNA fiber-FISH (EDF-FISH), including quantitative DNA fiber mapping (QDFM), molecular combing (MC) and dynamic molecular combing (DMC); (3)In situ PCR-based FISH; (4) Bacterial (or yeast) artificial chromosome-FISH (BAC-FISH or YAC-FISH); (5) Tyramide signal amplification-FISH (TSA-FISH); (6) Polypeptide nucleic acid-FISH (PNA-FISH) and (7) padlock-FISH.
王玲 宁顺斌 宋运淳 吕应堂*
关键词： 荧光原位杂交；多色荧光原位杂交；DNA 纤维；分辨率；灵敏度；特异性；物理作图；RNA表达图谱
Measurements of chlorophyll fluorescence kinetics from dark-starved cells, light-grown cells and mixotrophic cells of Synechocystis sp. PCC 6803 were obtained using a pulse amplitude modulation (PAM) fluorometer. Photosystem Ⅱ photochemical efficiency Ⅱand the extent of reduction of Q－A in the three kinds of cells described above were compared. The millisecond delayed light emission (MDLE) of light-grown cells and mixotrophic cells were also detected. On the basis of the analysis of fluorescence kinetic parameters, comparison of the slow phase of MDLE and the influence of inhibitors of photosynthetic electron transport3-(3,4-dichlorophenyl)-1,1-dimethylurea(DCMU), 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone (DBMIB) on the mixotrophic growth of Synechocystis sp. PCC 6803, it was concluded that the reasons for higher growth rate under mixotrophic than that under photoautotrophic might be that glucose promoted the photoautotrophic growth of mixotrephic cells and the donation of eletrons to the plastoquinone pool from the respiratory substance and the transform of energy was promoted by photosynthetic system, which provided the energy needed by anabolism of cells caused by the glucose added to the medium.
集胞藻Synechocystis SP. PCC6803利用葡萄糖生长与光合能量转化的关系
王永红1 叶济宇2 米华玲2 李元广1 张嗣良1
（1. 华东理工大学生物反应器工程国家重点实验室，上海200237；2. 中国科学院上海植物生理研究所，上海200032）
摘要：用PAM叶绿素荧光仪测定了饥饿细胞、光自养细胞和混合营养细胞的叶绿素荧光 ,并对 3种类型细胞的荧光参数 :PSⅡ实际光化学效率 φⅡ和还原型质醌Q-A 进行了比较。用双重转盘磷光机测定了光自养细胞和混合营养细胞的毫秒延迟发光。根据叶绿素荧光动力学分析和毫秒延迟发光的结果及光合电子传递抑制剂 3,4_二氯苯基二甲脲 (DCMU)、二溴百里香醌 (DBMIB)对集胞藻 6 80 3(Synechocystissp .PCC 6 80 3)混合营养生长影响进行了分析 ,集胞藻 6 80 3混合营养培养的生长速率显著高于光自养培养的原因可能在于一是外源葡萄糖没有抑制反而是促进了混合营养细胞的光自养生长 ,二是呼吸基质向质醌库提供电子 ,使光合机构的能量转化加强 ,从而促进了集胞藻6 80 3细胞的利用葡萄糖的合成代谢。
R5002-12, a salt tolerant line of Phragmites communis Trin., which was obtained from ethyl methane sulfonate (EMS) treated callus selected under saline stress, was compared with its wild line in respect to their molecular biological, physiological and biochemical characterizations. Five arbitrary primers were screened which showed differences in DNA amplified polymorphism between the variant and its wild line. Some new proteins appeared in the salt tolerant plant under salt stress. Electrophoresis of peroxidase and esterase also showed some differences in isozyme expression between them. The chlorophyll content of the variant was higher than that of the original variety, whether the plants were under salt stress or not.
许祥明 叶和春* 李国凤 陈建林
摘要：对通过细胞工程方法得到的耐盐芦苇（Ｐｈｒａｇｍｉｔｅｓ ｃｏｍｍｕｎｉｓ Ｔｒｉｎ．）变异系Ｒ５００２－１２与野生型植株进行了分子生物学和生理生化特性比较分析。筛选到５个ＲＡＰＤ引物对变异体和野生型植株的ＤＮＡＦ的随机扩增表现出不同的多态性，表明该变异体在分子水平上发生了变化。生理生化分析的结果表明，平行生长状态下的两种株系，其可溶性蛋白和同工酶的表达水平和种类不一样，变异体在ＮａＣｌ胁迫下，表达特异性的蛋白。实验还表明，无论胁迫
The protein kinases were identified at different developmental stages of apple (Malus domestica L. Borth. cv. Red Starking) and grape (Vitis vinifera L. × V.lubrusca L. cv. Kyoho) fruit, and these protein kinases were found to be greatly activated by Ca2+. This demonstrated that calcium-dependent protein kinase plays an important role in apple and grape fruits. The results also showed that calmodulin (CaM) had no stimulation effect, but the CaM antagonists, such as calmidazolium, W7 and trifluoroacetic acid (TFA), had some inhibitory effects on the activities of this kind of protein kinase in both fruits, indicating that the detected protein kinases may be a kind of calmodulin-like domain protein kinase or calcium-dependent protein kinase (CDPK). There were distinct differences between apple and grape fruits, both in the characteristics and in the activity evolution patterns of the protein kinases during fruit development. The activity of calcium-dependent protein kinase was little changed in the three stages of apple fruit development, while in grape fruit the activity of this protein kinase was much higher in stage Ⅱ than those in stage Ⅰ and stage Ⅲ. The calcium-dependent protein kinase in apple fruits was strongly activated by Mn2+, and it was sensitive to heat treatment, but in grape fruits it was neither stimulated by Mn2+ nor sensitive to high temperature. Besides, phosphatidyl-serine (PS) had little effect on the activities of calcium-dependent protein kinase in grape fruits, but had stimulative effects in apple fruits. It was thus proposed that there might be a kind of calcium- and phosphatide-activated protein kinase, i.e., PKC, in apple fruits. The differences among the kinds, characteristics and the activity evolution patterns of protein kinases during apple and grape fruit development, suggest that the protein kinases may be involved in the process of fruit development.
梁小娥 张大鹏* 贾文锁
摘要：在苹果 (MalusdomesticaL .Borkh .cv .RedStarking)和葡萄 (VitisviniferaL .×V .lubruscaL .cv .Kyoho)的不同发育阶段均检测到蛋白激酶活性 ,它们可被Ca2 + 强烈激活 ,表明依赖钙的蛋白激酶是苹果和葡萄果实中一类非常重要的蛋白激酶。钙调素 (CaM)对苹果和葡萄果实蛋白激酶没有激活作用 ,同时CaM拮抗剂calmidazolium、W7及三氟乙酸 (TFA)均可不同程度地抑制其活性 ,表明依赖钙的蛋白激酶中可能有含类似钙调素结构域的蛋白激酶(CDPK)的存在。在苹果和葡萄果实发育中 ,依赖钙的蛋白激酶无论在其活性变化还是特性上都存在着显著差异 :苹果果实发育的不同阶段依赖钙的蛋白激酶活性无明显变化 ,而葡萄果实在发育的第Ⅱ期蛋白激酶活性大大高于第Ⅰ、Ⅲ期 ;苹果果实依赖钙的蛋白激酶可被Mn2 + 强烈激活并对热敏感 ,而葡萄果实依赖钙的蛋白激酶却不受Mn2 + 及热处理的影响 ;此外 ,葡萄果实蛋白激酶活性不受磷脂酰丝氨酸 (PS)的影响 ,而苹果果实蛋白激酶可被PS激活 ,表明苹果果实中还可能有钙和磷脂激活的蛋白激酶即PKC的存在。苹果和葡萄果实发育中蛋白激酶种类、特性及其活性变化的不同 ,暗示了这两种果实发育调控的差异 ,也意味着苹果和葡萄果实发育调控可能与蛋白激酶密切相关。
The biocontrol capability of Candida guilliermondii (Cast) Langeroret Guerra against Rhizopus stolonifer (Ehrenb.ex Fr.) Vuill. postharvest rot of peach fruits was studied in vitro and in vivo under different storage temperatures. C. guilliermondii at 5.0×108 CFU (colony-forming unit)/mL of washed cells provided complete control of 5×104 spores /mL of R. stolonifer during storage at 25 ℃ for 4 d, 15 ℃ for 7 d and 3℃ for 30 d. Temperature had no significant effect on the biocontrol efficacy. Antagonist population increased 45.6, 34.4 and 33.1 times per site at 25℃, 15℃ and 3℃ for 3, 3 and 7 d，respectively, then the population stabilized for the remaining storage period. Cell-free culture filtrate of C. guilliermondii was not effective in preventing decay and resulted in even greater lesion diameter than those of sterile distilled water at 3 ℃.These results showed that competition for nutrient, not antibiotic production, plays a major role in the biocontrol capability of C. guilliermondii against rhizopus rot of peach fruits. As the interval between wounding and inoculation with the pathogen increased from 0 to 72 h, susceptibility of wounds to decay by R. stolonifer decreased from 100% of 0 h to 5% of 4 h and 0% of 24 h, then increased to 10% of 48 h and 40% of 72 h.
范青 田世平* 李永兴 徐勇 汪沂
摘要：研究了不同处理的枯草芽孢杆菌 (Bacillussubtilis (B-912 ) )在不同贮藏温度下对采后桃 (Prunuspersica L .)和油桃 (P .persicavar.nectarina Maxim .)褐腐病 (Moniliniafructicola (G .Wint)Honey)的防治效果。 2 5℃和 15℃贮藏温度下油桃的发病率一般高于桃 ,但在冷藏期间其发病率却一般低于桃。 10 6CFU/mL(CFU :Colony-FormingUnits,菌落形成单位 )的B-912能显著地降低褐腐病的发生 ,桃和油桃的发病率仅分别为 2 0 %和 40 %。 10 8CFU /mL的B-912能完全抑制贮藏在 2 5℃和 3℃下油桃和桃果实褐腐病的发生。单独接种 2 %CaCl2 的果实发病率显著地低于不加Ca2 + 的果实 ,但Ca2 + 和B-912配合运用时对褐腐病的抑制效果并不明显。B-912与扑海因配合使用能显著地抑制褐腐病的发生 ,其抑病效果好于单独使用B-912或扑海因的效果。B-912的滤液在invitro上能有效地抑制病菌孢子的萌发 ,在invivo上也能明显地抑制桃和油桃褐腐病的发生。由此表明 :B-912的抑菌机理与其产生的抗菌物质有关。
Segmental duplications on rice (Oryza sativa L.) chromosomes 8, 9, 11, and 12 were studied by examining the distributions of sequences resolved by 13 probes detecting multiple copies of DNA sequences. Four of the hybridization bands detected by a repetitive sequence probe, rTRS, were mapped to the ends of all the four chromosomes. Two or three of the bands detected by each of the other 12 probes were also mapped to different chromosomes. The bands detected by the same probe usually occurred in similar locations of different chromosomes. Loci detected by different DNA probes were often similarly arranged on different chromosomes. Chromosomes 8 and 9 showed colinearity of marker loci arrangement indicating a possible common origin. A segment on chromosome 9 was also very similar to the previously reported duplicated fragments on the ends of chromosomes 11 and 12 which were also detected in this study, indicating a likely common origin. Moreover, the various degrees of distributional similarity of the segments suggest a complex relationship among the chromosomes in the evolution of the rice genome. These results support the proposition that chromosome duplication and diversification may be a mechanism for the origin and evolution of the chromosomes in the rice genome.
王石平* 刘克德 张启发
摘要：利用 13个多拷贝探针 ,研究水稻 (OryzasativaL .)基因组第 8、9、11和 12染色体上的节段重复。由同一探针检测到的多拷贝位点通常位于不同染色体的相同部位。不同探针检测到的多拷贝位点在不同染色体上的位置顺序相同。第 8和第 9染色体上的相同多拷贝位点的线性排列 ,提示这两条染色体在进化上可能来源于同一原始染色体。而第 9染色体上的一个节段与前人报道的以及本研究进一步证实的第 11和第 12染色体短臂末端的重复区段相同 ,提示第 8、9、11和 12染色体可能在进化上存在同源性。这 4条染色体上表现出的不同程度的节段重复 ,为作者曾提出的水稻基因组形成和进化模式的推测提供了进一步的依据 ,即原始染色体的复制和基因的演变可能是水稻基因组形成和进化的重要机制。
Genetic similarities of 13 inbred lines of maize (Zea mays L.) were analyzed by restriction fragment length polymorphisms (RFLPs). The objectives of the study were to detect genetic similarities among 13 inbreds and to assign them to heterotic groups. By means of 24 probe-enzyme combinations (PECs) selected for locus specificity, clear patterns and reproducibility, 85 alleles were found with an average of 3.3 alleles per locus. The allelic frequency data were used to estimate genetic similarities among lines, and as a result the diversity index of 0.499 was obtained. Genetic similarities between the pairs of 13 lines ranged from 0.523 up to 0.802 with an average of 0.649. The UPGMA clustering algorithm analysis classified the 13 lines into five groups, which generally corresponded to known maize heterotic groups based on pedigree information. The authors concluded that RFLP-based markers could be used for investigating genetic relationships between maize inbred lines and assigning them to heterotic groups, but it seemed that a large number of PECs were needed to obtain reliable estimates of genetic similarity.
李新海 傅骏骅 张世煌 袁力行 李明顺
摘要：利用RFLP标记研究了 13个玉米 (Zeamays L .)自交系的遗传变异。从 30对探针 /酶组合中筛选出杂交带型清晰、稳定、重复性好的 2 4对组合 ,在 13个自交系中获得 85个等位基因杂交片段 ,平均每个位点为 3.3条 ,平均多态性指数为 0 .499。 13个自交系之间的遗传相似系数为 0 .5 2 3～ 0 .80 2 ,平均为 0 .6 49。UPGMA聚类分析表明 ,供试自交系共分为 5个类群 ,分群结果与其系谱关系基本吻合 ;表明利用RFLP标记可以研究玉米自交系之间的遗传关系 ,并将无系谱记载的自交系划分到相应类群中。
关键词： 玉米；RFLP 标记；遗传相似系数；杂种优势群
The interphase nuclei of parenchyma cells and epidermal cells of garlic (Allium sativum L.) clove were labelled with rabbit anti-actin antibody and FITC-conjugated goat anti-rabbit IgG antibody. The authors observed results with fluorescence microscopy and confocal laser scanning microscopy. The nuclei showed prominent green-yellow fluorescence, indicating the presence of actin in the nuclei. Fluorescence examination with TRITC-phalloidin showed distinctive red fluorescence in the nuclei, indicating that F-actin is present in the nuclei. Confocal laser scanning microscopy indicated the presence of F-actin containing network structures in the nuclei, but the network structures were absent and the nuclei still showed red fluorescence when the cells were treated with cytochalasin D before fixation; the red fluorescence in the nuclei was hard to be observed when the cells were treated with unlabelled phalloidin before the cells were stained with TRITC-phalloidin. These results indicate that F-actin is in the nuclei and forms network structures in the nuclei of garlic cells.
王冬梅1,2 王学臣2* 张伟成3
（1. 河北农业大学农学院，保定071001; 2. 中国农业大学生物学院，北京100094
摘要：采用免疫荧光和荧光分子探针技术与共聚焦激光扫描显微镜观察相结合，对大蒜（Ａｌｌｉｕｍ ｓａｔｉｖｕｍ Ｌ．）鳞片细胞间期核中是否存在Ｆ肌动蛋白进行了研究。结果表明，以兔抗肌动蛋折抗体为一抗、ＦＴＴＧ－羊抗兔ＩｇＧ抗体为二抗进行免疫荧光标记实验，在荧光镜下观察到蒜瓣薄壁组织的细胞核及表皮细胞核均发出明亮的黄绿色荧光经共聚焦激光扫描显微镜进一步检查，整个细胞核呈黄绿色荧光，说明其中含有肌动蛋白。经ＴＲITC-鬼笔环肽（TRITC-phalloidin）标记后，细胞核散发出明亮的红色荧光，经共聚焦激光扫描显微镜做光切片及三维重组图像，发现核中有一个三维网络结构。细胞松弛素D（cytochalasin D）预处理后，核中三维网络结构不复存在，但核仍显示红色荧光；若经非标phalloidin预处理，则核中几乎看不到红色荧光和任何网络残迹。对照实验结果进一步表明，*肌动蛋白存在于大蒜细胞核中并以* 肌动蛋白纤束形成三维网络结构。
关键词： 间期核；F 肌动蛋白；异硫氰四甲基罗丹明-鬼笔环肽；细胞松弛素D；共聚焦激光扫描显微镜；大蒜
Four japonica varieties and two indica varieties were used for the genetic transformation of rice （Oryza sativa L.） by using Agrobacterium tumefaciens (Smith et Townsend) Conn EHA101 harboring binary vector containing GUS gene and selectable marker gene of NPTⅡ and HPT. Calli derived from mature and immature embryos of rice were infected and cocultured with Agrobacterium at logarithmic phase. The highest transformation frequency was 55.1% (indica) and 85.2% (japonica) respectively according to the estimation of hygromycin resistant calli produced. The ratio of transgenic plants regenerated from the calli of indica and japonica varieties was 37.8% and 69.0% respectively. The putative transformed plants were confirmed by GUS assay, PCR analysis and Southern blotting. The segregation of foreign genes in T1 progeny corresponded to the Mendelian ratio. This transformation procedure of rice will provide an efficient model for the transformation of monocots.
黄健秋* 卫志明 安海龙 徐淑平 章冰
摘要：利用根癌土壤杆菌 (Agrobacteriumtumefaciens (SmithetTownsend)Conn)介导的转化方法对 4个粳稻 (OryzasativaL .ssp .japonica)品种和 2个籼稻 (O .sativassp .indica)品种进行了转化。在对影响根癌土壤杆菌转化水稻效率的多种因素进行比较研究后 ,建立了根癌土壤杆菌介导的水稻高效转化和再生系统。将水稻成熟胚和未成熟胚来源的愈伤组织用根癌土壤杆菌EHA10 1/pGIH感染后 ,筛选出抗性愈伤组织并获得转化植株。其中抗性愈伤组织产生频率最高达 5 5 .1% (籼稻 )和 85 .2 % (粳稻 ) ,转化植株产生频率最高达 37.8% (籼稻 )和 6 9.0 % (粳稻 )。GUS染色、转基因植株总DNA的PCR和Southern杂交检测等结果表明 ,T_DNA上的外源基因已整合进了转基因植物基因组中。对转基因T1代水稻植株的遗传分析结果证明外源基因能稳定遗传给后代 ,且大多数株系的分离比符合 3∶1。该转化系统的建立为将外源有用基因导入水稻并高效稳定地表达奠定了基础。
The sequences of the ITS region (including ITS-1, 5.8S rDNA and ITS-2) of nuclear ribosomal DNA from 15 species of the genus Amaranthus L. and outgroup Celosia cristata L. were determined. The result shows that the size of the ITS region of Amaranthus is from 629 to 632 bp, and the length variation is only found in ITS-1 (250-253 bp). On the basis of phylogenetic analysis of nucleotide sequences, the Amaranthus species in China may be devided into three sections, viz., sect. Spinosus, sect. Amaranthus and sect. Paucestamen; the cultivated species, viz., Amaranthus paniculatus L., A. cruentus L., A. caudatus L. and A. hypochondriacus L. can be treated as the subsp. of A. hybridus L.; A. taishanensis F.Z.Li and A. tenuifolius Willd are both closely related to species in the sect. Paucestamen. The study also indicated that the number of stamens has more phylogenetic information than other characters, such as the number of sepals and dehiscence/indehiscence of fruits in Amaranthus.
宋葆华1,2陈之端2 汪小全2 李法曾1*
摘要：运用PCR直接测序法 ,对苋属 (AmaranthusL .) 15个种及外类群鸡冠花 (Celosiacristata L .)nrDNA的ITS区(包括ITS_1,5 .8SrDNA和ITS_2 )进行序列测定。结果表明苋属植物的ITS序列总长度为 6 2 9～ 6 32bp ,长度变异仅发生在ITS_1区 (2 5 0～ 2 5 3bp)。采用PAUP软件进行系统发育分析表明 :分布于中国的苋属植物可分为 3组 ,即刺苋组 (sect.Spinosus) ,五蕊组 (sect. Amaranthus)和 2-3蕊组 (sect.Paucestamen) ;栽培种AmaranthuspaniculatusL .,A .cruentusL .,A .caudatusL .和A .hypochondriacusL .可作为A .hybridusL .的种下等级 ;新种A .taishanensisF .Z .Li和新分布种A .tenuifoliusWilld与 2_3蕊组 (传统 3被组 )关系密切。另外 ,研究结果分析表明 :雄蕊数目比花被片数目和胞果是否开裂等性状在苋属植物分类中更有意义。
An idea of plant functional types (PFTs) classification is brought forward based on the topographical pattern of plants, and a case study at Daloling region, lying in the northern part of Chinese subtropical zone, is presented. By means of extensive field study of the mountain forests, the quantitative attributes of the major 55 evergreen broadleaved tree species in the communities located at various topographical positions were acquired. The detrended canerical corre spondence analysis (DCCA) method was used to analyze: 1) The correlationships among the habitat temperature, moisture and illumination conditions and the 6 topographical attributes as elevation, mountain aspect, slope shape, slope position, slope direction and slope gradient of the habitat. 2) The diverse patterns of 55 species on the multidimensional topographical gradients. The scores of ordination were then used for a two way indicator species analysis (TWINSPAN) to the species. According to the results of previous analyses, the 55 evergreen broadleaved tree species at Dalaoling were classified into 10 PFTs. A discussion about the validity and limits of this PFTs accessing approach were given in the end.
（1. 北京大学城市与环境科学系，北京100871；2. 中国科学院植物研究所，北京100093）
摘要：提出基于植物分布的地形格局划分植物功能型 (PFTs)的思路 ,并以位于中国亚热带北部的大老岭地区为研究区域进行案例研究。通过大量的森林群落调查获得该地区 5 5种主要的常绿阔叶树在不同地形部位群落中的数量特征 ;采用去势典范对应分析 (DCCA)方法 :1)海拔、坡面、坡形、坡位、坡向、坡度等 6个地形特征指标与群落生境的热量、水分和光照条件的关系 ;2 ) 5 5种植物在多维地形梯度上的分异格局。然后利用排序得分对物种进行二元指示种 (TWINSPAN)分类。依据上述分析 ,将大老岭的常绿阔叶树种划分成 10个PFTs。讨论了这种PFTs划分途径的有效性和局限。
Two novel flavone glycosides, 3′-hydroxy-5,4′-dimethoxy-6,7-methylenedioxyflavone-3-O-［β-D-xylopyranosyl(1→6)］-β-D-glucopyranoside(1)and5,4′-dimethoxy-3′-isopropenylacetyl-6,7-methylenedioxyflavone-3-O-［β-D-xylopyranoxyl(1→6)］-β-D-glucopyranoside (2), were isolated from Polygonum sphaerostachyum Meisn., and their structures were deduced by spectral and chemical methods. This is the first report on the isolation of flavone glycosides from P. sphaerostachyum.
安红纲1 郑尚珍2* 沈彤2 郑敏燕2 沈序维2
（1. 张掖师范专科学校化学系，甘肃张掖734000；2. 西北师范大学化学系，兰州730070）
摘要：从圆穗蓼 (PolygonumsphaerostachyumMeisn .)中分离得到 2个新黄酮甙 ,经光谱分析和化学方法鉴定为 :3′_羟基_5 ,4′_二甲氧基_6 ,7_二氧亚甲基黄酮_3_O_[β_D_吡喃木糖基 (1→ 6 ) ]_β_D_吡喃葡萄糖甙 (1)和 5 ,4′_二甲氧基_3′_异丙烯基乙酰基_6 ,7_二氧亚甲基黄酮_3_O_[β_D_吡喃木糖基 (1→ 6 ) ]_β_D_吡喃葡萄糖甙 (2 ) ,分别命名为圆穗蓼素A和圆穗蓼素B。
Biome (vegetation) reconstruction of the Middle Holocene ((6 000±500) a BP) and the Last Glacial Maximum ((18 000±2 000) a BP) in China was accomplished based on pollen data from “China Quternary Pollen data Base" and biomesation procedure. There are 116 pollen data used for 6 ka BP biome reconstruction. The 6 ka BP Biome shows the following differences as compared with the present vegetation: 1. Forests of eastern China expanded westwards to the steppe area. 2. Temperate deciduous forests shifted about 4 degrees latitudinally northwards and replaced by cool temperate mixed forest and taiga at present. 3. Tundra in Tibet Plateau was greatly shrunken. 4. Seasonal rainforest was replaced by rainforest in southern China. All these changes must be attributed to the increasing temperature and humidity during Middle Holocene, except some areas of southwestern and tropical areas of southern China where climate might be even cooler, but more humid than nowadays. Biome of 18 ka BP based on 39 pollen data displayed: 1. Steppe and desert expanded southwards and eastwards reaching the northern margin of the present evergreen broad-leaved forest. 2. Evergreen broad-leaved forest retracted southwards to the present tropical zone and the tropical forest banished completly. The vegetation changes must be resulted from cold and dry climate during the Last Glacial Maximum.
中国中全新世（6Ka BP）和末次盛冰期（18 Ka BP）生物群区的重建
摘要：利用中国第四纪孢粉数据库提供的１１６个６ｋａ ＢＰ（±５００年）和３９个１８ｋａＢＰ（±２ｋａ）的花粉数据，根据生物群区化方法（ｂｉｏｍｉｚａｔｉｏｎ）重建了中国中全新世（６ｋａ ＢＰ）和未次盛冰期（１８ｋａ ＢＰ）两个关键时段的生物群区。结果表明，中全新世东部森林系统地向北推进，温带落叶阔叶林向北推进约４个纬度。大部分森林明显向草原区推进，青藏高原的冻原大面积退缩，在西南地区局部和热带地区气候较今略为冷湿，热带季雨林转变为热带雨林。末次盛冰期，草原大面积向南扩张，抵达现代的常绿阔叶林区的北缘，热带森林消失，常绿阔叶林退缩到现代热带区域边缘。
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