Recent advances on the biodiversity, ecological roles, and functional metabolites of endophytes were summarized with some speculative comments for better understanding of this subject.
To study the taxonomy of the family Boraginaceae further, the pollen morphology and exine ultrastructure of 10 species in the genus Cordia L. belonging to the family Boraginaceae were examined, and four aperture types were found. These types are 3-porate, 3-colporate, 3-syncolpate and 3-colporoidate. There are four ornamentation types on the exine surface: microspinulate, spinulate, reticulate and irregularly striatereticulate. The characteristics of pollen morphology in this genus show that Cordia L. is a unique taxon and a rather primitive genus in the Boraginaceae.
刘家熙1 席以珍2* 宁建长2 张静梅1 李雅轩1 赵云云1 孙晓红1
（1. 首都师范大学生物系，北京100037；2. 中国科学院植物研究所，北京100093）
摘要：为了深入探讨紫草科 (Boraginaceae)的分类问题 ,用光学显微镜和扫描电子显微镜观察了该科破布木属(CordiaL .) 10种植物的花粉形态和外壁超微结构。发现该属花粉具三孔、三孔沟、三拟孔沟和三合沟 4种萌发孔类型。外壁表面具微刺状纹饰、刺状纹饰、网状纹饰和不规则的条纹网状纹饰。破布木属的花粉特征表明 :该属花粉在紫草科中既是独特的分类群 ,又是比较原始的属种。
The dynamic changes in the distribution of lignin and hemicelluloses (xylans and xyloglucans) in cell walls during the differentiation of secondary xylem in Eucommia ulmoides Oliv. were studied by means of ultraviolet light microscopy and transmission electron microscopy combined with immunogold labelling. In the cambial zone and cell expansion zone, xyloglucans were localized both in the tangential and radial walls, but no xylans or lignin were found in these regions. With the formation of secondary wall S1 layer, lignin occurred in the cell corners and middle lamella, while xylans appeared in S1 layer, and xyloglucans were localized in the primary walls and middle lamella. In pace with the formation of secondary wall S2 and S3 layer, lignification extended to S1, S2 and S3 layer in sequence, showing a patchy style of lignin deposition. Concurrently, xylans distributed in the whole secondary walls and xyloglucans, on the other hand, still localized in the primary walls and middle lamella. The results indicated that along with the formation and lignification of the secondary wall, great changes had taken place in the cell walls. Different parts of cell walls, such as cell corners, middle lamella, primary walls and various layers of secondary walls, had different kinds of hemicelluloses, which formed various cell wall architecture combined with lignin and other cell wall components.
贺新强 崔克明* 李正理
摘要：利用紫外光显微镜、透射电子显微镜结合免疫胶体金标记,研究了杜仲(Eucommia ulmoid es Oliv.)次生木质部分化过程中木质素与半纤维素组分(木葡聚糖和木聚糖)在细胞壁分布的动态变化.在形成层及细胞伸展区域,细胞壁具有木葡聚糖的分布,而没有木聚糖和木质素沉积.随着次生壁S1层的形成,木质素出现在细胞角隅和胞间层,木聚糖开始出现在S1层中,此时木葡聚糖则分布在初生壁和胞间层;随着次生壁S2层及S3层的形成和加厚,木质素逐步由细胞角隅和胞间层扩展到S1、S2和S3层,其沉积呈现出不均匀的块状或片状沉积模式.在次生壁各层形成与其木质化的同时,木聚糖逐渐分布于整个次生壁中,而木葡聚糖仍局限分布于初生壁和胞间层.结果表明,随着细胞次生壁的形成与木质化,细胞壁结构发生较大变化.细胞壁的不同区域,如细胞角隅、胞间层、初生壁和次生壁各层,具有不同的半纤维素组成,其与木质素等细胞壁组分结合共同构成不同的细胞壁分子结构.
n vitro pollination and its embryological studies were carried out in two japonica cultivars of rice (Oryza sativa L.), “Chunjiang 05" and “95046". N6 basic medium supplemented with different exogenous hormones was used for ovary culture after in vitro pollination. The main results were as follows: (1) both cultivars were induced to set kernels after in vitro pollination. The frequency of seedset was 52.1%, including 28.4%normal embryo development, 2.2% abnormal embryo development and 21.5% callus formation. (2) The processes of embryo and endosperm development after in vitro pollination were basically as normal as those in vivo , except there was some retardation in the first division of zygotes and primary endosperm nuclei as well as in their subsequent development. However, both kernels and plantlets could be produced finally. (3) A few abnormal embryos were observed, for instance, proembryos with elongated suspensor and vacuolated proembryos. (4) Two types of calli in the cultured ovaries appeared, namely, the compact callus and the fragile callus, which were able to differentiate into adventitious buds and roots.
（1. 武汉大学植物发育生物学教育部重点实验室，武汉430072；2. 沈阳农业大学生物科技学院，沈阳110161）
摘要：采用2个水稻（Oryza sativa L.)品种“春江05”（早粳）和“95046”（晚粳），对离体授粉过程中的胚胎学进行了详细的研究。结果表明：（1）2个品种均胡离体授粉结实，平均结实率为52．1％，其中28．4％胚胎发育正常，2．2％胚胎发育异常，21．5％愈伤组织化；（2）离体授粉时的胚胎发育途径和体内自然发育基本相同，中是合子和初生胚乳核首次启动分裂及以后的发育均较延缓，但最终也能萌发成幼苗。（3）观察到具细长胚柄的原胚及液泡化原胚等异常的胚胎类型；（4）子房内形成的愈伤组织分为致密和松散两种类型，二者均可化出不定芽和不定根，还对离体授粉的方法，离体授粉中正常和异常的胚胎发育途径进行了讨论。
Changes in the pattern of microtubule distribution and organization during megagametogenesis in the embryo sac of rice (Oryza sativa L. cv. IR36) were re-examined using a modified polyethylene glycol sectioning technique before immuno-fluorescence staining of microtubules. In the sectioned materials the pattern of distribution and structural organization of the microtubule cytoskeleton were quite well preserved. Fine details of the patterns of structural changes and re-organization of the microtubule cytoskeleton in the major stages of development during embryo sac megagametogenesis (viz. functional megaspore, uni-nucleate, 2-nucleate, 4-nucleate, 8-nucleate and mature stage) could be clearly observed and easily followed. Some new organizational patterns of microtubules associated with the probable movement and positioning of the polar nuclei were observed.
徐是雄1 刘向东2 朱洪亮2 卢永根2
（1. 香港大学植物学系，香港；2. 华南农业大学植物分子育种研究中心，广州510642）
摘要：用PEG包埋切片法及荧光抗体标记技术对水稻 (Oryzasativa L .)雌配子体发生过程中微管骨架的变化进一步研究。经PEG包埋切片技术处理的胚囊内的微管结构能够保持得比较完整 ,特别是在一些较大和成熟的胚囊内 ,效果更佳 ,微管清晰度高。对雌配子体发生过程中的一些主要时期的微管结构变化作了详尽描述和分析 (包括 :单核、二核、四核、八核和成熟胚囊时期 )。发现了一些新的微管结构 ,如在中央细胞中有纵向微管 ,这些微管在两个极核移至中央部位时存在 ,之后当极核移至靠近卵细胞时便消失 ,显示中央细胞纵向微管与极核的移动和定位可能有关。
A mutant UW3, which is unable to fix N2 in the presence of Mo (Nif-) but undergo phenotypic reversal to Nif+ under Mo deficiency, was able to grow in Mo- and NH3-deficient medium containing Mn, and the growth was accelerated by Mn at low concentration. A partly purified nitrogenase component Ⅰ protein separated from UW3 grown in the Mn-containing medium was shown to contain Fe and Mn atoms (ratio of Fe/Mo/Mn: 10.41/0.19/1.00) with C2H2- and H+-reducing activity which almost equal to half of that of MoFe protein purified from wild-type mutant of Azotobacter vinelandii Lipmann. This protein was obviously different from MoFe protein in both absorption spectrum and circular dichroism, and the molecular weight of subunits in Mn-containing protein was close to that of α subunit in MoFe protein. The preliminary results indicated that the protein containing Mn might be a nitrogenase component Ⅰprotein.
黄巨富 汪道涌 董志刚 汪志平 张华峰 吕玉兵 许祥明 赵颖
摘要：棕色固氮菌(Azotobacter vinelandii Lipmann)突变种UW3能在无Mo 而含Mn的无氨培养基中固氮生长.低浓度的Mn对UW3突变种生长有促进作用.从在Mn中生长的UW3菌体中分离得到的部分纯固氮酶组分Ⅰ蛋白含有Mn和Fe原子(Fe/Mo/Mn为10 .41∶0.19∶1.00)并具有OP MoFe蛋白一半的还原乙炔和质子的活性.这种蛋白的吸收光谱和圆二色谱与MoFe蛋白存在明显的差异,含Mn蛋白的亚基分子量都与 MoFe蛋白的α亚基相近.初步结果表明,这种含Mn蛋白可能是一种固氮酶组分Ⅰ蛋白.
Previous studies have examined the effects of red light (R) on phototropism of maize ( Zea mays L. cv. Royaldent Hit 85) coleoptiles. The R effect on time-dependent phototropism (TDP) was further studied by characterizing its fluence-response relationship. The results showed the R effect was a low-fluence-response, unlike those on pulse-induced phototropisms that show a very-low-fluence-response mode. A subsequent pulse of far-red light (FR) could reverse the R effect. TDP responsiveness, however, recovered as the following FR was extended. The FR-dependent increase in TDP responsiveness was obtained even coleoptiles were pretreated only with FR. It suggested that TDP responsiveness could also be established in response to a FR signal. The fluence-response relationship for the effect of FR was then investigated. The effect of FR depended on the time of irradiation and required high photon fluences. Because reciprocity was invalid at the higher fluence range, the effect of FR would be a high-irradiance-response mode. Relation between phytochrome action modes and possible multiple pathways for phototropic signal transduction was analyzed based on the experiment results.
摘要：先前的研究考察了红光对玉米 (Zea mays L. cv. Royaldent Hit 85) 胚芽鞘向光性反应的影响.本研究进一步分析了红光对蓝光照射时间依赖型向光性(TDP)影响的光量-反应曲线,发现该反应不像红光对脉冲蓝光诱导的向光性的影响那样属于超低光量反应,而是一种低光量反应,且之后的脉冲远红光可以逆转红光对TDP影响的效果.但远红光预处理延长后,逆转了的TDP反应性可以得到恢复.不仅如此,暗适应胚芽鞘接受不同时间的单独远红光预处理后可同样获得与预处理光量成比例的TDP反应性,表明暗适应胚芽鞘在接受远红光预处理后亦可建立起对长时间向光性蓝光照射的反应能力.远红光对TDP反应性影响的光量-反应曲线分析揭示,该远红光影响依赖于照射时间并要求高光量.鉴于高光量范围内上述远红光影响不符合所谓反比定律,远红光对TDP反应性的影响很可能属一高辐照反应.根据上述研究发现探讨了植物光敏素作用模式与不同向光性反应信号转导途径之间可能存在的相互关系.
Oryza sativa L. ssp. japonica and indica exhibit different sensitivity to photoinhibition and they show different stability of their core proteins D1 in the chloroplast photosystem Ⅱ. Using in situ hybridization, psbA , the gene encoding D1 protein of O. sativa ssp. japonica cv. 9516, and that of O. sativa ssp. indica cv. Shanyou 63 was cloned. As revealed by homology comparison of their sequences, the sequences are identical in the regions of promoter and 5′-UTR; differences are found in individual bases in the coding region all of which, being in the third position of respective codons, however, do not affect the amino acids coded finally; a difference is noted in the length of the oligo-U sequence in the region of 3′-UTR. It is thus apparent that, rather than a result of any difference in the amino acid sequences, the differences in the sensitivity to photoinhibition of D1 proteins between japonica and indica rice may be related to the upstream factors that regulate expression of psbA or to differences of photoprotective mechanisms.
张方 谢先芝 陈凡 吴乃虎*
摘要：粳稻(Oryza sativa L. ssp. japonica)和籼稻(O.sativa ssp. indica)对光抑制的敏感程度存在差异,它们的叶绿体光反应中心Ⅱ核心蛋白D1的稳定性不同.以菌落原位杂交法克隆了粳稻"9516”和籼稻"籼优63”叶绿体 D1蛋白的编码基因psbA.核苷酸序列同源比较显示:两者在启动子区和5′-UTR完全相同;编码区存在着个别碱基的差异,但均位于三联体密码的第三位,不影响氨基酸编码特性 ,在蛋白质氨基酸序列上没有差异;在3′-UTR内存在寡聚U长度的差异.因此,粳稻和籼稻 D1 蛋白对光抑制作用敏感性的差异与其蛋白质的氨基酸序列结构无关,可能与调控psbA基因表达的上游因子或光保护机制的差异有关.
关键词： 粳稻；籼稻；光抑制；D1 蛋白；psbA
To mutagenize two conserved CCCT and PTK motifs in the central domain of Chinese strain of potato Y potyvirus (PVY-C) helper component proteinase (HC-Pro), four mutants of HC-Pro gene were obtained by PCR and site-directed mutagenesis, and then were inserted into the constitutive expression vector pBin438. Leaves from tobacco ( Nicotiana tabacum L. cv. K326) were transformed with these four plant expression plasmids by Agrobacterium -mediated transformation, respectively. Southern and Western blotting analyses showed that these four mutants were integrated into tobacco genomic DNA and could express the corresponding proteins in most of the transgenic plants. The challenge of transgenic plants with potato X potexvirus (PVX) revealed that the expression products of PVY-C HC-Pro mutants in transgenic plants greatly abolished functions of HC-Pro in enhancing the accumulation and pathogenicity of PVX, indicating that CCCT and PTK motifs of HC-Pro were required for PVX/PVY synergism. Meanwhile, the results demonstrated that PVY-C HC-Pro had a function in accelerating the long-distance movement of PVX in these transgenic plants for the first time.
李为民1,2 鲁瑞芳1* 郭明1 陈毓荃2 彭学贤1
（1. 中国科学院微生物研究所植物生物技术开放实验室，北京100080；"# 西北农林科技大学基础科学系，陕西杨凌712100）
摘要：采用PCR和定点突变法,对马铃薯Y病毒中国株系(Chinese strain of potato Y potyvirus, PVY_C) 蚜传辅助成分(helper component proteinase, HC_Pro)基因中心区域的CCCT 基序和PTK基序进行了定点改造,获得了4种突变体.然后将突变体克隆到植物表达载体pBin438 中, 所得到的重组体通过根癌土壤杆菌(Agrobacterium tumefaciens (Smith et Townsend) Conn)介导法转化了烟草(Nicotiana tabacum L. cv. K326). Southern blotting和Western blotting分析表明4种突变体已经成功地整合到烟草的基因组中, 并在蛋白水平上得到了表达.马铃薯X病毒(potato X potexvirus, PVX)对转基因烟草的攻毒实验表明, 4种突变体均使PVY_C HC_Pro严重丧失了促进PVX病毒粒子在寄主体内积累和提高 PVX致病性的功能,说明CCCT、PTK基序为PVY_C HC_Pro介导PVX/PVY协生作用所必需.同时证明了HC_Pro具有增强PVX在寄主体内长距离运输的功能.
关键词： 马铃薯Y病毒；马铃薯X 病毒；蚜传辅助成分基因；突变；协生作用
There are more than 6 000 clones of Hevea brasiliensis Mull. Ary germplasm in the germplasm garden of Chinese National Key Biotechnology Laboratory for Tropical Crops and some of them are elite germplasm demonstrated by production and previous studies. AFLP (amplified fragment length polymorphism) fingerprinting analysis was performed on 25 clones (15 of Wickham clones and 10 of Amazon wild clones which possess phenotypes with high-yielding/low-yielding, cold-tolerance/cold-sensitivity, oidium-resistance/oidium-sensitivity, tapping panel dryness (TPD)/healthy) respectively through a 377 DNA sequencer (P. E. Corp.) and PAGE electrophoresis results were analyzed by using GeneScanTMand GenotypeTM Analysis software (P.E.Corp.). The fragment profiles of different clones were obtained. Five hundred and eighteen fragments were generated by two primer combinations screened from 64 primer combinations and 511 fragments appeared to be polymorphic (98.6%). Genetic distance ranged from 0.25 to 0.81 between clones and ranged from 0.07 to 0.17 within RRIM600 clone. A specific 320 bp fragment of the oidium-resistant clones was found through genotype analysis. These results showed that AFLP fingerprints were highly reproducible and powerful and can be widely used in germplasm identification and genetic diversity analysis of Hevea brasiliensis. In addition, based on the AFLP data, cluster analysis was performed. Cluster results showed that all the clones studied were almost clustered into a group one by one.
罗安定 陈守才* 吴坤鑫 符少萍
Salt-affected soil is a serious global problem. Most of wheat (Triticum aestivum L.) are sensitive to high levels of salt in soil; However, a number of wild relatives of wheat are tolerant to high levels of salt. Several lines, including the hybrids between wheat and Secale cereale L. and the hybrids between wheat and Leymus chinensis (Trin.) Tzvel., were investigated under salt stress. Four hundred accessions of collections were screened by salt stress during germinating and seedling stages. Eleven lines showed high tolerance to salt stress, they are Triticum aestivum L. cv. Hongmazha (landrace), Keyi 26, Hope; wheat-rye hybrid, 98-46, 98-113, 98-131; wheat- Leymus hybrid, 98-160, 98-161, 98-163. The lines with remarkable tolerance to salt stress are 98-160, 98-113. Genomic in situ hybridization and acid polyacrylamide gel electrophoresis (A-PAGE) analysis of gliadin and SDS-PAGE analysis of low molecular weight glutenins proved that 98-131 was a stable 1BL/1RS translocation and 98-113 was an addition line with one pair of unidentified rye chromosomes. Further salt stress response test of 1B/1R substitution/translocation lines indicated that 1RS might have salt tolerance gene(s). SSR markers were employed to target the salt tolerance genes of 98-160 in its F2 population with salt sensitive line, Banacaka Mska. The analysis displayed that SSR markers WMS67 and WMS213 mapped on 5BL were linking to salt tolerance gene(s). Genetic distance of the two markers to the critical gene(s) are 13.9 cM (centMorgan), 31.0 cM, respectively. It is suggested that in 98-160 line, the salt tolerance might be controlled by major gene (s) on 5BL.
刘旭 史娟 张学勇* 马缘生 贾继增
摘要：通过对 40 0份材料的芽期、苗期鉴定 ,筛选出 11份耐盐性较强的普通小麦 (Triticumaestivum L .)、小麦和黑麦 (Secalecereale L .)、小麦和延安赖草 (Leymuschinensis (Trin .)Tzvel.)杂交后代材料 ,其中耐盐性突出的材料有 :普通小麦品种“红蚂蚱”、“科遗 2 6”、“希望”(Hope) ;小麦与黑麦杂交后代材料 98-46、98-113、98-131;小麦与延安赖草杂交后代材料 98-16 0、98-16 1、98-16 3。耐盐性表现最突出的材料是 98-113和 98_16 0。细胞学鉴定和原位杂交及醇溶蛋白酸性聚丙烯酰胺凝胶电泳 (A-PAGE)分析和低分子量谷蛋白SDS_PAGE分析 ,证明 98-113是稳定的小麦 黑麦二体附加系 ,但具体附加的是黑麦的哪条染色体还不清楚 ;98-131是小麦 黑麦 1B/ 1R易位系。结合其他 1B/ 1R材料的耐盐表现 ,提出了黑麦 1R染色体短臂上存在耐盐基因的可能性。对 (98_16 0×BanacakaMska)F2 代分离群体苗期抗盐鉴定分析 ,表明在这一杂交组合中的耐盐性状可能由一个主效基因控制。应用SSR标记技术 ,筛选到了与 98-16 0耐盐性状连锁的SSR标记WMS6 7和WMS2 13,它们与耐盐基因的遗传距离分别为 13.9cM (centMorgan)和 31.0cM。结合小麦SSR图谱分析 ,将该主效抗性基因定位在 5BL上。
A strategy of mRNA differential display was used for screening specific expression genes for cold acclimation in cucumber (Cucumis sativus L.). “Jinyan No.4”, a cold sensitive cultivar of cucumber, was treated under the conditions of 8 ℃ for 0, 6, 12, 24, 48 and 72 h, respectively, once it grew until two true leaves stage. A cold specific cDNA clone named as ccr18 was obtained. Data of differential display and Northern blot analysis showed that it expressed at cold acclimation for 12 h or more, and the longer duration at cold condition the higher it expressed. Southern blot assay suggested that it was a gene with single copy in chromosome of cucumber. Sequencing data showed the size of the cDNA clone was 639 bp in length. It shared 88% sequence with a BAC F14P3 genomic sequence of Arabidopsis thaliana chromosome Ⅲ at protein sequence level.
低温诱导的黄瓜ccr18 基因的cDNA 克隆及其表达特性分析
康国斌1 许勇1 雍伟东2 葛磊2王丽萍2 张海英1 王永健1 种康2*
（1. 国家蔬菜工程技术研究中心，北京100089；2. 中国科学院植物研究所分子与发育生物学研究中心，北京100093）
摘要：采用mRNA差异显示银染技术克隆得到在黄瓜（Cucumis sativus L.)冷敏型品种“津研4号”低温锻炼中特异表达基因的cDNA克隆（ccr18)，其大小为639bp。在基因组中以单拷贝或低拷贝形式存在。Northern blot分析显示ccr18基因在12、24、48和72h低温处理的黄瓜中表达，在6h低温处理及对照中没有表达。这表明ccr18基因与黄瓜低温锻炼相关，序列同源性比较表明，它与拟南芥(Arabidopsis thaliana)染色体ⅢBAC库中的F14P3基因组序列具有88％的同源性。
关键词： 黄瓜；低温驯化； cDNA克隆；mRNA差异显示
This study was conducted at the Kraichtal, southern Germany. Through the measurements of the relative illuminance under canopy and the coverage of many undergrowing species in 13 plots of forest communities, the correlation between the relative illuminance and the coverage of the species was calculated. The adaptation of 12 undergrowing species to light condition was determined based on the above calculation. Combining the indicator values of the species to ecological factors like light, humidity, temperature, acidity and nitrogen content in the soil with the constancy values of species in communities, the ranking order of undergrowing species in the communities was also examined. The results show: 1) In determining the light distribution in a forest community, scattered light condition is preferable because the interference from the drifting of light spots under the tree canopy can be reduced, and thus relatively stable distribution of light radiation can be obtained. 2) The distribution of 9 species, out of 12 species studied, was linearly correlated with the light condition under the canopy. For 7 of the 9 species, the correlation between the coverage of species and the relative illuminance was positive, and negative for 2 of them. For the other 3 species under the canopy the coverage was not correlated with the relative illuminance. 3) Compared with the light indicator values of species, the quantitative analysis of the relationships between species coverage and relative illuminance is more effective to reflect the adaptation of the species to light conditions under canopy and to reveal the ecological range of illuminance level of the species. 4) The relative adaptability of different species to light conditions directly affects the inter-specific relationships of the undergrowing species and may determine their ranking order in a community. The species with euphotic ecological range of illuminance level were easier to adapt to different light conditions under tree canopy and thus were able to exist in most forest community types with high constancy values.
江源1 Manfred MEURER2
（1. 北京师范大学资源科学研究所，教育部环境演变与自然灾害重点实验室，北京100875；2.Institute of Geography and Geoecology, University of Karlsruhe,Karlsruhe 76128,Germany)
摘要：通过在 13个样地中测定林下相对照度和多个植物物种的盖度指标 ,建立了林下相对照度与林下植物盖度变化的相关关系 ,对德国南部落叶阔叶林下 12种植物的光适应性进行了分析。结合植物的生态因子指示值和种在群落中的恒有度等生态指标 ,探讨了林下植物群落地位的形成原因。结果表明 :1)在散射光条件下进行森林群落中的光照分布特征测定 ,能够降低光斑造成的干扰 ,获得相对稳定的光分布 ;2 )在被研究的 12个物种中 ,有 9种植物在林下的分布与光照条件相关显著 ,其中 7种植物的盖度与相对照度之间具有正相关关系 ,2种植物具有负相关关系。其余 3种植物的盖度与相对照度之间无显著的线性相关 ;3)与光指示值相比 ,盖度与照度之间关系的定量分析能够更清楚地反映林下植物的光适应性 ,揭示植物的光生态幅特征 ;4)光适应性直接影响着林下植物的种间关系 ,也影响着物种的群落地位和作用。光生态幅广的植物 ,在群落中具有较强的适应能力 ,因此能够在多种群落类型中出现 ,表现出较高的恒有度值。
An improved biomass estimation method that converts timber volume to total forest biomass was used to estimate forest biomass carbon storage and its changes over to the past 50 years in China, by using inventory data of seven periods from 1949 to 1998 and forest biomass data obtained from direct field measurements. By the mid-1970s, forest carbon decreased by 0.62 Pg C (Pg=1015 g), with a decreasing rate of 0.024 Pg C per year. Since then the biomass carbon showed a significant increase, from 4.38 Pg C by the end of 1970s to 4.75Pg C by 1998, with an increasing rate of 0.022 Pg C per year, due mainly to the increased reforestation and afforestation. During the last two decades, planted forests have sequestered 0.45 Pg of carbon, with an annual rate of 0.021 Pg C. The average carbon density of plantations showed a significant increase from 15.3 Mg/hm in the mid-1970 to 31.1 Mg/hm in 1998, suggesting that the rising global temperature and CO2 fertilization may enhance this increasing uptake as well as expansion of planted forests.
摘要：利用1949年至1998年间7次森林资源清查资料,结合使用森林生物量实测资料,采用改良的生物量换算因子法,推算了中国50年来森林碳库和平均碳密度的变化,分析了中国森林植被的CO2源汇功能.结果表明,70年代中期以前,主要由于森林砍伐等人为作用,中国森林碳库和碳密度都是减少的,碳储量减少了0.62 Pg C (Pg=1015 g),年均减少约0.024 Pg C.之后,呈增加趋势.在最近的20多年中,森林碳库由70年代末期的4.38 Pg C增加到 1998年的4.75 Pg C,共增加0.37 Pg C,年平均增加0.022 Pg C.这种增加主要由人工造林增加所致.20多年来,由于人工林增加导致碳汇增加0.45 Pg C,年平均增加吸收0.021 Pg C/a.人工林的平均碳密度也显著增加,共增加了约一倍.这除了人工成林增多外,气温上升和CO 2浓度施肥也可能是促进森林生长的重要因子.
Acorns of Quercus aliena var. acuteserrata Maxim. are often predated by small mammals and birds in natural forests. These animals not only eat the acorns during the acorn ripening season, but also cache and hoard most of the remaining acorns on the forest floor in the soil for their future use. These buried acorns form the main seed resource for regeneration. Burying depth is potentially important for germination and for seedling development. The effects of burying depth on germination and seedling development in relation to acorn size were studied in an experiment, in which acorns were planted at 6 cm-, 12 cm- and 18 cm-depth. The experimental results showed that fewer acorns germinated as burying depth increased. From the deeply buried acorns fewer seedlings emerged at later time than from those acorns buried less deeply. They appeared to have more difficulties to emerge above-ground than the seedlings from shallowly buried acorns. The deeply buried acorns and their seedlings also appeared to be more susceptible to rot. Acorn size did not significantly affect germination and emergence of the seedlings. As early emerged seedlings had longer developmental periods in their first growing season, and therefore grew better than the late emerged seedlings, seedlings from the shallowly buried acorns took the advantage.
郭柯1,3 李睿2,3 Marinus J.A.WERCER 3
（1.中国科学院植物研究所，北京100093；2. 浙江大学地球科学系，杭州310028；3.Department of Plant Ecology,Utrecht Unixersity,Utrecht,The Netherlands)
摘要：锐齿槲栎 (Quercusalienavar.acuteserrata Maxim .)林内活动的许多小型哺乳动物和鸟类不仅采食橡子 ,而且还常窖贮或在土壤中埋藏大量的橡子以便季后利用。这些埋藏的橡子构成了发育有效更新苗的主要种子来源。橡子被埋藏的深度和橡子的大小对幼苗的发育有潜在的影响。把橡子埋藏在 6、12和 18cm 3个土层深度中的实验结果显示 :随着埋藏深度的增加 ,橡子的发芽率和发芽橡子的幼苗出土率都有明显下降 ;由深埋橡子发育的幼苗出土比较困难 ,所需时间较长 ,也更易腐烂 ;橡子的大小对发芽和幼苗出土没有明显的影响 ;早出土幼苗在第一个生长季内由于有较长的生长发育期 ,季末发育得较好 ,所以 ,由浅埋橡子发育的幼苗在更新成功方面有优势。
Desertification is a process in which vegetation cover degrades followed by increased wind and water erosion. Plants adapted to moving sand conditions are able to reverse this process. They can stabilize the substrate. Not much data is available on the soil stabilization capacity of plants. This study was conducted to investigate the wind-induced sand displacement around plants in relation to their biomass. Sand displacement is examined in relation to the biomass allocation pattern of three different plant species. A new method was developed to experimentally investigate plant sand-binding capacity. The relationship between sand displacement and plant biomass was not linear. Apart from the amount of biomass, species-specific plant characters like the biomass allocation pattern and plant structure may be very important in determining the sand-binding capacity.
Bas ROELS 1,2 Sebastiaan DONDERS 1,2 董鸣*!
(1.Department of Plant Ecology, Utrecht Unixersity,P.O.Box 800.84,3508 TB Utrecht,The Netherlands；
摘要：荒漠化是植被覆盖退化、风蚀水蚀加剧的过程。适应流沙条件的植物能够逆转荒漠化 (沙化 )过程 ,能够固沙。可用于研究植物固沙能力的数据不多。为了研究与植物生物量相关的植株周围的“风成沙移置 (wind_inducedsanddisplacement)” ,在研究中 ,将植株周围的风沙移动与 3种植物的生物量配置格局联系起来。并发展了一种新方法 ,以对植物固沙能力进行实验研究。风沙移动与生物量的关系不是线性的。除了植物生物量大小外 ,种类特异的植物特征 ,如生物量配置格局和植物枝叶的结构特征 ,在确定植物固沙能力方面也很重要。
Five compounds (1-5) were isolated from the rhizome of Beesia calthaefolia (Maxim.) Ulbr. Based on chemical and spectral evidence, their structures were determined as beesic acid (9-phenyl-2E, 4E, 6E, 8E-nontetraenoic acid, 1), vanillic acid (2), oleanolic acid-3-O-α-L-arabinopyranosyl-28-O-α-L -rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester (3), hederasaponin B (oleanolicacid-3-O-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl-28-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester, 4) and beesioside Q (oleanolic acid-3-O-β-D -glucopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl-28-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester, 5), respectively. Compound 1 was isolated from natural sources for the first time and compound 5 was a new compound.
鞠建华1* 刘东1 林耕1 许旭东1 杨峻山1* 涂光忠2 马立斌2
（1. 中国协和医科大学中国医学科学院药用植物研究所，北京100094；2. 北京微量化学研究所，北京100060）
摘要：从铁破锣(Beesia calthaefolia (Maxim.) Ulbr.)根茎中分离得到5个化合物(1～5),经化学和波谱学方法鉴定,其中2个为有机酸--铁破锣酸(beesic acid, 9-phenyl_2E, 4E, 6E, 8E-nontetraenoic acid, 1)和香草酸(2);3个为齐墩果酸型三萜皂甙:oleanolic acid-3-O-α-L-arabinopyranosyl-28-O -α-_L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6) -β-D-glucopy ranosyl ester (3),hederasaponin B (oleanolic acid-3-O-α-L-rh a mnopyranosyl-(1→2)-α-L-arabinopyranosyl-28-O-α-L-rhamnopyranosyl-(1→ 4-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester, 4) 和铁破锣皂甙Q (beesioside Q, oleanolic acid-3-O-β-D-glucopyranosyl_(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl-28-O-α-L-rhamnopy ranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester, 5).化合物1系首次从自然界中分离得到,化合物5为新化合物.
The relationship between superoxide and singlet oxygen in PSⅡ particle of spinach under strong illumination was studied with spin-trap ESR technique. The generation of superoxide was increased under D2 environment which prolonged the half life of singlet oxygen. The generation of superoxide was decreased when histidine existed as a scavenger of singlet oxygen. It is highly possible that the superoxide generated in PSⅡ particle originates from singlet oxygen.
刘科1孙健1,2徐英凯1 陈中伟1 张启元1 张兴康1 匡廷云2 刘扬1*
（1. 中国科学院化学研究所，北京100080；2. 中国科学院植物研究所，北京100093）
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