The early stage of pollen chamber development in ovule and the cytological mechanism of nucellar cell death were studied in Ginkgo biloba L. DNA ladder appearance and TUNEL assay demonstrated that the nucellar cell death, doomed to bring about pollen chamber formation, was a process of programmed cell death (PCD). A spatial distribution of PCD was visualized during the development of pollen chamber. Together with the observation under the scanning electron microscope, these results have revealed that the early developmental pattern of pollen chamber consists of four phases. Firstly, several layers of the nucellar cells at the micropylar end elongate longitudinally. Thereafter, the uppermost layer of the nucellar cells at the micropylar end initiate PCD; and the nucellar cell death extends in a basally and laterally oriented direction to form a cavity. Finally, the epidermal cells at the micropylar end detach from the other epidermis by dehiscence, bringing about the opening of the pollen chamber. The early development of pollen chamber begins sometime after the stage of megasporocyte and continues by the time of the formation of megaspore tetrad, and finally completes at the stage of development of female gametophyte. This shows a synchronous development of megaspore and pollen chamber.
李大辉 杨 雄*崔 旭 崔克明* 李正理
摘要： 对银杏(Ginkgo biloba L.)胚珠贮粉室的早期发育过程以及珠心细胞死亡的细胞学机制进行了研究.DNA电泳出现DNA ladder和TUNEL标记说明参与形成贮粉室的珠心细胞死亡是程序性死亡(PCD)过程,并且显示出在贮粉室形成中,PCD的发生有一定的空间分布式样.结合扫描电镜观察,贮粉室的早期发育可分为4个阶段:起始事件是位于珠孔端的3至4层珠心细胞纵向伸长;接着,位于珠心组织最上部(珠孔端)的珠心细胞启始死亡;然后,这些已经纵向伸长的珠心细胞向基地和侧向地逐渐死亡,形成一个空腔;最后,珠孔端珠心表皮细胞以开裂的方式与其余表皮细胞脱离而形成贮粉室的开口.大孢子母细胞时期,贮粉室尚未发生;四分体阶段,贮粉室已经开始形成;到雌配子体发育时期,贮粉室已经完全产生.反映大孢子发育和贮粉室发生的同步性.
通讯作者。E-mail:ckm @ pku.edu.cn或yangwh @ hotmail.com。
Cell cycle kinetic activity in the cortical cells of the lentil (Lens culinaris Medic. cv. Verte du Puy) primary root during germination was examined both temporally and spatially. Immunohistochemical and cytological evidence indicated that DNA replication and cell divisionstarted in the cortical cells of the lentil primary root after around 13 and 17 h of imbibition, respectively. The first cells in DNA synthesis and the first mitotic figures all appeared in the cortical cells about 1 mm from the root cap junction, but these divided cells had synthesized their DNA during the maturity of seed instead of during germination. The kinetic pattern of activity of the first cell cycle showed that these cells were not activated synchronously, but re entered the cell cycle in turn depending on their places in the root tip. However, the adjacent cells partially synchronously proceeded their cell cycle.
喻富根* 庞延军 赵剑春 王 强
摘要： 观察了兵豆（ Lens culinaris Medic）初生根原皮层组织的细胞周期在其种子萌发过程中时间和空间上的动态变化。免疫组织化学和细胞学证据表明，原皮层细胞分别在种子吸胀大约13h和17h开始DNA 复制和细胞分裂。最早进行DNA复制和细胞分裂的细胞位于远基端1mm附近，但这些分裂细胞的DNA复制是在种子成熟过程中完成的，而不是在萌发后。第一个细胞周期的激活样式表明，这些细胞并不同步激活，而是依次进入细胞周期，且进入的次序与自身在根尖中的相对位置有关。在兵豆初生根原皮层组织中，邻近位置上的细胞的细胞周期同步化程度较高。
通讯作者。E-mail: fugen @ nju.edu.cn.
It has been hypothesized that under iron stress high ferric chelate reductase (FCR) activity in the absorptive root of plants tolerant to iron deficiency will be induced and result in subsequent Fe2+ transport across the plasmalemma. The activity of FCR and expression of FCR gene ( FRO2 ) in Citrus junos Sieb. ex Tanaka tolerant to iron deficiency and Poncirus trifoliata(L.) Raf. susceptible to iron deficiency were determined to elucidate the physiological difference which causes the different tolerance of the two citrus rootstocks to iron stress. The activity of FCR was detectable in excised roots and was stimulated about 20 times in C. junos and only about 3 times in P. trifoliata under iron deficiency for four weeks. The FRO2 of Arabidopsis was used as a probe, the tissue print technique was used to ascertain the expression of the FCR gene in C. junos and P. trifoliata under iron stress. High level transcripts were observed in the absorptive root, young green stem as well as new leaf of C. junos under iron stress for two weeks, and the transcripts were accumulated only slightly in P. trifoliata at the same time. The results showed that the obvious increase of FCR activity was an important reason for the tolerance of C. junos to iron deficiency, and the regulation of FCR activity seemed to be at the transcriptional level, and the expression of FRO2 occurred in the root, stem and leaf.
李 凌 范艳华 罗小英 裴 炎 周泽扬*
摘要: 用耐缺铁的香橙 (Citrusjunos Sieb .exTanaka)和极不耐缺铁的枳 (Poncirustrifoliata (L .)Raf.) ,在铁胁迫条件下对根的三价铁螯合物还原酶活性变化和酶基因的表达情况进行了研究。离体根的酶活性测定表明 ,在铁胁迫 4周时 ,香橙根的酶活性增强约 2 0倍 ,枳仅增强约 3倍。用拟南芥的三价铁螯合物还原酶基因作探针进行组织印迹的Northern杂交检测香橙和枳三价铁螯合物还原酶的mRNA ,在铁胁迫 2周时 ,香橙吸收根、幼茎和新叶中均检测到强烈的表达信号 ,而枳相同器官的表达信号则极其微弱。实验结果表明 ,三价铁螯合物还原酶活性在缺铁胁迫下被诱导强烈增加是香橙耐缺铁的重要原因 ,该酶活性的调控发生在转录水平上 ,而且该酶基因在诱导条件下在根、茎和叶中均有表达。
通讯作者。E-mail: zyzhou @ swau.edu.cn.
Changes of ACC and MACC levels, ACC synthase activity as well as ethylene production in the leaves of two spring wheat (Triticum aestivum L.) cultivars 8139 (with relatively low drought resistance) and 504 (with relatively high drought resistance) during water stress were determined. The levels of ACC and MACC in both cultivars decreased in the first 24 h of water stress and increased in the second 24 h while the activities of ACC synthase increased continuously throughout the entire period of treatment (48 h). As water stress progressed, ethylene production decreased continuously in cv. 8139 but remarkably increased earlier and decreased later in the cv. 504. Moreover, the decrease in RWC of stressed leaves was greater and the changes in ACC and MACC levels as well as ACC synthase activity were higher in the drought sensitive cv. 8139 than in the drought resistant cv. 504 during water stress. The levels of ACC and MACC, activities of ACC synthase and productions of ethylene in the stressed leaves in two cultivars were significantly altered by the application of MGBG (an inhibitor of SAMDC) and AOA (an inhibitor of ACC synthase) where their effects on these items were almost opposite. They were increased by the former inhibitor but reduced by the latter. All of these results suggested that the level of ethylene production in plants did not depend on the level of ACC during water stress. The increase in the level of ethylene in the drought resistant cultivar during the earlier period of water stress might be a phenomenon of adaptation to water stress and be correlated with the development of the drought tolerance in plants and playing role in the transduction of stress signal. The role of MACC, however, was primarily in the regulation of ethylene production under water stress.
陈坤明1，2 宫海军1 陈国仓1 张承烈1
（1. 兰州大学生命科学学院，兰州730000；2. 天水师范学院生物系，天水741001）
摘要: 水分胁迫使两个抗旱性不同的春小麦（Triticum aestivum L.)品种“8139”（抗旱性较弱）和“504”（抗旱性较强）叶片ACC和MACC含量于胁迫初期下降后期升高，ACC合酶活性持续升高，乙烯释放量在8139中下降而在504中先大幅升高而后下降。两种作用效果相反的抑制剂MGBG（抑制SAMDC活性）和AOA（抑制ACC合酶活性）均明显影响了两品种春小麦叶片以上各指标的变化。结果表明，水分胁迫下作物乙烯的释放量并不与其合成直接前体ACC的量成正相关；胁迫乙烯在抗性品种中于胁迫初期的升高可能是植物胁迫信号传导的响应之一，是一种干旱适应现象，可能与作物的干旱忍耐形成有关，而MACC具有调节胁迫乙烯释放的特殊生理作用。
Seedlings of the gymnosperm,Pinus edulis Engelm., have a distinctive pattern of starch accumulation following germination; however, the enzymes involved in starch synthesis have not been studied in gymnosperm species. In this study, enzymes and starch were extracted from P. edulis seedlings germinatedin the dark at room temperature. Granule bound proteins of 58 kD and 91 kD were recognized by a pea SS Ⅱ antiserum. The 58 kD granule bound protein was purified and identified as granule bound starch synthase Ⅰ by alignment of the N terminal sequence with that of granule bound starch synthase Ⅰfrom several angiosperms.Elution of soluble starch synthase activity from a DEAE Sepharose column showed two starch synthase activity peaks, indicating at least two isoforms of soluble starch synthases. Primer affinities of soluble starch synthases were investigated. Glycogen from rabbit was the best primer for soluble starch synthase. The enzymological properties of Pinus starch synthases appear to be similar to those reported for angiosperms.
严海燕1** J.B.MUROHY 2
（1. 郑州大学生物工程系，郑州450052；2. Departnebt of Horticure,Unixersity of Arkansas,Fayetteville AR 72701,USA）
摘要： 裸子植物食松(Pinus edulis Engelm.)幼苗在萌发后具有淀粉积累的独特特征,而淀粉合酶在裸子植物中尚未有研究.这项研究对在室温下暗中萌发的食松幼苗的淀粉合酶进行了提取和研究,结果显示: 58 kD和91 kD的淀粉粒结合蛋白均为豌豆淀粉合酶Ⅱ抗体所识别. 58 kD淀粉粒结合蛋白被纯化出来, 其N端序列与其他几种被子植物淀粉粒结合的淀粉合酶Ⅰ的N端序列有很高的相似性,并与豌豆、大麦、马铃薯淀粉粒结合淀粉合酶Ⅰ有免疫相似性,被鉴定为淀粉粒结合的淀粉合酶Ⅰ.从DEAE-Sepharose 柱上洗脱出来的可溶性淀粉合酶表现出两个淀粉合酶活性峰,表明至少有两类可溶性淀粉合酶同工酶.对可溶性淀粉合酶的前体亲和特性进行了研究.以兔肝糖原为前体时, 可溶性淀粉合酶的亲和性最高.裸子植物淀粉合酶的酶学特性表现与已研究的被子植物相似.
The eelgrass (Zostera marina L.) was treated with artificial seawater (ASW) of different salinities (100%, 150% and 200% seawater) for 5 d. The activities of two enzymes extracted from the plant leaves were determined under a salinity grade in vitro. So were the photosynthesis rates of the plants from the three treatments in the media with different salinities (100%, 150%, 200%, 300% ASW) and some physiological data. The data showed that under increased salinities （concentrated seawater）, Na+, Cl-, MDA (malon dialdehyde) and glucosecontents and the osmotic potentials (absolute value) in the leaves increased with the salinity elevation in the medium (ASW), but both K+ and free amino acid (mainly proline) contents decreased. Malate dehydrogenase (MDH) from the plant leaves under a salinity grade showed its activities (A) as follows: A 100% ASW>A 150% ASW>A 200% AS. Phosphoenolpyruvate carboxylase (PEPC) extracted from the 100% ASW and 200% ASW treated plants showed similar activities (both insensitive to salinities) under the salinity grade in vitro, but the activities of PEPC from plants treated with 150% ASW were dependent on salinity. Whether the plant is stressed at 150% ASW and can stand higher salinity than seawater needs to be studied further. Meantime, the data do not agree with the opinion that the adaptation of the eelgrass to seawater salinity is partly fulfilled by its insensitiveness to salinities in some metabolic enzymes. It can be inferred that the lack of transpiration may be an important aspect of the plant's tolerance to seawater salinity.
摘要： 分别以3个盐度(100%、150% 和200%人工海水)处理大叶藻(Zostera marina L.)植株5 d,然后在体外测定了大叶藻叶片中两个胞内酶(PEP羧化酶和苹果酸脱氢酶)的耐盐性和在不同盐度介质中(100%、150%、200%、300%人工海水)经不同盐度(100%、150% 和200%人工海水)海水预处理的大叶藻叶片光合速率以及一些生理指标的改变.结果表明在高于海水的盐度下,大叶藻叶片中丙二醛(MDA)、还原性糖和Na+, Cl-含量及渗透势(绝对值)均随海水盐度的提高而增加,但K+和游离氨基酸的含量均降低.从处理5 d的植株中提取的苹果酸脱氢酶在体外每一盐度下,其活性(A)大小依次为: A100% ASW>A150% ASW>A200% ASW(artificial seawater),并且其活性对盐度敏感(低盐度激活高盐度抑制);但从100%及200%人工海水(ASW)处理的植株中提取的PEP羧化酶的活性在体外对盐度不敏感,而从150%人工海水处理的植株中提取的PEP羧化酶的活性对盐度具有很高的抗性.实验结果显示由150%人工海水处理的植株,在每一特定的盐度下其光合速率均高于另外两组处理(100% ASW和200% ASW),并且3个处理的光合速率均与其PEPC在不同盐度下的活性表现相一致.但是,经150% ASW 处理的大叶藻植株是否受到盐害还有待于进一步探讨.实验表明"大叶藻耐盐性在一定程度上是由于其代谢酶对盐度的耐性造成的"这一说法是不合适的;不存在蒸腾作用可能是大叶藻耐盐机理的重要组成部分.
通讯作者。E-mail:zhaokefu @ 263.net.
Achyranthes bidentata polysaccharides (ABPS), water soluble polysaccharides, isolated from the roots of Achyranthes bidentata Bl. of Amaranthaceae family, was divided into four parts, named as Con.1, Con.2, Con.3 and Con.4, respectively, by chromatography on DEAE Sepharose fast flow column and Sephadex G 100 column in order. Con.1 was the constituent of high molecular weight and the other three were all of low molecular weight. Micro Kjeldahl analysis showed that Con.1 contained 3.95% of nitrogen and neither did the other three parts. The antisenile effects of the four parts of ABPS were studied with Drosophila melanogaster. Results showed that Con.1 has no antisenile effect and all the others could significantly increase the average body weight by 3.85%-5.47% and significantly prolonged the average lifespan by 2.61%-3.16%of D. melanogaster at the concentration of 2 or 5 mg/g (ABPS/medium).
谈 锋 邓 君
摘要：牛膝多糖(Achyranthes bidentata polysaccharides, ABPS)是苋科植物牛膝(Achyranthes bidentata Bl.)根中的水溶性多糖,先后用DEAE-Sepharose fast-flow柱和Sephadex G-100柱将牛膝粗多糖分为4个组分,分别命名为:Con.1、Con.2、Con.3和Con.4.Micro-Kjeldahl试验表明,Con.1中含有氮元素3.95%,另3个小分子组分不含氮元素.以果蝇为动物模型研究了该4个牛膝多糖组分的抗衰老作用,结果表明,大分子组分Con.1对果蝇无抗衰老作用,而另3个小分子量组分在培养基中浓度为2和5 mg/g(多糖质量/培养基质量)时,都可显著或极显著地使果蝇平均体重增加3.85%-5.47%, 并使果蝇平均寿命延长2.61%-3.16%.
关键词： 牛膝；多糖；DEAE-Sepharose 快速柱层析；Seohadex-G-100 柱层析；果蝇；抗衰老作用
Plasma membrane vesicles of chrysanthemum (Dendranthema morifolium (Ramat.) Tzvel.) callus was purified by sucrose gradient centrifugation to investigate the influence of sound stimulation on the lipid physical states and metabolism of plasma membrane. The results showed that sound stimulation decreased the content of phosphodiesters and the fluorescent intensity of DPH, but increased the light scattering value of the membrane, the fluorescent intensity of MC540 and the content of phosphomonoesters, indicating that the vesicles got looser, the charge density and hydrophobicity of membrane surface decreased under sound stimulation of some strength and frequency. However, the membrane fluidity increased under the condition. Meanwhile, the anabolism of membrane lipid increased and the catabolism decreased. It can be seen that the physical state and metabolism of membrane lipid is sensitive to sound stimulation.
赵虎成1,2* 王伯初2 蔡绍皙2 席葆树1
摘要： 以蔗糖梯度法纯化的菊花(Dendranthema morifolium (Ramat.) Tzvel.)愈伤组织质膜微囊为材料,研究了声波刺激下质膜膜脂代谢和物理状态的变化.结果表明, 一定强度(100 dB)和频率(1 000 Hz)的声波刺激使质膜磷酸二脂含量和二苯己三烯(DPH)荧光偏振值降低,质膜光散射值、MC540荧光强度和磷酸单脂含量增加.表明一定强度和频率的声波刺激使质膜变疏松,膜的流动性增加,膜表面电荷密度和疏水性降低,膜脂合成代谢增加,分解代谢减弱.由此可见,膜脂物理状态和膜脂代谢对声波刺激极为敏感.
The effect of matrix attachment regions (MARs) on foreign gene expression in transgenic plants was studied. The β-glucuronidase (GUS) gene (uidA) was flanked by the MARs isolated from the genome of maize to form plant expression vector. The vectors with and without MARs were transferred into tobacco (Nicotiana tabacum L.) through Agrobacterium mediated transformation procedure. GUS activity assays indicated that MARs could increase expression level of uidA gene. The mean GUS activity could be increased twofold as compared to that of transformants without MARs, and the highest GUS activity of transformant could reach tenfold. The correspondence between GUS activity and mRNA accumulation was positive and indicated that MARs could improve transcription of foreign gene.
李旭刚 曾千春 陈松彪 徐军望 常团结 朱祯*
摘要： 为研究核基质结合区(matrix attachment region, MAR)在转基因植物中的功能,将来自玉米基因组的MAR序列构建在植物表达载体T-DNA中, 并将报告基因β-葡糖醛酸酶(β-glucuronidase, GUS)基因(uidA)插入两段MARs序列之间.将此载体与不包含MARs序列的植物表达载体分别转化烟草(Nicotiana tabacum L.).GUS活性检测表明,MARs可以显著提高外源基因uidA在转基因烟草中的表达水平,平均表达水平提高2倍,最高单株活性可达10倍.并且转基因植株GUS活性高低与稳定mRNA的量成正比,表明MARs在转录水平提高基因表达.
通讯作者。E-mail;zzhu @ genetics.ac.cn.
The high molecular weight (HMW) glutenin subunits and their coding genes from Aegilops umbellulata Zhuk. (UU , 2n = 2x = 14) were characterized using SDS PAGE analysis and molecular approaches. SDS PAGE analysis showed that the 1Ux subunits from four different accessions possessed electrophoretic mobilities close to, or slower than, that displayed by the 1Dx2.2 subunit of common wheat.The electrophoretic mobilities of the 1Uy subunits were generally similar to those shown by the 1Dy subunits of common wheat. The complete open reading frames of the 1Ux and 1Uy genes were amplified by PCR and subsequently cloned and sequenced. Amino acid sequence comparisons suggested that the primary structure of the 1Ux and 1Uy subunits were identical to that of published HMW glutenin subunits from related species. Phylogenetic analysis indicated that the HMW glutenin subunits of Ae. umbellulata were most closely related to those encoded by the D genome of Triticeae.
刘志杰 张学民 万永芳 刘坤凡 王道文*
摘要： 运用SDS-PAGE和分子克隆技术,对小伞山羊草(Aegilops umbellulata,UU, 2n = 2x = 14)的高分子量麦谷蛋白亚基(1Ux, 1Uy)及其编码基因进行了鉴定.SDS-PAGE分析表明小伞山羊草不同基因型中的1Ux的电泳迁移率接近或慢于普通小麦1Dx2.2亚基的电泳迁移率,1Uy亚基的电泳迁移率一般接近或慢于普通小麦的1Dy类亚基.采用PCR扩增技术获得了1Ux和1Uy亚基编码基因的全长编码区,并对一个1Uy基因的全长编码区进行了全序列测定.对推导的氨基酸序列进行比较发现1Ux和1Uy亚基具有与来自于其他物种的高分子量麦谷蛋白亚基一致的一级结构,聚类分析显示1Ux和1Uy亚基与D基因组编码的高分子量麦谷蛋白亚基在起源和进化上具有较高的相似性.
通讯作者。E-mail::dwwang @ genetics.ac.cn.
Gossypium hirsutum L. and G. barbadense L. are the two cultivated tetraploid species of cotton. The first is characterized by a high yield and wide adaptation, and the second by its super fiber property. Substitution line in which a pair of intact chromosomes of TM 1 (G. hirsutum) were replaced by a pair of homozygous chromosomes of 3 79 (G. barbadense) is an excellent material for genetic research and molecular tagging. In this study, substitution line 16 （Sub 16） was used to evaluate the performance of the 16th chromosome in G. barbadense in TM 1 background. The genetic analysis using the major gene plus polygene mixed inheritance model in F2∶3 family revealed that there might exist 2 QTLs respectively for boll size, lint percentage, lint index, fiber length and the first fruit branch node, 1 QTL for fiber elongation and flowering date, and no QTL for seed index, fiber strength and Micronaire in chromosome 16. However, 9 QTLs （LOD (logarithm of odds)≥3.0） controlling 6 quantitative traits were significantly identified in linkage group of chromosome 16 constructed in (TM 1×3 79) F2by interval mapping. Among them, 1 QTL for boll size, fiber length, flowering date and fiber elongation could explain 15.2%, 19.7%, 12.1%, and 11.7% phenotypic variance respectively, 2 QTLs for lint index could explain 11.6% and 41.9%, and 3 QTLs for lint percentage could explain 8.7%, 9.6% and 29.2% phenotypic variance respectively. One unlinked SSR marker was associated with one QTL respectively for boll size and flowering date and they could explain 1.60% and 4.63% phenotypic variance. The traits associated significantly with chromosome 16 from Sub 16 were boll weight, lint percentage, lint index, fiber length, fiber elongation and flowering days.
任立华 郭旺珍 张天真*
陆地棉(Gossypium hirsutum L.)和海岛棉(Gossypium barbadense L.)是两个栽培四倍体棉种.前者产量高、适应性广,后者纤维品质优良.置换了海岛棉一对染色体的陆地棉置换系是研究海陆杂种此对染色体上基因互作的优异材料.在对第16染色体的置换系(简称Sub 16)进行遗传评价的基础上,利用(TM-1×Sub 16)F 2∶3家系对位于第16染色体上的重要农艺性状进行遗传分析,发现第16染色体上有铃重、衣分、衣指、纤维长度、第一果枝节位的QTLs 各2个,纤维伸长率、开花天数的QTL各 1个,没有检测到子指、纤维强度、麦克隆值的QTL.在构建第16染色体的RAPD、SSR分子标记连锁图基础上,利用分子标记对相应重要农艺性状进行区间作图,检测到铃重、开花天数、纤维长度、纤维伸长率的QTL各1个,在F 2∶3株系群体中能解释的表型变异分别为15.2%、12.1%、19.7%和11.7%;检测到2个衣指QTLs,在2∶3株系群体中能解释的表型变异分别为11.6%和41.9%;检测到3个衣分QTLs,在F 2∶3株系群体中能解释的表型变异分别为8.7%、9.6%和29.2%.单标记检测到铃重、开花天数的QTL各1个,在F 2∶3株系群体中能解释的表型变异分别为1.60%和4.63%.证明了第16染色体与铃重、衣分、衣指、纤维长度、纤维伸长率、开花天数等性状的关系.
关键词： 异源四倍体棉花；置换系；第16 染色体；遗传；分子标记；QTL 作图
通讯作者。Tel.:+86-25-4395311;Fax: +86-25-4395307;E-mail:cotton @ njau.edu.cn.
The behavior of wheat rye translocation chromosome and alien chromosome including Thinopyrum and Haynaldia chromosome at meiosis was investigated in two hybrids by fluorescence in situ hybridization(FISH). Misdivision of translocation chromosome at anaphase Ⅰ and rye chromatin micronucleus at tetrad stage were observed. A plant with one normal 1BL/1RS translocation chromosome and one 1BL/1RS translocation chromosome deleted about 1/3 of rye chromosome arm in length was identified. One plant with wheat Thinopyrum non Robertson translocation chromosome was also detected in the F2 population of Yi4212×Yi4095. That could be the results of unequal misdivision of wheat rye 1BL/1RS translocation chromosome and Thinopyrum chromosome during meiosis. No interaction between translocation chromosome and alien chromosome at meiosis was supported by the data of the distribution frequencies of translocation chromosome and Thinopyrum or Haynaldia chromosome in the progeny of two hybrids. The results may be useful to cultivate new germplasms with different length of rye 1R short arm and wheat alien non Robertson translocation lines under wheat background.
摘要： 利用荧光原位杂交技术分析了两个小麦-外源种杂种花粉母细胞中1BL/1RS 小麦-黑麦易位染色体和外源染色体包括中间偃麦草(Thinopyrum intermedium (Host) Barkworth & DR Dewey)、簇毛麦(Haynaldia villosa (L.) Schur)染色体的减数分裂行为. 我们首次发现:在减数分裂后期, 1BL/1RS 小麦-黑麦易位染色体发生错分裂,形成两个易位染色单体. 这种错分裂导致易位染色单体在末期Ⅰ分配到两个正在形成的细胞核内,错分裂的易位染色单体进一步形成微核,并在四分体期观察到黑麦的微核出现.从贵农22×遗4095 的F2代植株中检测到一个2n=41的植株,其含有一对1BL/1RS 小麦-黑麦易位染色体,核型分析表明,其中一条黑麦染色体臂比另一条的黑麦染色体臂短1/3左右.在遗4212×遗4095的F2代中检测到一个具有中间偃麦草染色体小片段易位到小麦染色体端粒部分的小麦-中间偃麦草易位植株.这可能是由于在减数分裂过程中发生非均等分裂导致小麦-黑麦1BL/1RS易位染色体的黑麦染色体段臂缺失1/3及小麦-中间偃麦草非罗伯逊易位.在两个杂种F2植株中,中间偃麦草染色体分布频率为39.6%, 簇毛麦染色体分布频率为43.4%, 1BL/1RS 小麦-黑麦易位染色体分布频率分别为51.8%和56.6%.实验结果表明,1BL/1RS 小麦-黑麦易位染色体与外源染色体包括中间偃麦草、簇毛麦染色体在减数分裂过程中没有相互作用.小麦-黑麦1BL/1RS易位染色体在减数分裂过程中可以发生错分裂,并导致杂种后代黑麦染色体臂发生缺失.这对于培育以小麦为背景含有不同长度的黑麦1R染色体短臂的种质及小麦-外源染色体非罗伯逊易位的小片段易位系具有指导意义.
关键词： 减数分裂；染色质单价体1BL/1RS 易位染色体；荧光原位杂交
通讯作者。E-mail:ywli @ gebetucs.ac.cn; xjia @ genetics.ac.cn.
Green fluorescent protein (GFP) gene was expressed transiently in 2-3 d old rice embryos by electroporation with the aid of a specially designed loading net. Under suitable conditions (500 μF capacitance, 300 V/cm Voltage, 100 μg/mL plasmid DNA), the percentage of embryos expressing GFP was up to 35%. The highest electroporation efficiency (40%) was obtained at pH 5.8 of the electroporation buffer. The GFP gene driven by the Ubi promoter produced the highest efficiency. Thus, on the basis of optimizing electroporation conditions, a transformation system has been developed for young embryos in rice. The electroporated 4-6 d old embryos regenerated plantlets under the controlled cultural conditions. Fluorescence microscopic observations indicated that GFP gene expressed in their calli and R0 plantlets.
王胜华 赵 洁 杨弘远*
摘要：幼胚的遗传转化对研究植物胚胎发育相关基因的表达与调控具有重要意义, 也为植物遗传改良提供新的技术.本研究借助一种自制的特殊装置,采用电激法将GFP基因转入2-3天水稻幼胚,得到瞬时表达, 4-6天水稻幼胚经电激后再生了植株,并在愈伤组织阶段及R0植株中检测到GFP荧光的转基因植株,从而建立了水稻幼胚的遗传转化实验系统.在电容为500 μF、电压为300 V/cm,浓度为100 μg/mL的条件下,幼胚GFP的电激转化频率可达35%. 在pH 5.8的电激缓冲液中,最高转化频率可达40%.在三种不同的启动子实验中,以Ubi启动子的转化频率最高.
通讯作者。Tel:86-27-87682378;Fax: 86-27-87646010;E-mail: hyyang @ whu.edu.cn.
Graft can induce inheritable variations in the progenies of the scion plants. Seedling of mungbean (Vigna radiata (L.) Wilczek) was grafted onto the stem of sweet potato (Ipomoea batatas (L.) Lam.). The growth of the cion was maintained until the scion produced selfed seeds. We sowed the seeds for several generations under normal conditions. Distinct genetic variations appeared in the progenies. Similar variations did not appear in the generations of the scion sowed normally without graft. The variations seemed to be induced by the graft and they inherited steadily. For understanding the possible mechanism of the phenomenon (graft induced inheritable variation), we analyzed the cytoplasmic and genomic DNA of the variations. The results showed that there was no restriction fragment length polymorphism (RFLP) in the cytoplasmic DNA between the original scion and the variation. However, significant difference between the scion and variation was recognized by random amplified polymorphic DNA (RAPD) analysis. In addition, there was no evidence that indicated the gene transformation from stock to scion. Our results suggest that the non specific grafting has a pragmatic potential for plant breeding and crop improvement and, the genetic variation seems not to be caused simply by DNA transformation but most likely the stress induced mutation.
张丹华1 孟昭璜2 肖卫民1 王学臣3 苏都莫日根1*
（10 北京大学生命科学学院，北京133NO1；50 商丘农林研究所，河南商丘6OS333；P0 中国农业大学生物学院，北京133326）
摘要：植物嫁接可以导致接穗的后代中有可遗传性变异的发生.我们将绿豆(Vigna radiata (L.) Wilczek)的幼苗嫁接在红薯(Ipomoea batatas (L.) Lam.)的茎上, 维护其生长至结实.将收获的绿豆种子连续几代播种于普通环境时, 其后代中出现了明显的遗传变异.这些变异在未经嫁接的绿豆接穗品系中并不出现.为了研究这种嫁接诱导变异现象可能的机理, 我们对变异品系的细胞质和细胞核DNA进行了分析.结果显示,在原绿豆和变异品系之间未发现细胞质DNA的RFLP(限制性酶切片段多态性)差异.而细胞核DNA却发生了高频率的序列重组.同时,本研究没有发现砧木与接穗间基因转移的迹象.根据以上事实,我们推测远缘嫁接变异很有可能是嫁接生长逆境诱导的抗逆变异.
关键词： 嫁接；遗传变异；绿豆；红薯；RAPD 分析；作物改良
通讯作者。Tel:+86-10-62753126;Fax:+86-10-62751526;E-mail:sodmergn @ bio.pku.edu.cn。
As an important group of plant cellular organelles, the molecular mechanism of plastid division is poorly understood. Recent studies have revealed that the homologs of ftsZ gene, an essential prokaryotic cell division gene, are involved in plastid division process of plant cells. Antisense and sense expression constructions were employed to investigate the functions of the two ftsZ genes, NtFtsZ1 and NtFtsZ2 , in transgenic Nicotiana tabacum L. plants. Although antisense expression of NtFtsZs reduced the native protein level obviously, the size and number of chloroplasts in transgenic tobacco plants had no effect. In contrast, overexpression of NtFtsZs in transgenic plants strikingly changed the number and morphology of chloroplasts. Even only 1-2 huge chloroplasts could be seen in the mesophyll cells of some overexpression transgenic plants. Analyses of chloroplast ultrastructures and chlorophyll content of different transgenic plants suggested that NtFtsZs gene have no direct influence on the normal development and function of chloroplasts. The changes in chloroplast morphology must be a compensation for the change in chloroplast number. The different phenotypes of chloroplasts in antisense and sense transgenic plants implied that different members from the same ftsZ gene family may have similar function in controlling plastid division. Meanwhile, the changes of chloroplast morphology in sense transgenic plants represented the possible plastoskeleton function of ftsZ in higher plant.
王 东 孔冬冬1 鞠传丽2 胡 勇2何奕昆1,2*孙敬三*
（1. 中国科学院植物研究所，北京100093；2. 首都师范大学生物系，北京100037）
摘要： 质体作为植物细胞中一类重要的细胞器,控制其分裂的分子机制一直都不清楚.最近的研究表明,植物细胞中与原核细胞分裂基因ftsZ类似的同源基因控制着质体的分裂过程.通过正反义转化分析了两个烟草的ftsZ基因(NtFtsZ1和NtFtsZ2)在转基因烟草中的功能.二者的反义表达并未对转化烟草细胞中叶绿体的分裂和形态产生明显影响,但二者过表达转化植株中叶绿体的数目和形态都发生了明显的变化,在某些转化植株的叶肉细胞中甚至只有1～2个巨大的叶绿体存在.对不同转化植株的电镜观察和叶绿素含量分析认为,NtFtsZs基因可能对叶绿体的正常发育和功能没有影响,叶绿体形态的变化是对其数目减少的一种补偿.正反义转化植株中叶绿体的不同表型暗示高等植物中同一家族的ftsZ基因可能在控制质体分裂方面具有相同的功能.同时,过表达植株中叶绿体形态的变化被认为是高等植物Fts Z质体骨架功能的体现.
通讯作者。E-mail:yhe @ duke.edu;sunjs@ ns.ibcas.ac.cn.
The fingerprints of 27Leymus chinensis(Trin.) Tzvel accessions from different regions in China were generated and their genomic DNA variations were assayed via amplified fragment length polymorphism (AFLP). A total of 537 DNA fragments were amplified ranging from 75－530 bp using 8 AFLP primer combinations, among which 89 (16.6%) were monomorphic and 329 (61.3%) were polymorphic. The average number of DNA band produced by each primer combination was 66.13 and the total polymorphic rate was 78.84%. PICs (polymorphic information contents) scores for AFLP ranged from 0.0－0.5 and the mean PIC was 0.216. PIC scores were maximum (0.5) for 8.5% of the AFLP markers. All the results revealed that there was rich polymorphism in genomic DNA of L. chinensis. A DNA molecular dendrogram was established for 27 L. chinensis genotypes based on genetic variation and UPGMA cluster analysis of 537 AFLP markers amplified by 8 primer combination, suggesting that the genetic variation with high frequency showed close correlation with their ecotopes and geographical distributions. Twenty seven L. chinensis genotypes could be divided into four groups. Among them the lower genetic relationship was shown. The reason of high genetic variation frequency in L. chinensis species and formation of varieties was discussed.
刘 杰 朱至清 刘公社* 齐冬梅 李芳芳
摘要: 羊草是禾本科牧草之王,在当前我国西部生态建设和草原畜牧业发展中发挥着重要作用.用AFLP方法对27份我国不同地区分布的羊草(Leymus chinensis (Trin.) Tzvel)材料进行了基因组DNA多态性分析,8对AFLP引物组合在27个不同羊草基因型中共扩增出537条带,产生出的DNA片段大小分布在75 bp-530 bp之间.其中单态性带89条,占16.6%,多态性带329条,占61.3%.平均每对引物组合扩增的DNA带数为66.13,总的多态性比率为78.84%.AFLP多态信息含量PIC值分布于0.0-0.5之间,平均PIC值为0.216,出现的PIC最大值(0.5)约占AFLP标记的8.5%,说明羊草基因组DNA的多态性比较丰富.以537个AFLP标记为原始数据,根据Nei和Li的方法对27份羊草材料进行遗传变异和聚类分析的结果表明:羊草种内有高频率的遗传变异发生,且与地理分布和生态环境密切相关;27份羊草不同基因型被划分为四大类群,不同类群相互间的遗传距离相对较大,在树状图中表现为较远的亲缘关系.对羊草种内遗传变异发生的原因和品种的形成进行了初步讨论.
关键词： 羊草； AFLP亲缘关系
The gas well system permanently installed in the soil was adopted for studying the dynamic relationship between CO2 profiles and seedling root growth of Pinus sylvestris var. sylvestriformis(Takenouchi) Cheng et C. D. Chu. The study was conducted in the Open Research Station of Changbai Mountain Forest Ecological System, The Chinese Academy of Sciences from 1999 to 2001. Four treatments were arranged in the rectangular open top chambers (OTCs): ambient CO2+no seedling, 700 μmol/mol CO2+no seedling, ambient CO2 +seedlings, 700 μmol/mol CO2+seedlings. By collecting and analyzing soil gas synchronously, it was found that the dynamics of CO2 profiles were related to the biological activity of seedlings. There were more roots distributed in the top soil and the boundary layer across soil and sand, which made more contributions to the CO2 profiles due to respiration root. Compared with the ambient CO2, elevated CO2 led to the peak of CO2 concentration distribution shifted from soil surface layer to the boundary layer as seasonally growing of seedling roots. It is suggested the gas well system is an inexpensive, non destructive and relatively sensitive method for study of soil CO2 concentration profiles.
韩士杰 张军辉 周玉梅 邹春静
摘要： 采用固定在土壤中的气井系统,监测土壤剖面的CO2动态及其与长白赤松 (Pinus sylvestris var. sylvestriformis (Takenouchi) Cheng et C. D. Chu) 幼苗根系发展之间的关系.实验研究共设4种CO2处理,分别是环境CO2浓度,无苗;CO2为700 μmol/mol,无苗;环境CO2浓度,有苗;CO2为700 μmol/mol,有苗.通过对土壤剖面CO2气体的同步采集与分析表明:土壤CO2廓线与幼苗根系的生物活性密切相关.在土壤表面及壤土和沙土的边界层中,根系分布密集,根系的呼吸作用对那两个土层CO2贡献大;随着幼苗的季节生长,与环境CO2浓度比较,CO2倍增将导致土壤剖面上CO2浓度最大区域由表面向壤土和沙土边界层的转移.本文采用的气井系统提供了一种对土壤无破坏、经济、简单并且能够用于监测幼苗地下过程的廓线研究方法.
On the sunny days, there were little diurnal changes in both azimuth and directional angle for either sun or shade leaflet. However, there existed a significant diurnal change in midrib angle that reflected movements regarding evasion of light stress around noon hours. On the cloudy day, a very little diurnal difference was found in azimuth, directional and midrib angle. It is suggested that changing light environment is the main factor for inducing leaflet movement of Robinia pseudoacacia, and the rhythmical movement does not attribute to the leaflet movement. Leaf orientation control test showed that the photosynthetic rate (Pn), stomatal conductance (gs) and transpiration (Tr) of the artificial fixed leaflets were significantly lower than that of control leaflets. And the leaf temperature (Tl) of the fixed leaflets significantly exceeded that of control leaflets, which may attribute to the significant difference of light interception between the fixed and control leaflets. The light dependent leaflet movement is the morphological adjustment of maintaining optimal physiological status.
张守仁* 马克平 陈灵芝
通讯作者。Tel:+86-10-82599519;E-mail:zsr @ ns.ibcas.ac.cn;zhangsncn @ hotmail.com.
The woodland steppe ecotone in the southern Nei Mongol Plateau is located at the northern edge of the east Asian monsoon influences.A marked southeastern-northwestern (SE-NW) precipitation gradient exists in this region. Quantitative reconstruction of palaeo precipitation of this region is helpful to reveal the development of monsoon climate and to predict the future desertification. Based on modern vegetation and surface pollen studies, a pollen precipitation transfer function in the study region was established. Pollen data from three sediment sequences within the ecotone were used to reconstruct palaeo precipitation during the Holocene. The processes of precipitation changes in the three sequences were quite different. There was a tendency of precipitation declined from the onset of the Holocene to 1 100 a BP in Haoluku. But, in Liuzhouwan and Xiaoniuchang, both located south of Haoluku, the annual precipitation reached highest values during 7 800-6 200 aBP and 7 200-5 000 a BP, respectively. The influences of southwestern (SW) monsoon and the variances of topographical conditions have possibly caused these temporal spatial variances.
刘鸿雁* 崔海亭 田育红 徐丽宏
摘要： 内蒙古高原东南部森林草原过渡带位于中国东部季风气候尾闾区,是全球变化研究的关键区域.这一地区降水量存在着明显的东南至西北(SE-NW)梯度.在现代植被和表土花粉分析的基础上,建立了内蒙古高原东南缘森林草原过渡带孢粉-降水量转换函数.将研究区森林草原过渡带内3个湖泊沉积剖面的孢粉分析结果代入转换函数,定量恢复了这一地区全新世降水量的变化过程.结果表明:3个剖面全新世以来降水量变化的过程存在明显的差异,北部的好鲁库剖面在1 100 a BP以前一直呈减弱的趋势,而南部的碌轴湾剖面和小牛场剖面降水量在分别在7 800-6 200 a BP和7 200-5 000 a BP出现降水量的峰值,作者推断这种时空差异性与西南季风的影响、地形条件的差异有关.
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Comprehensive studies on the basis of pollen records from lake cores at 30 sites in the Qinghai Xizang Plateau have been used to reconstruct temporal spatial distributions of Holocene vegetations. Before the Holocene (prior to 12.0 ka BP) desert steppe vegetation was developed from the east to the west in the most parts of the Plateau, with a few exceptions in the extreme southeastern appeared. During the early Holocene (12.0-9.0 ka BP),deciduous broad leaved forest/coniferand broad leaved deciduous mixed forest were distributed in the east of Plateau(104° -98°E). Meadows or shrub meadow appeared in the middle of the Plateau (98° -92°E). Farther west to about 80°E, a steppe landscape was present. During the middle Holocene (9.0-3.2 ka BP), the palaeovegetations were sequentially conifer and broad leaved deciduous mixed forest and sclerophyllous broad leaved forest (104°-98°E)-conifer and broad leaved deciduous mixed forest (98°-94°E)-shrub meadow (94°-92°E)-steppe (92°-80°E). During the late Holocene (after 3.2 ka BP), the palaeovegetations were sequentially sclerophyllous broad leaved forest-conifer and broad leaved deciduous mixed forest-meadow-steppe-desert from east to west of the Plateau.
摘要：青藏高原30个点湖泊的孢粉记录综合研究显示: 在进入全新世之前(12 ka BP以前),除最东南部外,高原从东到西均发育为荒漠草原植被.全新世早期(12.0-9.0 ka BP)高原东南部(104°-98° E)为落叶阔叶林/针阔叶混交林; 中部(98°-92° E)为草甸或灌丛草甸,再向西至80° E左右为草原植被; 全新世中期(9.0-3.2 ka BP)高原由东向西古植被依次发育为针阔混交林和硬叶阔叶林(104°-98° E)→针阔混交林(98°-94° E)→灌丛草甸(94°-92° E)→草原(92°-80° E);全新世晚期(3.2 ka BP以后)由东向西古植被依次为硬叶阔叶林→针阔混交林→草甸→草原→荒漠.
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