短枝木麻黄地理种源遗传多样性的RAPD分析

利用RAPD分子标记对35个短枝木麻黄（Casuarina equise fifolia）种源的遗传多样性和亲缘关系进行了分析．15个随机引物共扩增了出201条DNA带．其中148条为多态性带，占73．63％．平均每个引物扩增出9．9条多态性带．种源的Shannon’s多样性指数为0．4354，Nei’s基因多样度为0．2884，表明短枝木麻黄种源的遗传多样性水平较高．35个种源彼此的遗传距离在0．0884～0．7539之间，平均0．4045．经过UPGMA聚类分析将35个种源划分为A、B、C、D、E、F6个类群。其中A群5个种源，B群17个种源，C群4个种源．D群2个种源，E群1个种源．F群6个种源．     

栽培温度及种源对青钱柳β谷甾醇含量的影响

在建立测定青钱柳（Cyclocarya paliurus）中β谷甾醇含量方法的基础上,探讨了不同温度对3个青钱柳种源1年生苗木中β谷甾醇含量的影响。结果表明：不同温度对青钱柳苗茎中β谷甾醇的含量影响显著,而对叶片和根中β谷甾醇的含量影响不显著（p＜0.05）。在30、25和20 ℃条件下,青钱柳苗茎中β谷甾醇平均质量分数分别为1.50 %、0.92 %和1.72 %;不同器官青钱柳β谷甾醇含量有差异性,以叶的含量为最高,茎次之,根的含量最低。温度和种源交互作用对青钱柳根部、叶片β谷甾醇含量的影响极显著。相对的高温和低温都有利于青钱柳根和茎中β谷甾醇的合成,但叶中的含量以在25 ℃时最高。     

鄂尔多斯盆地南缘晚古生代沉积物源及其对秦岭造山带北部演化的指示

鄂尔多斯盆地南缘位于华北克拉通盆地的西南部,其形成演化和沉积过程与华北克拉通南侧秦岭造山带的活动有紧密的联系.晚古生代沉积的物源特征能够帮助提取关于秦岭造山带的演化信息.基于对鄂尔多斯盆地南缘澄城和韩城2条出露本溪组－石千峰组的剖面岩石学特征的详细研究,从岩石性质、碎屑特征、重矿物组合和碎屑组分的Dickinson三角图解等方面进行分析讨论,获得了鄂尔多斯盆地南缘晚古生代物源的详细信息,并揭示了秦岭造山带北部晚古生代的演化过程.研究表明,本溪组－太原组的物源为秦岭造山带中的华北板块南缘带;山西组－石千峰组的物源来自于北秦岭构造带,物源区有向南迁移的特征.晚泥盆－晚石炭世商丹带的点接触初始碰撞造成华北板块南缘发生抬升,早二叠世秦岭造山带进入面接触碰撞阶段,造成北秦岭弧后盆地和岛弧带依次发生隆升,成为鄂尔多斯南缘沉积区的主要物源供给区.扬子板块与华北板块自东向西剪刀状的碰撞,造成鄂尔多斯南缘沉积的山西组－下石盒子组的古流向由南东－北西方向朝南西－北东方向的转变.     

A high-resolution clay mineralogical record in the northern South China Sea since the Last Glacial Maximum,and its time series provenance analysis

High-resolution clay mineralogical analysis of Core MD05-2904 in the northern South China Sea (SCS) covering the period since the Last Glacial Maximum shows that illite (29%–48%), smectite (14%–45%), chlorite (17%–28%), and minor kaolinite (6%–14%) comprise the clay mineral assemblage, and that time series variation does not present glacial-interglacial cyclicity. Provenance analysis indicates three end-member sources: almost all smectite derives from Luzon, all kaolinite is sourced from the Pearl River, and illite and chlorite originate from both the Pearl River and Taiwan. By comparing clay mineral compositions in surface sediments from the three major source areas and of the SCS, we reconstructed a time series of clay mineral contribution from the major provenances to the northern slope of the SCS using the linear separation method for illite crystallinity. There were three stages of provenance change. (1) During 24.1–17.5 ka BP, contributions from Taiwan and Luzon were similar (30%–40%), while that from the Pearl River was only 25%. (2) During 17.5–14.0 ka BP, the contribution from Luzon decreased rapidly to 20%–25%, while that from Taiwan increased to 35% from an average of 25% at 18 ka BP, and that from the Pearl River increased largely to 40%. (3) During the Holocene, differences in contributions from the three major provenances increased: the contribution from Luzon increased slightly and then remained at 27%–35%, that from Taiwan increased rapidly and then remained at 55%–60%, and that from the Pearl River decreased to 15%. The change in clay mineral contributions from different provenances is influenced mainly by clay mineral production, monsoon rainfall denudation, oceanic current transport, and sea-level change.     

不同时期广西马尾松优良种源的遗传多样性变化趋势

马尾松是我国南方重要的乡土树种,近30年来,受人为干扰和破坏十分严重。为了解目前广西马尾松天然遗传资源现状,评价当前种质资源收集对遗传多样性保护的有效程度,采用SSR标记对3个时期收集的广西马尾松3个优良种源进行遗传多样性研究。结果表明:现阶段,马尾松桐棉种源群体的Shannon 多样性指数(I)为 0.64,观测杂合度(H_o)为 0.35,期望杂合度(H_e)为 0.36; 古蓬种源群体Shannon 多样性指数(I)为 0.53,H_o为 0.36, H_e为 0.32。说明广西马尾松遗传多样性仍处于较高水平。将3个种源的遗传多样性进行对比,发现桐棉种源的遗传多样性最高,古蓬种源次之,云开大山种源相对较低。群体间遗传分化系数(G_ST)为0.04,Wright固定指数(F_ST)平均值为0.026,基因流(N_m)大小为9.56,说明3个种源间不存在明显的遗传分化,群体间基因交流顺畅。将不同时期的遗传多样性进行对比分析可知:桐棉种源在18 a内 Shannon 多样性指数(I)下降了5%、期望杂合度(H_e)下降了10%; 古蓬种源Shannon 多样性指数下降了13%、期望杂合度(H_e)下降了14%。说明随着时间的推移,马尾松天然资源受到人为干扰愈来愈强烈,遗传多样性正逐步丧失,急需开展有针对性的保护。     

中国黑龙江东部鸡西盆地白垩纪多期砾岩特征及古地理意义

对鸡西盆地白垩纪不同时期砾石统计结果显示: 下白垩统城子河组和穆棱组砾石主要成分为石英岩和花岗岩, 与盆地周缘露头前中生代基底主要岩性相吻合; 上白垩统猴石沟组砾石成分流纹岩、安山岩、凝灰岩增多, 出现石英砂岩和少量泥岩, 砾石很大一部分来源于下白垩统。 6个统计点的砾石主要为次棱角状到圆状, 长短轴之比集中在1~2, 粒径以小砾为主, 粒径长度符合正态分布; 沉积环境判别函数显示砾石主要属于河流(三角洲)成因。研究表明城子河组沉积时期, 盆地西部的张广才岭和盆地内的古隆起为盆地提供物源, 城子河组到穆棱组的沉积过程是一个水体不断扩大的过程; 穆棱组沉积中晚期, 盆地西部成为盆地主要物源区。晚白垩开始, 在强烈的逆冲作用下, 盆地及周缘发生区域抬升, 抬升区遭受强烈剥蚀, 为盆地提供物源, 低洼处沉积猴石沟组。     

殷商青铜器矿料来源与铅同位素示踪应用

出土地点相距较远的殷商青铜器具有相似的铅同住素组成特征，却与周代以后的青铜器存在明显的差异，具有异常铅同位素组成的殷商青铜器，其资源产地却是一个谜。地质、地球化学与考古学的多学科综合研究，特别是铅同位素示踪方法的应用可能是解开这个谜底的重要途径。     

Radiometric dating of sediments derived from metamorphic rocks of the Dabie orogenic belt in the Jurasic and Early Cretaceous

Using isotopic dating of tuff, heavy mineral and lithofacies, correlation of Jurassic strata on the northern margin of the Dabie orogenic belt (DOB) has been enabled in the Fenghuangtai, Zhougongshan, Maotanchang and Jingangtai formations, which might be as young as Early Cretaceous. Depositional systems have been interpreted as mainly alluvial fan, braided stream and overbank, secondarily fan-delta and lacustrine. The palaeocurrent systems of the Jurassic-Cretaceous basins can be divided into two classes: one transverse adjacent to the southern margin, the other longitudinal close to the middle flowing from west to east. Mesozoic sedimentary source rocks are mainly from the DOB and, according to their geochemistry, experienced evolution in a volcanic arc tectonic setting. The Jurassic-Cretaceous strata have been subdivided into four Chronosomes, and their overlapping progressively from east toward west implies that exhumation of the DOB characterized diachronous. Based on stratigraphic evidence from eclogite conglomerates found in the Maotanchang and Fenghuangtai formations, the first exposure of UHP (ultrahigh pressure) rocks in the DOB occurred in Jurassic-Lower Cretaceous time. Further, phengites and Triassic zircons found in the Lower Jurassic Fanghushan Formation suggest that denudation began in the Early Jurassic.     

内源激素动态变化与马尾松优良种源抗寒性的关系

以广西桐棉和广西古蓬马尾松（Pinus massoniana Lamb.）种源叶片为材料,应用间接酶联免疫法（ELISA）测定内源激素脱落酸（ABA）、赤酶素（GA3）、吲哚乙酸（IAA）、玉米核苷（ZR）含量,分析不同种源苗期的抗寒性与内源激素含量的关系。结果表明,马尾松抗寒力的评价指标为内源GA3含量、ABA/GA3（k值）和ZR/ABA值,内源GA3含量越高,抗性越差;k值越大,抗寒力越强;ZR/ABA值越大,抗寒力越强。     

柴西西岔沟剖面新生界碎屑锆石裂变径迹年龄对物源区构造活动的制约

对柴西西岔沟新生界碎屑锆石裂变径迹年龄的研究表明:沉积源区主要为遭受150～290 Ma热事件影响的阿尔金山带,在晚近纪晚期以后有古近系的加入;同时记录的发生于源区的构造热事件最早为海西早期,在海西中期有所加强,海西晚期之后至燕山早期为主要时期,尤以海西末-印支期最为鼎盛;在整个新生代源区抬升渐强、剥蚀加快.阿尔金断裂在8 Ma活动加强,在新近纪晚期表现为活动加剧,同名山系快速隆升,成为柴西主要物源区.柴西地区沉积源区在相对固定的态势下,也有一定分异性,即物源区的变更.古阿尔金断裂是存在的,随青藏高原内不同块体依次向北拼贴,且阿尔金断裂具有多阶段活动的特点.