Studies on mass summer mortality of cultured zhikong scallops (Chlamys farreri Jones et Preston) in China

Mass mortalities of cultured zhikong scallops (Chlamys farreri) have occurred each summer in most culture areas of northern China since 1996. Among the hypothesized causes are high culture density, infectious disease and genetic inbreeding. To investigate these potential agents, C. farreri were deployed at three densities (low, medium and high) at three sites (Jiaonan, Penglai and Yantai) in the summer of 2000. Scallops were sampled for survival, growth and histopathology before, during and after a mortality episode. Most of the mortality occurred in July and August, during and toward the later part of the spawning season, when water temperature reached 23-26 degrees C. Final cumulative mortalities reached 85% to 90% at all three sites. Scallops in the medium and high densities had higher initial death rates than did those at the low density. High densities also inhibited growth. Ciliates from the genus Trichodina, larvae of various organisms and anomalous secretions were observed in sections of the gill cavity, with highest prevalence during and at the end of the mortality period. Prokaryotic inclusion bodies were found in the soft tissues, but their prevalence was low and apparently without correlation with mortalities. Genetic analysis with random amplified polymorphic DNA markers showed slightly lower heterozygosity in the cultured stocks (0.301) than in the wild stocks (0.331). It is possible that the mortalities are caused by a combination of several factors such as stress associated with reproduction, high temperature, overcrowding and poor circulation in the growout cages, opportunistic invaders or pathogens, and possibly inbreeding. (c) 2005 Elsevier B.V. All rights reserved.

Identification of quantitative trait loci for growth-related traits in the Pacific abalone Haliotis discus hannai Ino

The locations and effects of quantitative trait loci (QTL) were estimated for nine characters for growth-related traits in the Pacific abalone (Haliotis discus hannai Ino) using a randomly amplified polymorphic DNA (RAPD), amplification fragment length polymorphism (AFLP) and SSR genetic linkage map. Twenty-eight putatively significant QTLs (LOD > 2.4) were detected for nine traits (shell length, shell width, total weight, shell weight, weight of soft part, muscle weight, gonad and digestive gland weight, mantle weight and gill weight). The percentage of phenotypic variation explained by a single QTL ranged from 8.0% to 35.9%. The significant correlations (P < 0.001) were found among all the growth-related traits, and Pearson's correlation coefficients were more than 0.81. For the female map, the QTL for growth were concentrated on groups 1 and 4 linkage maps. On the male map, the QTL that influenced growth-related traits gathered on the groups 1 and 9 linkage maps. Genetic linkage map construction and QTL analysis for growth-related traits are the basis for the marker-assisted selection and will eventually improve production and quality of the Pacific abalone.

A preliminary genetic linkage map of the pacific abalone Haliotis discus hannai Ino

Preliminary genetic linkage maps were constructed for the Pacific abalone (Haliotis discus hannai Ino) using amplified fragment length polymorphism (AFLP), randomly amplified polymorphic DNA (RAPD), and microsatellite markers segregating in a F, family. Nine microsatellite loci, 41 RAPD, and 2688 AFLP markers were genotyped in the parents and 86 progeny of the mapping family. Among the 2738 markers, 384 (including 365 AFLP markers, 10 RAPD markers, and 9 microsatellite loci) were polymorphic and segregated in one or both parents: 241 in the female and 146 in the male. The majority of these markers, 232 in the female and 134 in the male, segregated according to the expected 1:1 Mendelian ratio (alpha = 0.05). Two genetic linkage maps were constructed using markers segregating in the female or the male parent. The female framework map consisted of 119 markers in 22 linkage groups, covering 1773.6 cM with an average intermarker space of 18.3 cM. The male framework map contained 94 markers in 19 linkage groups, spanning 1365.9 cM with an average intermarker space of 18.2 cM. The sex determination locus was mapped to the male map but not to the female map, suggesting a XY-male determination mechanism. Distorted markers showing excess of homozygotes were mapped in clusters, probably because of their linkage to a gene that is incompatible between two parental populations.

碳离子辐射大丽花矮化突变体的RAPD分析

大丽花经兰州重离子加速器提供的80MeV/u12C6+离子束辐照后产生矮化突变体,用随机扩增多态性(Random Amplified Polymorphic,RAPD)DNA技术对野生型和突变体进行检测分析。结果表明,在所用的25条引物中,1.80×108/cm2剂量辐照后有18条引物扩增出现多态性片断,扩增条带多态率19.57%;1.08×108/cm2剂量辐照后仅有6条引物扩增出现多态性片断,扩增条带多态率5.76%。用Jaccard公式对扩增产物进行统计分析,结果表明,两种剂量C6+辐照后与对照相似性系数分别为0.65和0.92。高剂量辐射后DNA易发生突变,在品种改良和诱变育种中相对较高剂量的选择可能更为有效。

马尾藻种群遗传及早期发育的研究

本研究运用RAPD和ISSR两种分子标记技术，对采自山东半岛4个不同地理位置的鼠尾藻（Sargassum thunbergii）和海黍子（S. muticum）种群进行了遗传多样性和遗传结构的研究，从而对其种群间的地理隔离、基因流动水平及其影响因素做出估计和判断，为马尾藻自然资源的保护和开发提供依据。在室内对鼠尾藻有性生殖幼苗的早期发育和生长进行了研究，了解其繁殖生物学特性，为鼠尾藻人工种苗的培育提供依据。主要研究结果如下： 对4个鼠尾藻（S. thunbergii）地理种群的遗传多样性研究中，筛选出了28条RAPD 引物和19条ISSR引物，分别扩增产生了174和125个位点。选用的三种不同指标，即多态位点比率（P％，percentage of polymorphic loci），平均预期杂合度（H，the expected heterozygosity）和 Shannon's 信息多样性指数（I，Shannon's information index），均可反映出鼠尾藻种群内部的遗传多样性呈较低水平。而群体间遗传距离（D，Nei’s unbiased genetic distance）矩阵和固定化指数（FST,the fixation index）矩阵均反映出群体间高度的遗传分化。通过分子变异分析（AMOVA，Analysis of molecular variance）来区分来自种群内部和种群之间的遗传变异，揭示出多数的遗传变异（57.57% 或59.52%）来自于鼠尾藻种群之间。另外，Mantel分析表明，4个鼠尾藻种群间的遗传分化与地理距离呈正相关（r>0.5），遵循传统的IBD（isolation by distance）模式，UPGMA（unweighted pair group method with arithmetic averages）聚类分析也反映出相似的结果。 对4个海黍子（S. muticum）地理种群遗传结构的研究中，筛选出的24条RAPD 引物和19条ISSR引物分别扩增出164和122个位点。遗传多样性评估结果表明，海黍子种群内部存在较低或者中等水平的遗传多样性，而D矩阵和FST 矩阵均显示种群间存在高水平的遗传分化。并且，发现D和FST 矩阵在RAPD和ISSR分析中均具有高且显著的相关性。AMOVA分析显示，种群之间的遗传变异高于种群内部。Mantel分析和UPGMA聚类分析均发现海黍子种群间的遗传分化遵循IBD模式，即与地理隔离呈正相关（r>0.6）。 并且，RAPD和ISSR分析的结果高度一致（r>0.9，P<0.05），均揭示4个海黍子种群之间存在高度的遗传分化。 对鼠尾藻有性生殖幼苗早期生长发育的研究结果表明，其早期发育过程属于马尾藻科（Sargassaceae）中典型的“8核1卵”型。在一定条件下培养两个月后，产生了1～2个小叶，幼苗的长度达2～3毫米。生长实验发现，温度（10, 15, 20, 25℃）和光照强度（9, 18, 44, 88 µEm-2s-1）对培养第一周幼苗的生长均有显著的影响（ANOVA, P<0.01）。在两个月的培养中，幼苗对温度和光强的耐受范围较宽，在10℃～25℃，9～88 µEm-2s-1条件下均可生长，最适温度和光强为25℃，44 µEm-2s-1；低温（10℃）对幼苗的生长有显著抑制。不同光质对幼苗生长的影响显著（P<0.01），相同光强条件下，蓝光和白光相比较，蓝光显然不能满足鼠尾藻幼苗早期生长的需要。

葡萄属植物系统学研究

葡萄属（Vitis.L.）植物隶属于葡萄科(Vitaceae)，主要分布于北温带，最南可以分布到南美洲的委内瑞拉和亚洲的越南以及印度北部。本文通过对该属分类研究历史的回顾，认为该属存在的问题主要表现在如下几个方面： 1）葡萄属自1753 年由Carl Linne创立以来，虽经planchon于1887年做了修订，但属的范围仍需进一步界定;2）在Planchon之后的100多年中未见有一全面的分类学修订工作，出现在该属的800多个名称需要考证;3）对一些广布种的变异认识不足，导致了大量可疑种。针对这些问题本文进行了如下几个方面的工作： l、形态学：通过大量的野外工作和标本观察，对该属植物的主要性状做了分析，讨论了这些性状状态在葡萄属中的变异规律及演化趋势，将灌木状习性、退化的卷须以及不裂的叶片视为进化的性状。 2、细胞学：利用前人对葡萄属(Vitis.L.)染色体数目的统计及一些杂交实验分析的结果，结合形态学等方面的特征分析，认为在葡萄科，染色体基数X=10为原始的，而x=19则为衍生的。葡萄属的染色体基数xl9(2n=38)，多倍体较少见;麝香葡萄属[Muscadinia (Planch.) Sma11]的染色体基数为x=10 (2n=20)．与蛇葡萄属、酸蔹藤属和爬山虎属的一致。葡萄属和麝香葡萄属间的杂种是不育的。 3、孢粉学：对葡萄属32种5变种及麝香葡萄属[Muscadinia (Planch.) Sma11]1种的花粉外壁做扫描电镜观察，结果发现花粉外壁雕纹在这两属间和葡萄属内变异较小，对区分属以及属下种上类群意义不大，但对种的鉴别有重要的价值。 4、植物化学：前人对植物化学的工作表明，植物的一些次生代谢产物如类黄酮化合物在葡萄科各类群中的分布规律较好地反映了各类群间的关系。这些结果较好地支持了Planchon对葡萄属范围的界定。 5、山葡萄复合体(V.amurensis complex)包括山葡萄(V.amurensis Rupr.)、燕山葡萄(V.amuresis Rupr. var. dissecta Skvorts.=var.yanshanensisD．Z．Lu et H．P．Liang)、百花山葡萄(V.baihuashanensis M．S．Kang et D．Z．Lu)、复叶葡萄(V.piasezkii Maxim.)、少毛复叶葡萄[V. piasezkii Maxux1．var. pagnuccii (Planch.) Rehd.]共3个种和2个变种，广泛分布于中国北方，形态变异较大。本文对该复合体做了形态分析，并用RAPD (Random Amplified Polymorphic DNAs)分子标记方法分析了这几个类群的关系。综合这些结果，归并了燕山葡萄和百花山葡萄。 在上述工作的基础上，我们得出了如下的结论： l、葡萄属在葡萄科中是一个进化的类群。整理后的葡萄属包括8系62种、l亚种和15变种，其中有2个新系、1个新组合系、2个新变种、1个新组合种和l3个新异名。 2、本文赞同SmaU在1903年作出的分类学处理，把麝香葡萄作为一个独立的属，比葡萄属原始但与葡萄属有着最近的亲缘关系。 3、依据形态特征和APD分析结果把山葡萄复合体的3个种2变种归并为2种l变种，即山葡萄、复叶葡萄和少毛复叶葡萄，认为分子标记技术在分析属内近缘种闻关系上很有价值。 4、葡萄属具有东亚和北美2个现代分布中心，该属可能起源于北美的东部，在晚白垩纪经白令陆桥散布至欧亚大陆。

云南4个马品种的随机扩增多态DNA(RAPD)分析

腾冲马和新丽江马品种内的遗传变异显著高于文山马和乌蒙马,遗传变异68.06%存在于群体内。系统聚类图中品种内大多数个体聚在一起,文山马和乌蒙马聚成一个大类,腾冲马和新丽江马又聚成一个大类,说明文山马和乌蒙马以及腾冲马和新丽江马有较近的亲缘关系。

ACHT操作引起黑麦(Secale cereale)染色体的畸变和重建

用ACHT处理黑麦萌动种子，对修复前后材料的观察和分析结果表明：1. ACHT操作引起染色体数目变化和染色体断裂损失。在一定 条件和范围内，不同处理引起的这种变化具有显著差异，条件越剧烈，染色体数目变化的范围和频率愈大，断片发生的数量和频率 也愈高，同时修复前后染色体数目的变化范围和频率与断片发生的数量和频率以及它们的修复频率均表现明显的相关性。2. ACHT 操作引起染色体畸变的多样性。经ACHT处理后，胚根细胞染色体有4种断裂方式，包括着丝粒断裂、次溢痕断裂、长臂断裂和短臂 断裂等，其中着丝断裂频率最高；产生6种断片类型，包括有着丝粒和端粒的、有着丝粒而无端粒的、有部分着丝粒和端粒的、有 部分着丝粒而无端粒的、只有端粒的、既无着丝粒也无端粒的断片等。3. ACHT操作引起遗传结构重建的多样性。经ACHT处理后， 对修复24-72小时材料进行核型比较(按Stebbins 和 Levan 标准)和随体分析，处理细胞在染色体数目、大小、形态、位置等方面 均发生显著变化，说明ACHT处理使这些细胞的染色体结构和染色体组型发生了深刻变化。进一步通过Giemsa C— 带分析，观察到 多种重建染色体类型，包括易位型染色体、附加型染色体、无着丝粒染色体、化染色体、增加的m染色体以及某些带型特异的染色 体等。4. RAPD 分析从分子水平上验证了ACHT能有效地引起遗传结构的改变。所用10种引物对处理和对照材料基因组DNA的扩增产 物在条带数目、条带位置及带型特征等方面均有明显差异，其中4种引物出现条带减少，6种引物出现条带增加，后者还包括一个带 位移动。这说明两种材料的基因组DNA具有明显的RAPD反应多态性差异。This paper descripes some results draw on the basis of the observation and analysis on the rye before and after repaired through treating its budding seeds by ACHT in contrast to without ACHT: 1. ACHT manipulation caused the number variation and breakage damage of rye chromosome. Within certain conditions and timits, this phenomenon caused by different treats had signifcant difference: the more the treatment condition is drastie, the more the chageable range and frequence of rye chromosomae number, and so is the produced fragments. Meanwhile, there existed striking relationship among the changeable range and frequence of rye chromosome, the produced number and frequence of fragments and repairing frequence. 2. ACHT manipulafion engendered the diversify of rye chromosomal aberration. Four breakage patterns and six sorts of fragment were observed by watching the chromosome of the rye radicle treated by ACHT, including centric breakage (occuring in the highest frequence), secondary constriction breakage, long arm breakage and short arm breakage to the former, Comprising that with both centromere and telomere, that with centromere and without telomere, that with partial centromere and with telomere, that with partfial ceetromere and without telomere, that only with telomere and that neither with centromere nor with telomere, etc. 3. ACHT manipulation engendered the diversify or rye genetic structs reconstruction. Karureotype analysis(according to Stebbins and Levan) and satellite anaeysis were carried out to rye radicle through 24-72-hour-long recoverage after ACHT manipulation, which showed remarkable change happened on the rye chromosomal number、shape、arm ration and pattern, etc. and also on the satellite number、size、shape and location etc. Those indicated that ACHT manipulation engendered violent changes to rye chromatin structure and chromosome type. Further Giemsa C-banding analysis showed many types of reconstructed chromosome, such as translocation、addition、without centromere、st and other chromosome. 4. RAPD analysis checked the validity of ACHT on changing genetic structure of rye on the level of molecular biology. The treated and recovered rye has different amplifying band pattern by using IO valid arbitary primers selected from 40 comparing with the control.

Genetic variation and phylogeographic history of Picea likiangensis revealed by RAPD markers

Repeated cycles of retreat and recolonization during the Quaternary ice ages are thought to have greatly influenced current species distributions and their genetic diversity. It remains unclear how this climatic oscillation has affected the distribution of genetic diversity between populations of wind-pollinated conifers in the Qinghai-Tibetan region. In this study, we investigated the within-species genetic diversity and phylogenetic relationships of Picea likiangensis, a dominant forest species in this region using polymorphic DNA (RAPD) markers. Our results suggest that this species has high overall genetic diversity, with 85.42% of loci being polymorphic and an average expected heterozygosity (H (E)) of 0.239. However, there were relatively low levels of polymorphism at population levels and the differences between populations were not significant, with percentages of polymorphic bands (PPB) ranging from 46.88 to 69.76%, Nei's gene diversity (H (E)) from 0.179 to 0.289 and Shannon's indices (Hpop) from 0.267 to 0.421. In accordance with our proposed hypothesis, a high level of genetic differentiation among populations was detected based on Nei's genetic diversity (G (ST) = 0.256) and AMOVA analysis (Phi (st) = 0.236). Gene flow between populations was found to be limited (Nm = 1.4532) and far lower than reported for other conifer species with wide distribution ranges from other regions. No clusters corresponding to three morphological varieties found in the south, north and west, respectively, were detected in either UPGMA or PCO analyses. Our results suggest that this species may have had different refugia during the glacial stages in the southern region and that the northern variety may have multiple origins from these different refugia.

空间搭载水稻种子后代基因组多态性及其与空间重离子辐射关系的探讨

神舟三号飞船搭载带核径迹辐射探测器的水稻种子装置,回收后应用随机扩增多态性DNA(randomamplified polymorphic DNA,RAPD)技术,分析了201粒升空种子长出植株的基因组多态性。在检测的189个基因座位范围内,30.2%的植株中发现与地面对照不同的扩增带,单株的多态性座位数为1￣25。特异扩增带的测序及单核苷酸多态性(single-nucleotide polymorphism,SNP)分析进一步证明了空间搭载水稻种子确实可导致当代植株基因组发生变异。同一技术分析个别种子连续世代的基因组多态性,结果显示,当代的部分多态性可遗传至后代。7粒受空间高原子序数、高能粒子轰击的种子,在当代植株均显示不同程度的基因组多态性,从胚受粒子击中的3粒种子后代中,筛选出农艺性状明显变异的突变株系,初步暗示了空间高能重离子辐射对诱导基因组的多态性,乃至遗传性表型变异的有效性。

应用RAPD技术初步分析无裂栉江珧四种类型的基因组DNA

利用 3个随机引物 (S4 5 3,S4 5 4 ,S4 6 3)对无裂栉江珧 (Atrina pectinata L inaeus)的 4种类型 :青口、黄口、沙螺、棘螺基因组 DNA进行 RAPD分析 ,并对 RAPD的实验条件行了优化研究。10～ 2 0 ng的高纯度 DNA用作模板 ,退火温度为 39℃时 ,RAPD扩增的效率较高 ,扩增的带纹清晰可辨。3个引物中 ,引物 S4 5 3和 S4 6 3获得了清晰的 RAPD扩增结果 ,引物 S4 5 4未获得有效扩增 ,共扩增出 8条清晰的 DNA

~(12)C~(6+)重离子辐照胡麻种子初步研究

本文研究了6×108cm-2、1.8×109cm-2和3.6×109cm-2的12C6+重离子束辐照对胡麻种子M1代生物学性状和DNA分子多态性等方面的影响。6×108cm-2辐照处理可引起胡麻发芽率提高,促进植株株高,增强花粉活力。同时辐照处理使胡麻种子千粒重和含油量有不同程度提高,辐射剂量越高,两者数值越大,3.6×109cm-2辐射剂量的胡麻种子千粒重和含油量与对照组的相比分别高出了16.5%和19.9%,此外在此剂量处发现了花粉发生了形态变化。辐照处理对胡麻DNA分子也产生了影响,筛选出的14个随机引物可以扩增出清晰、稳定、重复性好的DNA片段,有52个是多态性DNA片段,比率为52.5%。

滇金丝猴的随机扩增多态DNA与遗传多样性分析

对6只笼养滇金丝猴(Rhinopithecus bieti)进行了随机扩增多态DNA(RAPD)及遗传多样性分析.用45个10bp随机短引物对每只滇金丝猴的基因组DNA进行了扩增,平均每个个体观察到的RAPD标记约为130个左右,单个引物获得的标记在1～7个之间.80%的RAPD标记表现为无多态的单型性.个体间的遗传距离为0.052,表明笼养滇金丝猴群体的遗传多样性很低.此研究结果与在蛋白多态研究中得到的一致.贫乏的遗传多样性一方面使目前处于濒危境地的滇金丝猴生存情况更加危险,同时其本身也可能是造成目前滇金丝猴濒危的原因之一.另外,通过成对的遗传距离分析,构建了这一群滇金丝猴的谱系关系图,提出了让遗传距离较远的个体间进行交配的笼养繁育计划.