植物线粒体遗传的研究进展

对植物线粒体遗传方式、遗传机理的最新进展进行了综述。被子植物线粒体的遗传方式以单亲母系遗传占绝对的统治地位,在裸子植物中,不同的种差别较大,松科、红豆杉科线粒体多为母系遗传,而南洋杉科、杉科、柏科和三尖杉科的线粒体主要为父系遗传方式。绝大数植物线粒体遗传有其不同于质体遗传的特征,线粒体在雄性生殖细胞中持续存在,甚至参与受精进入合子,但又更多地表现为母系遗传。     

昆虫线粒体DNA Cyt b基因研究进展

线粒体DNA具有进化速率较核DNA快,遗传过程不发生基因重组、倒位、易位等突变,并且遵守严格的母系遗传方式等特点,其广泛应用于昆虫分类和界定、系统发育关系及种群遗传变异和进化等研究。细胞色素b（cytochromeb,Cyt b）是线粒体13个蛋白质编码基因中结构和功能被研究得最为清楚的基因之一,本文对mtDNA和Cyt b基因的分子特点及Cyt b基因在昆虫研究中的应用进行简要综述。     

油桐属与石栗属叶绿体的核酸、蛋白质及超微结构的初步研究

叶绿体超微结构是叶绿体形态和功能的重要内容之一。叶绿体除在光合作用中具有重要的功能外,在高等植物细胞质遗传中,作为细胞器也具有重要的作用。据估计,叶绿体DNA的信息量足以编码分子量为40000道尔顿的多肽约150—300个。不同种的叶绿体蛋白质存在差异。不同品种的叶绿体显微结构也存在明显差异。前文已发现油桐属和石栗属在叶片的核酸、蛋白质以及叶绿素含量上存在明显差异。本文试图对该两属的叶绿体超微结构及核酸和蛋白质含量进行比较研究,以提供进一步依据。     

水分胁迫对杂种马褂木与双亲重要生理性状的影响

水分胁迫状态下鹅掌楸属 (Liriodendron)种间正反交F1 杂种及双亲的一些重要生理性状的研究表明 :水分胁迫状态下亲本与杂种叶片的相对含水量、叶绿素含量、蛋白质含量的降低速率和RNase活力的升高速率排序为马褂木 >北美鹅掌楸 >正交F1 >反交F1 ;短时间水分胁迫对马褂木伤害最大。3H Gly标记取得的直接证据证明 ,水分胁迫导致亲本与杂种RNase基因在翻译水平上表达而从头合成RNase ,RNase基因表达强度排序为马褂木 >北美鹅掌楸 >正交F1 >反交F1 。蛋白质生物合成抑制剂取得的间接证据表明 ,水分胁迫状态下双亲RNase活力升高除与细胞质mRNA翻译有关外 ,还可能涉及叶绿体和 或线粒体RNase的释放、活化和 或合成 ,而正反交杂种RNase活力升高可能主要来自细胞质mRNA的翻译而不涉及到叶绿体和 或线粒体。上述实验证据充分证明 ,杂种马褂木正反交F1 杂种具有对水分胁迫抗性的显著超亲杂种优势 ,而正反交杂种中反交F1 的抗性又强于正交F1 。研究结果从水分胁迫抗性差异角度揭示了杂种马褂木强大正向生长、适应性和抗性杂种优势现象形成的分子机理 ,并表明在杂种马褂木杂种优势固定利用实践中必须特别注意反交F1 杂种无性系的选育与开发     

油桐育种程序系列研究

经对来自１０个省（区）１８４个种质资源号及２７５个地方品种、单亲家系、双亲家系和无性系系统的研究分析与选育，基本摸清油桐主要性状的遗传参数，并得出油桐为“常异花授粉树种”的结论；制定了油桐育种程序和途径，选育出３个优良家系、４个优良无性系、１个“矮早丰”优良品种和１个优良杂交组合；收集了来自全国油桐产区的种质资源４５１个；生产并推广良种１３ｘ１０４ｋｇ。应用这些良种的遗传增益（△Ｇ）在３４．０％－５９．８％。这一研究为油桐生产和遗传改良提供了理论依据，并提供了部分育种和生产资料。     

银杏分泌腔的超微结构特征及与分泌物积累的关系

在光学显微镜和电子显微镜下对银杏叶片分泌腔的发生发育进程、超微结构特征及与分泌物积累的关系进行了系统研究。结果表明：银杏叶片分泌腔是以裂溶生方式发生、发育。首先，原始分泌细胞团中央几个细胞的胞间层膨胀、溶解，形成裂缝状胞间隙；然后，分泌细胞的胞间层继续溶解。胞隙增大，同时中央的一些分泌细胞退化、溶解、脱落于腔内。银杏分泌腔内分泌物的合成主要在分泌细胞的质体和内质网中进行，但线粒体、高尔基体和细胞质也似乎参与分泌物的合成和转输。当分泌物在质体或内质网上合成后，以小泡形式接近质膜，并与质膜融合，释放分泌物于质膜和细胞壁之间，然后这些分泌物主要以扩散渗透形式穿出壁外在分泌腔内积累。     

小五台山地区植物多样性研究

在概述小五台山自然地理环境、植物研究历史的基础上,分析了小五台山的高等植物多样性,结果表明:1)小五台山地区有苔藓植物244种,其中小五台山特有种2种;维管植物1 393种,其中被子植物1 320种,被子植物科数占河北省被子植物总科数的71.5%;2)小五台山分布国家一级、二级重点保护植物33种;3)中国特有植物8属,以小五台命名的模式标本植物5种。因此,小五台山是河北省植物物种多样性最为丰富的区域之一;并针对当前小五台山保护区植物多样性的现状,提出相应的建议。     

银染过程的时间考量

本文介绍了水稻几种细胞质雄性不育品种线粒体DNA的AFLP(Amplified Fragment Length Ploymorphism)预扩、选扩和变性的PCR程序.两种PAGE银染的方法中,强碱法简便节约,而弱碱法的成像效果好,但操作过程中时间的把握至关重要.     

油松单亲本子代测定和优良家系选择的研究

笔者对24年生油松单亲本子代测定林进行研究,以算术平均数加n倍标准差作为评价个体家系优劣的划分标准,从参试的81个家系中选择生长表现优良、遗传稳定性高的优良家系,并对其生长性状做了遗传增益的估算。结果表明:参试的81个家系的树高性状差异明显;确定了其优良家系为双36,双42,孝70;81个家系树高遗传增益为14.72%,胸径遗传增益为10.65%.对提高油松初级种子园良种繁育的成效及建立升级换代种子园具有重要意义。     

华北落叶松单亲本子代测定林遗传变异和选择研究

单亲本子代测定林遗传变异的研究是种子园升级换代,建设1.5代种子园的基础工作,是种子园提高种子质量的有效途径。通过对山西省静乐县国家华北落叶松良种基地20年生华北落叶松种子园70个单亲本家系子代测定林进行研究,结果显示:不同家系间树高和胸径差异显著;通过树高和胸径双重选优,共选出优良家系25个,并进行了统一编号;树高遗传增益为11.95%,胸径遗传增益达11.75%.为种子园升级换代奠定了技术基础。     

Nuclear,chloroplast, and mitochondrial DNA polymorphisms as biochemical markers in population genetic analyses of forest trees

DNA analyses have been used only occasionally to investigate genetic polymorphisms in forest tree populations. Nonetheless, these analyses have already contributed to significant discoveries, such as paternal chloroplast and maternal mitochondrial DNA inheritance in Pinaceae. DNA polymorphisms will be increasingly exploited in the future by forest population geneticists, because available technology permits large sample sizes and yields excellent resolution. The utility of chloroplast, mitochondrial, and nuclear DNA polymorphisms is expected to be greatest when less expensive genetic markers are unavailable, insufficiently numerous, or ineffectively polymorphic. For example, DNA fingerprinting may permit the unambiguous elucidation of genetic relationships within and among populations of woody species.     

Genetic evidence for paternal inheritance of the chloroplast in four Australian Callitris species (Cupressaceae)

The mode of chloroplast inheritance was investigated in the four Australian conifer species; Callitris columellaris, C. intratropica, C. gracilis and C. verrucosa (Callitroideae, Cupressaceae), as a basis for future use of chloroplast genetic markers for the genus. Open-pollinated seeds and the foliage tissue of the mother trees were collected from one population per species, in which two distinct chloroplast haplotypes at the trnL (UAA) 5′ exon–trnF (GAA) region were co-distributed. In total, the DNA sequences of the chloroplast fragments in 255 samples were determined, and the haplotypes of the germinated seedlings and the mother trees were compared. Among the 16 mother trees examined across all species, 12 trees were shown to have produced at least one offspring with a different haplotype from the mother, indicating the occurrence of paternal inheritance of chloroplast in the fertilization processes. In binomial GLMM analyses, the haplotype of mother trees in C. columellaris, C. gracilis, and C. verrucosa did not significantly affect those of their offspring, and the predicted frequency of seedlings’ haplotypes was compatible with the observed frequency in adult canopy trees. These findings provide a genetic support that paternal inheritance of chloroplast DNA via pollen dispersal would be dominant in the Callitris species.     

Plant somatic hybrid cytoplasmic DNA characterization by single-strand conformation polymorphism

Unlike maternal inheritance in sexual hybridization, plant somatic hybridization allows transfer, mixing and recombination of cytoplasmic genomes. In addition to the use of somatic hybridization in plant breeding programs, application of this unique tool should lead to a better understanding of the roles played by the chloroplastic and mitochondrial genomes in determining agronomically important traits. The nucleotide sequences of cytoplasmic genomes are much more conserved than those of nuclear genomes. Cytoplasmic DNA composition in somatic hybrids is commonly elucidated either by length polymorphism analysis of restricted genome regions amplified with universal primers (PCR-RF) or by hybridization of total DNA using universal cytoplasmic probes. In this study, we demonstrate that single-stranded conformational polymorphism (SSCP) analysis is a powerful, quick and easy alternative method for cytoplasmic DNA characterization of somatic hybrids, especially for mitochondrial DNA. The technique allows detection of polymorphisms based on both size and sequence of amplified targets. Twenty-two species of the subfamily Aurantioideae were analyzed with eight universal primers (four from chloroplastic and four from mitochondrial regions). Differences in chloroplastic DNA composition were scored in 98% of all possible two-parent combinations, and different mitochondrial DNA profiles were found in 87% of them. Analysis by SSCP was also successfully used to characterize somatic hybrids and cybrids obtained by fusion of Citrus sinensis (L.) Osb. and C. excelsa Wester protoplasts.     

尾叶桉与巨桉杂种F1代生长性状遗传分析

【目的】测定尾叶桉与巨桉杂种F 1多年度的生长性状,估算其遗传参数,开展优良杂交组合及杂种优良单株选择,为桉树亲本选配和杂种应用提供科学依据。【方法】以尾叶桉与巨桉6×6析因交配F 1代杂种为材料,应用ASReml-R软件估算1、2、4.5、8.3和10.3年生时生长性状的遗传力、显性效应、加性效应、亲本效应和配合力等遗传参数;计算每个杂交组合单株材积的平均值,以所有组合的平均值+标准差为标准进行优良杂交组合选择;基于所有单株的材积,采用平均值+2倍标准差(标准Ⅰ)和平均值+3倍标准差(标准Ⅱ)2个标准进行杂种优良单株选择。【结果】尾巨桉F 1代杂种在各年龄时的生长表现均优于对照尾叶桉亲本自由授粉子代。每个年份树高、胸径和单株材积在组合间均存在极显著( P <0.01)或显著( P <0.05)差异,在区组间差异不显著。1年生和2年生时杂种各生长性状的母本加性方差分量低于父本加性方差分量, 4.5年生时父、母本加性方差分量较为接近,8.3和10.3年生时母本加性方差分量则高于父本加性方差分量。随年龄的增长,杂种的树高和胸径单株遗传力呈现由中度至低度遗传控制的变化趋势,杂种家系遗传力呈现高—中—低度遗传控制的趋势,且杂种家系遗传力大于单株遗传力。显性方差与加性方差的比值则随年龄的增长呈递增趋势。年-年和性状-性状双变量遗传、表型呈显著或极显著正相关。4.5年生时,母本U21及父本G8的一般杂交力(GHA)最高,U21×G5组合的特殊杂交力(SHA)最高;8.3年生时,母本U21及父本G19的GHA最高,U2×G19的SHA最高。【结论】尾巨桉F 1杂种1~2年生时父本效应大于母本效应,且加性效应大于显性效应,4.5年生时父、母本效应对杂种生长的贡献率相当,8.3~10.3年生时杂种的母本效应大于父本效应,且显性效应大于加性效应。同时评选出7个优良杂种,筛选出1个优良母本和2个优良父本,并依据标准Ⅰ、Ⅱ分别选出40株和16株优树,为今后大规模人工制种及推广应用提供可靠的亲本材料和优良无性系。     

Sequencing and quantifying plastid DNA fragments stored in sapwood and heartwood of <Emphasis Type="Italic">Torreya nucifera</Emphasis>

The selection of wood species and the styles of sculpture play key roles in the characterization of Buddhist statues. After Jianzhen, a Chinese Buddhist monk, visited Japan in the mid-eighth century, wood of the genus Torreya had been frequently used to produce single-bole statues. Establishing measures for the accurate identification of wood in the genus Torreya is effective for investigating the drastic change in the production of statues during this period. Analyzing the plastid deoxyribonucleic acid (DNA) fragments extracted from wood is considered helpful in the identification of species in the same genus. This study analyzed the sequences and residual amounts of plastid DNA fragments in the wood of Torreya nucifera. Nucleotide substitutions in the plastid DNA were clearly identified between T. nucifera and the species distributed in China, indicating that the wood of Torreya sp. can be discriminated based on the plastid DNA sequences. DNA polymorphism analyses revealed sequence diversity for the intergenic spacers on the T. nucifera plastid DNA. A series of polymerase chain reaction (PCR) analyses demonstrated that the plastid DNA fragments with a length of approximately 100 bp could be amplified from the residual DNA extracted from the T. nucifera sapwood with longer elapsed years after cutting. Therefore, an identification of wood species in the genus Torreya based on their plastid DNA is considered to be one of the most effective measures taken in the study regarding the historical changes of Buddhist statues.     

植物DNA甲基化研究进展

植物经常暴露在各种生物和非生物的胁迫之下,这些胁迫会影响植物的生长发育和繁殖并最终导致植物死亡。为了抵御不利的环境条件,植物已经进化出复杂而精细的网络来感知胁迫并激活防御系统。为此,植物激活许多信号转导通路,这些信号转导通路可以改变一些胁迫响应基因的表达,从而引起植物形态、生理和生化的改变以适应逆境。DNA胞嘧啶甲基化是高等真核生物的主要表观遗传机制之一,在维持基因组稳定性和调节基因表达方面起着关键作用。表观遗传变异比遗传变异更为灵活。一旦环境条件发生变化,为了适应新的环境植物都会发生表观遗传的改变。许多研究表明DNA甲基化参与植物的发育和应激反应。基于相关研究对DNA甲基化进行了综述,对植物逆境胁迫有重要意义。     

核桃早实基因的SCAR标记

根据与核桃早实性状连锁的RAPD标记OPB-08958序列,设计SEA-F/SEA-R和SEB-F/SEB-R2对SCAR引物。在亲本、杂交后代和栽培品种(系)中的检测结果表明:SEA-F/SEA-R引物对在早实亲本‘绿园’中能稳定扩增出SCAR-SEA958特异标记;在‘绿园’ב绿丰’杂交F1后代群体中,SCAR-SEA958标记与核桃早实性状共分离,与核桃早实性状间的遗传距离为1.99cM;用晚实优系‘T-12’和栽培品种‘元丰’及‘T-12’ב元丰’杂交F1后代,检测SCAR-SEA958标记的分离情况,SCAR-SEA958与核桃早实性状共分离;在9个核桃栽培品种(系)中,SCAR-SEA958在8个供试品种的7个早实品种上出现,在1个早实品种‘鲁光’和1个晚实优系‘T-12’上没有扩增出条带。SCAR-SEA958标记在不同遗传背景下有较高的稳定性。     

Effect of parent genotype on somatic embryogenesis in Scots pine (Pinus sylvestris)

Controlled crosses of seven Scots pine (Pinus sylvestris L.) trees produced 49 families that included both reciprocals and selfings. Embryogenic cultures were initiated from immature megagametophytes and after 6 months in maintenance culture, mature somatic embryos were produced from the surviving 166 lines. The effect of parent genotypes on the cultures was evaluated at initiation of the tissue culture period, after 6 months in maintenance culture and at embryo maturation. The effect of the maternal parent was most pronounced at culture initiation. After 6 months in tissue culture, the maternal effect had decreased and the effects of both parents were significant. By the somatic embryo maturation stage, the maternal effect was still considerable but the paternal effect was no longer detectable. There was little correlation between the ranking of mothers and fathers, indicating that the maternal effect was caused by factors other than the paternal effect. No mother x father interaction was found, indicating that mothers successful at initiation and after 6 months in tissue culture, pollinated by any of the successful fathers, produced somatic lines and mature somatic embryos.     

RAPD技术在珍稀濒危植物遗传多样性研究中的应用

生物多样性是现代生态学研究的核心问题和热点之一 ,遗传多样性则是一切多样性的基础和最重要的成分。现代分子生物技术的发展 ,为生物遗传多样性研究提供了许多新的方法 ,其中RAPD技术凭借其自身独特的优势成为这一领域的重要研究手段。珍稀濒危物种遗传多样性的研究 ,有助于实施最佳的保护策略 ,因此具有重要的研究意义。本文阐述了RAPD技术的原理及特点 ,综述了该技术在珍稀濒危植物遗传多样性方面的应用 ,并展望了该技术在珍稀濒危物种研究和保护中的应用前景。