蜡梅插花及盆景制作研究

蜡梅(wintersweet)是中国的传统名花,蜡梅插花及蜡梅盆景深受大众喜爱,具有较高的研究价值。通过对蜡梅插花及蜡梅盆景实地调研和文献分析,归纳出蜡梅插花的三种形式为单插、束插和配插,蜡梅盆景有小盆栽蜡梅、造型蜡梅和古桩蜡梅三种类型,针对蜡梅插花花期短等问题,提出了研制增加蜡梅插花时限的制剂等相应措施,也提出了蜡梅盆景资源合理利用的建议,对蜡梅插花和盆景制作有一定的借鉴指导作用。     

DNA标记技术在冬虫夏草遗传多样性研究中的应用

随着实验方法和研究技术的发展,遗传多样性的研究从形态学水平,细胞学水平,生化水平发展到了DNA分子水平。利用这些分析方法,我们可以有效地研究物种的遗传多样性。通过冬虫夏草分子标记技术的遗传多样性研究,可获取冬虫夏草DNA的遗传标记及检测方法,有效的鉴别其品种和产地,以及在分子水平上研究冬虫夏草的遗传多样性。     

红树植物桐花树遗传多样性研究进展

遗传多样性作为生物多样性的重要组成部分,是生态系统多样性和物种多样性的基础.桐花树是热带亚热带海岸红树林树种中的广布种之一,研究其遗传多样性具有重要的理论和实践意义.等位酶,ISSR、RAPD和AFLP等分子标记已用于桐花树的遗传多样性研究中.综述了此方面的研究进展.总体而言,桐花树在物种和种群水平上具有较高的遗传变异水平.     

中国蝗虫生物多样性研究进展

生物多样性研究层次主要有物种多样性、遗传多样性、生态系统多样性和景观多样性。中国蝗虫生物多样性研究已经由物种多样性研究进入遗传多样性研究层次，生态系统多样性和景观多样性研究几乎处于空白。中国蝗虫物种多样性的研究于20世纪50年得到了注意，全国各地的研究进展不平衡，西部地区研究比较全面、深入，蝗虫资源基本清楚。遗传多样性研究由细胞水平（染色体）转入分子水平的研究，细胞水平研究相对较深入。     

分子生物学技术在根瘤菌遗传多样性研究中的应用

遗传多样性作为多相分类的主要手段,在根瘤菌的分类和多样性研究中备受关注.随着根瘤菌寄主研究范围的不断扩大和分子生物学技术的不断应用,根瘤菌的遗传多样性特征将得到更深入的揭示.本文综述了根瘤菌遗传多样性的组成、研究现状及研究方法进展,以期为细菌分类工作者提供一定的研究依据.     

“腊梅”为何改成“蜡梅”

近日读《山东教育》2004年第6期,在“各抒己见”栏目中,薛炳群老师在《腊梅·蜡梅》一文中就究竟是“腊梅”还是“蜡梅”提出了自己的观点。笔者查阅《新华词典》,发现“腊梅”条中仅有“腊梅,一作蜡梅”,而解释词义则是放在“蜡梅”词条中。可见,“腊梅”与“蜡梅”这两种写法都不能算错。那么,苏教版教材为什么把“腊梅”改成“蜡梅”呢?蜡梅一名不知源于何时,据有关资料记载,最晚应在唐代。唐代诗人崔道融有诗云:“故里琴尊侣,相适近蜡梅。”杜牧也有诗“蜡梅还见三年花。”蜡梅为什么称蜡梅呢?宋代任渊在《黄庭坚诗序》里说:“香气似梅…     

作物遗传多样性的保护和持续利用

由于长期不合理的利用，造成作物品种单一，遗传特性趋于一致，作物资源陷入枯竭，因此必须加大保护作物遗传多样性的力度。章阐明了遗传特性趋同所带来的危害，着重探讨了保护作物遗传多样性的方法以及保护和利用的关系。     

作物遗传多样性的保护和持续利用

由于长期不合理的利用，造成作物品种单一，遗传特性趋于一致，作物资源陷入枯竭，因此必须加大保护作物遗传多样性的力度。本阐明了遗传特性趋同所带来的危害，着重探讨了保护作物遗传多样性的方法以及保护和利用的关系。     

IRAP分子标记技术在遗传学实验教学中的应用

遗传学实验教学中,物种遗传多样性分析是对遗传学知识的实际应用。该实验利用IRAP分子标记对贵州火龙果核心种质遗传多样性进行评价,实验内容包括植物DNA提取和检测、PCR扩增、凝胶电泳检测和遗传多样性分析等,实验结果可揭示火龙果种质间的遗传关系。作为开放性综合实验,本实验训练了本科生分子遗传学实验技能,培养了学生综合运用遗传学知识探索科学问题的能力,提升了学生科研思维和创新能力。     

“蜡梅”不是“腊梅”亦非梅花

翻阅一些资料,发现将「蜡梅」作「腊梅」者很是普遍,甚或将蜡梅与梅花等同者.中国是蜡梅的故乡。世界上目前已知的蜡梅有两个属,一在北美(主要是少量的夏蜡梅);一在中国。按植物学分类划分,蜡梅属蜡梅科。《辞海》,关于「蜡」条的释文中有「淡黄如蜡的     

温度胁迫对蜡梅种子萌发的影响

在室内条件下,初步探究了温度对蜡梅种子萌发的影响.结果表明:(1)蜡梅种子千粒重为212.094±4.168 g.种壳限制蜡梅种子吸水进程,有种壳,浸种96 h,吸水率不足8%,去除种壳,10 h内,吸水率达80.2%.(2)四个温度处理下,萌发率(%)大小为:25℃(78.33)>15℃(77.5)>30℃(55)>4℃(0),4℃下,萌发率为0,15℃种子基本能正常萌发,但萌发活力指数下降,25℃下,种子萌发率,发芽势,活力指数最高,萌发速率最快,30℃下,萌发率显著下降.(3)根TTC还原活力(mg/g/h)比较:25℃(0.5348)>15℃(0.4361)>30℃(0.3318),温度对幼苗鲜、干重、含水量无显著影响,对胚根长度影响显著.可见,种壳限制蜡梅种子吸水,进而影响其萌发.低温限制蜡梅种子萌发,在一定范围内,降温对蜡梅萌发影响不大,高温则延迟萌发,且降低蜡梅种子萌发速度和质量,蜡梅萌发适合的温度在25℃左右.     

Species-specific SCAR markers for authentication of Sinocalycanthus chinensis

INTRODUCTION Calycanthaceae consists of three genera: Caly-canthus, Chimonanthus and Sinocalycanthus. Chi-monanthus and Sinocalycanthus are restricted toChina, and Calycanthus is distributed in NorthAmerica (Zhang and Liu, 1998). Sinocalycanthuschinensis Cheng et S.Y. Chang, the only representa-tive in the genus Sinocalycanthus, is a deciduousshrub endemic to China. Both biological and an-thropological causes have led to the recent decline ofthe species, which is now known from onl…     

A genetic diversity comparison between captive individuals and wild individuals of Elliot＇s Pheasant （Syrmaticus ellioti） using mitochondrial DNA

Maintaining genetic diversity is a major issue in conservation biology. In this study, we demonstrate the differences of genetic diversity levels between wild and captive individuals of Elliot‘s Pheasant Syrmaticus ellioti. Wild individuals showed a higher genetic diversity level than that of the captive individuals. Nucleotide diversity and haplotype diversity of wild individuals were 0.00628 and 0.993, while those of captive individuals were 0.00150 and 0.584 respectively. Only 3 haplotypes of mtDNA control region sequence were identified among 36 captive individuals, while 16 unique haplotypes were identified among the 17 wild individuals in this study. One captive haplotype was shared by a wild individual from Anhui Province. It is concluded that a low number of founders was the likely reason for the lower level genetic diversity of the captive group. Careful genetic management is suggested for captive populations, particularly of such an endangered species, to maintain genetic variability levels.     

河北汉族、蒙族、满族三民族8对遗传性状基因频率分析

目的 :为了探讨遗传性状与种族差异之间的相关性。方法 :采取统一发表 ,在老师的配合下根据吴汝康等人的“人体测量法”对河北汉、蒙、满三民族共 74 6人的 8对遗传性状进行了调查。结果 :计算出每对性状的出现率和基因频率 ,分析三民族之间的差异 ,并且与我国其它民族进行了比较。结论 :不同种族遗传性状有明显不同 ,在进化过程中不同种群形成了不同的基因库。     

Word reading and reading comprehension: stability, overlap and independence

Longitudinal twin data were analyzed to investigate the etiology of the stability of genetic and environmental influences on word reading and reading comprehension, as well as the stability of those influences on their relationship. Participating twin pairs were initially tested at a mean age of 10.3 years, and retested approximately five years later. Both word reading and comprehension were found to be highly stable, and genetic influences were primarily responsible for that stability. In contrast to studies with younger participants, no unique genetic influences were observed at follow-up testing in this older sample. High genetic correlations were obtained between word reading and reading comprehension at both ages, indicating common genetic influences. However, significant genetic influence on comprehension was also observed, independent of that on word reading. Although the phenotypic relation between the two measures appeared to decline across time, the genetic etiology of this relation was highly stable.     

Confirmatory factor analysis of word recognition and process measures in the Colorado Reading Project

Measures of word recognition (REC) and two component skills, phonological coding (PHON) and orthographic coding (ORTH), were subjected to multivariate behavioral genetic analysis. Data were obtained from a sample of identical and fraternal twin pairs wherein at least one member of each pair was reading disabled (RD), and from a sample of twins wherein both members of each pair read in the normal range. Confirmatory factor analysis was used to fit the genetic, common environmental, and specific environmental covariance components for REC, PHON, and ORTH within the RD and normal simples. The resulting heritability estimates for REC, PHON, and ORTH were 0.59, 0.41, and 0.05 in the RD sample, and 0.35, 0.52, and 0.20 in the normal sample. After dropping the nonsignificant common environment parameters from the models, the genetic correlations between REC and PHON and between REC and ORTH were respectively 0.81 and 0.45 in the RD sample, and 0.68 and 0.45 in the normal sample. Differences between the genetic correlations were significant in the RD sample (p<0.005), marginally significant in the normal sample (p<0.10), and highly significant in the combined sample (p<0.001), indicating that genetic influences on individual differences in REC are more strongly related to genetic variance in PHON than in ORTH. These results are consistent with previous demonstrations of substantial genetic covariance between the disabled group's deficits in REC and PHON, but not between REC and ORTH (Olson et al., 1989; Olson and Rack, 1990).     

A Twin-Sibling Study of Observed Parent-Adolescent Interactions

Numerous behavioral genetic studies call attention to the strong and pervasive genetic influence on developmental characteristics. However, this research has been criticized for its use of poor environmental measures and a failure to examine the complex processes that are a hallmark of research in child development. This study addresses this criticism by examining the genetic and environmental components of parent-child interactions. Mother, father, and 2 adolescent siblings (10–18 years) from each of 675 families were observed interacting in 10-min dyadic problem-solving sessions. 6 groups of siblings that differed in genetic relatedness were examined (MZ and DZ twins, full siblings in nondivorced families; full, half, and unrelated siblings in stepfamilies). Results suggest a greater genetic component to adolescent behavior than to parent behavior. Both adolescent and parent behavior showed strong effects of nonshared environment, even after error of measurement was removed.     

Sources of continuity and change in activity level in early childhood

Actigraphs and parent and observer ratings were used to explore genetic influences on continuity and change in activity level (AL) in early childhood. Over 300 pairs of twins wore actigraphs for a 48-hr period in the home and laboratory at ages 2 and 3. AL was genetically influenced at both ages with little evidence of differential heritability across age. For all measures, genetic influences contributed to phenotypic continuity. With the exception of the actigraph measure of AL in the home, new genetic effects emerged at age 3 indicating that genetic factors influence both continuity and change in AL in early childhood. Nonshared environmental influences were also a source of change in AL across the transition from infancy to early childhood.     

A Knowledge Base for Teaching Biology Situated in the Context of Genetic Testing

Recent developments in the field of genomics will impact the daily practice of biology teachers who teach genetics in secondary education. This study reports on the first results of a research project aimed at enhancing biology teacher knowledge for teaching genetics in the context of genetic testing. The increasing body of scientific knowledge concerning genetic testing and the related consequences for decision-making indicate the societal relevance of such a situated learning approach. What content knowledge do biology teachers need for teaching genetics in the personal health context of genetic testing? This study describes the required content knowledge by exploring the educational practice and clinical genetic practices. Nine experienced teachers and 12 respondents representing the clinical genetic practices (clients, medical professionals, and medical ethicists) were interviewed about the biological concepts and ethical, legal, and social aspects (ELSA) of testing they considered relevant to empowering students as future health care clients. The ELSA suggested by the respondents were complemented by suggestions found in the literature on genetic counselling. The findings revealed that the required teacher knowledge consists of multiple layers that are embedded in specific genetic test situations: on the one hand, the knowledge of concepts represented by the curricular framework and some additional concepts (e.g. multifactorial and polygenic disorder) and, on the other hand, more knowledge of ELSA and generic characteristics of genetic test practice (uncertainty, complexity, probability, and morality). Suggestions regarding how to translate these characteristics, concepts, and ELSA into context-based genetics education are discussed.     

Mathematical ability of 10-year-old boys and girls: genetic and environmental etiology of typical and low performance

The genetic and environmental etiologies of 3 aspects of low mathematical performance (math disability) and the full range of variability (math ability) were compared for boys and girls in a sample of 5,348 children age 10 years (members of 2,674 pairs of same-sex and opposite-sex twins) from the United Kingdom (UK). The measures, which we developed for Web-based testing, included problems from 3 domains of mathematics taught as part of the UK National Curriculum. Using quantitative genetic model-fitting analyses, similar results were found for math disabilities and abilities for all 3 measures: Moderate genetic influence and environmental influence were mainly due to nonshared environmental factors that were unique to the individual, with little influence from shared environment. No sex differences were found in the etiologies of math abilities and disabilities. We conclude that low mathematical performance is the quantitative extreme of the same genetic and environmental factors responsible for variation throughout the distribution.