查询词典 genetic

Chapter 8 presents a new method to solve file allocation problem based on genetic algorithms.

文件分配问题是计算机网络和分布式系统中一个非常重要的问题。

Alfalfa (Medicago sativa L.) belongs to the typical allogamy, and the sampling strategies are closely related to its molecular genetic diversity analysis.

紫花苜蓿为异花授粉植物，其DNA多态性研究的取样策略与遗传多样性分析直接相关。

During the postgenomics era the information about genomic sequence and gene functions provides a new foundation for evolutionary biology and ecology As the first whole-genome sequenced plant Arabidopsis thaliana and its wild relatives have played a critical role in understanding the evolution of genomics and speciation Both A halleri and A lyrata are closely related to the model species A thaliana A halleri ssp gemmifera occurs in northeastern China Japan and Taiwan; while its sister A halleri ssp halleri is mainly distributed in Europe Geographical barriers such as Tienshan Mountain Range isolate these intraspecific sisters Likewise A lyrata ssp kamchatica and ssp lyrata occur in East Asia and North America respectively Such distribution patterns seem to be consistent with allopartic speciation The comparison between ancestral and extant polymorphism by multilocus can be informative about the population genetics of speciation In this study we collected and analyzed DNA sequences of 98 genes from four wild relatives of A thaliana A halleri ssp gemmifera A halleri ssp halleri A lyrata ssp kamchatica and A lyrata ssp lyrata The ancestral states of these four species were compared to each other in terms of level of genetic variation However the ancestral species at the time of speciation were substantially more polymorphic than the extant geographical populations The observations are not fully compatible with speciation by strict allopatry At some species pairs parapatric speciation seems more reasonable in speciation of Arabidopsis The 98 gene sequences are also used for the congruence test between gene genealogy and species phylogeny Only 28 genes support the species phylogeny but there are 23 genes supports another major genealogy { lyrata} thaliana Based on the phylogenetic position change of A lyrata ssp kamchatica and Ks value for each species pair suggested the recent directional gene flow between A halleri ssp gemmifera and A lyrata ssp kamchatica

阿拉伯芥是第一个完成基因体定序的开花植物，其基因体资讯提供植物学研究的重要依据；在解析阿拉伯芥属物种的亲缘关系以及种化机制等重要的演化议题时，阿拉伯芥近缘的野生物种自然成了不可或缺的关键；跟阿拉伯芥近缘的物种包括A halleri及A lyrata，其中A halleri ssp gemmifera主要分布於中国东北、日本以及台湾，与近缘的A halleri ssp halleri其分布於欧洲隔著天山及大陆的障蔽，而A lyrata ssp kamchatica主要分布於东北亚及台湾，与分布於北美五大湖的A lyrata ssp lyrata被北极圈所分隔，这样的分布模式暗示异域种化的可能。藉由多基因分析比较祖先物种与现生物种遗传歧异度的相关可提供讯息探讨种化时期的族群遗传结构，本研究针对A halleri ssp gemmifera、A halleri ssp halleri及A lyrata ssp kamchatica、A lyrata ssp lyrata四个物种，两对互为亚种的姊妹群，以阿拉伯芥为外群进行研究，在四个物种完成98个同源基因的分子序列，利用套装软体MCMCcoal来估算祖先物种的遗传变异，亦估算现生物种的核苷酸歧异度，观察到？多物种配对中祖先物种遗传多型性大於现生物种DNA歧异度，显示异域种化模型并无法完全解释阿拉伯芥属物种的种化模式，在某些物种配对间邻域种化模式应比异域种化更为可能；在基因树与物种树的比较，98个基因片段的亲缘模式只有28个是与已知物种树一致的，有23个基因其树状图支持{ lyrata} thaliana的型式，藉由kamchatica位置的变化以及估算各物种配对间的平均同义置换率，推测在A halleri ssp gemmifera与A lyrata ssp kamchatica间具有近代的单方向基因交流。

Allopolyploid played an important role in crop genetic and germplasm enhancement.

异源多倍体在作物遗传改良和种质创新中发挥着重要的作用。

Recent studies indicate that extensive genetic and epigenetic changes often occur at the early stage of allopolyploid\'s genome formation,these changes have played a significant role in stabilization of newly formed genome of species.

研究表明，异源多倍体在形成的早期会出现广泛的基因组遗传和表观遗传变化，这些变化直接关系到物种的形成和稳定。

The research progress on synthetic allopolyploid including type, inducement method and utilization status in crop genetic improvement were summarized, and the feasibility and importance for using it to improve crop varieties were discussed. Finally, the existing problems in relevant researches were analyzed, and the future studies were prospected.

概述了近年来植物人工异源多倍体的研究进展，包括人工异源多倍体的类型、诱导方法及其在植物遗传改良中的应用现状，探讨了利用人工异源多倍体进行农作物品种遗传改良的可行性和重要性，并对相关研究中的问题进行了分析和展望。

Discussions are given of the fate of Ms2 during translocation in the hexoploid triticale, the exchange of the names for 4A and 4B chromosomes in common wheat and the possible expoitation of the new locus Ms2 (4BS), and the following speculations are made: In geneic genes of allopolyploid organisms the donor chromosomes tend to be intergenomically translocated to their phylogically and evolutionarily close chromosomes with the same order number and the same arm; it is cofirmed that the 7th International Conference of Wheat Genetics was right to exchange the names between chromosomes 4A and 4B of common wheat in 1988; and as a new genetic marker and a breeding tool for all the chromosome B-carrying species in the tribe of Tritceae, Ms2 (4BS) may have wide application in building and expanding the gene pool of germplasm resources of various species of wheat.

对 Ms2基因在六倍体小黑麦与原太谷核不育小麦远缘杂交中易位时的走向，普通小麦4A与4B染色体的互换更名以及 Ms2(4BS)新位点的开发利用进行了讨论：认为异源多倍体生物核基因的组间易位倾向于从供体染色体向进化亲缘关系较密切，且染色体序数与染色体臂相同的部分同源染色体易位；1988年第7届国际小麦遗传学会对普通小麦4A与4B染色体的互换更名是正确的； Ms2(4BS)作为一个新型的遗传标记，作为小麦族内所有携带B染色体组的物种的育种工具和在拓建各类小麦种质资源的基因库等方面均有广泛的用途。

Recent records show that the Grand Masters were seeded with biological agreements to send their genetic knowledge to Orion and Alpha Centauri; these agreements were triggered the moment that they chose to ascend out of the distortion that they had gone into.

近期记录显示，大师是带着将他们的基因知识送给猎户座和半人马α星的生物协议而被播种的；这些协议在他们选择来提升出所进入的扭曲时被触发。

Alternaria alternata isolates from different places in Yunnan province were analyzed for genetic diversity by using Random Amplified Polymorphic DNA.

运用RAPD分子标记技术分析了来自云南各地24个烟草赤星病菌株的遗传多样性。

In plants and algae that undergo alternation of generations, a gametophyte is the multicellular structure, or phase, that is haploid, containing a single set of chromosomes, and has its own information on genetic expression.

在植物世代交替的生活史中，配子体是产生配子和具有单倍数染色体的植物体，并且有自己的遗传表达信息。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。