Diploid and Polyploid Hybridity Throughout the Evolutionary History of Glycine (Leguminosae)

尽管事实上豆类属大豆包括栽培大豆（G. max），但关于其进化历史和分类学关系仍有许多有待了解。 这些包括与一个古老的基因组复制事件，生殖隔离的“基因组组群”之间的关系，其中约25二倍体多年生物种的属属于整个属的起源，以及这些基因组群内密切相关的物种之间的遗传分化的复杂历史。 所有这些问题都有一个共同点，即杂交可能在产生核、叶绿体和线粒体基因DNA变异中所观察到的模式中发挥了作用。 多倍体（多套染色体）和杂交单独或一起异源多倍体，是两个最重要的过程，形成植物的基因组，包括栽培植物，如小麦，玉米，棉花和大豆。 在甘氨酸的情况下，不知道杂交是否参与了多倍体的形成，假设发生在1500万年前，如果是这样，什么物种是两个基因组的供体。 这个问题和其他问题，在逐步更近的阶段，在历史上的甘氨酸，涉及的作用，多倍体和杂交，可以通过研究大量的基因在不同的染色体上或在不同的基因组区室（叶绿体，叶绿体）。 这些基因的最大来源是核基因组，该项目利用大豆和其他豆类的基因组项目（例如，蒺藜苜蓿（Medicago truncatula）为研究提供了许多候选基因。 将评估大约100个核基因在解决系统发育问题中的效用，同时考虑到大豆遗传图谱上的位置等其他标准。 分析方法将包括使用各种方法的同源性重建，评估不一致性，测试多分裂和杂交，网络建设和混合评估。这项工作将解决处理不一致、识别和使用低拷贝核基因以及研究多倍性等一般问题。更好地理解多倍体和杂交，特别是在大豆中，对于植物生物学和遗传学具有广泛的相关性和意义，因为这些现象普遍存在。 该项目将通过培训本科生和研究生以及一名博士后研究员，包括将参加暑期研究实习的少数民族本科生，对科学基础设施产生影响。 与康奈尔大学生物教师研究所的合作将导致为高中和初中学生开发遗传学实验室。 该项目的范围是国际性的，研究人员来自美国和澳大利亚，并涉及在这两个国家以大豆种子收集的形式使用和提高种质资源。

Despite the fact that the legume genus Glycine includes the cultivated soybean (G. max), much remains to be learned about its evolutionary history and taxonomic relationships. These include the origin of the entire genus associated with an ancient genome duplication event, relationships among the reproductively isolated "genome groups" to which the approximately 25 diploid perennial species of the genus belong, and the complex history of genetic differentiation among closely related species within these genome groups. All of these issues have in common the possibility that hybridization has played a role in producing the patterns observed in DNA variation from nuclear, chloroplast, and mitochondrial genes. Polyploidy (multiple sets of chromosomes) and hybridization separately, or together in allopolyploidy, are two of the most important processes that shape the genomes of plants, including cultivated plants such as wheat, maize, cotton, and soybean. In the case of Glycine it is unknown whether hybridization was involved in polyploid formation, as hypothesized to have occurred 15 million years ago, and if so, what species were the donors of the two genomes. This and other questions at progressively more recent stages in the history of Glycine that involve the role of polyploidy and hybridization can be addressed by studying a large number of genes on the different chromosomes or in different genomic compartments (mitochondrion, chloroplast). The largest source of such genes is the nuclear genome, and this project taps genomic projects in soybean and other legumes (e.g., Medicago truncatula) to provide many candidate genes for study. Around 100 nuclear genes will be assessed for their utility in addressing phylogenetic questions, taking into account such additional criteria as position on the soybean genetic map. Analytical methods will include phylogeny reconstruction using various approaches, assessment of incongruence, testing for polytomies and hybridity, network construction, and admixture assessment. The work will address general issues of dealing with incongruence, identifying and using low copy nuclear genes, and studying polyploidy. Achieving a better understanding of polyploidy and hybridization in general, and particularly in Glycine, is of broad relevance and significance for plant biology and genetics because of the prevalence of these phenomena. The project will have an impact on the infrastructure of science by training undergraduate and graduate students and a postdoctoral fellow, including minority undergraduate students who will participate in summer research internships. Collaboration with the Cornell Institute for Biology Teachers will lead to the development of phylogeny laboratories for high school and middle school students. The project is international in its scope, with researchers from the United States and Australia, and involves the use and enhancement of germplasm resources in the form of Glycine seed collections in both countries.