Collaborative Research: Systematic Analysis of Evolutionary Radiation of Eupatorieae (Asteraceae)

田纳西大学的Edward Schilling博士与德克萨斯大学的Jose Panero博士合作进行的这项研究将分析菊科（向日葵）部落Eupatorieae的系统关系和系统发育历史。该部落包括园艺物种，如甜叶和火星草，以及有毒杂草，如暹罗杂草和克罗夫顿杂草。对它进行系统研究特别有兴趣，因为它有大量的物种（超过2400种）和广泛的分布，主要是在新大陆，但似乎是相对较近的起源。新信息的主要来源将是叶绿体基因组的DNA序列数据，将从代表140个属的180个样本中获得超过10,000个碱基对的序列数据。每个样本核糖体区域的核DNA序列总计约1100个碱基对也将获得。对这些广泛数据集的评估将依赖于基于计算机的方法，包括简约分析，以产生显示部落成员之间关系的系统发育（“家谱”）。将这棵树与其他来源的数据进行比较，以帮助了解导致该部落物种多样性的形态或染色体变化的时间和顺序。该系统发育树还将为解决有关拟鸟属和亚族分类的争议问题提供依据。结果将是一个更稳定和可预测的分类，并将确定单系群体，这可以成为未来分类研究的目标，以澄清部落的整体生物多样性。这项研究将通过增加关于菊科的公共基线信息，培训和教育学生，以及应用于关于菊科的资源，产生广泛和持久的影响。为收集植物材料而进行的广泛的野外工作，其中大部分是在受到人类入侵威胁的热带和亚热带地区进行的，将通过科学收藏的凭证标本沉积来记录。DNA序列研究的结果将存入GenBank，这是一个可供其他研究人员免费访问的公共数据库。研究生参与研究将提供一个庞大而广泛的家庭的基本系统分类以及分子系统发育的实验室和分析程序方面的培训。该项目还将为本科生提供参与研究的机会，并将与McNair计划等倡议协调，以面向历史上在科学研究中代表性不足的群体的学生。这项研究的新科学发现，包括对翼上鸟科分类的调整，将在同行评议的期刊上发表。通过扩大基于网络的资源，广泛提供有关Asteraceae的系统分类和系统发育关系的信息，将实现信息的更广泛传播，使用包括图像和图形在内的格式，使公众能够访问和理解这些信息。

This collaborative research by Dr. Edward Schilling at the University of Tennessee with colleague Dr. Jose Panero from the University of Texas will analyze the systematic relationships and phylogenetic history of the Asteraceae (sunflower) tribe Eupatorieae. The tribe includes horticultural species such as sweetleaf and blazingstar, as well as noxious weeds such as Siam weed and Crofton weed. It is of particular interest for systematic studies because it has a large number of species (over 2400) and a widespread, primarily New World distribution, yet appears to be of relatively recent origin. A primary source of new information will be DNA sequence data from the chloroplast genome, and more than 10,000 base pairs of sequence data will be obtained from each of 180 samples representing 140 genera. Nuclear DNA sequences of the ribosomal regions totaling about 1,100 base pairs per sample will also be obtained. Assessments of these extensive data sets will rely on computer-based methods, including parsimony analysis, to produce a phylogeny ("family tree") that shows the relationships among members of the tribe. Comparison of the tree with data from other sources will be done to help understand the timing and sequence of morphological or chromosomal changes that have led to the species-level diversity of the tribe. The phylogenetic tree will also provide the basis to resolve contentious issues regarding the generic and subtribal classification of Eupatorieae. The result will be a more stable and predictive classification, and monophyletic groups will be identified that can be a target for future taxonomic studies to clarify the overall biodiversity of the tribe. This research will have broad and lasting impacts through its additions to the body of publicly available baseline information about Eupatorieae, training and education of students, and applications to resources about the family Asteraceae. The extensive fieldwork, much of it in tropical and subtropical areas that are actively threatened by human encroachment, to collect plant material will be documented by deposition of voucher specimens in scientific collections. Results of DNA sequence studies will be deposited at GenBank, a public database that is freely accessible by other researchers. Participation of graduate students in the research will provide training in basic systematics of a family that is large and widespread as well as in the laboratory and analytical procedures of molecular phylogenetics. The project will also provide opportunities for undergraduates to participate in research, and will coordinate with initiatives such as the McNair Program to target students from groups historically underrepresented in science research. New scientific findings from the research, including adjustments to the classification of Eupatorieae, will be documented by publication in peer-reviewed journals. Broader dissemination of the information will be accomplished by expansion of web-based resources to make information about systematics and phylogenetic relationships of Asteraceae widely available, using formats including images and graphics that make it accessible and understandable to the general public.