Phylogeny of Malvatheca (Malvaceae) and the Pace and Place of Its Evolution

锦葵科（锦葵科）的系统发育及其进化的速度和地点

• 批准号: 0416096
• 负责人: David Baum
• 金额: --
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0416096&HistoricalAwards=false
• 关键词: Phylogeny; Malvatheca; Malvaceae; Pace; Place

0416096Baum Malvatheca is a group of about 2000 plant species that includes several economically important species (cotton, okra, kenaf, and balsa), united phylogenetically from the traditionally recognized cotton (Malvaceae), cocoa (Sterculiaceae), balsa (Bombacaceae), and linden (Tiliaceae) families on the basis of DNA sequence evidence. Most Malvatheca (more than 1700 species) are members of a group called the Eumalvoideae, which are primarily herbs and shrubs with a worldwide distribution. Prior work by Dr. David Baum and his colleagues suggested that the ancestors of Eumalvoideae were mangroves and coastal treelets that grew in Australasia; but only a handful of living species, the "Australasian grade," have retained this habit and distribution. The previous work also showed that the Australasian grade is likely descended from a group of Central and South American trees, the "Bombacaceous grade." The Eumalvoideae differs from the Australasian and Bombacaceous grade in the number of species it contains and in its extremely rapid molecular evolution (estimated at more than nine-fold that of the Bombacaceous grade). The proposed research, with colleagues Randy Small and Patrick Moss, aims (1) to use DNA sequences of plastid genes and the nuclear gene GBSSI to estimate when the Australasian grade arose, when and where the Eumalvoideae arose, and to shed light on the molecular mechanisms that may have led to accelerated molecular evolution and enhanced species diversification of Eumalvoideae; and (2) to use sequences of both plastid and nuclear DNA data to estimate the phylogenetic relationships within three important groups. These are (2a) Bombacoideae, a group that includes many large trees with spectacular flowers that grow in South and Central America as well as some African and Asian groups (e.g., the baobabs). The study will shed light on how the latter dispersed to Africa/Asia and will also clarify patterns of floral evolution. (2b) Matisieae, a group that includes ecologically significant understory trees from Central and South America. The study will shed light on the group's flower and fruit evolution. (2c) Malagasy Hibisceae, a group of putative relatives of Hibiscus that occur only in Madagascar. The study will resolve their phylogenetic relationships, which remain almost completely unknown, and will clarify when and from whence they arrived in Madagascar.During the funding period the PI will continue teaching a workshop for K-12 teachers on phylogenies ("tree thinking") and will develop new curricular materials for this purpose. He will recruit undergraduate researchers through the University of Wisconsin Undergraduate Research Scholars program, which has a high proportion of minority/financial aid students. Additionally, the researchers will teach a course on modern methods in Madagascar and continue to maintain the Malvaceae pages at the popular Tree of Life website.

[416096] baum Malvatheca是一组大约2000种植物，包括几个经济上重要的物种（棉花、秋葵、红麻和巴尔沙），根据DNA序列证据，在系统发育上与传统上公认的棉花（Malvaceae）、可可（sterculliaceae）、巴尔沙（Bombacaceae）和椴树（Tiliaceae）家族结合在一起。大多数Malvatheca（超过1700种）是umalvoideae的成员，主要是草本和灌木，分布在世界各地。大卫·鲍姆（David Baum）博士和他的同事们之前的研究表明，桉树科的祖先是生长在澳大拉西亚的红树林和沿海小树；但只有少数现存的物种，即“澳大拉西亚级”，保留了这种习性和分布。之前的研究还表明，澳大利亚的树种很可能是中美洲和南美洲的一组树的后裔，即“Bombacaceous grade”。真马科与澳大拉西亚和炸弹科的区别在于它所包含的物种数量和它极快的分子进化（估计是炸弹科的九倍多）。该研究由Randy Small和Patrick Moss共同完成，目的是：(1)利用质体基因的DNA序列和核基因GBSSI来估计澳大拉西亚等级的产生时间、真马科的产生时间和地点，并揭示可能导致真马科分子进化加速和物种多样化增强的分子机制；(2)利用质体和核DNA序列数据来估计三个重要群体之间的系统发育关系。这些是（2a） Bombacoideae，这一组包括许多生长在南美洲和中美洲以及一些非洲和亚洲的大型树木（例如猴面包树），它们有着壮观的花朵。这项研究将阐明后者是如何分散到非洲/亚洲的，也将阐明植物进化的模式。（2b）枫树科，包括中美洲和南美洲具有重要生态意义的林下植物。这项研究将揭示该群体的花朵和果实的进化。（2c）马达加斯加木槿科（Malagasy Hibisceae），一组被认为是木槿的近亲，只生长在马达加斯加。这项研究将解决它们的系统发育关系，这几乎是完全未知的，并将澄清它们何时以及从何处到达马达加斯加。在资助期间，PI将继续为K-12教师讲授系统发生（“树形思维”）讲习班，并为此目的开发新的课程材料。他将通过威斯康辛大学本科研究学者项目招募本科生研究人员，该项目有很高比例的少数族裔/经济援助学生。此外，研究人员将在马达加斯加教授一门关于现代方法的课程，并继续在流行的生命之树网站上维护Malvaceae页面。