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

Malvatheca是一组约2000种植物物种，包括几种经济上重要的物种（棉花、秋葵、洋麻和轻木），基于DNA序列证据，它们与传统上公认的棉花（锦葵科）、可可（梧桐科）、轻木（木棉科）和林登树（椴树科）家族在遗传学上联合。 大多数Malvatheca（超过1700种）是一个名为Eumalvoideae的组的成员，主要是世界各地分布的草本和灌木。 大卫·鲍姆博士和他的同事们之前的研究表明，Eumalvoideae的祖先是生长在澳大拉西亚的红树林和沿海树木;但只有少数现存物种，即“澳大拉西亚级”，保留了这种习性和分布。 先前的研究还表明，澳大拉西亚等级很可能是从一组中美洲和南美洲的树木，“木棉科等级。“Eumalvoideae与澳大利亚和Bombacaceae等级的不同之处在于它包含的物种数量和其极其快速的分子进化（估计是Bombacaceae等级的9倍以上）。 这项研究由Randy Small和帕特里克Moss共同完成，目的是（1）利用质体基因和核基因GBSSI的DNA序列来估计澳大利亚级的出现时间，Eumalvoideae的出现时间和地点，并阐明可能导致Eumalvoideae加速分子进化和增强物种多样性的分子机制;（2）同时利用质体和核DNA序列数据来估计三个重要类群的系统发育关系。这些是（2a）木棉亚科，一个包括许多生长在南美洲和中美洲以及一些非洲和亚洲群体（例如，猴面包树）。 这项研究将揭示后者是如何分散到非洲/亚洲的，也将阐明花卉进化的模式。(2b)紫藤科，一组包括生态重要的林下树木来自中美洲和南美洲。 这项研究将揭示该群体的花和果实进化。(2c)马达加斯加木槿科（Malagasy Hibiscaceae），是木槿属的一个假定的近缘种，仅分布于马达加斯加。这项研究将解决他们的系统发育关系，这仍然几乎完全未知，并将澄清他们何时从何处到达马达加斯加。在资助期间，PI将继续教授K-12教师关于树的讲习班（“树的思维”），并将为此目的开发新的课程材料。 他将通过威斯康星州大学本科研究学者计划招募本科研究人员，该计划的少数民族/财政援助学生比例很高。 此外，研究人员将在马达加斯加教授一门现代方法的课程，并继续在流行的生命之树网站上维护锦葵科的页面。

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.