Systematic Studies of Perennial Species of Sunflowers (Helianthus)

向日葵属多年生植物的系统研究将遵循两条主要研究路线。其一是利用叶绿体DNA限制酶切点突变分析的数据来阐明几个系统发育问题。这些包括向日葵属与推测有亲缘关系的属的关系，向日葵属下群之间的关系(组.向日葵、纤毛虫和Atrorubentes)，以及两个神秘种H.porteri和H.agrestis的关系。第二条主要研究路线将是利用化学、叶绿体DNA和核糖体DNA限制酶位点分析和同工酶的数据，澄清出现在美国东南部的该属物种中涉及杂交或多倍体的特定情况。该项目的结果将是为向日葵提供一个确切的系统发育图，作为了解该属的生物地理和化学进化等主题的基础，并澄清该属在美国东南部的系统学。

Systematic studies of perennial species of Helianthus will follow two major lines of research. One is to use data from analysis of chloroplast DNA restriction site mutations to clarify several phylogenetic problems. These include the relationship of Helianthus to the putatively related genus, Phoebanthus, the relationships among the infrageneric groups of Helianthus (sects. Helianthus, Ciliares, and Atrorubentes), and the relationships of two enigmatic species, H. porteri and H. agrestis. A second major line of research will be to use data from chemistry, chloroplast DNA and nuclear ribosomal DNA restriction site analysis and isozymes to clarify selected situations that involve hybridization or polyploidy in species of the genus that occur in the southeastern United States. The results of the project will be to provide a firm phylogeny for Helianthus as a basis to understand topics such as biogeography and chemical evolution in the genus, and to clarify the systematics of the genus in the southeastern United States.