Systematic Studies of Viguiera and Related Genera (Asteraceae)

在新一轮的新热带向日葵大属分类研究中，田纳西大学的爱德华·席林博士将在墨西哥和阿根廷进行田野工作，收集样本，进行深入的形态和分子特征分析，这对划分物种和评估与其他向日葵属的亲缘关系很有用。对叶绿体DNA突变的初步分析表明，限制位点图谱将特别有用。分子数据提供的系统发育框架将允许对该群体的几个墨西哥和中南美洲血统的形态和染色体变化进行严格研究。此外，席林博士还将能够测试，是一次墨西哥祖先的迁徙，还是多次迁徙，最能解释南美洲安第斯山脉相关物种的多样性。

In renewed taxonomic studies of the large neotropical genus of sunflowers Viguiera, Dr. Edward Schilling of the University of Tennessee will conduct field work in Mexico and Argentina to amass samples for intensive morphological and molecular analyses of characters useful in delimiting species and in assessing relationships with other sunflower genera. Preliminary analysis of mutations in chloroplast DNA demonstrates that restriction- site mapping will be especially informative. The phylogenetic framework provided by the molecular data will then permit rigorous study of morphological and chromosomal changes in the several Mexican and Central-South American lineages of the group. Also, Dr. Schilling will be able to test whether a single migration from ancestral Mexican stock or multiple migrations best explains the diversity of related species in Andean South America.