REU: Molecular Reassessment of Introgression Among Annual Helianthus Species (Asteraceae)

50多年来，渐渗在植物进化中的作用一直是人们强烈兴趣和研究的主题。导入是通过杂交和重复回交将基因从一个物种转移到另一个物种。渐渗的经典例子使用形态特征作为这一过程的证据。由于很难用特定的基因来解释形态数据，这些研究只是初步估计了渐渗作为植物进化机制的意义。Loren Rieseberg博士将应用强大的蛋白质和DNA分析的新分子方法来测量可能杂交的植物种群和物种之间的基因流动。向日葵的一年生物种向日葵是研究渗透的理想类群，因为这些植物已经有了广泛的形态和细胞学数据库。此外，进化论者经常引用这一群体的成员作为内向的杰出例子。Rieseberg博士的项目的目标是：1)利用蛋白质(等位酶)和DNA证据确定一年生向日葵中渗透的意义；2)建立向日葵组11种植物基于DNA的系统发育；3)建立植物渗透的一般分子分析方法。

The role of introgression in plant evolution has been the subject of intense interest and speculation for over fifty years. Introgression is the transfer of genes from one species to another through hybridization and repeated backcrossing. The classic examples of introgression have used morphological features as evidence of this process. Because of difficulties interpreting morphological data in terms of specific genes, these studies have provided only tentative estimates of the significance of introgression as an evolutionary mechanism in plants. Dr. Loren Rieseberg will apply powerful new molecular methods of protein and DNA analyses to measure gene flow among populations and species of presumptively hybridizing plants. The annual species of sunflower, Helianthus, are an ideal group for studying introgression because of the extensive morphological and cytological data base already available for these plants. Furthermore, evolutionists frequently cite members of this group as outstanding examples of introgression. The objectives of Dr. Rieseberg's project are: 1) to determine the significance of introgression among the annual sunflowers using protein (allozyme) and DNA evidence; 2) to construct a DNA-based phylogeny for the 11 species of section Helianthus; and 3) to establish a general methodology for the molecular analysis of introgression in plants.