Nicotiana chloroplast genome

The chloroplast DNA restriction fragment patterns of several higher plants from different classes, subclasses, orders, and families were examined. Regardless of the restriction enzyme used, there were few similarities among these restriction patterns. Within the genus Nicotiana, however, most of the restriction fragments were common to all species examined. The few uncommon fragments remaining were distributable with respect to the taxonomic classification of Nicotiana species. Estimates of divergence between selected families, genera, and species were obtained using data gathered from several restriction enzyme patterns.