This press release is available in German.
In a variant of maize known as pod corn, or tunicate maize, the maize kernels on the cob are not 'naked' but covered by long membranous husks known as glumes. According to scientists from the Max Planck Institute for Plant Breeding Research in Cologne and Friedrich Schiller University in Jena, this variant arises from the activity of a leaf gene in the maize cob that is not usually active there. Thus, pod corn is not a wild ancestor of maize, but a mutant that forms leaves in the wrong place.
Pod corn has a spectacular appearance that has fascinated naturalists for two centuries. In this maize variant, the kernels are wrapped in fine glumes which look like thin paper in their dried form and resemble a leaf sheath. The male flowers, which are arranged in a panicle at the end of the stem axis, are also surrounded by long glumes, and sometimes even develop kernels that can otherwise only be found in the cob. The pod corn leaves resemble those of the normal maize plant. Pod corn had a ritual significance for some Native American tribes and can therefore be found throughout the American continent.
The putative significance of pod corn for the domestication of maize has long been a matter of controversy. Some scientists believed pod corn to be a wild, precursor of the varieties with naked kernels common today. Others disagreed with this view and they were right, as we now know. The wild ancestor of today's common maize varieties is not pod corn but the unimpressive sweet grass teosinte.
Heinz Saedler, Gnter Theien and their colleagues have now discovered how the spectacular appearance of pod corn arises. Their findings reveal that this variant has nothing to do with the domestication of maize, but is a mutant that forms leaves in the wrong place. Genetic experiments from the 1950s prov
|Contact: Professor Heinz Saedler|