AVENACHLOROPLASTS: SPECIES RELATIONSHIPS AND THE OCCURRENCE OF STROMACENTRES

Abstract
An electron microscope survey of 30 species or forms in the genus Avena showed that an aggregate of fibrils, the stromacentre, is a characteristic feature of the chloroplasts of hexaploids, tetraploids and diploids that contain the A. strigosa genome. It does not occur in the diploids of the A. ventricosa group. The possible role of A. magna in the evolution of the hexaploid oats is discussed in relation to this character, which despite being part of the plastid phenotype, must be under the influence of the nucleus.