KORN, ROBERT W. Department of Biology, Bellarmine College, Louisville, KY 40205. - Developmental leaf spots.
Patterning of leaf spots was analyzed in the pond lily (Nymphaea
oradrata Ait.) and the spotted dracaena (Dracaena godseffiana
Sander) and compared to that in the maize(Zea mays
)aleurone from reverse transposition. Aleurone sectors are clearly
cell lineages because (a) the number of cells follows expected
geometric distribution when sizes, as log 2 number of cells, of
lineages are plotted against frequency and (b) the shapes are somewhat
quadrilateral. Red spots on the pond lily leaf also follow a pattern
expected of cell lineages by the shape of the areas, however, their
frequencies of sizes of spots unexpectedly follow a normal
distribution. These red-celled clones come from a daughter cell with
an oriented specialized cell plate. By contrast, the yellow regions of
the spotted laurel are circular instead of quadrilateral suggesting
they do not come from a cell lineage process but by diffusion of a
chloroplast inhibitor from a central source cell.
Key words: clones, leaf, mosaic, motlling, pattern