A histological study of lateral root initiation and development inZea mays

Summary A light microscopic study has been made of the origin and development of lateral roots inZea mays.The initiation of a lateral occurs adjacent to a xylem pole and involves an increase in cytoplasmic basophilia and subsequent divisions of cells of the pericycle and the parenchyma of the stele of the mother root.Cells derived from the parent pericycle form most of the young lateral but its epidermis and root cap are composed of cells of endodermal origin.Two different types of polysaccharides are secreted by cells of the young lateral root. One type which is PAS-positive and non-metachromatic, is produced by the epidermal cells, while the other type, metachromatic and only slightly PAS-positive, is secreted by the root cap cells.