Pollen Ultrastructure in Anther Cultures ofNicotiana tabacum

Open Access
Publisher Website
Google Scholar
Abstract
Ultrastructure of embryogenic tobacco pollen was examined at the first division of the vegetative cell. Structurally empty zones formed before division by the degradation of gametophytic cytoplasm were rapidly re-populated with ribosomes, mitochondria, dictybsomes, and organelles interpreted as lipid centres. The latter appeared to be active in synthesis, and were associated with a vesicular component. Starch accumulation also began at the first division in plastids carried over from the mother cell. Each daughter cell possessed a typical primary wall confluent with the inner layers of the intine. Plasmodesmata traversed the wall between the two cells. The cells were either equal or unequal; equal divisions occurred in both the longitudinal and transverse planes. In many proembryoids, the generative cell showed signs of degeneration. The cell was either attached to the intine or detached from it. Detached cells sometimes divided. The data, are discussed in relation to other embryogenic and morphogenic systems induced from normally quiescent or highly differentiated cells.

This publication has 0 references indexed in Scilit: