KORN, ROBERT. Bellarmine College, Louisville, Ky.. - Analysis of Shoot Organization in Six Species of the Cupressaceae Based on Chimerical Behavior.
Six species of the Cupressaceae, the variegated Leyland cypress
(Cupressocyparis leylandii), davurian juniper (Juniperus javurica),
savin (Juniperus 'expansa variegata), California incense cedar
(Calocedrus decurrens), American arbor vitae (Thuja occidentalis
'lutae zebrina) and the sawara false cypress (Chamaecyparis pisifera
'nana aureovariegata') were examined for the behavior of albino-green
shoots.The fate of the variegations in these six plants is the same in
two important respects. First, the majority (89%) of sprays with the
original sector become completely yellow. Second, sectorial branch
sprays of the original sectorial sprays become either completely green
or yellow in a 1:1 ratio. Based on the first finding, it is concluded
that there is one rather than two to four apical initials in the shoot
apex as generally postulated. The second finding demonstrates there is
no selection for either type, a feature postulated by others. This
single apical initial, or apical cell, is a member of a cell lineage
that forms sectors while persisting throughout the life of the
shoot.cell
Key words: apical cells, chimeras, conifers