Untersuchungen zur Sproßvariation der Cupressaceae: 3. Quantitative Auswertung des Scheckungsmusters immerspaltender Periklinalchimären1)

Abstract

The frequency of chimera-dissociation is examined in relation to the quantity of the leafpairs originating from a shoot tip in any ever-sporting periclinal chimeras of the family of Cupressaceae (Juniperus sabina variegata, Juniperus chinensis plumosa argenteo-variegata, Juniperus chinensis plumosa aureo-variegatn, Chamaecyparis thyoidcs variegata, Chamaecyparis nootkatensis argenteo-variegata) . White sports appear extremely rare in the new shoot tips of the axillary buds. Reduplications in L 1 followed by partial or total individualization of the chlorophylldefect tissue hardly take place in this shoot tips. The frequency of the white sports however strongly increases with proceeding distance of the axillary shoot tips from the originating-places measured in the number of the produced leaf-pairs. The morphological findings (origin of the first white sector in hitherto green branches) were confirmed by research of shoot tips in Juniperus sabina variegata : the frequency of periclinal divisions in L 1 increases with the distance of shoot tips from the originating-place. Chamaecyparis pisifera plumosa argentea shows with regard to the origin of white sports distinct differences between top side and bottom side of the dorsiventral raised branches. White sectors originate in the bottom sid more frequently (62%) than in the top side. Periclinal divisions are obviously more frequent in the bottom flank side of L 1 . Well defined differences cannot be established between top side and bottom side of branches in Chamaecyparis lawsoniana argenteo-variegata and Chamaecyparis nootkatensis argenteo-variegata .