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CHANGE OF LEAF CHARACTERS AND READINESS TO FLOWER IN A SINGLE TREE PROGENY OF CHAMAECYPARIS PISIFERA (SIEB. ET ZUCC.) K. KOCH
Plumosa Aurea have been observed for six years and eight months after seed germination.
During this period, leaf form has been assessed at irregular intervals.
According to the different development of leaf characters different groups of individuals could be ascertained: 22 individuals had a significant squarrosa-form (sr) (so-called juvenile form) which did not show any changes during the time of observation.
Forty-two individuals changed their leaves from the sr-form of the seedlings to a squarrosa-plumosa-form within 75 months; six individuals with a distinctive plumosa-character changed their appearance within 50 months after germination and the 16 squammosa-types reached this so-called adult form within 25 months after the seed had germinated.
So an influence of the age of tree on the leaf characters of the seedlings could be proved only for the squarrosa-plumosa-and plumosa-types, but none of these groups entered the squammosa-form within the observation time.
These leaf characters are closely related to a significant flowering readiness under influence of gibberellic acid in squarrosa-plumosa-and plumosa-types and to frost sensitivity, high branch density, differing needle colour, high rooting ability, and other characters in juvenile squarrosa-types.
The segregation noted in this progeny indicates, in the characters observed, a high heterozygosity in the parent tree which belongs to the plumosa-type.
This broad variability of the progeny represents a potential source of selection advantages under natural conditions.
Besides the fact that leaf characters changed during the observation period, the time interval until such changes occurred is a property of importance in this progeny.
Formation of strobili under the influence of gibberellic acid is not limited only to the more "aged" squarrosa-plumosa-type but can also be induced in the "juvenile" squarrosa-type.
Thus, the readiness to flower in these two leaf types seems rather to be correlated with the age of the ortet and its special developmental state related to the readiness to flower than to depend on its leaf type.