STUDIES ON TOPOPHYSIS IN ASEXUAL REPRODUCTION OF GINKGO BILOBA L.

The topophysis on asexual reproduction of Ginkgo biloba L. was studied. Theresults of variance analysis show that the topophysis remains stable through asexual reproduction,and possesses distinct difference among various cultivars. The older ages ofmaternal plants and scions are,the more distinct topophysis is. The topophysis is verysimilar through various asexual reproduction methods,and possesses reappearance distinctly. In vivo,the heterogeneity of growth on l-year-old long shoot can be divided Intothree shoot segments. After from cultivars grafted to reproducing a large number ofseeds,the topophysis of long shoot can be divided into strong-weak-strong phases. Wehave found that by the scions and cuttings taken from the hasal multitrunks,or prunning, rejuvenation and straightening up the top of a twig, the topophysis can be con-'trolled or eliminated.