© 1988 Heron Publishing—Victoria, Canada
Growth, cambial activity and phloem structure in compatible and incompatible peach/plum grafts
A. Moing (1) and J. P. Carde (2)
1. Station d’Arboriculture Fruitière, Institut National de la Recherche Agronomique, Centre de Recherches de Bordeaux, 33140
Pont de la Maye, France / 2. Laboratoire de Physiologie Cellulaire Végétale, U.A. au C.N.R.S. no. 568, Université de Bordeaux I, Avenue des Facultés, 33405
Talence Cedex, France / Received March 29, 1988
Summary
Peach (Prunus persica L. Batsch) shoots grafted onto compatible or incompatible clones of rootstocks of myrobolan plum (Prunus cerasifera L. Ehrh. cv. myrobolan) were observed in a greenhouse for 100 days after grafting. The incompatible grafts showed foliar
symptoms of incompatibility and reduced shoot growth about 60 days after grafting. Light microscopic studies revealed that
cambial activity stopped earlier in the rootstocks, than in the scions, of incompatible grafts. Structural modifications were
also observed in the phloem of incompatible grafts. Compared with the compatible graft rootstock, the number of sieve elements
differentiated from the cambial zone was reduced in the incompatible graft rootstock, whereas the production of parenchyma
cells was not affected. No important ultrastructural alteration was observed in the sieve tubes of the incompatible grafts.
However, osmiophilic granulations near the plasma membrane of sieve plates were observed more frequently in the rootstocks
of incompatible grafts than in ungrafted myrobolan controls. It is concluded that the external symptoms of incompatibility
are not related to massive structural modifications or degeneration of the conducting tissues.
