IN VITRO PROPAGATION OF WALNUT (JUGLANS REGIA L.): CRITICAL FACTORS FOR THE INDUCTION OF THE ROOTING RESPONSE

In this work an overview on the results obtained by the Propagation Department of the “Istituto Sperimentale per la Frutticoltura” of Rome on in vitro rooting of walnut during some years of research is reported.
Factors evaluated were: culture basal medium and macrosalt concentration, length of the darkness treatment, type and dosage of auxin, transplant to a hormone free medium after 10 days of rooting induction, presence of absence of agar in the rooting medium, localised infection of basal part of microcuttings with Agrobacterium rhizogenes, wild type
.
Critical factors to obtain a good rooting response were: a solid DKW medium with ½ strength macrosalts, supplemented with 10µM IBA and a darkness treatment of 10-12 days (induction phase). The transferring of microcuttings to a hormone free medium after the induction phase was also very important.
Localised infection with A. rhizogenes allowed to obtain higher rooting percentages.
Roots obtained with the bacterium infection were genetically different in the same explant: normal (non transgenic), totally transgenic, chimeric or transgenic, but still containing bacteria.

V International Walnut Symposium

E. Caboni, C. Damiano

Agrobacterium rhizogenes, auxin, chemical and physical factors, basal medium

https://doi.org/10.17660/ActaHortic.2005.705.44