Abstract

Nodal and apical segments of Quercus robur, coming from both adult plants and germinals gave rise, with different modalities and times, to the formation of stalks of a few cm in length (Figure1). At this point, the new nodes formed were put in culture. The lengthening of the new stems continued for a few months, with slow growth (about 1cm in 20-30 days). Following further withdrawals, the nodes put in culture in October and November 2016 stopped their growth. A physiological arrest is hypothesized, to be expected also in plants grown in vitro. The increase in auxin concentration alone (IAA 0.75mg/l), tested in an attempt to promote faster elongation, did not give the expected results. Trials are underway to use both concentrations and plant growth regulators in combination, in an attempt to resume the elongation of the new stalks. As mentioned above, tests are underway to obtain any somatic embryogenesis from adult leaf tissues. At this regard, in the face of enlargements on the surface of the tissue, somatic embryos have not yet been differentiated. Rooting tests have begun on the first elongated stems obtained in vitro.