THE INFLUENCE OF VEGETATIVE PROPAGATION METHODS ON ROOT FUNCTIONING IN EUCALYPTUS GRANDIS × NITENS

The purpose of this study was to deepen our understanding of the root hydraulic properties of micro- and macropropagation plants, using a clone of Eucalyptus grandis × nitens (GN107). We included seed-propagated E. grandis and E. nitens in experiments that were conducted in the field after 16 months.
Although differences were non significant between micro- and macropropagated GN107 plants, the former had marginally (19%) lower root hydraulic conductance (Kr), and also showed significantly lower K_r when compared to E. grandis. Nevertheless, there were no significant differences in root xylem vessel characteristics across all plants.
Hence when normalised by leaf area (LA) and root area (RA), differences in specific root hydraulic conductance were non significant, although roots of macropropagated plants were more efficient (K_r/LA, 35% and K_r/RA, 48%, respectively) in conducting water to the leaves than those produced via micropropagation.
Both types of vegetatively propagated trees produced shallower I-beam shaped, whereas seed-propagated E. grandis and E. nitens produced deeper T-beam shaped roots.
None of the micropropagated GN107 trees produced equivalents of tap-roots (i.e. symmetrical lateral roots with a sinker immediately below the root-shoot junction, i.e. ‘tap sinker’) at 16 months, when compared to half of the extracted macropropagated GN107 trees.

III International Symposium on Acclimatization and Establishment of Micropropagated Plants

M.E.O. Mokotedi, M.P. Watt, N.W. Pammenter

high pressure flow meter, root hydraulic conductance, xylem histology, root architecture

https://doi.org/10.17660/ActaHortic.2009.812.55