ROOTING CAPACITY OF CUTTINGS AS A CRITERION FOR THE EVALUATION OF THE PROGENY OF FIVE OLIVE CULTIVARS

The use of the overall rooting behaviour was studied, as an evaluation criterion for the progeny of five olive cultivars. Plant material was a population of 274 olive seedlings derived from: (i) selfing of ‘Kalamon’ (S1 progeny); (ii) crosses of ‘Kalamon’ x ‘Koroneiki’ and ‘Amphissis’ (testcross progenies); (iii) open pollinated ‘Kalamon’, ‘Amphissis’, ‘Koroneiki’, ‘Chalkidikis’ and ‘Manzanillo’ (half-sib progenies). Leafy cuttings from: (i) S1 progeny; (ii) the two testcross progenies; (iii) 45 seedlings (9 from each of the five half-sib progenies) selected at random, were treated with IBA, 4000 mg/l, and placed for rooting under mist. Leaf drop of cuttings showed its highest percentage in progenies of ‘Kalamon’ (half-sib: 47%, S1: 40%, testcross ‘Kalamon’x‘Amphissis’: 40%). Half-sib progenies of ‘Amphissis’ and ‘Koroneiki’ exhibited the lowest leaf-drop percentages (7% and 4%, respectively). The results showed this trait, which is persistently connected with ‘Kalamon’ progeny, to be genetically regulated, and thus the characterization of ‘Kalamon’ as a difficult-to-root cultivar, due to excessive leaf drop of its cuttings, can be explained and justified. Rooting percentages were inversely proportional to leaf drop. Other traits connected with the general rooting behaviour of all the progenies tested are discussed.