Preliminary study on in vivo rooting of two Olea europaea L. genotypes

The formation of adventitious roots is an essential process in propagation of olive tree. The ability of rooting is critical in several strongly recalcitrant olive cultivars. The adventitious root formation involves complex changes in the metabolism and it is evident that the knowledge of root development is important to understand the developmental biology processes useful in the rooting improvement for commercial purpose. Several factors, at biochemical and molecular levels, interact in the formation and development of adventitious roots. The process of root promotion was studied by analysing biochemical markers (total soluble carbohydrates and proteins) in the two cultivars 'Leccino' and 'Leccio del Corno', easy and difficult-to-root respectively. The content of total soluble carbohydrates in control and auxin treated. cuttings increases during the root differentiation from 2(nd) to 4(th) weeks after treatment. A new protein of about 25 kiloDaltons (kDa) is induced in the first days from auxin treatment in 'Leccino' while in 'Leccio del Corno' it is present only at the end of the rooting period. Work is in progress for the best characterisation of the newly synthesized proteins by radio-labelling and for the construction of subtractive cDNA libraries.