Extraction and determination of ascorbate and dehydroascorbate from apoplastic fluid of stem of rooted and non-rooted cuttings in relation to the rhizogenesis.

Starting from semihardwood shoots of peach rootstocks (Prunus cerasifera E.) cv. Mr.S.2/5, plum rootstocks (Prunus cerasifera × P. salicina) × (P. cerasifera × P. persica) cv. Ishtarà and olive tree (Olea europaea L.) cv. Frantoio, cuttings were collected and treated with 0 mgL-1 and 2500 mgL-1 of indolebutyric acid (IBA) by immersion the base of the cuttings. After 60 days of planting, the cultivars Mr.S. 2/5, Ishtarà and Frantoio presented a significative difference with relation to the rooting induction by application of the indolebutyric acid (27.5, 47.5 and 41.25 %, respectively), inducing a higher number of roots per cutting without at the same time significantly increasing the length of the roots themselves. The levels of ascorbate and dehydroascorbate in the rooted and non-rooted cuttings of the three cultivars were determined. These parameters varied in function of the consistency of the cuttings from each species, but showed a positive correlation between the increase of the rooting and the increase of the ascorbate in the reduced form.