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 branches of peach and plum rootstocks (Prunus cerasifera E.) cv. mrs2/5, 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 mg.L and 2500 mg.L of indolebutyric acid (iBa) by immersion in the base of the cuttings. after 60 days of planting, the cultivars mrs2/5, 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.