STUDIES ON ROOTING AND ADAPTATION TO NON STERILE CONDITIONS IN MICROPROPAGATION OF PEAR CULTIVARS
Specific production of some pear cultivars requiring grafting on an interstock and the increasing attacks of the fire blight disease (Erwinia amylovora) and the infestation of pear psylla (Psylla pyri) in the recent years, have preconditioned the use of the in vitro method in the production of planting material. The aim of the study included optimization of the parameters of rooting and adaptation to ex vitro conditions in micropropagation of four pear cultivars Red Bartlett, Bartlett, Alexander Lukas, Packhams Triumph and wild pear rootstock. The effect of IAA in three increasing concentrations (2.0 mg/L, 2.5 mg/L and 3.0 mg/L) on a basic nutrient medium a modified MS medium was studied at the stage of rhizogenesis. The results showed differences among the separate cultivars that could be explained by their individual genetic types. The best root formation in Red Bartlett and Bartlett was observed with the participation of IAA 2.5 mg/L, while in Packhams Triumph all the three studied concentrations of the auxin induced a high rooting percentage. Analogous results were also obtained about the mean number and length of the rootlets formed. After adaptation of the in vitro rooted plantlets to external conditions, a high percentage of survival was reported for all the cultivars from 78.7% in Bartlett to 96.6% in Packhams Triumph. The best characteristics of vitality were observed in the cultivars Packhams Triumph and Alexander Lukas, the stem height increment for the two-month period after planting being 5.2 cm and 4.1 cm, respectively. Studies were also carried out about the increase of the number of the plants obtained by treating the non-rooted plants with IBA solution. The best results in that aspect were obtained in Packhams Triumph 98,1% of survival, followed by the wild pear rootstock 91.1%.
Kornova, K.M. and Popov, S.K. (2013). STUDIES ON ROOTING AND ADAPTATION TO NON STERILE CONDITIONS IN MICROPROPAGATION OF PEAR CULTIVARS. Acta Hortic. 981, 465-470
pear cultivars, micropropagation, rooting, auxins, adapting to ex vitro conditions