This work was carried out in order to study the apple (Malus sp.) organogenesis after callus formation in M.7 apple rootstock leaf explants multiplied in vitro. The experiment was carried out in the Tissue Culture Laboratory at Embrapa Temperate Climate by using abaxial and adaxial leaves touching the culture media, with or without scarification associated with benzylaminopurine (BAP) and forchlophenuron (CPPU) at 5mM. The MS basal medium used was added to sucrose (30 gL-1), myo-inositol (100mgL-1) and agar (6gL-1). It was also added naphtalene acetic acid (NAA) at 0.5 mM. The treatments remained in darkness for three weeks under room temperature and this led to 100% callus formation and then the material was subjected to 16 hour photoperiod with light intensity of 20 mE.m-2s-1 and temperature of 25 ± 2ºC. The use of scarification associated with CPPU promoted the highest callus intensity independently of the leaf disc surface. Higher callus regeneration was achieved under abaxial surface leaf disks associated with CPPU. So, the use of scarifical explants with the abaxial surface touching the medium led to an increase in callus intensity. The use of scarification and medium containing CPPU, led to the formation of higher callus intensity independently of the leaf disk surface touching the medis.
In vitro; Culture tissue; explant
