IN VITRO SHOOT PROLIFERATION COMPETENCE OF APPLE ROOTSTOCKS M. 9 AND M. 26 ON DIFFERENT CARBON SOURCES

Competence of two apple rootstocks M. 9 and M. 26 for in vitro shoot proliferation was appraised using a miscellany of carbon sources i.e., sorbitol, sucrose, glucose and mannitol which were employed @ 0, 5, 15, 25, 35 and 45 g l -1 . The most auspicious outcome was achieved by sorbitol @ 35 g l -1 (T9) being the optimal carbon source for both the genotypes. M. 26 had a positive interaction with sorbitol at this concentration to produce the best caulogenic response in terms of a paramount shoot length (3.01 cm) and an overriding fresh weight increment (402 mg) whereas M. 9 at the same concentration gave an eminent shoot number (9.8). Sucrose and glucose also had a positive carryover effect on apple shoots to some extent but proved to be inferior to sorbitol. Results yielded by mannitol were highly indigent in comparison to other carbon sources. Rootstocks exhibited an inconsistency regarding their aptitude for shoot proliferation. M. 26 was recognized as a better rootstock with an acquisition of 1.05 cm shoot length and 154.6 mg fresh weight while M. 9 stood better with maximum shoot number of 2.3.