Hormonal manipulation for rapid micropropagation of sugarcane varieties CoS 99259 and CoSe 01235

Effect of growth regulators on the respons-es of shoot tip explants of sugarcane varieties CoS 99259 and CoSe 01235 was studied during in vitro micropropagation. Shoot cultures were raised from approximately 1.0 cm long shoot tip explants com-prising apical meristem and 1–2 leaf primordia on agar (8.0 g/l) solidified Murashige and Skoog's me-dium. The established shoot cultures were multi-plied on MS medium containing various concentra-tions and combinations of BAP, kinetin, NAA and GA₃. The results showed that MS medium contain-ing BAP, Kinetin and NAA (0.5 mg/l each) was most suitable for producing optimum number of shoots in both the varieties. Maximum 92% shoot cultures developed vigorous root system on 1/2 strength MS liquid medium containing 50 g/l su-crose and 5.0 mg/l NAA. The rooted shoots were washed, hardened for 45 days in the green house and transplanted to the field. Over 96% plant survival was recorded 15 days after transplantation.