Explants derived from hypocotyls and cotyledons segments of 56 day seedlings

and hypocotyls are superior to cotyledons in the induction of callus. Different hormones and concentrations play an important role in the callus induction and growth. 2

4-D is an important hormone of induced callus. State of the callus growth is better on basic medium MSB medium containing 0.1 mol/L2

4-D and 0.1 mol/L KT. The effects of various sugar sources is different on the formation and growth of cotton callus. The results indicat that glucose is benifit to the induction and proliferation of cotton callus

sucrose comes second. Maltose and lactose are not good to the induction and growth of callus. The addition of mannitol restrain the induction of callus. The medium MSB containing twice of KNO3 and NH4NO3 reduced by half can induce a number of embryogenic callus. Furthermore

we discuss Agrobacterium-mediated carrying NP-1 transformation and some factors affecting the transformation frequency. It is appropriate for Agrobacterium infecting explants 10min and coculturing 48h

then transferred into the medium supplemented with 500 mg/L Cefotaxime and 50 mg/L kanamycin to select resistant callus.