CALLUS INDUCTION, SOMATIC EMBRYOGENESIS AND PLANT REGENERATION IN COTTON (Gossypium hirsutum L.)

Cotton is an important fibre crop of the world and it is also a good source of oil and high quality protein meal. Somatic embryogenesis in cotton plays a key role in cotton transformation. Somatic embryogenesis forms the basis of cellular totipotency in higher plants. Four cotton cultivars viz., MCU 5, MCU 12, MCU 13 and SVPR 2 along with two model varieties viz., Coker 310 and Coker 312 were used to assess the somatic embryogenic efficiency. Hypocotyl and cotyledonary leaves were used as explants for callus induction. Hypocotyl was found to be the best for in vitro study. Coker 312, MCU 13, Coker 310 and MCU 12 responded well for callus induction. Coker lines alone responded well for somatic embryogenesis. The best medium for proliferation of callus was standardized as MS + 0.1 mgl-1 2,4-D + 0.5 mgl-1 kinetin. Among the different combinations tried, MS + 1.9 gl-1 KNO3 was found suitable for somatic embryogenesis. An efficient protocol for the production of high frequency of callus and somatic embryos of cotton has been developed.