Cytokinins improve shoot regeneration efficiency in two Indian cotton (Gossypium hirsutum cv. Narashima and G. arboreum cv. AKA-7) cultivars

In the present investigation, regeneration of the two elite Indian cotton cultivars Gossypium hirsutum L. cv. Narashima and Gossypium arboreum L. cv. AKA-7 is reported using hypocotyl, cotyledon and shoot tip explants. The explants were cultured on MS (Murashige and Skoog, 1962) medium supplemented with twelve different combinations and concentrations of 6-benzyl amino purine (BAP) and kinetin (KIN), and the shoot regeneration was investigated. High shoot regeneration (86 and 90%) as well as shooting efficiency (83.8 and 85%) was obtained with shoot tip explant on medium containing BAP (1 mg/l) and KIN (1 mg/l) in cv. AKA-7 and Narashima, respectively. Generally, almost in all treatments where BAP and KIN were applied alone or in combinations, shoot tip explants gave higher shoot regeneration efficiency percentage than hypocotyl and cotyledon explants. Elongation of multiple shoots was achieved on MS medium supplemented with GA3 (0.1 mg/l). Shoots successfully rooted on MS hormone free medium followed by hardening and acclimatization of regenerated plantlets. Fully developed cotton plants were obtained only after eight weeks of in vitro culture. The described protocol is highly efficient, rapid and reproducible and could be used for genetic transformation of cotton plants.

Keywords:

Hypocotyls , Shoot tip explants , Cotton transformation , Regeneration