Effect of Kanamycin on Explant Selection in Genetic Transformation Experiments of Sorghum

Madhu P; Pushpa K; Venkatesh BhatB; Balakrishna D

Volume : IV, Issue : VII, July - 2015

Effect of Kanamycin on Explant Selection in Genetic Transformation Experiments of Sorghum

Madhu P, Pushpa K, Venkatesh Bhatb, Balakrishna D

Abstract :

Efficient genetic transformation of sorghum plant requires an effective selection marker system thatprecisely differentiates transformed cells from non–transformed ones. Hence the present study was undertaken to optimize the selection marker antibiotic kanamycin to screen transformed cells in sorghum transformation experiments with vectors harbouring nptII gene. Shoot meristem explants of sorghum were grown in somatic emyo induction media containing various concentrations of kanamycin. At lower concentrations of kanamycin (20mg/L and less), the growth of shoot apices was unaffected and the survival rates were very high (87.5–100%) during the three sub–culture passages. At a kanamycin concentration of 50 mg/L the percentage of survival decreased gradually with three subcultures – 62.5, 25 and 0% survival respectively, while at concentrations of 200 and 800 mg/L, these were higher mortalities of explants in the first subculture itself (only 31.3–37.5% survival). The least concentration of kanamycin at which all susceptible explants died was 50 mg/L (after three subcultures). Therefore it is suggested that 50 mg/L of kanamycin may be used as the optimum concentration for the selection of sorghum shoot meristem explants transformed with vectors harbouring the nptII gene.