HIGH PLANT REGENERATION FREQUENCY FROM THE IMMATURE EMBRYO CULTURE OF INBRED MAIZE (ZEA MAYS L.) LINES

Aims: To establish the culture conditions and identify maize genotypes with high plant generation capacity for further genetic engineering research.
Methodology: Five inbred maize lines H1, H29, H95, H240, and CML161 were used in this study. The callus induction and plant regeneration were carried out on N6 basal medium supplemented with different concentrations of growth regulators, silver nitrate, and L-proline. The callus induction and plant regeneration frequency were recorded and statistically analyzed.
Place and Duration of Study: Plant Cell Genetics Laboratory, Institute of Biotechnology, Vietnam Academy of Science and Technology, between July 2012 and August 2013.
Results: 2 mg/L of 2,4-Dichlorophenoxyacetic acid is the optimum concentration for callus induction in the maize lines studied. N6 basal medium supplemented with 2 mg/L of 2,4-D, 15 mg/L of silver nitrate, 100 mg/L of casein hydrolysate, 10 mM of L-proline, 20 g/L of sucrose, and 10 g/L of glucose was the most suitable for callus culture. We obtained high shoot regeneration frequencies in three maize lines H240 (78.26%), H95 (83.33%), and H1 (84.77%) on N6 basal medium supplemented with 60 g/L sucrose and various concentrations of 6-Benzylaminopurine.
Conclusion: Three inbred maize lines (H240, H95, and H1) that have high regeneration ability were identified. The regeneration systems for high generation frequency for these three maize lines were, also, established: N6 basal medium with 60 g/l sucrose supplemented with 0.2 mg/l, 1.0 mg/l, and 2.0 mg/l of BAP were proved to be the optimum for high regeneration frequencies of H240 (78.26%), H1 (84.77%) and H95 (83.33%) maize lines, respectively. The new identified inbred maize lines with high plant regeneration frequency will be the useful materials for maize genetic engineering research.