Callus induction and plant regeneration efficiency of five selected Egyptian rice cultivars,
Giza 177, Sakha 101, Sakha 102, Sakha 103, and Sakha 104, were studied using mature embryos as
explants. Both plant genotype and medium composition influenced the rate of callus formation.
Mature embryo explants of the genotype Sakha 104 grown on N6 medium supplemented with 2 mg l-
1 2,4-D and 8.5 mg l-1 silver nitrate gave the highest callus induction frequency (95%). Among the
five genotypes tested, Giza 177, Sakha 104, and Sakha 103 showed the highest frequency of
embryogenic callus formation (48.3%, 48%, and 47.3%, respectively), on N6 medium supplemented
with 2 mg l-1 dicamba. The highest shoot regeneration efficiency of 75.3 and 70.7%, was observed
for Sakha 101 and Sakha 104, respectively, on MS medium supplemented with 1 mg l-1 NAA and 2
mg l-1 kinetin.
Keywords: Oryza sativa, Somatic embryogenesis, Shoot organogenesis, Silver nitrate, Dicamba.