No abstract

This experiment was conducted to optimize the culture conditions to induce calli from chilli pepper (Capsicum annuum L.) local cultivar. The mature seeds were surface sterilized for one min with 70% Ethanol followed by 20 min with (0%, 2%, 4% or 6%) NaOCl and were germinated on MS medium with 2 mg/L GA 3 . Seedlings and mature fruits were used as explants source. The placenta, pericarp, hypocotyls, cotyledonal leaves, shoot tips and roots were cultured on MS media supplemented with.0 mg/L). Callus fresh weight was recorded after 4 weeks in culture. The results showed that the best sterilizing method was with 70% Ethanol followed by 20 mints with (4% or 6%) NaOCl, however 6% NaOCl reduced seed's viability. Callus was induced from all explants cultured on MS media supplemented with IAA and Kinetin except the placenta and the pericarp. The results showed that the hypocotyls surpass all other explants in the mean callus fresh weight which was 160.58 mg compared with 147.81 mg, 134.95 mg, and 122.33 mg for cotyledonal leaves, shoot tips and roots respectively. Moreover the analysis of the interaction between the growth regulators and the explants showed that 2 mg/L IAA and Kinetin had significant effect on callus mean fresh weight which was (309.74, 339.14, 358.48, and 284.64) mg for the shoot tips, cotyledonal leaves, hypocotyls and roots, respectively. On the other hand, 2 mg/L 2,4-D or NAA was the best concentration for callus induction from the placenta and the pericarp. The pericarp gave a mean fresh weight of 276.90 mg in the presence of 2,4-D compared with 253.60 mg for the placenta. Moreover the pericarps gave significantly higher fresh weight than the placenta with an average of 210.3mg and 184.9 mg respectively in the presence of 2 mg/L NAA. In conclusion the best sterilization method of chilli pepper seeds is by 70% ethanol for one minute followed by 20 min in 4% (NaOCl). The best explants for callus induction only is the Hypocotyls grown on MS medium supplemented with 2 mg/L of IAA and Kinetin under the conditions of the current experiment.