Effect of Brassinolide ,Cytokinin and Auxins on In Vitro propagation of Citrus Rootstock (Swingle Citrumelo)

Abstract

Astudy on in vitro micropropagation of a citrus Rootstock (Swingle Citrumelo)Was Conducted at the tissue culture lab.located in postgraduate building /Collage of Agric./Uni.of Baghdad from September 2010 till August 2011. single nodal segment or terminal shoots were explanted on MS medium supplemented with som plant growth regulators( Brassinolide ,Cytokinin and Auxins ). The aims of the study were increasing number of length shoots ; rooting and plantlet acclimatization. Results showed that 3% of NaOCl was the best for explant disinfestation only 10% of explants were contaminated although 4.5 or6.0 %of NaOCl gave 100% disiafestation ، the concentration were poisonous. Single nodal segments responded better than terminal shoots. in the establishment stage. MS medium supplemented with 2.0 mg / L BA + 0.4mg / L IAA was superior on shoot multiplication ( 11.10 shoots / explant) . While MS medium supplemented with 2.0 mg / L NAA + 0.048 mg / L BL. Was more effective on root number 9.44 roots / explant. Most plantlets 95% were acclimatized when They were cultured on soil consisted of 1 : 1 sand : peatmoss.