Effect of explants source and different hormonal combinations on direct regeneration of basil plants (Ocimum basilicum L.)

Ocimum basilicum L. a herbaceous species belonging to the lamiaceae family is considered as a valuable plant for its pharmaceutical, aromatic and culinary properties. The major problem with the use of Lamiaceae species for pharmaceutical purposes is the plant to plant variability, mainly due to genetic and biochemical heterogeneity. In vitro shoot regeneration and multiplication is an impressive mean for precipitate propagation of species in which it is necessary to obtain a progeny with a high level of uniformity. In this research, two successive experiments were performed: first, the effects of explants source on MS medium supplemented with four different concentrations of BAP were studied in order to investigate the morphogenic responses; and second, the effects of different levels of two growth regulators (BAP and IAA) either individually or in combination on multiple shoot induction from nodal segments were evaluated. Maximum percent of regeneration (96.67+/-0.33) and average number of shoot (5.6+/-1.15) were observed on the medium containing 11 muM BAP + 0 muM IAA. Regenerated shoots were separated and rooted on the same half strength MS medium supplemented with 3.42 μM IAA alone for two weeks. Similarly in the second experiment, increasing BAP concentration led to decreased rooting. Moreover, a positive correlation between increasing the BAP level in culture media and vitrification of regenerated shoots was observed. The lowest and the highest vitrification values were achieved in the media containing 0 and 33 mum BAP, respectively.