Establishment of an efficient tissue culture protocol is an essential prerequisite in harnessing the advantage of cell and tissue culture for genetic improvement. The present study deals with the effect of desiccation created in the culture media i.e. in MS media supplemented with BAP (2.0 mgl-1) and kin (1.0 mgl-1) by increasing the concentrations of agar (0.8, 1.2, 1.6 and 2.0 percent). The observations were recorded on percent plant regeneration, shoot development and number of shoots in the cotyledons of four genotypes of tomato viz. Punjab Upma, Castle Rock, VFN-8 and IPA-3. The percent plant regeneration decreased significantly with the increase in the concentration of agar in the media in all the genotypes. However, among genotypes maximum plant regeneration was recorded in IPA-3 followed by Castle Rock, Punjab Upma and VFN-8. But there was a significant increase in the number of shoots with the increase the concentration of agar up 1.6 percent in the media. The number of shoots were 9.03, 9.0, 8.93 and 12.51 on MS+BAP (2.0 mgl-1) + kin (1.0 mgl-1) + 1.2% agar in Castle Rock, Punjab Upma, VFN-8 and IPA-3 respectively. The further rooting and shoot elongation were carried out by transferring 1-2cm shoots on to ½ MS basal media. This simple protocol of creating desiccation conditions can be utilized for increasing the number of shoots in tomato. Besides, this can serve as a boon in tomato genetic transformation.
Keywords: Solanum lycopersicum, tissue culture, agar concentration, regeneration