Organogenesis in fennel (Foeniculum vulgare Mill.) Shailendra Nath Saxena*, Priyanka Kothari, S. S. Rathore, Ishan-Ulla-Khan and Rohit Saxena National Research Centre on Seed Spices, Tabiji, Ajmer-305206 ABSTRACT Organogenesis was achieved in fennel (Foeniculum vulgare Mill.) using hypocotyls explant from in vitro germinated seedlings. Banzylaminopurin, Naphthaleneacetic acid and Indoleacetic acid are able to induced shoot regeneration but the effect of combination of Banzylaminopurin with Naphthaleneacetic acid was more pronounced. High frequency shoot regeneration (8 shoots explant -1 ) was obtained on combination of Banzylaminopurin 0.1 mg l -1 , Naphthaleneacetic acid 0.1 mg l -1 and Indoleacetic acid 0.5 mg l -1 . Interaction of Banzylaminopurin with Naphthaleneacetic acid and Indoleacetic acid resulted in increase in number of regenerated shoots. Different kind of callus morphology was observed but it had no relationship with regeneration potential. The regenerated plants are normal and healthy. Key words : fennel, callus, organogenesis, Foeniculum vulgare, shoot regeneration Abbreviations: BAP=Banzylamino purine; IAA=Indoleacetic acid; NAA=Naphthaleneacetic acid INTRODUCTION Application of tissue culture techniques in the improvement of fennel (Foeniculum vulgare Mill.) crop is limited. A reproducible and highly regenerating in vitro pro- tocol is a pre- requisite before tissue culture system ac- tually used in crop improvement programme for gene in- sertion and expression. Limited information is available on response of somatic tissues to differentiate and de- velop plantlets in vitro from callus culture of fennel. Tis- sue culture studies in fennel is however, limited and re- ported protocols are using different PGR combination and explants (Maheshwari and Gupta 6, Hunault 5, Manoir et al. 7, Anzidei et al. 1, Anzidei et al. 2, Fiore et al. 4). The purpose of this study was to develop regeneration proto- col and exploit somaclonal variation in regenerated plants for crop improvement. MATERIALS AND METHODS Clean and healthy seeds of fennel variety AF 1 were obtained from seed store of National Research Cen- tre on Seed Spices, Ajmer and surface sterilized with 0.1% mercuric chloride for 4 minutes and thoroughly washed with sterilized distilled water 4-5 times. These surface sterilized seeds were placed in a sterilized test tube on a filter paper for germination in a BOD at 25 o C. The lower half of filter paper was immerged in distilled water. Hypocotyl segment from germinated seedlings (10- 15 days old) were used as explants and inoculated on MS medium (Murashige and Skoog, 8) supplemented with various concentration of BAP, NAA and IAA (0.1 -1.0 mg International J. Seed Spices 2(2), July 2012:1-4 *Corresponding author: Email: shail.nrcss@gmail.com l -1 ) alone and in combination. Cultures were incubated at 27±1 0 C under fluorescent light in a 14/10 hrs. photo pe- riod. Light intensity was maintained at 35 µmol M -2 S -1 at bench level. Observations were recorded periodically on number of explants inoculated and responded, morphol- ogy of callus and number of shoots explant -1 . RESULTS AND DISCUSSION Response was increased from 50 to 75 per cent as the concentration of BAP increased in the medium from 0.1 to 1.0 mg l -l . Number of days to callus induction was slightly less on higher concentration of BAP. In all the treatment produced callus was of good quality with yellow and friable morphology. None of the treatment having BAP alone showed shoot regeneration from callus (Table 1). Almost 100 per cent explants responded on me- dium supplemented with high concentration of NAA i.e. 1.0 mg l -1 . At all the concentration produced callus was of good quality with yellow and compact callus morphology. The shoot initiation was observed on either low or higher concentration of NAA in the medium. Three shoots ex- plant -1 were recovered on these treatments. Response was further improved when NAA was replaced with IAA as alternative auxin source. As compare to NAA, 100 per cent explants responded on the medium supplemented with low concentration (0.1 mg l -1 ) of IAA (Table 1). Higher concentration of IAA produced less response; however, both low and high concentration of IAA resulted in good number of regenerated shoots (Table 1). Combination of similar concentration of BAP and NAA (0.1, 0.5 and 1.0 mg l -1 ) in the medium produced