Abstract

In vitro plantlet regeneration via organogenesis was observed in leaf and nodal explants cultured on Murashige and Skoog (MS) medium fortified with various concentrations ofthidiazuron (TDZ), benzylaminopurine (BAP) or kinetin (Kn) in sponge gourd (Luffa cylindrica L) accession number 1868). TDZ was superior to BAP or Kn in inducing more number of shoots in leaf and nodal explants. Conversely, TDZ was inferior to BAP or Kn in causing shoot elongation. TDZ at 0.5 mg/L induced maximum number of shoots (9.55± 0.54 and 5.80 ± 0.45) and caused minimum shoot elongation (1.20 ± 0.25 and 3.05 ± 0.45 cm) in leaf and nodal explants, respectively, after 4 weeks of culture. On the other hand, BAP or Kn (1.5 mg/L) also induced maximum number of shoots (4.55 ± 0.25 and 3.70 ± 0.25) and (3.25 ± 0.27 and 3.10 ± 0.16) maximum shoot elongation (cm) (2.60 ± 0.32 and 5.00 ± 0.27) and (2.20 ± 0.25 and 3.90 ± 0.35) in leaf and nodal explants, respectively, after 4 weeks culture. Micro-shoots transferred to MS + IBA (1.0 mg/L) produced roots in all cultures after two weeks of inoculation. Root tip squashes of the regenerated plantlets was diploid (2n = 26) and did not reveal any chromosomal aberrations. Plantlets were acclimatized in pots for two weeks and then transplanted to research field with 70% survivability. Histochemical assay of nodal explants with callus showed deep blue spots, which confirmed the successful transformation of gus gene using particle gun.

Key words: Luffa cylindrica (L.) 1868, plantlets, root tip squash, GUS gene, thidiazuron.

Abbreviation

Abbreviations: MS, Murashige and Skoog; TDZ, thidiazuron; BAP, benzylaminopurine;Kn, kinetin; IBA, indole 3-butyric acid; HCl, hydrochloric acid; YEB, yeast extract broth.