Direct shoot regeneration of three Petunia cultivars

Abstract

A tissue culture system for acquiring high efficiency regeneration of Petunia was optimized. Leaf explants of Alvan, Large Flower Alvan (LF Alvan) and Mahalat cultivars of Petunia hybrida were cultured separately on MS medium including various concentrations of TDZ and BA without auxin in order to assess direct shoot regeneration. Alvan showed the highest frequency of shoot regeneration (100%) and the highest mean number of shoots per explant (25.33) on MS containing 2 mg/l TDZ. For LF Alvan cultivar the highest percentage of shoot organogenesis (100%) and the highest mean number of shoots per explant (18.20) were observed when MS medium containing 1 mg/l BA was used. With the Mahalat cultivar the maximum rate of direct regeneration was obtained on MS supplemented with 0.5 and 1 mg/l BA (80%). The mean number of shoots per explant (9.63) was obtained when 2 mg/l TDZ was used. Regenerated shoots were successfully elongated (2 to 3 cm in length) and transferred into half-strength MS as the rooting medium supplemented with 0.1 mg/l NAA. The shoots were successfully rooted, acclimatized and transferred to the greenhouse.