Effect of FeSO4 and pH on Shoot Regeneration from the Cotyledonary Explants of Tossa Jute

Abstract

Contamination free healthy seedling is required for plant regeneration. In order to achieve this, seeds of tossa jute were germinated on both agar supported hormone free MS medium and cotton supported hormone free liquid MS medium in vitro. Percentage of seeds germinated on cotton supported medium was found to be much higher (97.6%) than seeds germinated on agar (45.8%) supported medium. Seedlings grown on cotton supported medium were healthier than the seedling grown on agar supported medium. To optimize the FeSO4 concentration and pH level for in vitro shoot regeneration from the cotyledon explants of tossa jute (var. O-9897 and O-72), the explants were inoculated onto MS medium (0.5 mg/l IAA and 3.0 mg/l BAP) which was maintained with different concentrations of FeSO4 (0, 28, 56, 84 and 112 mg/l) and a wide range of pH levels (4.0 to 7.5). The highest rate of shoot regeneration was achieved in a shoot-regenerating medium with 56 mg/l FeSO4 and a pH of 5.5. Shoot multiplication and growth rate were significantly affected by different concentrations of FeSO4. Shoots were not formed in a FeSO4 free medium. Percentage shoot regeneration and number of shoots produced per explant were significantly affected by the pH but both variety respond well in pH 5.5. When the pH was adjusted below or above 5.5, the growth rate of the shoot significantly decreased.