Abstract:
Experiments on induction of callus in vitro and subsequent regeneration of
plantlets in three high dry matter content of sweet potato germplasms such as
368572.36, 322300.92 and 471068.05 were conducted during July to
December, 2005. For induction of callus, three levels of each of BAP ( 0, 2.0
and 4.0 mg/I ) and NAA (0, 0.05 and 0.10 mg/I) and for regeneration of
plantlet, BAP (0, 2.0 and 4.0 mg/I) and IBA (0, 0.5 and 1.0 mg/l) with MS
basic salts were used. The germplasms did not vary significantly for most of
the parameters studied. Either callusing or regeneration of plantlet did not
occur either with the control treatment of BAP+NAA or BAP+IBA,
respectively. All cultures of the germplasm 368572.36 under 4.0 mg/l BAP +
0.05 mg/I NAA formed callus within 11.80 days, whereas, the germplasm
322300.92 under 4.0 mg/I BAP ..... 0.10 mg I l';AA gav e largest callus both in
diameter (13.47 mm) and in weight (2667.59 mg) and also growth rate. 0.22
mm/day and 66.69 mg/day, respectively. All the germplasms under 2.0 or 4.0
mg/I BAP and 0.5 or 1.0 mg/I IBA formed maximum 93.33-100.00°-'o shoots in
.... ....
callus cultures \\ ithin 7.31-11A1 days. Under the above BAP and IBA
combinations, the germplasms exhibited >3.0 shooting index and >2 shoots
per culture. All the germplasms under the combinations of BAP and IBA
attained plant height of >4.0 cm, producing 4-6 leaves per plant, 0.71-1.03 cm
internode length, 0.68-0.90 leaf per week and 0.81-0.98 cm/day growth rate.
The treatment of BAP singly did not form any root. The other treatments
formed roots within the range of 5.2-11.0 days and rooting index varied from
0.33-2.46. The germplasms fanned maximum 3.6 roots per plant under 2.0
mg/l BAP + 1.0 mg/l IBA and maximum length was 4.44 cm in gennplasm
471068.05 under 2.0 mg/l BAP + 0.5 mg/I IBA.
