Abstract:
Limited availability of healthy planting materials of grape varieties is the major constrain to
expand the grape cultivation in Sri Lanka. Application of in vitro propagation of grapes, by adding
BAP (Benzyl Amino Purine) as a growth hormone induced proliferation to propagate grapes in
large quantities is the best option. However, when adding high BAP concentrations it produces
callus other than shoots and in lower concentrations it exhibits low proliferation rate. Therefore
this study was conducted to find the best BAP concentration for multiple shoot induction of grapes,
var.Sonaka. Young intermodal segments (new sprouts) and shoot tips (1 -2 cm length) were taken
from mature veins were used as explants and surface sterilized with 5% Clorox for 10 min to
minimize pathogenic contaminants. Murashige and Skoog (MS) medium was used as the culture
media, supplemented with BAP hormone levels vary from (0.3, mg/L to lmg/L) and BAP hormone
with constant level of O.Olmg/L Naphthalene Acetic Acid (NAA). Proliferation rate and
percentage of callus induction were recorded in 2 weeks intervals. Results indicated that 0.5 BAP
added culture media produced the highest average number of shoots per cultured ex plant. (6
elongated shoots/ex plant, P= 0.024) Hormone concentrations which were higher than 0.5mg/L
(0.6, 0.7, 0.8,1.0 mg/L) were produced both shoots and callus. When it produced callus, shoots
were not healthy for subsequent sub culturing. Hormone concentrations which were below
0.5mg/L were produced less number of shoots (2 shoots/ex plant) and those shoots were long and
weak in appearance. Therefore lower concentrations are good for shoot elongation and not for
shoot proliferation. The medium supplemented with BAP and NAA hormone did not show any
significant different. We can conclude that, 0.5mg/l BAP level in the MS medium produce highest
number of shoots with no callus production.
