Abstract:
Two experiments were performed for
in vitro
establishment, proliferation and shoot
growth in axillary bud explants of Sebri pear culti
var. In the first experiment, the effect of
different concentrations of IBA(Indole-3-butyric ac
id) on explants’ establishment was
evaluated. In a second experiment, the influence of
several combinations of PGRs (Plant
growth regulators)on shoot proliferation and shoot
growth was investigated. IBA at 0 and
0.1 mg L
-1
concentration led to successful bud establishment.
At higher IBA
concentrations, callus was induced, but fewer expla
nts were successfully initiated. BAP
increased shoot proliferation, while TDZ(Phenyl-N'-
(1, 2, 3-thiadiazol-5-yl) urea) did not
show any effect on shoot proliferation. BAP, at 3 m
g L
-1
was more effective than 2 mg L
-1
on the number of proliferated shoots. Maximum shoot
length was obtained for the
medium containing BAP(6-benzylaminopurine) (2.0 and
3.0 mg L
-1
)+IBA (0.1 mg L
-1
) and
BAP (2.0 and 3.0 mg L
-1
)+IBA (0.1 mg L
-1
)+GA
3
(0.5 mg L
-1
). IBA in BAP combinations
induced lateral bud swelling, while GA
3
(Gibberelic acid) inhibited it. Maximum leaf
number was obtained for MS medium with 2.0 mg L
-1
TDZ and 0.5 mg L
-1
GA
3
.
Moreover, medium supplemented with 2.0 mg L
-1
BAP+IBA (0.1 mg L
-1
)+GA
3
(0.5 mg L
-
1
) and 2.0 mg L
-1
TDZ+GA
3
(0.5 mg L
-1
)
produced maximum shoot length. Vegetative
growth habit varied with different combinations and
BAP concentrations, being the
highest in BAP (2.0 mg L
-1
)+IBA (0.1 mg L
-1
) treatment. The combination of BAP at 2 mg
L
-1
and 0.5 mg L
-1
of GA
3
is finally recommended for a proliferation of Sebr
i pear
cultivar.
Keywords
: Establishment,
In vitro,
Pyrus communis
,
Pyrus pyrifolia
, Shoot proliferation.
