Banana cultivation in Egypt is limited by water
availability. The tolerance to occasional water
stress was tested on small plantlets
regenerated from shoot tip explants. Aseptic
cultures of banana cultivars Maghraby, Valery,
Grand Nain and Hindy were established and
initiated on MS-basal medium supplemented
with benzyladenine (BA, 3 mg/l) and agar (6
g/l). Growing explants were recultured, at 4
week intervals, on fresh medium until the onset
of proliferation (ca. 2 months), then
multiplicated on medium containing BA (5 mg/l).
The produced shoots were used to evaluate the
in vitro responses of cultivars to polyethylene
glycol (PEG) and medium liquification. The
elevated levels of PEG (>15 g/l) progressively
inhibited shoot survival, but the response was
more evident in Maghraby and Valery than in
Grand Nain and Hindy. The growth and
development of both shoots and roots
demonstrated the same order of cultivar
response, but in different directions (i.e.,
decrease of shoot formation and increase of
root initiation). At 20 g/l PEG, medium
liquification improved the above criteria,
especially those of the cultivar Hindy. The
accumulation of sugars and proline in shoots
was positively correlated with water deficitinduced
by PEG and agar, while the reverse
was true for N, P and K. The cultivars Hindy
and Maghraby showed the highest and the least
sugars and proline accumulation, respectively.
It was concluded that the Hindy cultivar is the
most adapted and tolerant to water shortage,
because of its strongest accumulation of
compatible solutes and its greatest stimulation
of root development.
Key words: Banana; Medium liquification; Osmotic stress;
Polyethylene glycol; Potassium, Pr‾ Sugars.
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