Gamma Rays and CarbonIon-Beams Irradiation for Mutation ...

Novak et al. (1990) reported considerable phenotypic variation
among the plants regenerated from shoot-tips after mutagenic treatment. In
early stages of plant development the irradiation affected emergence and
expansion of the younger leaves and several plants formed compact leaf
rosettes. Aberrant morphology of laminae was observed mainly in younger
leaves which indicate a damage of the apical meristem.
The results from the present study at the “Gamma Greenhouse”
coincided with his report when meristems of irradiated banana plant were
found atrophied by high irradiation doses during preparations for in vitro
propagation as is shown in Fig. 14. Yu (2006) also mentioned that young
tissue with exuberant metabolism and fast growth has higher radiation
sensitivity than more slowly growing adult and old tissue. Tissues that have
fast cell division are more sensitive than tissues with slowly dividing cells;
thus, the bud and roots of highly evolved plants are more sensitive than
stem and leaves. In this study, in order to reduce such damage, short-term
irradiation exposures could be explored. Double leaf and spindle were the
most relevant characteristics. YSL was the most frequently observed
characteristic in ‘Cavendish Enano’, ‘FHIA-01’ and ‘Orito’, except in
‘Williams’.
3. 3. 4. Juglone toxin screening
An experiment carried out by Stierle et al. (1991) determined
that juglone was the most biologically active phytotoxin which induced the
formation of necrotic lesions on cultivars of banana at 0.1 µg. In the
present study, when the three susceptible irradiated cultivars were tested
using 150 ppm of juglone, the reaction within and across cultivars were
different. Values ranging from 5.97 mm 2 to 45 mm 2 of necrotic area were
observed. In ‘Cavendish Enano’ (94% of the evaluated plants) and
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