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

4. 3. 2. 3. Juglone toxin response
The analysis of variance reported not significant differences
between cultivars. Fig. 44-C and Fig. 45-C are showing the LDNA-%
frequency distribution by class limits of “Cavendish Enano’ and ‘Williams’,
respectively. Lowest II-% values in ‘Cavendish Enano’ varied from 38.0 to
44.9 days and 33.0 to 39.9 days in ‘Williams’ simply observed between
dotted vertical lines. Additionally, LDNA-% values from non-irradiated
plants did not show values as lower as 44.0 % in ‘Cavendish Enano’ and
38% in ‘Williams’. Fig. 46 shows high (A) and low-affected (B) leaf discs
by juglone. Buiatti and Ingram (1991) mentioned that leaf discs technique
have been mainly used for early screening of segregation population within
classical breeding program, or to direct in vitro selection of tolerant cells.
Leaf-disc bioassays have been reported effective to evaluate resistance in
several crops. Ostry et al. (1988) working with Septoria musiva, a disease
of Populus spp, described that this method was sufficiently sensitive to
distinguish among clones with high, moderate or low resistance, however it
should only serve as a preliminary screening technique before field test.
Sackston and Vimard (1988) used the leaf-discs immersion technique to
study a host-pathogen interaction to distinguish resistant or susceptible
sunflower lines to Plasmopara halstedii.
Other techniques such as micro-cross sections of banana
plantlets also have been used to select plants in vitro culture levels. Since
Okole and Shulz (1996) obtained high regenerable callus and plantlets from
micro-cross section of banana and plantain, they applied this method to
select M. fijiensis-resistance cell lines. Okole and Shulz (1997) studied a
double selection system; at first, micro-cross section was performed to
access the growth into a crude fungal filtrate and then the regenerated shoot
bud was subjected to the purified fungal toxin 2,4,8-trihydroxytetralone.
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