Page 449 - Biosystems Engineering
P. 449
Exogenous Bior egulators–Fruit Composition & Storability 425
logarithmic transformation using the analysis of variance. The differ-
ences between means were evaluated using Duncan’s multiple range
test at a 5 percent level of significance.
The result gave information on calcium uptake by fruits and short
shoots growing in the vicinity of the fruits (i.e., organs that could com-
pete with the fruits for calcium). In the papers of Benson and Stahly, 14
47
3
Marcelle et al., and Banuelos and Bangerth, only the influence of
growth regulators on calcium uptake by fruits was investigated.
Their results suggest that exogenously applied growth regulators
may change the activity of particular sinks in the plant in relation to
calcium.
In both years of the 2-year experiment, daminozide had no dis-
tinct influence on the uptake of radioactive calcium by whole plant
segments (Tables 15.2 and 15.3). However, in 1988 this retardant
caused a change in distribution of Ca among particular parts of the
45
plants (Table 15.3). Thus, treatments with daminozide, regardless of
the method of application, caused a significant drop of Ca in long
45
shoots while concomitantly evoking an increase of the amount of iso-
45
tope in the fruit (Table 15.3). Some increase in Ca content was also
visible in short shoots; however, the differences with control were
insignificant. In 1987, calcium distribution among analyzed plant
parts was similar in the control and daminozide-treated branches
(Table 15.2).
Differences in calcium uptake by whole analyzed segments in
both 1987 and 1988 are not surprising in the light of the results of
26
other authors. According to Faust and Miller and Tromp , the influ-
72
ence of daminozide on calcium uptake depends on numerous factors,
for example, the relationship between shoots and fruit growth. Such
factors change from year to year. The increased accumulation of Ca
45
in fruits in 1988 probably resulted from more efficient suppression of
the long-shoot competition by daminozide.
Auxin diminished radioactivity in whole-plant segments in 1988
when it was applied 4 weeks after blooming (i.e., 3 days before the
start of radioisotope feeding) (Table 15.3). However, there was no evi-
45
dent influence of IAA treatment on the distribution of Ca in particu-
lar plant parts. Nevertheless, in 1987 the exogenous auxin applied
2 weeks after blooming changed the distribution of calcium in inves-
tigated plant segments (Table 15.2).
Translocation and uptake of calcium, and transport of IAA are
closely independent. 2,29 Our results coincide well with those of Banu-
elos and Bangerth. In their experiment, treatments of fruits with auxin
3
caused increased translocation of calcium to the fruits. Increased Ca
45
uptake in short shoots in our experiment may also be interpreted as
the effect of IAA transported from the fruits in a basipetal direction.
45
A lower percentage of Ca in the long shoots probably resulted
from increased sink activity of the fruits due to the application of IAA.