Figure 4. The GAs/ABA ratio in the SAM of soybean lines isogenic for E genes of
Clark cv. Average data for 2010-2012 growing seasons. (A) The IAA/ABA ratio of
the control plant group are shown at LD (16h); (B) the IAA/ABA ratio of the
experimental plant group, which were grown for 14d at SD (9h). Sampling points
were accordant to the experimental group: before daylength shortening (0), on the 7th
(7d) and 14th (14d) days of photoperiod shortening.
Source: developed by the author
Under the 9h photoperiod conditions, all soybean lines displayed an increase in
the GAs/ABA ratio, but the increase intensity was determined by the genotype of the
lines (Fig. 4, B). The highest increase of this ratio was observed in the SAM of SD
lines Е1Е2Е3 (8,4 times) and ND line е1е2е3 (4 times), compared with the initial level.
For this reason, in the end of the experiment, the GAs/ABA ratio was almost the same
in the SAM of all soybean lines at 9h photoperiod (Fig. 4, B). The GAs/ABA ration
was the highest in the SAM of ND line е1е2Е3 at both 16h and 9h photoperiod, that
mostly due to the highest GAs content (Fig. 4, B, Tab 2).
Therefore, at the end of the experiment the IAA/ABA ratio was 2,3-2,7 times
lower in the SAM of SD lines and in the 1,2-3 times higher in the SAM of ND lines at
9h photoperiod, compared with ratio at 16h photoperiod ones. Only the DN е1е2Е3
line displayed approximately equal levels of this ratio at both 9h and 16h photoperiods
(Fig. 3, A and B). The similar effect of 9h photoperiod was observed in dynamics of
GAs/ABA ratio in the SAM of SD lines, which was 2 times higher than at 16h
photoperiod. But the all DN lines had approximately equal levels of this ration at both
photoperiodic conditions (Fig. 4, A and B).
0,0
2,5
5,0
7,5
10,0
12,5
15,0
17,5
20,0
22,5
25,0
0d
7d
14d
0d
7d
14d
G
A
s?
A
BA
ra
ti
o
Е1Е2Е3
Е1е2е3
е1Е2е3
е1е2Е3
е1е2е3
A
B
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