Our data have been shown that there was no significant difference in the level of
GAs/ABA ratio in the SAM, compared with that in the leaves ones of all soybean lines.
But this ratio in SAM was the lowest in the SD line E1E2E3, and the highest - in the
DN line е1е2Е3 (Fig. 4).
Table 2. The contents of plant hormone in the SAM of soybean lines isogenic
for E genes of Clark cultivar, μg/g of dry weight. Average data for 2010-2012
growing seasons. Sampling points were accordant to the experimental group: before
daylength shortening (0), on the 7th (7d) and 14th (14d) days of photoperiod
shortening
Sampling
points
IAA content, μg/g
ABA content, μg/g
GA content, μg/g
Daylength, h
16
9
16
9
16
9
SD isoline / genotype Е1Е2Е3
0 d
4.03±0.2
4.03±0.2
0.97±0.05
0.97±0.05
10.7±0.9
10.7±0.9
7 d
5.27±0.3
8.03±0.6
1.17±0.06
1.46±0.07
23.4±1.2
1.7±0.07
14 d
6.16±0.4
3.28±0.1
1.7±0.08
2.15±0.10
9.9±0.9
1.3±0.06
SD isoline / genotype Е1е2е3
0 d
5.23±0.4
5.23±0.4
0.78±0.04
0.78±0.04
5.5±0.4
5.5±0.4
7 d
5.50±0.4
11.01±1.0
0.97±0.06
1.33±0.06
32.6±1.3
14.7±1.1
14 d
6.70±0.5
3.14±0.1
1.63±0.07
2.03±0.09
29.9±1.3
19.6±1.2
ND isoline / genotype е1Е2е3
0 d
5.10±0.3
5.10±0.3
1.07±0.06
1.07±0.06
19.6±1.2
19.6±1.2
7 d
4.40±0.2
4.63±0.3
1.45±0.07
2.03±0.09
16.9±1.1
26.1±1.3
14 d
5.80±0.4
12.85±1.0
1.97±0.08
2.14±0.10
14.7±1.1
27.2±1.3
ND isoline / genotype е1е2Е3
0 d
5.32±0.4
5.32±0.4
0.79±0.04
0.79±0.04
16.2±1.1
16.2±1.1
7 d
2.87±0.09
5.61±0.4
1.21±0.06
1.71±0.07
26.4±1.3
23.6±1.3
14 d
6.60±0.5
9.45±0.6
1.4±0.07
1.96±0.08
36.4±1.3
23.6±1.3
ND isoline / genotype е1е2е3
0 d
6.35±0.4
6.35±0.4
0.93±0.05
0.93±0.05
14.0±1.0
14.0±1.0
7 d
2.56±0.09
6.23±0.4
1.33±0.06
1.62±0.07
7.8±0.8
8.2±0.9
14 d
8.12±0.6
12.43±1.0
1.63±0.07
1.83±0.08
2.6±0.11
4.7±0.3
Source: compiled by the authors
A greater number of short days (14 SD) led to the inverse dynamics of this ratio
in the SAM of SD and ND lines (Fig.3, B). It is explained by an accumulation of IAA
in the SAM of the ND lines and its decrease in SD lines against an increase of ABA
content in all soybean lines, especially in the SAM of SD lines (Tab. 2).
Altogether, all soybean lines displayed the increase of this ratio towards the end
of the experiment (Fig.3, A), mostly due to the intensive outflow of GAs to SAM
during secondary week of experiment against the ABA level no significantly increase
(Tab. 2). It should be noted, that such increase of GAs/ABA ratio was more significant
in the SAM of the DN lines, compared with that at the SD lines ones.
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