INTRAVARIETAL
POLYMORPHISM OF BARLEY VARIETIES ON RESISTANCE AGAINST EDAPHIC STRESSES
Lisitsyn Eugene, Tiunova Ljudmila,
Lisitsyna Irina
North-East Agricultural Research
Institute, 166-a
Under the theory of adaptation process (Udovenko G.V.,
1995) after plants have stressed, and have got in rather comfortable growth
conditions, their further vegetation will occur at a level of a normal metabolism,
or at other level which is distinct from normal, depending on a degree of plant
potential stress-resistance. In a case when action of the stressful factor has
not led to deviations of metabolic processes far from limit rates of reaction,
performance of the genetic program of a normal metabolism proceeds. When deviations
have left for limit rates of reaction, but have remained in adaptation zone,
there is a transition of a metabolism to a little lower level and, accordingly,
various morphological parameters of plants will be underestimated.
Development of the majority of elements of yield
structure as quantitative parameters is under the genetic control of big number
of various genes which actions are frequently opposite directed and masks each
other. Dragavtsev (2002) has suggested studying action of not individual genes,
but the whole genetic systems determining development of any quantitative
parameter. On his opinion, the structure of these genetic systems under
different conditions of growth and development of plants can include different
number of various genes. The basic attention should be given to direction and
quantitative shifts in action of these genetic systems at plant cultivation
under various ecological conditions. Applying this approach, we can calculate
quantitative and qualitative shifts in action of genetic systems of plants not
only in various growth conditions, but also at an estimation of various methods
and ways of selection of breeding material and to reveal plants or groups of
plants most suitable for the breeding purposes.
So, we investigated distinctions in reaction of
intravarietal groups of barley on two edaphic stressors (a drought and high
content of exchangeable aluminum) with the purpose of a choice of strategy of
breeding of the resistant plants at early stages of development (under laboratory
conditions).
Material and methods. We used barley cultivars
Novichok and Ecolog (breed in North-East Agricultural Research Institute,
For studying of qualitative and quantitative shifts in
action of the genetic systems the technique of graphic estimation developed by
Dragavtsev (2002) was applied. Groups of plants on fig. 1 and 2 are designated
as follows: division on Al-resistance - 1, 3 – short-roots, 2, 4 – long-roots
groups of Novichok and Ecolog, accordingly; division on drought resistance - 5,
7 - short-roots, 6, 8 - long-roots groups of Novichok and Ecolog, accordingly.
Results and
discussion. The received data on yield structure are submitted
in table. From the data of the table it is follows, that both varieties at selection on reaction to both
stresses did not show differences between groups on such parameters, as weight
of lateral ears, the weight and number of grains in lateral ears, weight of a
sheaf, weight of a grain from a sheaf and weight of 1000 grains. But reaction
of intravarietal groups of both varieties to a drought and aluminum
considerably differed on other parameters. It is necessary to note, that
a variety Novichok at dividing by reaction on Al3+ has not shown distinctions
of intravarietal groups on all 14 estimated parameters that, obviously, is
connected with a high level of its potential acid- and Al-resistance. Variety
Ecolog, on the contrary, practically has not shown distinctions of
intravarietal groups at division by reaction on drought – the only parameter on
which differences were marked is height of plants.
Table –
Development of yield structure of intravarietal groups of barley
|
Variety |
Novichok |
Ecolog |
||
|
Group on root length |
Short-root |
Long-root |
Short-root |
Long-root |
|
Division
by Al-resistance |
||||
|
Plant height, sm |
84,3 |
84,3 |
71,4 |
73,1* |
|
ear length, sm |
9.35 |
9.60* |
8.57 |
8.90* |
|
ear mass, g |
1.44 |
1.54* |
1.48 |
1.56* |
|
number of grains in ear |
24.3 |
24.4 |
23.1 |
24.0* |
|
mass of grain in ear, g |
1.30 |
1.38 |
1.35 |
1.46* |
|
Division
by drought resistance |
||||
|
Plant height, sm |
83,4 |
78,1* |
69,7 |
75,6* |
|
ear length, sm |
10.32 |
9.74* |
9.00 |
8.87 |
|
ear mass, g |
1.51 |
1.36* |
1.46 |
1.52 |
|
number of grains in ear |
24.3 |
22.0* |
21.6 |
21.8 |
|
mass of grain in ear, g |
1.35 |
1.23* |
1.32 |
1.31 |
* - significant differences between intravarietal groups, P < 0.05
Fact that some of the investigated varieties have not
shown statistically significant differences between groups on parameters of
development of some elements of yield structure, causes a question: whether it
can testify what intravarietal selection in this case has no practical value at
creation of edaphically resistant populations?
It is
possible to count a principal cause of absence of significant distinctions the
fact, that plants were raised in comfortable conditions without stressful
factors. As stressors action at early stages of development has not led to
shift of plants metabolic reactions out of limits of adaptation zone so
deviations in development of morphological parameters were rather weak.
Accordingly, it is difficult to estimate as far these groups differ on
potential adaptibility.
Construction of graphs of distribution of plants in two-dimensional
system of coordinates "mass of an ear - mass of a straw" allows to
reveal potential distinctions between groups of plants (fig. 1).
As it is seen in fig. 1, long-root groups of both
investigated barley varieties were more adaptive (have the greater shift to the
right from a vertical axis, or smaller shift to the left from it). But for attraction
- on the contrary, long-root groups were considerably worse then short-root
groups (were below on vertical). Groups of Novichok barley, not distinguished
on character of developments of elements of yield structure after division by
Al-resistance level, have precise differences on attraction – short-root group
had a positive shift in action of the given genetic system, and long-root group
- negative shift. On value of shift in action of genetic system of adaptibility
long-root group, on the contrary, had advantage in comparison with short-root
group. Intravarietal groups of Ecolog barley, divided by drought resistance
level, poorly differed both on a direction, and on values of shifts in action of
both genetic systems.
Other system of coordinates - "mass of a grain - mass
of chaff" allows to characterize work of one more genetic system -
redistributions of plastic matters within ear aside grains or chaff (fig. 2).
As it is seen in fig. 2, long-root groups of barleys also had advantages in
compare with short-root groups in micro-distribution of plastic matters (shifts
upwards on a vertical axis), except for a variant of division of plants of
Novichok by a level of drought resistance where short-root group had
significant advantages then long-root group.
Conclusion. Thus, even at cultivation under
comfortable conditions plants of intravarietal groups divided on a level of
resistance against any edaphic stressful factor (in this case on drought
resistance and Al-resistance) in most cases keep distinctions in action of
genetic systems of adaptibility, attraction and micro-distribution of plastic matters
within ear which are not shown in character of development of elements of crop
structure in the absence of stressful factor. Cultivation of plants divided
into groups of resistance against stressors at early growth stage, under
comfortable conditions allows to receive the greater amount of seed material
for the further work, than at cultivation under stressful conditions of field
or growth chamber experiments. Thus use of the graphic analysis of action of
the investigated genetic systems allows to choose for the further work the most
adapted plants or groups of the plants which are not distinguished by morphological
parameters
References
Dragavtsev V.A. Algorithms of an ecologo-genetical survey
of the genofond and methods of creating the varieties of crop plants for yield,
resistance and quality. –
Udovenko G.V. Resistance of plants against abiotic
stresses // Physiological bases of selection of plants / V.A. Dragavtsev, G.V.
Udovenko, N.F. Batygin, etc. Theoretical bases of selection. -
