**Dominance and recessiveness of parameters of Aluminum-resistance of
barley F~2~ hybrids at different concentrations of stress factor**

**E. M. Lisitsyn and I. I. Lisitsyna**

North-East Agricultural Research Institute, 166-а Lenin street, Kirov,
610007, Russia

e-mail: edaphic@mail.ru

Till now there is no uniform opinion in the scientific literature about
number and type of ac­tion of genes coding barley aluminum resistance.
For example, Rigin, Yakovleva (2001) considers, that it is controlled by
two oligogenes, as a minimum, with possible action of genes with weaker
effect. Other authors assume the control of the parameter by one
dominant gene *Pht* \[Stolen, Andersen, 1978\], or gene *Alp* \[Reid,
1971\], both located on chromosome 4 \[Minella, Sorrells, 1997\].

Gourley et al \[1990\] concluded, that type of action of genes coding
aluminum resistance in sorghum (additive, partially or completely
dominant), depends not only on a researched geno­type, but also on used
Al concentration. Aniol \[1995, 1996\] has established, that when the
concentration of aluminum in test solution is low (30-40 µМ), cereal
cultures (wheat, rye) use mechanisms that block accumulation of aluminum
in roots (for example, chelation of aluminum at the expense of exudation
of organic acids by root system), at higher concentration of aluminum in
root growth en­vironment (200-300 µМ) the basic role is played by other
physiological mecha­nisms of Al-resis­tance. Thus the author remarks
\[Aniol, 1997\] that the aluminum resistance of wheat plants at a
concentra­tion of 296 µМ is controlled by 2 genes and at a concentration
of 592 µМ aluminum resistance is controlled by three genes. He wrote,
that genes located in D-genome of wheat, are expressed only at high Al
concentration, and genes located on chromosome 5А are expressed at all
studied concentrations.

The aim of our research was to determine the influence of Al
concentration on a direction and character of dominance of parameters of
roots growth of barley F~2~ hybrid seedlings.

**Material and Methods**

The direct and reciprocal F~2~ hybrids of four selection numbers of
barley (№№ 565-98, 889-93, 999-93 and 1030-93), bred in North-East
Agricultural Research Institute (Kirov, Russia) were taken for the
analysis. By results of the preliminary laboratory analyses the parental
forms of these hybrids differed significantly on a level of
Al-resistance that corresponded to the research aim. A level of
Al-resistance (relative root length - RRL) was estimated under
conditions of rolled culture on five-day barley seedlings according to
the technique described earlier \[Lisitsyn, 2000\] by divi­sion of value
of root length of each individual seedling in test treatment variant
(0.5 and 1.0 mM of aluminum as sulphate salt, рН 4.3) on value of
average root length of control variant (without the stress factor, рН
6.0). Each sample volume consists of 99-105 seedlings in each treatment
variant.

Character of dominance for parameters of root growth of F~2~ hybrid
plants was estimated by equation \[Petr, Frey, 1966\]:

*d = [F~2~ - MP ]{.underline}*

*HP-MP*

,

where *d* = degree of dominance; F~2~, НР, МР = means of F~2~ hybrids,
resistant parent value, and mid parent value, respectively.

**Results and Discussion**

Expression of Al-resistance genes appreciably depend on a concentration
of aluminum in test solution and with its increase the resistance of all
hybrids was reduced without exception (table 1).

Table 1. Parameters of root growth of barley F~2~ hybrids under
laboratory condition

  ----------------- ----------- ------------ ----------- ---------- ----------
  Hybrid            Root                                 RRL, %     
                    length, mm                                      

                    0 mM Al     0.5 mM Al    1.0 mM Al   0.5 mM     1.0 mM

  565-98 x 889-93   109.2±1.5   71.2±1.2     56.3±1.0    65.2±0.6   51.6±0.5

  889-93 x 565-93   103.0±1.1   84.7±1.3     71.3±1.2    82.3±0.7   69.2±0.7

  565-98 x 999-93   113.6±1.6   71.8±1.8     48.3±1.2    63.2±0.9   42.6±0.6

  999-93 x 565-98   103.3±2.2   65.8±0.9     55.3±1.2    63.7±0.5   53.5±0.7

  565-98 x 1030-93  112.7±1.1   74.2±1.1     57.0±1.3    65.8±0.6   50.6±0.7

  1030-93 x 565-98  110.8±1.4   79.3±1.3     65.2±1.0    71.6±0.7   58.8±0.5

  889-93 x 999-93   107.7±2.2   76.0±1.7     61.0±1.5    70.5±0.7   56.6±0.8

  999-93 x 889-93   106.9±1.1   70.7±1.5     58.2±0.8    66.1±0.8   54.5±0.4

  889-93 x 1030-93  107.6±1.4   75.0±2.0     64.5±1.5    69.7±1.1   59.9±0.8

  1030-93 x 889-93  102.1±1.6   79.0±1.0     62.9±0.8    77.4±0.6   61.6±0.5

  999-93 x 1030-93  104.9±1.6   75.6±1.6     52.2±1.7    72.0±0.9   49.8±0.9

  1030-93 x 999-93  111.2±1.2   77.4±1.0     59.6±1.2    69.5±0.5   53.6±0.6
  ----------------- ----------- ------------ ----------- ---------- ----------

As it is visible from data, submitted in table 2, depending on the cross
and aluminum concentration used, for some hybrids the large value of
root length was dominated, for others hybrids -- the smaller value, but
for the third part of hybrids dominance of root length was absent
practically. It is possible to note the same character of dominance for
RRL parameter. The similar phenomenon was earlier marked in the
literature for other cereals. So, \[Camargo, 1981, 1984\] pointed out,
that Al-resistance of wheat F~2~ population was coded by dominant genes
at con­centration of aluminum 3 mg/l, but became recessive at increase of
concentration of the stressful factor up to 10 mg/l. Similar results
were described in the researches with wheat \[Bona et al., 1994\].

Table 2. Influence of direction of crossing on character of dominance of
parameters of root growth of barley F~2~ hybrids

  ----------------- ----------- ---------- ------------ ---------- ----------
  Hybrid            Degree of                                      
                    dominance                                      
                    of a                                           
                    parameter                                      

                    Root length                         RRL        

                    0 mM Al     0.5 mM Al  1.0 mM Al    0.5 mM     1.0 mM

  565-98 x 889-93   0.33        -0.78      -1.94        -1.21      -5.35

  889-93 x 565-93   -0.94       0.34       1.26         0.99       5.00

  565-98 x 999-93   1.19        -1.42      -1.51        -4.65      -3.13

  999-93 x 565-98   -0.44       -2.12      -0.70        -4.50      -0.85

  565-98 x 1030-93  -0.81       -0.45      -0.51        -0.37      -0.40

  1030-93 x 565-98  -2.00       -0.05      0.44         0.11       0.13

  889-93 x 999-93   4.33        1.18       1.10         -0.16      0.23

  999-93 x 889-93   3.80        -0.38      0.40         -1.16      -0.47

  889-93 x 1030-93  -0.25       10.14      1.98         1.67       1.15

  1030-93 x 889-93  -1.11       15.96      1.58         3.47       1.40

  999-93 x 1030-93  -0.35       1.05       -4.00        0.59       0.17

  1030-93 x 999-93  0.44        1.49       7.00         0.30       1.22
  ----------------- ----------- ---------- ------------ ---------- ----------

As it is follows from data, submitted in table 2, depending on a
concrete combination of crossing domination of root length under control
conditions, under both Al treatments and of RRL parameter can have
positive or negative meanings, changing from negative super-domination
till positive super-domination. Character and direction of domination
can coincide for parameters of roots length under control conditions and
under aluminum treatment, but sometimes can have an opposite direction.

Directions of crossing caused opposite character of dominance of
researched parameters of Al-resistance for hybrids 565-98 х 889-93 and
889-93 х 565-98. This tendency is some less ex­pressed at hybrids
received from crossing of breeding numbers 565-98 and 1030-93. At the
same time direct and reciprocal hybrids between breeding number 565-98
and breeding number 999-93 for main part of researched parameters have
shown only different degree of dominance, but not its different
direction.

Direct and reciprocal hybrids between selection numbers 889-93 and
1030-93 had least dif­ferences on a direction and character of dominance.

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