1022-7954/03/3911- $25.00 © 2003
Russian Journal of Genetics, Vol. 39, No. 11, 2003, pp. 1265–1270. Translated from Genetika, Vol. 39, No. 11, 2003, pp. 1498–1504.
Original Russian Text Copyright © 2003 by Shapturenko, Kudelko, Yatsevich, Khotyljova.
To date, the upper limit of productivity of wheat, an
extremely important cultivated plant, has practically
been reached. The genetic diversity of wheat is gradu-
ally being exhausted, and its replenishment due to
recombinations and mutations is not rapid enough .
Further progress of this cultivated plant requires
searching for new approaches and developing methods
of the enrichment of its gene pool. A possible approach
is studying and using the mechanisms that can affect
recombination rate, thus favoring an increase in genetic
variability of wheat. It has been assumed that the aneu-
ploid state can serve as such a destabilizing factor .
Most studies on aneuploidy in wheat deal with
monosomic plants, whereas 42-chromosome plants,
whose proportion in the offspring of each monosomic
is about 25% , are used only as control for estimating
the effect of monosomy. The formation of the diversity
of 42-chromosome plants, whose lines have passed
through the monosomic state for various chromosomes
of the wheat genome, remained largely unexplored.
There are a few data that disomic plants originating
from different monosomic lines differ from one another
[4, 5]. Among the available published data, we found
only one study  where the variability of disomic
plants was analyzed. Joshi and Singh , having found
differences between lines with respect to the time of
earing, hypothesized that this heterogeneity resulted
from spontaneous mutations in monosomic plants.
Monosomic lines of wheat cultivar Opal were devel-
oped at the Institute of Genetics and Cytology of the
National Academy of Sciences of Belarus with the use
of aneuploid Chinese Spring plants. In the course of
this work, it was found that some disomic plants origi-
nating from monosomic offspring of the sixths and sev-
enths backcrosses stand out for some commercial traits
. In order to exclude the effect of the “foreign” cyto-
plasm on the expression of the nuclear genome, the
Opal monosomic series was transferred to the Opal
cytoplasm through an Opal
monosomic line crossing.
However, the differences between 42-chromosome
plants were preserved [8, 9].
A complete series of disomic lines from the off-
spring of 21 monosomic lines of spring wheat Opal was
obtained, which allowed us to comprehensively study
the observed variation using various methods of genetic
In the course of this study, we tested disomic lines
for combining ability, studied the heterosis effect in F
hybrids of disomic lines obtained through topcrossing,
and analyzed the molecular genetic polymorphism of
these lines as related to the heterogeneity of disomic
plants with respect to morphological traits.
MATERIALS AND METHODS
The material of this study was a complete series of
disomic lines of soft spring wheat Opal developed on
the basis of a series of monosomic lines of Opal with
the cytoplasm of the same cultivar (Fig. 1).
Formation of New Original Material
Based on the Genetic Heterogeneity of the Disomic Offspring
of Aneuploid Wheat Plants
M. N. Shapturenko, L. I. Kudelko, A. P. Yatsevich, and L. V. Khotyljova
Institute of Genetics and Cytology, National Academy of Sciences of Belarus, Minsk, 220027 Belarus;
fax: (172) 84-19-17; e-mail: firstname.lastname@example.org
Received April 28, 2003
—A series of disomic lines of spring wheat Opal developed on the basis of monosomic lines of this
cultivar has been studied. The lines have been tested for combining ability, and the heterosis effect has been
studied in disomic lines of F
hybrids obtained by topcrossing. The line have been demonstrated to differ both
from one another and from cultivar Opal in the expression of quantitative traits, combining ability, and the
degree of heterosis in F
. These data suggest that recombinations accompanying the formation of the mono-
somic series have changed their genetic program. To test this suggestion, intramolecular heterogeneity of 42-
chromosome plants has been analyzed using polymerase chain reaction (PCR) and isoenzyme analysis. The
results conﬁrmed the differences at the DNA and protein levels. According to the results of molecular analyses,
A-genome lines are the most polymorphic. Strong heterosis effects have been detected in hybrid combinations
contributed by D- and B-genome lines, which are characterized by medium and low degrees of molecular
genetic polymorphism. Lines that are promising in terms of breeding programs have been identiﬁed.