ISSN 10227954, Russian Journal of Genetics, 2013, Vol. 49, No. 5, pp. 517–522. © Pleiades Publishing, Inc., 2013.
Original Russian Text © S.S.
Kirikovich, E.V. Levites, 2013, published in Genetika, 2013, Vol. 49, No. 5, pp. 602–608.
Currently, there are many examples of when the
ratio of phenotypes in a progeny cannot be explained
by existing concepts and genetic laws. This is clearly
demonstrated in the contributions of Mendel, as was
found later, on the agamospermous progenies of
. Agamospermy is a type of reproduction
in flowering plants with the formation of embryos and
seeds without the fertilization and with the participa
tion of the genome of only one parent .
The term “autosegregation” was introduced  to
describe the variability in agamospermous progenies;
initially, autosegregation was viewed as a consequence
of various disorders during development by agamo
spermy. However, the mass production of agamosper
mous sugar beet seeds  and the use of convenient
markers (isozymes) [4–6] allowed one to give a new
essence to the term “autosegregation”. Autosegrega
tion presupposes segregation of characters in agamo
spermous progenies determined by meiosis [3–6]. The
ground for this view was based on the data of the hypo
cotyl color in sugar beet seedlings, which indicate that
the ratio of colored and uncolored seedlings in the
agamospermous progeny was not 3 : 1, but 11 : 3 .
The authors explain this ratio by mixoploidy, namely,
by the presence of tetraploid cells among diploid cells
of sporogenic tissue. If meiosis takes place in a tetrap
loid cell, then the result is a diploid embryo sac with a
diploid egg capable of embryonic development with
out fertilization. As a result, the observed ratio of phe
notypic classes in the resulting agamospermous prog
enies is the ratio of tetraploid gametes developed into
the individual plants. Later, similar ratios were
detected by isozymes in sugar beet [5, 6]. These results
confirm the existence of such a sugar beet reproduc
tion type as meiotic diplospory (meiotic agamo
spermy). However, despite these data, there is an opin
ion that agamospermy is typical of only polyploid
forms of cultivated sugar beet .
Nevertheless, mitotic agamospermy has been
detected in a diploid sugar beet plant using the genetic
method when a seed embryo is formed from the cell
that has not undergone meiosis [4, 8–11]. Theoreti
cally, this progeny is to be uniform; however, the poly
morphism of marker enzymes has also been identified.
The explanation of this fact required new approaches
and assumptions, which are based on the idea that the
ability of agamospermous reproduction and polymor
phism detected in the progeny is determined by spe
cific features of the structural and functional organiza
tion of the plant genome, such as chromosomes poly
teny, chromosomes attachment to a nuclear membrane,
and chromatin diminution [10–13].
To test the assumptions, we performed experiments
that focused on changing the genome structure, where
Triton X100 (TX100) was used as a reactant to sepa
rate proteins and nucleoproteins from membranes.
The research carried out by us in wheat and sugar beet
demonstrated the efficiency of TX100 as an epimu
tagen for modifying gene expression. For example, the
inherited changes of morphological traits of the spike
[14, 15], and changes in the PCR profiles of enzyme
loci  were observed as a result of the effect of
Effect of Triton X100 on Genetic Segregation and Manifestation
of the Trait of Mono and Dicotyledonousness
in Sugarbeet (
S. S. Kirikovich and E. V. Levites
Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Science,
Novosibirsk, 630090 Russia
email: firstname.lastname@example.org; email@example.com
Received June 13, 2012
—The effect of Triton X100 (TX100) on the ratio of phenotypic classes and the expression of mor
phological traits in the progeny of sugar beet hybrids (No. 12 and No. 2) was investigated. It was shown that
the TX100 exposition on the unopened flower buds of sugar beet plants has different effects on hybrid prog
enies. In agamospermous progeny of hybrid plant N12
4, a significant decrease in the heteroallelic (het
erozygous) phenotypic classes of alcohol dehydrogenase (ADH1) fraction was determined. The progeny of
hybrid plant N2
2 did not express the traits of agamospermous origin, but the appearance of sugar beet
seedlings with one cotyledon leaf was detected in it. The obtained results indicate high efficiency of the
epimutagenic effect of TX100 on the early stages of plant ontogenesis.