Agriculture Reference
In-Depth Information
through 24, 30, and 36 h after its introduction. The fi rst labeled nuclei appeared 10
h after beginning of labeling. These data confi rm heterogeneity of phase of G 1 in dry
seeds.
In the research [8], Sidorov, Sokolov, and Andreev have processed the plantlets of
C. capillaris by ethylene imine. Plantlets were grown in the presence of colchicine.
During the fi ve generations of polyploid cells, the doubled rearrangements of chro-
mosomes were observed. Also in polyploid, cells were plantlet new rearrangements
of chromatid type, undoubted. In the study [9], plantlets were treated by ethylene
imine, then washed in tap water, and then cut into very small fragments in the form
of “gruel.” Intact plantlets were treated by this “gruel,” washed in the water off and
placed in Petri dish for sprouting in solution of colchicine. In metaphases of plantlets
treated by “gruel,” the authors detected new aberrations of chromosome of chromatid
type. This indicates the preservation of mutagen in cells treated by this “gruel.” These
authors named the appearance of new rearrangements in a series of generations of cells
“secondary mutagenesis.”
In the article given in Ref. [9] authors studied the effect of ethylene imine on dry
seeds. Rearrangements only of chromatid type were observed. It shows that chromo-
somes in the G 1 are not sensitive to the chemical mutagen. Ionizing radiation, vice
versa, damages chromosomes at all stages of cellular cycle.
However, here growth of frequency of alterations after the treatment of seeds by
ethylene imine is not observed, in contrast to our data (see Table 24.1, Figure 24.2).
Frequency of rearrangements had as tough wavy character (Table 24.4).
TABLE 24.4
Effect of ethylene imine (solution 0.1%) on the dry seeds of Crepis capillaris
(from Ref. [9])
Time of fixing (h)
Number of cells
Rearrangements
Number
(%)
2
554
36
6.50 ± 1.05
8
672
23
3.42 ± 0.70
12
1,018
88
8.64 ± 0.88
16
1,000
38
3.80 ± 0,61
There was no increase of number of alterations in dependence on time of fi xing.
Probably, here plantlets were fi xed later, then in my experiments, length of plantlets
varies. According to our observations, even 2 h after plantlet, the length of plantlets
varied. Wavelike character of effect of ethylene imine in Ref. [9] also shows hetero-
geneity of phase of G 1 in dry seeds. Maybe the synthesis of DNA under the mutagen
impact is yet more asynchronous.
The phenomenon of preservation of chemical mutagen in the cells of plants has a
practical value. Damages of chromosomes remained in cells are transmitted after divi-
sion and organogenesis of any plant. It is necessary to take into account genetic harm
 
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