Page 100 - Book of Abstracts

5 International Scientific Online Conference DOI: https://doi.org/10.15414/2021.9788055224015

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RELATIONSHIP OF PRODUCTIVITY OF ZEA MAYS L. HYBRIDS WITH ACTIVITY OF
NUCLEIC ACID SYNTHESIS
Afet Mammadova
Institute of Genetic Resources of the National Scientific Academy of Azerbaijan,
Baku, Azerbaijan; E-mail.: afet.m@mail.ru
The problem of productivity is closely related to the phenomenon of hybrid strength,
which manifests itself in an increase in the degree of development of individual traits, and,
perhaps, never directly affects the organization as a whole.
The effect of heterosis seems to be based on the activation of a gene or a complex of genes
and belongs to the category of phenomena directly or indirectly related to the mechanisms of
genetic regulation of the development of traits in ontogenesis.
The greatest effect in the study of heterosis has been achieved in maize. Power, yield, and
most of the economically important traits of corn are quantitative in nature and are controlled
by a large number of genes.
High-yield maize hybrids and their parental varieties were selected as the object of
research. The total content of nucleic acids in plant material was determined by the
spectrometric method; the method of stepwise fractional extraction was used to isolate DNA
fractions.
The study of the content of nucleic acids in corn leaves showed the activation of DNA and
RNA synthesis in high-yielding hybrids in comparison with parents. For example, analysis of the
data in the study of the Bi 73 x MK 22 hybrid showed the activation of both types of nucleic
acids: the DNA content was at the level of the best parental form in this indicator, the RNA
content was 24.75 higher than the average of both parents. In hybrid GB 2501 x MK 22, the total
DNA content was 15.2 % higher than the average indicator of the initial forms, RNA – by 47 %.
The structural state and functional activity of the DNA of the cell nucleus is heterogeneous.
Part of it is in a labile state in the composition of dispersed chromatin – euchromatin and is
functionally more active. Most of the DNA is tightly bound to histones and is a component of less
active chromatin. An insignificant part of DNA is bound in chromatin due to packing in
structures containing, in addition to proteins, RNA, and lipids.
Determination of the fractional composition of DNA showed a significant difference
between hybrids and parents in the functional state of DNA. In the studied productive maize
hybrids GB 2501 x MK 22, MK 22 x OK 18, Bi 73 x OK 18, Bi 73 x MK 22, an increase in total DNA
was accompanied by activation of labile DNA. For example, the amount of labile DNA in the GB
2501 x MK 22 hybrid increased by 7.3% in comparison with the average indicator of the
parental forms. In the maize hybrid MK 22 x OK 18, the amount of the labile DNA fraction was
7.5 mg%, in the maternal form – 7.2, and the paternal form – 5.8 mg. Labile chromatin
(chromatin containing labile DNA) is associated mainly with metabolic processes occurring in
growing cells or differentiated cells with active physiological function. The factors that
stimulate growth and metabolic processes in the body contribute to chromatin labilization.
Thus, in our studies, heterotic maize hybrids exceeded the parental forms in the activity
of nucleic acid synthesis. An increase in the total DNA content in hybrids is accompanied by the
activation of the synthesis of the labile DNA fraction. The activation of the synthesis of nucleic
acids in productive hybrids in comparison with the parental forms indicates an increase in the
physiological lability and functional activity of the genetic apparatus. Studying the activity of
nucleic acid synthesis makes it possible to identify high-yielding maize hybrids at the early
stages of ontogenesis.
Keywords: Zea mays, yield, nucleic acids.

5 International Scientific Conference Agrobiodiversity for Improving the Nutrition, Health, Quality of Life and |99
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Spiritual Human Development
November 3 2021
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