Izvestiya of Saratov University.
ISSN 1816-9775 (Print)
ISSN 2541-8971 (Online)


apomixis

FREQUENCY OF APOMIXIS BEI SOME ARTEMISIA SPECIES FROM SARATOV REGION (ASTERACEAE)

We have studied the characteristics of seed reproduction Artemisia 14 species from various parts of the Saratov region. It is shown that a population of five of them (A. vulgaris, A. salsaloides, A. dracunculus, A. glauca, A. austriaca) are characterized by high (at least 20-30%) frequency of gametophytic apomixis in plants, and three species (A. abrotanum, A. absinthium, A. armenica) have lower (10-15%) frequency of gametophytic apomixis.

Evolutionary role of apomixis: S. S. Khokhlov’s hypothesis in the light of modern data

In 1949 S. S. Khokhlov (one of the founders of the Russian scientifi c school on the problem of apomixes) proved the original conception of the progressive evolutionary role of apomixis. He contended that the basic direction of the reproductive system evolution in angiosperms is a gradual failure of sex reproduction and transition to apomixis. This hypothesis was heavily criticized and called a “scientist’s fantasy”.

Saratov Scientific School by the Problems of Biology and Genetics of Plant Reproduction Systems: Achievements and Perspectives

Saratov Scientific School by Biology and Genetics of Plant Reproduction Systems was formed under the leadership of Doctors of Biology S. S. Khokhlov and V. S. Tyrnov. Most of the unique research was performed in the Laboratory of Radiation and Experimental Genetics, established in 1958. Later it was transformed into the Department of genetics and reproductive biology of the Saratov State University Botanical Garden. Over the past 60 years, Saratov scientists have made a significant contribution to the development of fundamental and applied science.

Polyembryony Phenomenon in Apomictic Maize Line in vivo and in vitro

The article is focused on studying of cytoembryological preconditions of polyembryony in the not pollinated ovary of the apomictic maize line АТ-1 under in vitro and in vivo conditions. For an assessment of a nutrient medium role in polyembryony induction a relative analysis of the embryo sacs in cultivated in vitro and native plants ovaries has been lead. Dynamics of formation in them an apomictic twin proem- bryo is traced.

The Poa bulbosa L. Reproductive Strategy in the Steppe Phytocenoses of the Lower Volga Region

Poa bulbosa L. is a native cereal of the European and Mediterranean flora and an invasive species in North America. The study of its reproductive strategy in different environmental and climatic conditions is important for the development of effective methods of containment and prevention of invasions. Plants of two coenopopulations were investigated embryologically. In addition, the morphology of reproductive organs was analyzed in 175 herbarium specimens collected in the flora of the Lower Volga region from 1919 to 2017.

Evolutionary role of apomixis: S. S. Khokhlov’s hypothesis in the light of modern data

In 1949 S. S. Khokhlov (one of the founders of the Russian scientifi c school on the problem of apomixes) proved the original conception of the progressive evolutionary role of apomixis. He contended that the basic direction of the reproductive system evolution in angiosperms is a gradual failure of sex reproduction and transition to apomixis. This hypothesis was heavily criticized and called a “scientist’s fantasy”. In the second half of the 20th century the discovery of recombination repair led to a reassessment of the role of meiosis in the evolution.