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


amphimixis

Apomixis in Anthoxanthum nitens and A. repens (Poaceae L.) in the Saratov region flora

The article presents the results of cytoembryological analysis of four cenopopulations of two Anthoxanthum L. species from the fl ora of the Saratov region: A. nitens (Weber) Y.Schouten & Veldkamp and A. repens (Host) Veldkamp. Embryological characters of Hieracium-type apospory and pseudogamy were recorded in plants of both species: (1) formation of several eight-nucleate seven-celled embryo sacs in the ovule; (2) development of the proembryo in unfertilized megagametophytes with intact polar nuclei.

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”.

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.