Participation of Apomictic Cereals in the Composition of Steppe and Ecotone Phytocenoses in the North of the Lower Volga Region

Abstract

A geobotanical analysis of 160 steppe and ecotone plant communities with the participation of cereals in the north of the Lower Volga region (within Saratov oblast) has been carried out. The species diversity of apomictic cereals is significantly inferior to the diversity of their amphimictic relatives in the flora of the region and in the studied phytocenoses (24 apomictic and 109 amphimictic species in the flora; 17 and 34 species in the phytocenoses, respectively). At the same time, the dominants of the studied communities are equally represented by both amphimictic (14 species) and apomictic cereals (9 species). It is established that cereals with an amphimictic mode of reproduction dominate in 64 phytocenoses and apomictic cereals dominate in 48 ones. The number of phytocenoses in which apomicts are codominants significantly exceeds the number of plant communities with amphimicts codominance (46 and 22, respectively). The studied plant communities are similar in species richness and evenness. The data indicate successful competition between apomictic cereals and amphimicts and their significant contribution to the composition of steppe and ecotone phytocenoses in the northern Lower Volga region.