pollen

One of the large populations of the late tulip (Tulipa gesneriana L., 1753) grows in Fedorovsky district of the Saratov region on the territory of the regional “Ivanovo field” natural boundary where it is presented by three cenopopulations. The work is aimed at studying of mature pollen morphology of the given cenopopulation plants characterised by various variants of flower parts coloration. We analysed the dimension and other morphological features of the pollen fixed in 2012 when rich diversity of floral envelope coloration was registrated in the research area.

The results of the study of biometric characteristics and aerodynamic properties of pollen of North American species: Pinus radiata D. Don, Pinus sabiniana Douglas, Pinus coulteri D. Don and autochthonous Pinus nigra subsp. pallasiana (Lamb.) Holmboe, grown on the Southern Coast of the Crimea (SCC) are presented. The differences in the size of the pollen grains and their individual parameters are revealed. The pollen of introduced species is characterized by large sizes in comparison with native species.

Laburnum anagyroides Medik. (Leguminosae) is a promising ornamental woody plant, which is native to the Mediterranean. It is characterized by the following indicators of seed reproduction during introduction in the Lower Volga region: potential seed productivity is 5.24 ± 0.08 ovules on 1 ovary, real seed productivity is 1.53 ± 0.05 seeds per 1 fruit, the reproduction efficiency coefficient is 29.2%. Seeds quickly pass into a state of deep physical rest and cannot independently leave this state in spring.

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.

The mode of seed reproduction in four species Calamagrostis of peninsula Kamchatka (Russia) flora has been examined (C. langsdorffii (Link) Trin., C. lapponica Wahl., C. neglecta (Ehrh.) Gaertn., C. sesquiflora Trin.). In C. lapponica and C. neglecta studied plants are characterized by highly degree of pollen sterility (61,2 and 24,8% respectively) and significant variation of pollen grains size (CV = 17,4 and 18,7%), which is typical for apomictic forms.