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Aim. Thinopyrum intermedium, a wild wheat relative, for some reasons is on interest for its involvement to the introgressive hybridization with wheat. The basis for the purposeful work in this direction should be the information about the biological and genetic properties of the species, including the mating system. The mating system can be identified based on the genotyping of plants in populations for a polymorphic gene with codominant inheritance. Gene Glu was used as such a codominant gene. Methods. Cytological (determination of the chromosome number in metaphases of mitosis), electrophoresis of glutenin storage proteins, comparative analysis of electrophoretic spectra, and the population genetic methods for calculating the frequencies of genes and genotypes. Results. Plants were hexaploid, with 2n = 42 chromosomes. In a sample of fifty plants, a genetic control of components of the glutenin spectra has been established. They are controlled by three independent genes: Glu-Thi1-2 with four alleles 1-2 (cluster), 1, 2, 0, Glu-Thi1-4 with four alleles 1-4 (cluster), 1, 4, 0, and the three-allele gene Glu-Thi1-3-5. The participation of the three genes in the formation of the electrophoretic spectrum of glutenins is consistent with the hexaploid nature of Thinopyrum intermedium, which follows from the established number of 42 chromosomes. The information about the genetic control of glutenins is the basis for determining the mating system of this species. A simplified three-allele model of genetic control of glutenins' electrophoretic spectra was used for determination of the mating system of Thinopyrum intermedium. Conclusions. Plants of the studied Thinopyrum intermedium population have a mixed mating system and the probability of self-pollination ranging from 0,50 to 0,81, depending on the Glu gene, which is used for determination of heterozygosity of the plants. This biological characteristic is positive for prospective use of this species for wide hybridization. [ABSTRACT FROM AUTHOR]

Aim. Search for morphological traits that are essential for adaptive potential of the species and variable in different environments is an important part of microevolutional studies, as well as intraspecific and introgressive hybridization. Methods. Measuring and visual assessment of spike morphology. Results. Plants from five populations of Thinopyrum intermedium grown in different microgeografic conditions have been assessed for qualitative (spike color, spike hairiness, glume characteristics) and quantitative (flower number, spikelet number, spike length, spikelet length, distance between spikelets) spike morphology traits. Their associative variability for two years and its role in formation of morphotypes in populations have been investigated. The difference of average values of spike quantitative traits indicates the impact of microgeografic conditions and climate on morphotype formation. Associated manifestations of awns and shape of glume arm, arm shape and keel shape, some pairs of quantitative and qualitative traits either have been registered in both years of study or were characteristic for some particular year, and could have played role in plants' adaptation to abiotic conditions. Conclusions. In populations of Thinopyrum intermedium grown in different conditions, dynamic polymorphisms for qualitative and quantitative traits are important for plants' adaptability. Differences in average values of spike quantitative traits have been determined among all populations and years, which indicates the influence of microgeografic conditions and climate on these traits. [ABSTRACT FROM AUTHOR]