Structural and Functional Organization of the Leaves and Cellular Metabolism of the Hybridogenic Taxon Echinops saksonovii (Asteraceae, Asterales) Compared to the Parental Species

Hybridization is an important component of plant evolution and speciation. Interspecific and intraspecific crossings may lead to changes in the genome, thereby influencing the morphology, adaptation, growth, and development of new plant species. The hybridogenic species Echinops saksonovii Vasjukov originates from the introgressive hybridization of E. ruthenicus M. Bieb. and E. sphaerocephalus L. At the morphological level, E. saksonovii differed from its parental species in smaller linear dimensions of the leaves and a greater length of the stomata. The content of green pigments and carotenoids in the leaves of the hybridogenic species was 2.0 and 2.5 times higher, respectively. However, E. saksonovii is closer to its parental species E. ruthenicus in terms of the ratio of pigments. An increased content of lipids responsible for the formation of thylakoid and nonplastid membranes has been found in the lipid complex of E. saksonovii. Among secondary compounds, the leaves of E. saksonovii accumulated more flavonoids and proline. In terms of the quantitative content of phenolic compounds and peroxidation products, E. saksonovii is closer to its parental shade-tolerant species E. sphaerocephalus. Therefore, some features of the structural and functional organization and cellular metabolism have been revealed in the leaves of the hybridogenic species E. saksonovii compared to its parental species, which may contribute to a better adaptability and viability of E. saksonovii and, as a consequence, to its greater competitiveness.