VARIABILITY OF NUCLEOTIDE SEQUENCES OF THE NUCLEAR GENE GBSS1 (WAXY) AND REPRODUCTIVE RELATIONSHIPS IN THE StH-GENOMIC GROUP OF SPECIES ELYMUS CONFUSUS, E. PESCHKOVAE AND E. SIBIRICUS (POACEAE)
Elena V. Shabanova, Alexander V. Agafonov, Olga V. Dorogina
Central Siberian Botanical Garden, SB RAS, Novosibirsk, Russia
Keywords: Poaceae, Triticeae, Elymus, diagnostic traits, hybridization, GBSS1, inheritance, nucleotide sequences, taxonomy
Abstract
According to the descriptions, the Siberian species Elymus peschkovae Tzvelev and E. confusus (Roschev.) Tzvelev (Triticeae, Poaceae) differ in the presence or absence of trichomes on the surface of lemmas and the segments of the spikelet axis (rachillas). Two methods were used for studying the microevolutionary relationships between these species: hybridization of biotypes from different locations and analysis of the nucleotide sequences of the low-copy nuclear gene GBSS1. The created and grown hybrids in combinations E. peschkovae × E. confusus: AMU-8804 × BER-0807 and AMU-8804 × BUK-1109 showed complete seed sterility in two field vegetations. In the interspecific hybrid E. confusus TAR-0730 × E. peschkovae JTO-1708, a single grain was found from which an absolutely sterile individual was grown. Taking into account the vast species ranges, three hybrids were created between Magadan biotypes from the same habitat in the combination E. confusus MOL-1887 × E. peschkovae MOL-1882. The plants showed seed fertility (SF) values of no more than 1-2 grains per spike. Five grown F2 plants of this combination showed complete sterility. At the same time, intraspecific hybrids of E. confusus between biotypes from different geographical habitats in three cross-combinations showed a relatively high SF. In addition, a comparative study of the GBSS1 gene sequences in accessions from our collections was carried out compared with clones of reference species. Differentiation of clones by the St2 subgenome in E. confusus, E. peschkovae and E. sibiricus L. did not reveal any clear relationships between the species. At the same time, species specificity in the H1 subgenome was noted, confirming the existence of microevolutionary isolation of E. peschkovae and E. confusus. It was concluded that reproductive relationships between individuals of the two species are possible according to the model of introgressive relationships between E. fibrosus (Schrenk) Tzvelev and E. caninus (L.) L.
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