Preservation of Features of Anatomical Polymorphism of Deschampsia antarctica É. Desv. (Poaceae) During In Vitro Clonal Reproduction

Abstract

We studied the anatomical features of the leaf structure of Deschampsia antarctica É. Desv. (Poaceae) obtained from seeds collected from different habitats of the maritime Antarctic. These plants have been maintained in culture in vitro for more than 7 years. The plants include stable chromosome forms comprising diploids (2 n = 26), a diploid plant with B-chromosomes (2 n = 26 + 0–3B), a triploid with rearranged chromosome morphology, and myxoploids with different ratios of diploid and nondiploid cells in the root meristem. The D. antarctica plants that were studied generally had a similar anatomical structure in culture in vitro and in nature. At the same time, plants of different cultivated genotypes also displayed their own leaf structure features. In particular, qualitative features included asymmetric four-ribs and five-rib leaves instead of typical three-rib leaves for some genotypes, some individuals characterized by the presence of unicellular nonglandular pointed trichomes on an adaxial side, differences in vascular bundle sheath, and other features. No clear dependence of the anatomical structural features on the chromosomal status of the studied genotypes was evident. At the same time, differences were evident in traits that included the number of stomata, thickness of the outer cell walls of the epidermis, bundles sheath state, number of leaf ribs, and the persistent presence of trichomes under prolonged in vitro cloning. The findings indicate that D. antarctica plants collected from different locations of the maritime Antarctic for long-term cultivation in vitro under standard cultivation conditions retain the anatomical characteristics of the wild plants. The polymorphism of in vitro-cultivated plants is not related to the polymorphism of their karyotype, but is apparently due to the heterogeneity of the original plants and possibly the epigenetic fixation of a number of anatomical features produced in the natural microhabitats of D. antarctica populations.