On the rare species biology of the genus Iris L. in culture and natural habitats in the South Urals

The article represents a comparison of rare species morphometric indicators and seed productivity of the genus Iris in the South Urals. It's shown that I. scariosa, I. humilis and I. pseudacorus habitus deteriorate and seed productivity decreases under culture conditions, but I. pumila samples in culture outstrip plants in natural habitats. I. pumila is promising for cultivation in the South Ural region


Introduction
Species of the genus Iris L. are characterized with high decorative qualities; since the ancient times they have been introduced into flower culture and widely used in settlement greening, erven, gardens. There are a number of wild species promising for cultivation and breeding found in the natural flora. Many wild species of the genus are included in the Red Books of various regions, because they disappear under the influence of anthropogenic factors. Studying their biology, reproduction and other characteristics has not only important biological significance, but allows us to recommend the most resistant species with valuable decorative qualities to expand the range of flower-decorative plants. The introduction test was done in the South Ural Botanical Garden Institute of UFRC RAS (Ufa). The introducing conditions corresponded to a greater extent to the natural conditions for Iris pumila habitats, but significantly varied for the other three species, two of which grow in Trans-Urals, and I. pseudacorus -in quite different environmental conditions (wet meadows).

Materials and methods
Studying morphometry in culture and natural conditions was carried out according to V.N. Golubev [3] approach in the flowering phase on 25 average-generating individuals of each CP; a counting unit was one annual shoot. The following parameters were taken into account: clone diameter (dc), cm; number of vegetative escapes (Ne), pcs.; number of generative shoots per 1 plant (Ngs), pcs.; generative shoot height (h), cm; length (Ll) and width of a generative shoot second leaf (Sl), cm; length (Llpp) and width of the lower perianth lobe (Slpp), cm; length (Lupp) and width of the upper perianth lobe (Supp), cm; flower diameter (dfl), cm.
Seed productivity was determined by a standard technique [4] (Vainagiy, 1974). The number of flowers (Nfl) and fruits (Nfr) per a generative shoot was accounted; real (RSP) and potential (PSP) seed productivity, and seed productivity coefficient (Isp, %) were estimated.

Results
The species morphometric indicators comparison of the Iris genus in natural habitats and introduction according to the averaged data of all CPs of each species for 4-6 years of research ( Table 1) has shown that reliable differences between plants at a 5% significance level are revealed for most parameters of I. pumila and I. pseudacorus, but the differences are mostly unreliable (at t fact <2.064) for other two species.
I. scariosa, I. humilis, and I. pseudacorus habitus is worthening under culture conditions. I. pumila in culture surpasses plants in natural habitats. The differences are caused, first of all, by plant treatment in culture, higher soil moisture compared to the species natural habitats, and the lack of competition with other plant species. Investigations of the long-term average seed productivity of Iris species (Table 2) has demonstrated that I. scariosa, I. humilis, and I. pseudacorus have average values of the most reproductive parameters under conditions of introduction significantly lower than the average values obtained in natural populations. Note: unreliable differences by Student criterion are italicized Assessment of I. pumila seed productivity has shown the most reproductive parameters reliably exceed similar parameters under natural then cultural conditions, that is a significant indicator of a species adaptation in culture.
I. pumila is the most promising for cultivation in the South Ural region.