THE SEED PRODUCTIVITY OF PLANTS IN CENOPOPULATION TULIPA BIFLORA UNDER THE CONDITIONS OF The Republic of Kalmykia

Background: Viable seeds in the composition of populations are considered as an indicator of the life strategy of species. Hence, seed productivity can be considered as an important indicator of species adaptation to habitat conditions. The replaceable productivity of bulbous ephemeroids growing in arid conditions has not been studied sufficiently. In connection with the foregoing, our goal was to identify the seed productivity of plants in the tulip cenopopulations of the two-flowered tulip – Tulipa biflora Pall. (Liliaceae), which is recommended for protection in the conditions of Kalmykia. Materials and metods: Three cenopopulations of Tulipa biflora were studied in different plant communities on brown light loamy solonetzic soils. The sample size was no less than 30 plants of Tulipa biflora, their mature fruits were considered in the aspects of the measured features, their potential and actual seed production, as well as the percentage of seminification. The density of generative plants was taken into account at 10 sites of 0.5 square meters, located along the transect. Resalts: Biometric signs of the fetus in plants in Tulipa biflora populations were positively correlated with air temperature during the active vegetation period of the species. The potential and actual seed productivity of plants in the Tulipa biflora cenpopulations in 2017 is more than in 2016, however, the percentage of seminification marked the reverse results: in 2017 it was 4.7–10.4% lower. In this case, the plants of one of the Tulipa biflora cenopopulations, showed the greatest percentage of seminification in both studies: in 2016 – 77.5, in 2017 – 67.1 pieces of seeds per plant. The mature seed bank which is formed during the growing season in the cenopopulations of Tulipa biflora during the years under the study amounted to 782.8–1338.4 seeds per 1.0 sq.m. Conclusion: The idea of a bank of mature seeds was got – 782.8–1338.4 seeds per 1.0 m2, which is formed in the Tulipa biflora cenopopulations during the growing season, making up the reproductive potential for their renewal in the arid conditions of the Republic of Kalmykia