The variability of morphological features in plants and vitality structure of cenopopulations of species of genus Tulipa (Liliaceae) in the natural reserve "The Black Soil"

The article deals with the results of a study of variability of morphological features of plants and vitality structure of cenopopulation Tulipa gesneriana and Tulipa biflora, growing within the territory of the State Natural Biosphere Reserve “The Black soil” in the Republic of Kalmykia. We have investigated the species Tulipa gesneriana cenopopulation number 1 in the forb-grass (Poaceae - Mixteherbosa) community; cenopopulation number 2 in the composition of herbage-fescue-wormwood (Artemisia austriaca - Festuca valesiaca - Mixteherbosa) community, which grows in the meadow-chestnut soils; the species Tulipa biflora - cenopopulation number 3 as part lukovichnomyatlikovo - lerhopolynnogo (Artemisia lerchiana - Poa bulbosa) communities and cenopopulation number 4 as part of ephemeral-lukovichnomyatlikovo - wormwood (Artemisia - Poa bulbosa - Ephemerosa) community growing in the brown desert - steppe alkaline soils. Within the period from 2013 till 2015 the species under investigation revealed the variability of morphological features in environmental conditions existing in their growing season. The analysis of morphological structure of plants has shown that in 2014 Tulipa gesneriana had favorable conditions for the growth and development. Tulipa biflora displayed its maximum signs in 2015, the minimum - in 2014, except for the width of the lower and upper leaves. Twelve morphological features that characterize the vegetative and generative sphere of plants have been studied in populations Tulipa gesneriana, meanwhile Tulipa biflora had only nine ones. All studied traits in both species of the genus Tulipa varied on high and medium levels. At the same time Tulipa gesneriana and Tulipa biflora, regardless of species, the high level of variability were signs of “the length of interstices” and “flower arrow length”, “width of the lower sheet” and “width of the top sheet,” a low level of variability identified for the characteristic “length backsheet”. Assessment of life cenopopulation Tulipa gesneriana and Tulipa biflora in a three-year period of the study was performed by determining criterion Q and vitality index of IVC. It was revealed that in spite of the different species and phytocenotic affiliation, both coenopopulations under the study Tulipa gesneriana and both cenopopulations of Tulipa biflora according to their vitality structure refer to the depressive type.