The purpose of the master's thesis is to study the morphological adaptation of the root systems of petrophytic family Caryophyllaceae to extreme conditions. The work consisted of two blocks: Laboratory experiment to study the growth of Ni-excluder Silene baschkirorum roots on agar plates with the introduction of Ni, Ca, Mg in different combinations in comparison with the Ni-hyperaccumulator Alyssum obovatum. The structural features of the leaves and the underground sphere of the 6 types of Caryophyllaceae from natural habitats with moisture deficiency. The objects of the study were four perennial main-rooted species: Dianthus versicolor, Gypsophila altissima, Silene baschkirorum, Dianthus acicularis, and two annual species – Spergula arvensis and Arenaria serpyllifolia. The influence of Ni, Ca, Mg in different combinations on the growth of roots of seedlings Alyssum obovatum and Silene baschkirorum was studied in a laboratory experiment on agar plates under standard conditions at a constant temperature and a 16-hour photoperiod in accordance with the Protocol with modifications [Xu et al., 2013]. Morphological parameters of the leaf and underground sphere of Caryophyllaceae were measured by standard morpho-anatomical methods during adaptation to moisture deficiency [Иванова, 2014; Таршис, 2007]. The results of laboratory studies have shown that in all variants of the experiment the root system of Alyssum obovatum was in 1,5–5 times better developed than Silene baschkirorum. The introduction of metals stimulated the growth of the root system in A. obovatum and didn’t affect the growth of S. baschkirorum roots. Analysis of the leaf structure in 6 species of Caryophyllaceae growing in conditions of lack of moisture revealed that xeromesophytes Arenaria serpyllifolia, Dianthus versicolor, Gypsophila altissima have low leaf density both per area and per leaf volume in comparison with mesoxerophytic species Silene baschkirorum, Dianthus acicularis, Spergula arvensis. Analysis of the root system and absorbing roots revealed no differences between studied xeromesophytic and mesoxerophytic Caryophyllaceae species. It’s established that the adaptation of the underground sphere of the studied Caryophyllaceae to the moisture deficit is realized by species-specific ways of restructuring of the root system and absorbing roots.
|Date of Award||2019|
|Supervisor||Анна Анатольевна Бетехтина (Supervisor)|