Morphophysiological Parameters of Growth and Development of Seedlings of Gleditsia triacanthos L. in the Early Stages of Ontogenesis under Conditions of Changing Lighting Intensity

Background: Gleditsia triacanthos L. is a valuable taxon for agroforestry. This species is promising for the creation of protective plantations and has a wide range of economically valuable traits, in particular, drought tolerance. In this regard, the aim of the work was to evaluate morphophysiological parameters of growth and development of G. triacanthos seedlings at early stages of ontogenesis under conditions of changing light intensity. Methods: To achieve this goal, seeds of G. triacanthos were sown with subsequent selection of individuals for the study possessing homogeneity of genetic structure. Analysis of close relatedness of individuals of G. triacanthos showed low intraspecific diversity by Nei (0.27 to 0.62). To evaluate the development of seedlings of G. triacanthos at early stages of ontogenesis, morphophysiological methods were used. Result: Under unfavorable conditions due to low light, the growth and development of the embryonic root and seedling formation was slow. However, all subphases of G. triacanthos seed organogenesis were passed in 98% of individuals, thus forming seedlings under standard criteria. Accumulation of total chlorophyll content in unfavorable conditions was 3 times less compared to individuals in favorable conditions. At the same time, there was a tendency to increase the sum of chlorophylls in the leaves of G. triacanthos in each experimental group at 30 days (p less than 0.05). As a result, it was revealed that light intensity is a limiting parameter for accelerated growth and development of G. triacanthos seedlings.