Osmotic Stress Effect on Different Cytological Characters of Roots and Growth Parameters in Different Wheat Species

Aims: To show how and why seedling growth parameters and different cytological characters of the roots of different wheat species may vary during osmotic stress conditions. To identify species that are tolerant to a lack of moisture in the early stages of ontogenesis.
Study Design: The experiments were conducted in the greenhouse of the Institute of Plant Biology and Biotechnology at 26°C±2°Ð¡ and at 3000 lux illumination. All experiments were performed in three biological replicates. At least 25 plants were studied in replication.
Place and Duration of Study: This study was conducted in the Laboratory of Cell engineering, Institute of Plant Biology and Biotechnology Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan in 2014.
Methodology: Plantlets of different species of wheat were grown for 7 days in culture water; then, for 72 hours, they were exposed to stress (a 17.6% sucrose solution). Control plantlets were grown in water. Growth, biomass accumulation, and parameters of root security were measured. Cytological examination of the root cells was carried out with squash preparation.
Results: The differences between the types of growth parameters and cytological characteristics of the root cells under stress are shown. The species identified that are tolerant to a lack of moisture in the early stages of ontogenesis are T. dicoccum Schuebl. and T. aethiopicum Jakubz.
Conclusion: Ðs a result of the experiments shows a clearly expressed common nonspecific cytological responses of cells of the root system of cereals to osmotic stress - reduction of linear growth parameters, plasmolysis. At the same time are marked a variety of specific changes, which depend on the genotype of the test forms. Nonspecific response processes of cells in the root systems studied in various species of wheat to osmotic stress can offer recommendations as to which methods can be used to assess drought resistance among any species or varieties of wheat in the early stages of ontogenesis. The degree of species specificity studied in response to osmotic stress renders it possible to identify forms that are tolerant to a lack of moisture in the early stages of ontogenesis. Wheat species such as T. dicoccum Schuebl. and T. aethiopicum Jakubz, have the most stable indicators of the development of the root system of seedlings under osmotic stress; they can serve as valuable sources of these parameters when crossing them with cultivated varieties of wheat to improve drought resistance in modern varieties.