PHYSIOLOGICAL AND ANATOMICAL MODIFICATIONS OF DATURA STRAMONIUM L. ROOTS COLLECTED FROM DRY ENVIRONMENTS

The effect of variable availability of soil water in natural ecosystems on structural features of roots in differently adapted populations of Datura stramonium was evaluated. Datura stramonium was collected from eight water deficit habitats. Soil physico-chemical attributes such as moisture content (%), pH, ECe, saturation percentage, organic matter (%), ionic contents i.e., monovalent ions (Na+, K+, and Cl-) and divalent ions (Ca2+ and Mg2+) were analyzed. Root physio- anatomical attributes such as ionic contents in roots (Na+, K+, Ca2+, Mg2+ and P) and structural features of root such as epidermal and endodermal cell area, cortical region thickness, root radii, vessel number, root protoxylem and metaxylem, phloem area and xylem to phloem ratio were measured. The reduced availability of water significantly affected many functional and structural attributes. The most important one were reduced uptake of micronutrients and alteration in dermal, ground and conducting tissues. Population of dry habitats i.e., Jabba (JAB) and Choa Saidan Shah (CSS) tolerated the extremities of adverse environmental constraints by increasing epidermal and endodermal areas, and, cortical region thickness to protect them from mechanical injury. Additionally, decreased vessel number and increased metaxylem and protoxylem areas help to conserve more water in dry environments. In conclusion, roots of Datura stramonium possessed some physiological modifications by increasing uptake of sodium (Na+) and structural changes by changing dermal and vascular tissues of root in population grown in dry habitats i.e., Choa Saidan Shah (CSS) and Jabba (JAB) site.