Anatomical changes in the leaves and roots of Jatropha curcas L. cultivated under saline stress

Abstract

The species Jatropha curcas L. is among the most prominent sources of oilseeds, with low water requirement and nutrition, and promising to arid and semiarid regions, usually subject to soil salinization. The objective of this study was to evaluate the effect of different salt concentrations on the anatomy of leaves and roots of Jatropha curcas. Fifty seeds were sown in trays and the seedlings transferred to pots with a capacity of 5 liters, the test was conducted in a greenhouse. After 21 days of germination, the plants were subjected to the following saline treatments: 25; 50; 75; 100; 150 and 200 mM NaCl, and the control (0 mM NaCl) in a randomized design with five replicates per treatment. At the end of the 32 days of treatment, the third leaf and roots measuring approximately 5 cm in length, were collected and fixed in FAA 50. Transverse sections from the leaves middle portion and the middle region of the root were cut and stained with safrablau. Were observed the reduction in xylem and phloem leaf cells and changes in their distribution as a function of increasing concentrations of salt in the solution. In roots it was observed that the high salt concentration increased xylem cells and endoderm lignification and reduced diameter and number of vessel elements. Thus, the species studied has considerable anatomical changes in leaves and roots when grown under high salt concentrations.