HISTOLOGICAL AND MORPHOLOGICAL RESPONSES OF BACOPA MONNIERI (L.) PENNELL IN GLYCOPHYTIC AND HALOPHYTIC CONDITIONS

Bacopa monnieri (L.) Pennell (family Plantaginaceae) is an important therapeutic glycophytic plant used in the treatment of various ailments. It is found to grow even in brackish conditions. While surviving in such conditions, the plant evolves various adaptive mechanisms. The present study investigates the histological and morphological responses of Bacopa monnieri grown hydroponically under glycophytic and halophytic conditions. Plants were grown in Hoagland solution and subjected to various salt (NaCl) treatments. Plants cultivated without salt stress served as the control. Morphological analysis was done with the help of the graduated scale and graph paper. Histological investigations were carried out by hand sectioning followed by safranin and glycerine treatment. Photographs were taken with the help of Leica M 80 Stereomicroscope and Mag Cam. Significant morphological changes were observed regarding the leaf area, root and shoot length, tolerance index and stomatal index. The histological analysis revealed the presence of salt glands, starch granules, thickened cuticle, aerenchymatous cortex, prismatic crystals of calcium oxalate, phi shaped thickenings and Y, X shaped cytoplasmic strands in response to salt stress. The histological and morphological changes are the result of the mechanisms adopted by the plant to cope up with the saline stressful conditions.