Effect of Drought Stress (Mannitol) on Morphological Physiological Activity and Anatomy of Cow Pea Plant(Vigna unguiculata)

Abstract

In this study 21 days old seedlings of Cow pea plant (Vigna unguiculata L) were subject to different drought stress levels (0g, 0.1g and 0.2g mannitol) at germination and early seedling growth stage of plant development. Data were analyzed for growth parameters such as plant height, fresh and dry weight, leaf water content (LWC), and length of radicle and plumule during germination period, and biochemical parameters such as proline content, membrane stability index (MSI), malondealdehyde (MDA) content, chlorophyll content, and antioxidant enzyme activity Catalase (CAT) and Peroxidase (POD). In this study it was seen that the effect of salt stress reduced plant height, fresh and dry weight, LWC, radical and plumule length. Salt stress reduced the biochemical activities and also chlorophyll a, chlorophyll b and total pigment content. The decrease was 0.58,0.11 and 0.69 respectively. The result showed an increase in the activity of CAT enzyme in leaves and root with increasing salt concentration. An increase CAT activity were found with 0.1g, 0.2g mannitol treatment which represented values of relative increasing of 15.2g/L and 17.2 in leaves and 9.2g/L and 11.7g/L in root respectively. There was increase in the activity of POD enzyme in leaves and root with increasing salt concentration. The level of POD activity was found with 0.1g,0.2g NaCl treatment, which represented relative increase 71.14 and 82.34%in leaves.