Effect of mercuric chloride on seed germination, seedling growth and enzyme activities in maize (Zea mays L.) Bose Bandana1,*, Kumari Sweta1, Anaytullah1, Srivastava A.K.1, Kuril S.K.1, Singh P.K.2 1Department of Plant Physiology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi-221 005. 2Department of Botany, U.P. College, Varanasi-221 005. *Corresponding author: E-mail: bandana_bose2000@yahoo.com
Summary The phytotoxic effect of mercuric chloride on seed germination and seedling growth of maize (var. Jaunpuri) was studied by seed soaking treatment with different concentrations of mercuric chloride (0 to 3.0 mM). Different physico-chemical parameters were studied, viz., seed germination, length of plumule and radicle, absolute water uptake (AWU%), relative water uptake (RWU%), amylase activity (endosperm) and proline content (seedling). Increase in concentration of mercuric chloride from 0.5 to 3.0 mM decreased seed germination significantly when compared with control. Similar trend was noticed in other parameters like radicle and plumule length, AWC%, RWU% and amylase activity. However, seedling proline content increased with increase in HgCl2 concentration. In another experiment seed treatment for 48 h with mercuric chloride (0.5 to 1 mM), inhibited the no. of leaves, root length, shoot length, no. of adventitious root, leaf area, fresh weight of roots and shoot, chlorophyll and nitrogen contents and nitrate reductase activity while superoxide dismutase activity as well as membrane injury enhanced in 8 and 12 days old seedlings, respectively. However, values of no. of leaves, root length, shoot length and fresh weight of roots were not significant. Similarly, maize leaves collected from 12 days old control seedling when floated over mercuric chloride solution (0.5 to 1 mM) for 24 h a constant decline was noted in nitrate reductase activity whereas accelerations were recorded in superoxide dismutase activity and membrane injury. The finding suggested that the mercury has direct impact on membrane structure of the tissue and on the enzymatic activity of the plant system. Top Key words Absolute water uptake, mercuric chloride, relative water uptake, sulphyldryl. Top |