EFFECT OF ARSENIC-INDUCED TOXICITY ON SEED GERMINATION OF Vigna radiata (L.) R. WILCZEK AND Vigna mungo (L.) HEPPER: A COMPARATIVE STUDY

Abstract

Arsenic (As) is a highly toxic metalloid present in soils, sediments and water. Arseniccontamination in soil and/or groundwater is a global alarm because of its quick mobilization in theenvironment during recent decades. Exposure to arsenate causes considerable stress in plants,including inhibition of growth, physiological disorders and finally death. In West Bengal (India),several areas with agricultural practices are arsenic contaminated. The increased arsenic levels insoil severely affect the normal growth and development of plants and eventually result in areduction in the yield of many crops. Arsenic is not only being bioaccumulated via groundwater-plant-soil system, it is severely affecting the rural economy by reducing the crop yield.Development of safe crops for cultivation in arsenic contaminated soil is an important strategy tocounter the detrimental effect of arsenic accumulation in crop plants. Thus, understanding ofdifferent morphological traits is extremely important from very early stage of growth anddevelopment. Several studies on the effect of arsenic on some crops have shown that arsenic stresssignificantly hampers the growth, development and yield of several plants. However, comparativeanalyses of the effects of arsenic-stress on different crop plants have not been studied thoroughly.This study has been done with two species of Vigna viz. Vigna radiata (L.) R. Wilczek and Vignamungo (L.) Hepper to study their response to arsenic stress. Both of these crops showed significantdecrease in seed germination and radicle growth with increasing arsenic concentration. However,regarding seed germination, the two species responded differently upto 150 μM of arsenicconcentration, while at 200 μM, they responded similarly. Additionally, V. mungo was found to bemore sensitive than V. radiata regarding radicle growth at lower arsenic concentration. The studywill help for future agricultural practices of these economically important crops