hazardous index

Lead as a heavy metal and permanent chemical contaminant threat the health of environment and alive creatures through different artificial and natural sources. In order to investigate the effect of methyl jasmonate and lead stress on growth characteristics, the adsorption and accumulation of lead and hazardous index in basil, a pot factorial experiment was carried out based on completely randomized design in research greenhouse of Ferdowsi University of Mashhad. The treatments consisted of three levels of lead nitrate (0, 200 and 400 mg/kg soil), and methyl jasmonate spraying in three concentrations (0, 0.5 and 1 mM). The mean comparison of data represented the reduction in all the studied morphological traits and increasing the amount of lead in the leave and root of the plant and hazardous index with increasing lead stress levels and spraying with methyl jasmonate could partly improve some of these traits. So that spraying with 1 mM methyl jasmonate cause to increase 6.01% inflorescence length and cause to decrease lead amount of the eave 96.56, 79.31 and 99.20%, respectively and hazardous index, however, at o.5 mM methyl jasmonate cause to increase the number of branches and aerial fresh weight, 27.66 and 9.84%, respectively. Therefore, it seems that application of methyl jasmnate on stress conditions could improve partly the traits and so in some cases 1 mM methyl jasmonate concentration cause to decrease some morphological traits. Therefore, application of o.5 mM methyl jasmonate on lead stress is recommendable.