Author : Ellyzarti H. Muchrimsyah

Summary : The effect of lead on the germination and seedling growth of two rice varieties, Azucena and IR-20, were determined. The study indicated that germination per se was not affected and the viability of the lead-treated seeds was not daged. The effect of lead on germination was visibly shown in the complete inhibition of radicle initiation in IR-20, as well as in the malformed roots of the Azucena seedlings. Root cell division, as quantitatively expressed in terms of mitotic index, was decreased with the presence of lead in the germination medium. Pre-treatment of the seeds with 50 ppm phosphorus enhanced root formation, which was more effective in Azucena than in IR-20. The inhibited as shown by the shorter and less lateral roots formed, less tiller formation, smaller leaf area, and less biomass produced. Sufficient amount of phosphorus in the solution (6 ppm) enabled the seedling to grow better in the lead medium. The phosphate intake of plants was severely reduced by increasing concentration of lead in the culture solution. Again, sufficient amount of phosphorus in the growth medium, improved the growth as well as the phosphate intake of the plants.