Overview
Iqbal et al. examined lead (Pb) accumulation and growth responses in two Pakistani rice varieties (Super Basmati and Irri-6) grown in pots with soil spiked at 0, 50, 100, and 200 mg Pb/kg under varying salt (NaCl) concentrations (0, 50, 100, 150 mM). The study is primarily a phytotoxicity investigation using artificially contaminated soil at concentrations considerably above ambient field levels; its relevance to natural-occurrence surveillance is limited. However, it provides data on differential Pb accumulation between cultivars and between plant organs (straw vs. grain) under controlled conditions in Pakistan, a country with significant rice cultivation and soil Pb contamination concerns.
Key numbers
- Soil Pb spike levels: 0, 50, 100, 200 mg/kg
- Pb in rice grain: substantially lower than straw at all treatment levels (consistent with the general translocation barrier for Pb in rice)
- Salt stress generally reduced Pb uptake and accumulation in both varieties at moderate NaCl concentrations, with effects reversing at higher salinity
- Super Basmati accumulated less Pb in grain than Irri-6 under most treatment conditions
- Exact grain Pb values reported in tables (values given as µg/g dry weight) — at 200 mg/kg soil Pb, grain Pb in Irri-6 exceeded that of Super Basmati
Methods (brief)
Pot experiment; two rice varieties; factorial design crossing Pb dose (4 levels) and NaCl concentration (4 levels); FAAS for Pb determination; Pakistan.
Implications
Certification: Provides cultivar-level differentiation for Pb accumulation in basmati vs. non-basmati rice — useful context for sourcing guidance, though soil spike levels far exceed ambient. Courses: Illustrates the general principle that straw accumulates far more Pb than grain (the plant excludes Pb at the grain-filling step), which is relevant to animal feed vs. human food exposure discussions. App: B-tier; controlled contamination study not usable for ambient concentration estimates.
Related evidence
Update history
No substantive edit history is available in this build. The full commit record is available in git.