Advances in Environmental Research Volume 3, Number 3, September 2014 , pages 207-216 DOI: https://doi.org/10.12989/aer.2014.3.3.207 |
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Phytotoxic effects of mercury on seed germination and seedling growth of Albizia lebbeck (L.) Benth. (Leguminosae) |
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Muhammad Zafar Iqbal, Muhammad Shafiq and Mohammad Athar
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Abstract | ||
A study was conducted to determine the phytotoxic effect of mercury on seed germination and seedling growth of an important arid legume tree Albizia lebbeck. The seeds germination and seedling growth performance of A. lebbeck responded differently to mercuric chloride treatment (1 mM, 3 mM, 5 mM and 7 mM) as compared to control. Seed germination of A. lebbeck was significantly (p < 0.05) affected by mercury treatment at 1 mM. Root growth of A. lebbeck was not significantly affected by mercury treatment at 1 mM, and 3 mM. Shoot and root length of A. lebbeck were significantly (p < 0.05) affected by 5 mM concentration of mercury treatment. Increase in concentration of mercury treatment at 5 mM and 7 mM significantly (p < 0.05) reduced seedling dry weight of A. lebbeck. The treatment of mercury at 1 mM decreased high percentage of seed germination (22%), seedling length (10%), root length (21.85%) and seedling dry weight (9%). Highest decrease in seed germination (51%), seedling (34%), root length (48%) and seedling dry weight (41%) of A. lebbeck occurred at 7 mM mercury treatment. A. lebbeck showed high percentage of tolerance (78.14%) to mercury at 1 mM. However, 7 mM concentration of mercury produced lowest percentage of tolerance (51.65%) in A. lebbeck. The seed germination potential and seedling vigor index (SVI) clearly decreased with the higher level of mercury. Plantation of A. lebbeck in mercury-polluted area will help in reducing the burden of mercury pollution. A. lebbeck can serve better in coordinating in land management programs in metal contaminated areas. The identification of the toxic concentration of metals and tolerance indices of A. lebbeck would also be helpful for the establishment of air quality standard. | ||
Key Words | ||
mercury; seed germination; growth; seedling vigor index; tolerance; toxicity; Albizia lebbeck; tree | ||
Address | ||
(1) Muhammad Zafar Iqbal, Muhammad Shafiq: Department of Botany, University of Karachi, Karachi-75270, Pakistan; (2) Mohammad Athar: California Department of Food and Agriculture, 3288 Meadowview Road, Sacramento, CA 95832, USA; (3) Mohammad Athar: Department of Food Science and Technology, University of Karachi, Karachi-75270, Pakistan. | ||