Phytotoxicity of Arsenate and Salinity on Early Seedling Growth of Rice (Oryza sativa L.): A Threat to Sustainable Rice Cultivation in South and South-East Asia

• Published in: Bulletin of environmental contamination and toxicology Vol. 88; no. 5; pp. 695 - 702
• Main Authors: Mamunur Rahman, M., Azizur Rahman, M., Maki, T., Hasegawa, H.
• Format: Journal Article
• Language: English
• Published: New York Springer-Verlag 01.05.2012; Springer Nature B.V
• Subjects: Agriculture - methods; Aquatic plants; Aquatic Pollution; Arsenates - toxicity; Arsenic; Asia, Southeastern; Bangladesh; Conservation of Natural Resources; Cultivation; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Germination - drug effects; Grain cultivation; Groundwater; Groundwater - chemistry; Irrigation; Oryza - drug effects; Oryza - growth & development; Oryza - physiology; Oryza sativa; Phytotoxicity; Pollution; Rice; Salinity; Seed germination; Seedlings; Seedlings - drug effects; Seedlings - growth & development; Seedlings - physiology; Seeds; Sodium chloride; Soil - chemistry; Soil Pollutants - toxicity; Soil Science & Conservation; Waste Water Technology; Water Management; Water Pollution Control; Bangladesh; Vietnam; Myanmar (Burma); West Bengal India; Asia; East Asia; Thailand; India; Phytotoxicity; Arsenic; Rice; Salinity
• ISSN: 0007-4861; 1432-0800
• DOI: 10.1007/s00128-012-0580-4

Arsenic (As) contamination is an important environmental consequence in some parts of salinity-affected South (S) and South-East (SE) Asia. In this study, we investigated the individual and combined phytotoxicity of arsenic (As) [arsenate; As(V)] and salinity (NaCl) on early seedling growth (ESG) of saline-tolerant and non-tolerant rice varieties. Germination percentage (GP), germination speed (GS) and vigor index (VI) of both saline-tolerant and non-tolerant rice varieties decreased significantly ( p  > 0.01) with increasing As(V) and NaCl concentrations. The highest GP (91%) was observed for saline non-tolerant BRRI dhan28 and BRRI dhan49, while the lowest (62%) was for saline-tolerant BRRI dhan47. The ESG parameters, such as weights and relative lengths of plumule and radicle, also decreased significantly ( p  < 0.01) with increasing As(V) and NaCl concentrations. Relative radicle length was more affected than plumule length by As(V) and NaCl. Although VI of saline-tolerant and non-tolerant rice seedlings showed significant variation ( p  < 0.05), weights and lengths of plumule and radicle of different rice varieties did not show significant variation for As(V) and NaCl treatments. Results reveal that the combined phytotoxicity of As(V) and NaCl on rice seed germination and ESG are greater than their individual toxicities, and some saline-tolerant rice varieties are more resistant to the combined phytotoxicity of As(V) and NaCl than the saline non-tolerant varieties.