A REVIEW ON ALUMINUM TOXICITY AND QUANTITATIVE TRAIT LOCI MAPPING IN RICE (ORYZA SATIVA L)
Adnan Rasheed, Shah Fahad, Muhammad U. HASSAN, Mohd Tahir, M. Aamer, Ziming Wu
Abstract
Rice is one of the main staple foods of 50% of the world's population. Aluminum (Al) toxicity is affecting rice growth on acidic soils. We described positive and toxic effects of aluminum on rice, growth on acidic soils as well as function of mutant genes viz. Nrat1, ART1, STAR1 and STAR2 which require further analysis, especially regulation of ART1, STAR1 at transcriptional level to unfold their role in Al tolerance. Nrat1 gene involved in natural variations for Al tolerance and this would be a novel step in generating natural variation in rice populations. This review highlighted strong theoretical base to understand Al toxicity tolerance mechanisms in rice and we presented several quantitative trait loci e.g. qRRE-11, qRRE-1 controlling Al tolerance in rice at seedling stage which could be transferred via master-assisted selection to enhance Al tolerance in rice. Preliminary screening technique using Al toxic levels is an ideal way to screen resistant seedling in hydroponic environment with the secondary method entailing alterations in soil pH. The molecular basis of Al tolerance should be under more focus, including the novel markers and genes, secondary tolerance indices, BRILs population to develop tolerant varieties in rice but physiological base tolerance mechanisms cannot be overlooked.