Hydroponics Screening of Rice Genotypes for Iron Toxicity Tolerance

30 rice genotypes with different growing performances under Fe toxicity were screened under three levels, normal culture solution (control) and with excessive ferrous (Fe²⁺) concentrations of 600ppm and 800ppm. Remarkablegenotypic variation in tolerance to excessive Fe²⁺ was observed. Variance due to genotypes was found highly significant for visual bronzing scores (toxicity) and biomass, which indicated that the genotypes differ significantly at all three levels. At 600 ppm of Fe, IVT-33, CUL-8723 and CUL-18716 were showing lowest leaf bronzing values. Whereas, CUL-8723, Tulasi and CUL-18716 showing lowest bronzing values at 800 ppm of Fe. Overall CUL-8709, PM-709, ASD-16, CUL-210-29, AM-10-7 and CUL-90-03 were considered as highly susceptible genotypes for both observations and two Fe treatments. Tulasi was most tolerant genotype, as it shown lower leaf bronzing values, lower normalized values, higher biomass content and lower reduction percentage in biomass.