Abstract
A good understanding of existing variability in Mn and Al toxicity tolerance among chickpea accessions is required to tackle ion-induced toxicities through the use of tolerant accessions. This study sought to identify acid-tolerant accessions through hydroponic and pot experiments for promotion and adoption in acidic environments. About 26 accessions were screened in nutrient solutions containing 0, 15, and 60µM Al, and 2 and 150µM Mn concentrations, and in pot experiments of pH levels 4.5 and 6.5. The experiments were conducted in a glasshouse with temperatures averaging 17OC at night and 25OC during the day. Split plot designs with Al and Mn concentrations as the main plot factor and accessions as the sub-plot factor and replicated thrice were used. Relative tolerance index (RTI), relative root length (RRL), relative shoot length (RSL), relative root weight (RRW), and relative shoot weight (RSW) were used as indices for tolerance for Al, and RSL, RSW, and symptom scores for Mn. Accessions Saina 1, ICCVs 11514, 11519, 11504, 11316, and 07114 were consistently tolerant or moderately tolerant across all indices at 15µM Al. Chania 1, ICCVs 03305, 93954, 07313, 96329, and 97110 were sensitive. At 60µM Al, most accessions were sensitive across all indices. Pot RRL results correlated significantly (r = 0.8) with those from the hydroponic experiments at 15µM Al, with ICCV 11504, ICCV 11514, Saina 1, ICCV 07114, Chania 2, ICCV 11316, ICCV 00108, K036, Leldet 068, and ICCV 10515 being moderately tolerant. In screening for tolerance to Mn, ICCV 07313, 07101, 97128, 11514, Chania 2, and Saina 1 were tolerant. Pot RSL values correlated weakly (r = 0.1) with those of hydroponic experiments. In conclusion, ICCV 11514 and Saina 1 emerged as the accessions with moderate tolerance to soil acidic conditions