Screening and Identification of Aluminium Toxicity Tolerant Lentil (Lens culinaris Medik.) RILs based on Root Growth Studies and Organic Acid Exudation under Hydroponics

Background: Aluminium (Al) stress is among the prime limitations of crop production including Lentil, in acidic soils as Al solubilizes into phytotoxic forms at low pH causing root growth inhibition, minimizing plant-vigor and yield. The current study was performed to identify the Al tolerant RILs based on root-regrowth studies, short term growth culture and organic acid exudation in reaction to Al toxicity under hydroponics. Methods: The study involved screening for Al toxicity tolerance in recombinant inbred lines (RILs) population of lentil through root re-growth studies, short term growth response method under hydroponics treated with toxic concentration of Al (148 µM), organic acid exudation using HPLC and correlation analysis among the traits. Result: ANOVA for root and shoot traits revealed presence of highly significant genotypic differences for all the traits. High GCV along with high H2bs and GA% were observed for the traits revealing the influence of additive genes and suggested reliable selection of these traits for Al toxicity tolerance. Citric acid was exudated in highest amount in all the genotypes and was positively and significantly correlated with RRG. Based on the hydroponics study and organic acid exudation, RILs identified as tolerant were LRIL-10, LRIL-37, LRIL-68, LRIL-96, LRIL-97, LRIL-113, LRIL-125, LRIL-133, LRIL-143, LRIL-144 and LRIL-148. With further evaluation, these RILs may serve as important Al toxicity tolerant varieties suitable for acidic soil conditions. Also, these lines may serve as donors of Al toxicity loci and mapping of Al tolerance genes.