Radiation-based mutation induction produces a wide range of mutations, including point mutations, chromosomal rearrangements, deletions, and duplications. Mutation breeding for resistance to Stemphylium botryosum SB in lentil is a long-term process that requires careful selection, evaluation, and breeding efforts.

The initial step involves studying the variation of growth parameters under ionizing radiation. This includes analyzing the germination index of lentil seeds and determining the dose of radiation that results in a 50% reduction of growth, known as the LD50. Physiological and biochemical responses of lentil (Lens culinaris Medik.) genotypes under SB inoculation stress were evaluated as compared to their control counterparts. The chlorophyll content in fully opened leaves was found to be not reduced compared to control positive test, (measurements done for M1, 2, 3 and 4 generations). Significant variation in total phenolic and flavonoids contents and the antioxidant capacity (DPPH test) compared to wild type and positive control; the variation not showed same rates in mutant genotypes. Under SB stress, activities of measured anti-oxidant enzymes were perturbed. Proximate content showed variation in component composition for the different genotypes.  

Relevant data regarding infestation rate and disease severity rating are collected and recorded for the selected genotypes from the M2, M3, and M4 generations. Phenotypic traits that contribute to the selection of promising and valuable genotypes with respect to the breeding goal are identified. Based on the results of confrontation and infestation, six genotypes that meet the selection criteria are chosen and DNA analysis were done.