Mutation Breeding in Chickpea (Cicer Arietinum L.) for Increased Genetic Variability, Improved Quality and Agronomic Traits

Full text: Chickpea is grown worldwide, with its major cultivation area lying in the semi-arid tropics of Asia. Terminal drought is a major abiotic stress for chickpea grown in these areas, causing severe yield losses. Considering the impact of climate change on increasing the severity of terminal drought, this study is focused on inducing genetic variability in chickpea suffering from a narrow genetic base and isolating mutants resilient to terminal drought. A cultivar 'Vijay' was irradiated using 200 to 500Gy gamma rays and electron-beam. Another popular cultivar JAKI9218 was irradiated with 300Gy gamma rays. The M₁ plants were individually harvested and planted as plant-to-row progenies of M₂ generation. The selected mutants were grown as plant-to-row progeny in M₃ and M₄ generation. Agronomically important mutants were identified in M₂, including an early maturing mutant (induced by 400Gy electron-beam) maturing in 80-85 days as compared to parent cv 'Vijay' that matures in 90-100 days. Another mutant showed 2-3-fold higher proline accumulation compared to 'Vijay'. This mutant has elongated phenotype but no adverse effect on plant yield. Proline accumulation might help the plant survive stress conditions. A slow-transpiring mutant of cv JAKI9218 was isolated. The canopy temperature of the mutant (measured using an infrared-thermal camera) confirmed the slow-transpiring phenotype, which can help conserving soil moisture and, hence, a better performance under terminal drought stress. The mutants were found to be true breeding for the traits in advanced generations. Furthermore, both electron-beam and gamma ray-induced mutants accumulating high amounts of iron and/or zinc were also identified. The mutants identified in this study not only constitute an important repository of germplasm useful for basic studies, but also are useful in breeding programs to develop climate resilient varieties. (author)