Induced mutagenesis through gamma radiation in chickpea (Cicer arietinum L.): developmental changes and improved resistance to the parasitic weed Orobanche foetida Poir.

Induced mutagenesis trough gamma radiation was tested in chickpea to improve resistance to the parasitic weed Orobanche foetida. Seeds cv. Amdoun were exposed to increased doses up to 750 Gy. Germination rates and plant survival were scored 7 and 90 days after sowing, respectively. The 150 Gy dose was determined as the optimum dose limit causing 50% reduction in survival. The effects of doses ranging from 50 to 200 Gy were determined on various developmental traits. Fifty Gy treatment improved plant growth while doses of over 100 Gy, especially 200 Gy, reduced all the analyzed parameters of growth. Multi-shoots and delayed flowering were clearly observed in 150 and 200 Gy mutants. Gain in resistance to O. foetida and seed yield in 150 Gy mutants was demonstrated in field experiments. Genetic similarity coefficient among selected M2 plants and unirradiated plants ranged from 0.02 to 0.94, attesting of the high genetic variability induced. In conclusion, seed irradiation (LD50) was efficient in chickpea to create variable initial material in mutation breeding of new lines resistant to O. foetida.