Identification of novel mutants through Electron beam and Gamma irradiation in chickpea (Cicer arietinum L.)

Chickpea is an important food legume grown worldwide. There is an increasing concern on narrowing of genetic base in mos t of the gra in legumes including chickpe a. Mutagenesis using ionizing radiations is one of the many ways of increasing genetic variability. To explore the potential of electron beam irradiation for mutagenesis and to compare it to gamma rays, seeds of a popular chickpea variety ‘Vijay ’were irradiated with four doses (200–500 Grey) of either electron beam or gamma rays. The M1 plants were grown in the field, harvested individually, and sown in the subsequent year to raise M2 plant to row progenies. Chlorophyll and other morphological mutants were identified in the M2 generation. The mutation frequency was found to be more for electron beam irradiation as compared to gamma rays treatments of the same dose. The overall mutation frequency calculated as chlorophyll mutants per 1000 M2 plants was almost double in case of electron beam (17.82) as compared to gamma irradiation (8.64). The overall percent of M1 derived families segregating for chlorophyll mutations was 4.42% for gamma rays while it was 9.42% for electron beam. Mutagenic effectiveness and efficiency was also higher for electron beam irradiation as compared to gamma rays of same doses. Some morphological mutants like no serration mutant, missing leaflet mutant, round leaflets with open flower were observed. Other putative mutants with agronomical importance (large pod, more branches, green canopy at harvest, early flowering, early maturity etc) were also isolated. These mutants constitute an important repository and may find uses in basic studies as well as in chickpea improvement program.