INDUCED GENETIC VARIABILITY IN CHICKPEA (CICER ARIETINUM L.) III. FREQUENCY OF MORPHOLOGICAL MUTATIONS

A comparative study for frequency of morphological mutations induced by physical (gamma rays) and chemical (EMS) mutagens in M(2) population was conducted in two desi (Pb2000, C44), one each of kabuli (Pb1) and desi x kabuli introgression genotypes (CH 40/91) of chickpea. In M2 population, about 63 different types of morphological mutations in different parts of the plants, such as branching pattern, stem structure, growth habit, foliage type, plant height, pod and seed size, foliage color, flowering behavior and maturity was observed. The highest frequency of morphological mutations was observed in 300 Gy gamma irradiation (4.11%) of CH40/91 followed by 0.4% EMS (2.08%) of desi genotype C44. The overall frequency of mutations in physical mutagen was high in CH40/91 (2.69%) followed by Pb2000 (1.38%), C44 (1.02%) and Pb-1 (0.27%). The overall frequency of morphological mutations in chemical mutagen was very low in Pb2000 (0.45%) followed by Pb-1 (0.78%), C44 (1.53%) and CH40/91 (1.90%) as compared to physical mutagens. Overall frequency of morphological mutations in M2 population also indicated maximum mutability (2.30%) in introgression genotype (CH40/91) followed by desi genotype C44 (1.28%) and Pb2000 (0.91%), whereas kabuli type had lowest mutation rate (0.52%). The significant higher morphological as well as chlorophyll frequency of CH40/91 as compared to other three genotypes could be due to the diverse genetic nature. The gamma rays and EMS treatments differ in their mutation spectra/frequency.