Induced Chlorophyll Mutations in Lentil

Four mutations affecting chlorophyll synthesis in two small seeded (microsperma) and two large seeded (macrosperma) varieties of lentil (Lens culinaris Medic) were recorded following treatment with gamma-rays and N-nitroso-N-methyl urea (NMU). Albina and xantha were completely lethal. Chlorina with green-yellow colour had partial viability, and viridis mutants reached to maturity. The frequency of chlorophyll mutations was correlated with the dose of gamma-rays and NMU in both the varietal groups. At a common biological parameter (LD₅₀ for plant survival), the frequency of chlorophyll mutations was 1 5–2 times greater in the NMU treatment than with gamma-irradiation. There were no varietal or mutagenic differences with regard to the spectrum and relative proportion of chlorophyll mutations. The induction of four different chlorophyll mutations with similar relative proportion is a reflection of parallelism in genetic variability. NMU was 2 5—5 fold more effective and 1 4—1 8 fold efficient than gamma-rays. The chlorophyll mutations of the same categories induced in the microsperma varieties had better survival and fertility than in the varieties from the macrosperma group.