Frequency and Spectrum of Chlorophyll Mutations Induced by Physical and Chemical Mutagens in Basmati rice (Oryza Sativa I.)

The frequency and spectrum of chlorophyll mutations induced by γ-rays (20, 30 and 40 kR), EMS (0.5, 1.0 and 1.5 per cent) and sodium azide 0.5, 1.0 and 1.5 mM) were studied in three verities of rice, namely Basmati 370 and Ranbir Basmati, Saanwal Basmati. The highest frequency was obtained in 0.5 mM sodium azide treatment for Basmati 370 and Ranbir Basmati, whereas Saanwal Basmati exhibited highest frequency with 1.0 mM sodium azide both on M₂ family and seedling basis. Among the mutagens, the highest frequency was obtained with sodium azide followed by EMS and ?-rays for all three varieties. The spectrum of chlorophyll mutations of albino, xantha and striata was 68.27, 18.00 and 13.73 per cent, respectively Chlorophyll mutations occurred more frequently in Saanwal Basmati than Ranbir Basmati and Basmati 370.