Mutagenic Response of Isabgol (Plantago ovata L. forsk) to Gamma-rays

The fresh seeds of isabgol variety RI-87 were subjected to 15, 30, 45, 60, 75, 90, 105,120 and 135 Kr doses at Co₆₀ gamma-rays and lab as well as field experiment was carried out during rabi 2002-03 and 2003-04. The effects of gamma-rays were studied on different parameters such as germination percent, seedling height, seedling dry weight and pollen fertility in M₁ generation and frequency and spectrum of chlorophyll and viable mutants, mutagenic efficiency and effectiveness in M₂ generation with employing nine doses of gamma-rays and one control. Reduction of germination, seeding height, seedling dry weight and pollon fertility in the M₁ generation was observed with increases doses of gamma-rays. In general the frequencies of chlorophyll mutations increased in linear fashion at low and medium doses and were erratic reduction at higher doses. The spectrum of chlorophyll mutants included albina, xantha, chlorina, viridis, tigrina and others. The frequency of these mutants varied with treatments. The 105 kR doses of gamma-rays produce highest frequency of viable mutants. Occurrence of major viable mutants from seedling to adult growth stages were varied viz., broad and narrow leaves, paired spikes, coxcomb spikes, ball mutants, gappy spikes, partial and complete sterile. A dose rate of 90 kR and 105 kR were most effective as well as efficient treatments.