Gamma-rays induced morphological changes in gladiolus

A three year mutagenesis programme was Carried out using physical mutagens (gamma rays) on four Cultivars of gladiolus viz. Peter Pear (V1), Advance Red (V2), White Prosperity (V3) and Nova Lux (V4). Three sets of each variety, consisting of 20 uniform corms and each corm 30 g (5cm diameter) in weight, were irradiated With 5, 10 & 15 KRD of gamma rays at N.B.R.I., Lucknow in Feb., 2007. A set of 10 untreated corms of each variety was used as control. Reduction in survival rate.root length, no. of spike/plant, no. of floret/spike, days to flower, self life, vase life, floret size, no. of corm/plant and weight of corm/plant were observed after irradiation and with Increase in exposure of gamma rays. In M₁ generation, significant increase in plant height and spike length at 5 KRD & stunted growth of plant/spike length at 10KRD gamma irradiation were observed in all cultivars of gladiolus. Morphological abnormalities in leaf and plants with abnormal leaves increased with increase in exposure of gamma rays. Positive correlation exists between doses of gamma rays and number of spike/plant in M₁ generation. Floret/spike was positively correlated to 5 KRD gamma irradiation and it was become negative at higher doses of irradiation. In all the cultivars the intensity of inhibition increased with increasing exposures though lower exposure in some cases was stimulatory. Cent per cent mortality was recorded in plants treated with 15 KRD gamma rays and eliminated from population at the end of first year. On the basis of present observation it may be concluded that 5 to 10 KRD doses of gamma rays are suitable for induction of somatic mutation in various cultivars of gladiolus.