Effect of gamma irradiation on morphological changes, flowering and induced mutants in gladiolus

摘要

Investigation was carried out for 3 years (2011-12, 2012-13 and 2013-14). Gamma doses, i.e., 0.0, 1.5, 2.5, 3.5, 4.5 and 5.5 kR were applied on seven gladiolus varieties (Aldebaran, Jyotsana, Legend, Praha, Punjab Dawn, Pusa Kiran and Tiger Flame). Maximum plant height and leaf area index were registered with control which was at par with 1.5 kR irradiation. Early colour show of floret petal was recorded with 5.5 kR and it was exhibited late with control. Lower dose of gamma irradiation (1.5 kR) exhibited the maximum diameter of 1st floret. Maximum spike length was recorded with control and it was at par with 1.5 kR. Various morphological changes were observed on the plants and flowers in Pusa Kiran, Jyotsana and Praha varieties at 2.5 and 4.5 kR gamma irradiation doses. A mutant was identified during vM(1) and vM(2) in variety Tiger Flame at 4.5 kR dose of gamma irradiation. This mutant was isolated during vM(3) having yellow colour lower petals, whereas in parent genotype petals colour was orange. Flowers of mutant are arranged densely on the spike due to short internodal length, resulting in attractive look.