Morphological changes and induced mutagenesis in gladiolus varieties through gamma irradiation

An experiment was conducted for 3 years (2011-12 to 2013-14) at Varanasi to find out influence of various gamma doses, i.e. 1.5, 2.5, 3.5, 4.5 and 5.5 kR along with untreated (control) in different varieties of gladiolus, viz. Aldebaran, Jyotsana, Legend, Praha, Punjab Dawn, Pusa Kiran and Tiger Flame. During 1st and 2nd years various parameters were observed and data were pooled for statistical analysis, whereas during 3rd year stability of characters was observed among mutants. The experiment was laid out in randomized block design with 5 replications. Maximum leaf area was observed with control plants followed by 1.5 kR, 2.5 kR, 3.5 kR, 4.5 kR and 5.5 kR treatments. Narrower and short leaves were observed as gamma doses increased. Maximum length of spike at 1st floret opening was recorded with control followed by 1.5, 2.5, 3.5, 4.5 and 5.5 kR. There was no significant difference between 1.5 kR and 2.5 kR treatments on length of spike at 1st floret opening. Gamma dose at 2.5 kR registered durability of 1st floret followed by 1.5 kR, control, 3.5 kR, 4.5 kR and 5.5 kR treatments. No significant difference was observed between 2.5 kR and 1.5 kR treatments. Control plants gave maximum diameter of 3rd floret followed by 1.5 kR, 2.5 kR, 3.5 kR, 4.5 kR and 5.5 kR. Among varieties, cv. Jyotsana registered maximum length of spike, cv. Punjab Dawn resulted in maximum durability of floret and cv. Tiger Flame registered maximum diameter of 3rd floret. Interaction of = gamma doses and varieties were also found significant in all the characters studied. Various morphological changes were observed on gladiolus varieties in cv. Jyotsana, Legend and Praha at 1.5 to 3.5 kR doses of gamma. A mutant was identified from variety Tiger Flame at 4.5 kR of gamma irradiation. This mutant was observed during 1st and 2nd years. It was a stable mutant, hence, isolated during 3rd year. Flower colour of mutant was different to the parent. Lower petals of mutant were found of yellow colour. It looks very attractive.