EFFECT OF SOME CHEMICAL MUTAGENS ON MORPHOLOGICAL CHARACTERS AND CORM PRODUCTIVITY OF SOME GLADIOLUS SP. CULTIVARS

Two pot experiments were carried out at the Nursery of Antoniades Botanical Garden, Hort. Res. Inst., Alexandria, Egypt during the years of 2012 and 2013. The objectives of this study were to study the effect of soaking corms of three cultivars of Gladiolus sp., namely: Eurovision (Red), Nova Lux (Yellow) and Peter Pears (Peach) in the aqueous solution of either ethyl methane sulfonate (EMS) at the rates of 0, 0.1, 0.2, 0.3 and 0.4 % concentrations for 24 hrs. or colchicine at the rates of 0 and 0.1% concentrations for 24 or 48 hrs. on growth performance and corm production. The obtained results indicated that the different levels of EMS had a slight effect on sprouting date, but colchicine treatments induced a significant earliness in both seasons, with the dominance of soaking for 24 hrs. treatment. Cultivar factor had no pronounced effect on sprouting date. All treatments increased plant height over control, but the tallest plants were obtained from corms soaked in EMS at 0.1 or 0.2% concentrations. Plants of cv. Peter Pears were generally taller than those of Eurovision and Nova Lux cultivars. The greatest No. leaves/plant were recorded in the two seasons by soaking the corms in 0.1% colchicine solution for 24 hrs. Furthermore, soaking in 0.1% colchicine solution for 48 hrs. and in EMS one up to 0.3% level recorded also a higher No. leaves. Eurovision and Nova Lux cvs. gave higher No. Leaves than cv. Peter Pears in both seasons. However, the greatest No. Leaves/plant for the 3 used cultivars in both seasons were also attributed to treating with 0.1% colchicine solution for 24 hrs. Colchicine at 0.1% for 24 hrs. resulted the widest diameter and heaviest fresh weight of the new formed corms, as well as the highest number of cormels/plant over control and other treatments in most cases of the two seasons. The highest No. cormels/plant in the two seasons were recorded for Eurovision and Nova Lux cvs. also by soaking in 0.1% colchicine solution for 24 hrs., but for cv. Peter Pears that was gained by soaking in 0.1% EMS solution for 24 hrs. Therefore the study recommended to soak the corms of the three studied cultivars in 0.1% colchicine solution for 24 hrs. immediately before planting to get better growth performance and higher corm production.