Effect of combined doses of gamma ray and sodium azide (mutagenic agents) on the morphological traits of some varieties of okra (Abelmoschus esculentus)

Abelmoschus esculentus (okra) is a popular health food because of its high fiber, vitamin C and folate content. It is also rich in antioxidants, a good source of calcium and potassium. Three varieties of okra: Jokoso, NHAe47-4 and Beru (a local variety) were irradiated with 20, 40, 60, 80 and 100 kr doses of gamma rays then soaked in 2.0 mM and 3.0 Mm of Sodium azide for 2h with the aim of determining the effects of the combined mutagens on their morphology. There were significant differences between the control and the treated seeds used in their germination, seedling survival, seeding length, survival to maturity and height at maturity. The effective concentrations and doses of combined mutagens for Beru and NHAe47-4 varieties were: 2.0 mM + 20 kr, 2.0 mM + 40 kr, and 2.0 mM + 60 kr and 3.0 mM + 20 kr, 3.0 mM + 40 kr, and 3.0 mM + 60 kr) while the effective concentrations and doses for Jokoso variety were: 2.0 mM + 20 kr, 2.0 mM 40 kr 2.0 mM 60 kr and 3.0 mM + 20 kr only. Jokoso variety was worse affected than any other. Sodium azide and gamma rays can be used for inducing mutation that will produce genetic variability in Okra. Key words: Abelmoschus esculentus, germination, genetic variability.