Effects of gamma irradiation on morphology and protein differential in M1V1 population of Vanilla planifolia Andrews.

Purpose: Lower doses (1-10 Krad) of gamma-rays (γ) are frequently used in obtaining useful mutants in diverse plant species, whereas no report on gamma (γ) irradiation being used to develop new varieties of vanilla from vanilla cuttings. This study assessed the potential of lower doses of gamma-rays for vanilla mutation breeding.

Materials and methods: We compared the morphological differences between vanilla plants irradiated at different lower doses of gamma radiation (10, 30, 40, and 50 Gy). We quantified protein and compared variation from the extracted protein of vanilla shoots regenerated between treatments.

Results and conclusions: After 44 weeks, the results showed that the growth of M1V1 (mutation 1 in vegetative cycle 1) plants at 0 Gy (control) is highest compared with other doses of gamma radiation in terms of plant height and the number of shoots. However, the highest measurement for root length is at 10 Gy. The slowest growth rate was obtained from 40 to 50 Gy. Based on the unique band of protein that appears on the SDS-PAGE gel, 10 Gy has three unique bands at loci 0.105 RF, two bands lie at loci between 0.164 RF and 0.234 RF. While 30 Gy is absent two unique bands at loci 0.234 RF compared to 0 Gy. Thus, the dose of gamma rays at 10 Gy gave the highest number of protein fragments, which detected polymorphisms between the control (0 Gy) and the plants treated. To our knowledge, this is the first report of the protein variation in M1V1 of irradiated vanilla plants.