Creation of variation through gamma irradiation and polyploidization in Vitex agnus-castus L.

•Dry seeds were treated with seven gamma radiation and six antimitotic agent doses.•The LD50 was found as 55 Gy for seed germination and 41.3 Gy for seedling survival.•16 variants, 8 of which derived from 10 Gy irradiation, possessed unique features.•0.05% colchicine resulted with chromosome doubling and created polyploid plant.•Mutation and/or polyploidization have potential to create variation in chaste tree.

The article deals with the impact of gamma irradiation or chromosome doubling treatments in Vitex agnus-castus. The study aimed to measure the efficiency of gamma irradiation for creating variation and chromosome doubling agents (colchicine, oryzaline and trifluralin) for polyploidization in V. agnus-castus. These treatments should help produce more desirable growth habit and novel characteristics would expand the use of V. agnus-castus L. in landscaping. The seeds were treated with seven gamma irradiation doses (10, 20, 50, 100, 200 300, 400 Gray) from a Cobalt60 source and six antimitotic agent concentrations (0.05 and 0.1% colchicine, and 0.005 and 0.01% oryzalin and also trifluralin). The LD50 was found to be 55 Gy for seed germination and 41.3 Gy for seedling survival. The desired single-stemmed plant type was obtained with mostly 50 Gy irradiation dose. Single plants survived from each of colchicine treatment. Flow cytometer analysis confirmed the plant derived from 0.05% colchicine treatment to be a polyploid. The results revealed that mutation and/or ploidy manipulation have the potential to generate much needed variation in V. agnus-castus for use in landscaping.