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

Abstract

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.