Cytological and Morphological Responses of Strawberry (Fragaria spp.) to Polyploidization

Strawberry (Fragaria spp.) is broadly planted for its fruit, fragrance, color, taste, and sweetness. Some people are concerned about transgenic plants and their products. Furthermore, genetic diversity is one of the basics of plant breeding programs. Polyploidy induction is one of the solutions to create genetic diversity and to reduce the concerns about transgenic plants. This experiment was conducted in a randomized complete block design to induce polyploidy in strawberry (Fragaria spp. cv. Kurdistan) using different concentrations of colchicine. We aimed to examine the possibility of polyploidy induction, to determine the best concentration, and to evaluate strawberry responses to polyploidy. The tetraploidy percentage in the plants treated by 0.7% colchicine was more ‎than 80%. Tetraploid plants had a greater fruit ‎length and diameter, fresh fruit weight, and larger fruit ‎volume than the controls. Such plants had ‎a lower stomata number with a larger size and a larger chloroplast number ‎ than the diploids. ‎Ultimately, considering the flow cytometry results, and the number of modified plants, the best concentration was 0.7% colchicine treatment, which could be used as a suitable concentration for ploidy induction in strawberries.