Induction of polyploidy plants through colchicine treatments in balloon vine (Cardiospermum halicacabum)^©

The balloon vine (Cardiospermum halicacabum) is a popular plant with balloon-like fruits, but there are no cultivars. Polyploidization could be used to breed new cultivars. Here, we tried to breed polyploid balloon vines for improved horticultural value. Polyploidization was induced by immersing germinated seeds in colchicine solution. The frequency of tetraploids depended on concentration and treatment time. No tetraploids were obtained from seedlings treated at 1 mM. Some tetraploids were obtained from seedlings treated at 10 mM for 24, 36, or 48 h. All were diploid-tetraploid chimeras. Some chimeras had bigger leaves and fruits than diploids, but others showed no difference. Tetraploid seeds were obtained from chimeras and their progenies. From tetraploid seeds treated with 10 mM colchicine for 24 or 48 h, five survived, including one tetraploid-octoploid chimera. It had thicker leaves and grew more slowly than diploids and tetraploids.