Induction of tetraploid via somatic embryos treated with colchicine in Hevea brasiliensis (Willd. ex A.Juss.) Mull. Arg

Polyploidy is a potential way to breed new varieties with high yield and stress resistance in plants. In this study, we provided an efficient method for induction of tetraploid of Hevea brasiliensis by immerse somatic embryos in the liquid plant induction medium containing colchicine. The optimum concentration of colchicine is 5 mg/ml, and the optimum immersion time is 24-48 h. The highest average induction rate of tetraploid is 27.12% in Reyan73397 with 5 mg/ml colchicine for 48 h, and 38.89% in Reyan87662 with 5 mg/ml colchicine for 24 h. Finally, 82 tetraploids of Reyan73397 and 14 tetraploids of Reyan87662 were obtained. Compared to diploids, tetraploids exhibited less and lighter leaf veins, daker and thicker leaves, larger stomatal size and smaller stomatal density. These tetraploids have the potential to be used as parents to produce new triploid germplasms in Hevea brasiliensis breeding programs.

Automated summary

This study provides an efficient method for inducing tetraploids in Hevea brasiliensis by immersing somatic embryos in a liquid plant induction medium containing colchicine. The optimal concentration of colchicine is 5 mg/ml, and the optimal immersion time is 24-48 hours. The tetraploids obtained have characteristics such as lighter leaf veins, thicker leaves, larger stomatal size, and smaller stomatal density, compared to diploids.