Effects of Colchicine and Oryzalin on Polyploidy Induction and Production of Capsaicin in Capsicum frutescens L. Pawnpirun

Abstract

Polyploidy were induced in Capsicum frutescens L. seedlings using colchicine or oryzalin. Seeds were immersed in colchicine at concentrations of 0, 100, 200 and 300 mg/L or oryzalin at concentration of 0, 10, 20 and 30 mg/L under dark conditions at room temperature for 6 h before germination. The results showed that 300 mg/L colchicine could induce the highest rate of polyploidy in C. frutescens L. at 70%, while 20 and 30 mg/L oryzalin could induce polyploidy at the same rate of 40%. The stomatal guard cell size and fruit size of polyploid plants were larger than controls, enabling rapid screening of polyploid seedlings. The polyploid plants also produced a larger amount of capsaicin than controls. It was found that fruits from seeds treated with 300 mg/L colchicine produced the largest amount of capsaicin at 4.55 mg/g dry weight compared with controls that produced at 3.32 mg/g dry weight. While, fruits from the seeds treated with 30 mg/L oryzalin produced capsaicin at 4.44 mg/g dry weight compared with controls that produced at 3.25 mg/g dry weight.