STUDY ON THE EFFECT OF COLCHICINE ON IN-VITRO CULTURES OF TURMERIC (Curcuma longa L.) FOR POLYPLOID DEVELOPMENT

Abstract

Crop improvement possibilities in turmeric Curcuma longa (L.) are limited due to its triploid nature except for polyploidization. Colchicine is a chemical that is used frequently to make plants polyploidy. Hence, this research aimed to study the effect of colchicine on the ability to induce polyploidization of in-vitro turmeric cultures. The study consisted of two experiments: (1) assay on in-vitro culturing for callus induction and (2) assay on colchicine treatments and polyploidy screening. In experiment 1, turmeric rhizome buds were cultured on MS-solidified medium for callus induction with 100 mL coconut water, 2.5 and 4.5 mg L-1 2,4-Dichlorphenoxyacetic acid, 0.93 mg L-1 Kinetin and without growth regulators. In addition, cell suspension culture was tested for callus induction with 4.5 mg L-1 2,4-Dichlorphenoxyacetic acid and 0.93 mg L-1 Kinetin. For polyploidy induction in experiment 2, in-vitro developed root tip via callus tissues were transferred to liquid MS medium supplemented with various concentrations of colchicine for 2 days. Then, Acetocarmine staining method and microscopic observation were attempted to count the chromosome number. Nucleus size, nucleus area (µmSq), and perimeter (µm) were referred using microscopic observation under 1000× magnification and BEL capture software. As experiment 1 results, MS-solidified medium supplemented with coconut water (100 mL) was most effective in inducing callus and as experiment 2 results the change in the cell nucleus area (µmSq) of the turmeric cells with each concentration of colchicine; 0, 0.05, 0.10, 0.15, and 0.20 (%) for 2 days was 275.1b, 371.23a, 311.65ab, 285.85ab and 328.43ab and changes in the nucleus perimeter (µm) was 53.33b, 65.73a, 61.08ab, 58.75ab, and 63.45ab respectively. Therefore, 0.05% concentration of colchicine showed the highest results and was significantly different from each concentration. Threfore, it can be concluded that 0.05% colchicine concentration has an effect on nuclear size increment thereby possibly inducing polyploidization of turmeric.