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.
