Investigation the effect of colchicine and trifluralin on cytogenetic characteristics in root meristem cells of fenugreek (Trigonella foenum-graecum L.)

Doubling the number of chromosomes in a medicinal plant leads to variation in allelic composition and diversity of active enzymes in secondary metabolites biosynthesis route and can facilitate the process of secondary metabolism and increase secondary metabolite. This experiment was conducted in order to study the effect of colchicine and trifluralin on ploidy induction and cytogenetic characteristics of cells in the root meristem of fenugreek. Root tips were used for karyotypic studies. Seedlings were treated by colchicine solution at 0.25, 0.5 and 1 gl-1 concentrations and trifluralin solution 48% at 7.5, 15 and 22.5 μM concentrations for 12 and 24 h. The Video Analysis System was used for karyotype analysis. The basic chromosome number was X=8. Results showed that concentration of trifluralin and colchicine, treatments duration and interaction between them on the ploidy induction were statistically significant. The maximum ploidy induction was happened by seedling immersion in 22.5 μM trifluralin for 24 h and in 0.5 gl-1 colchicine for 12 h. Treatments affected the length of chromosomes and karyotypic formula. Result of analysis of variance based on completely randomized design (CRD) showed significant differences among the karyotype of control and treated samples for all karyotypic traits (p <0.01). Induced polyploidy affected by trifluralin was more than that of colchicines, although the concentrations of trifluralin were approximately 100 times lower than concentrations of colchicine. This indicates a greater ability of trifluralin in ploidy induction in this plant.