g.a. ranjbar

Protecting the germplasm of native tree species of the Caspian hyrcanian forests, especially the Caspian locust (Gleditschia capsica Desf.) is a priority of the research. In this study, somaclonal diversity in regenerated plants from different explants of Caspian locust was investigated using the Inter Simple Sequence Repeat (ISSR) marker under in vitro conditions. Mother leaf (natural) and stem, root and cotyledon explants from the regenerated plants as studied genotypes were selected and they were cultured in MS culture medium containing 0.5 mgL-1 TDZ and 0.5 mgl1 2,4-D. Somaclonal diversity was examined after six subculture inoculations. Polymorphism (PIC), Nei and Shannon diversity traits were used to investigate the diversity between genotypes and then clustering of genotypes was performed using UPMGA algorithm and Principal Component Analysis (PCA). The polymorphism percentage was 87.9% using 10 primers. Molecular Analysis of Variance (AMOVA) showed 16% diversity between genotypes and maternal origin. The results of cluster analysis grouped the genotypes into three distinct categories, which was also confirmed by principal component analysis (PCA). Accordingly, the mother basal and stem genotypes were grouped in a group. The mother basal had the highest and lowest similarity coefficients with stem and root genotypes, respectively. Therefore, it was suggested to use stem explants that have high genetic similarity with the mother genome for studies of Caspian locust tissue culture. In general, the results showed that somaclonal diversity among regenerated plants will increase with increasing number of subcultured.

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.