Somaclonal diversity in regenerated plants from stem, root and cotyledons of Caspian locust (Gleditschia capsica Desf.)

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.