Genetic diversity and population structure in tunisian castor genotypes (Ricinus communis L.) Detected using scot markers

Abstract

Due to the chemical and physical properties of castor oil (Ricinus communis L.) that make it a valuable raw material for numerous industrial applications, including the production of biofuel, interest to develop more and better varieties has been increased. In the present study, the representatives of the genus castor collected from 12 different parts of Tunisia were differentiated by the DNA fingerprinting patterns using 37 SCoT primers. PCR amplification of DNA using 37 primers for SCoT analysis produced 268 DNA fragments that could be scored in all 56 genotypes of Tunisian castor. The number of amplified fragments varied from 4 (SCoT 45, SCoT 31 and ScoT 17) to 10 (SCoT 3, SCoT 11, SCoT 14, SCoT 18 and SCoT 12). Of the 268 amplified bands 230 were polymorphic, with an average of 6.22 polymorphic bands per primer. To determine the level of polymorphism in the analysed group of Tunisian castor genotypes polymorphic information content (PIC) was calculated. The lowest values of polymorphic information content were recorded for SCoT 17 (0.411) and the the highest PIC values were detected for SCoT 14 (0.868) with an average of 0.751. A dendrogram was constructed from a genetic distance matrix based on profiles of the 37 SCoT primers using the unweighted pair-group method with the arithmetic average (UPGMA). According to analysis, the collection of 56 Tunisian castor genotypes were clustered into two main clusters (1 and 2). Of the 56 genotypes of Tunisian castor, 2 unique genotypes were separated (BA-5 and K-4). Genetically the closest were two genotypes from Tunisian region Souassi (S-2 and S-5) in subclaster 2bc. Results showed the utility of SCoT markers for estimation of genetic diversity of castor genotypes leading to genotype identification.