Objective
Ziziphus spina‑Christi is one of the key tree species in the Saharo‑Sindian forests and plays an important role in reforestation programs in Khuzestan Province. Ensuring the availability of high‑quality seeds and seedlings is a major priority for natural resource managers, and seed production areas, alongside seed orchards, serve as sustainable sources of forest reproductive material. This study aimed to evaluate the genetic diversity and structure of Z. spina‑Christi seed production areas in Khuzestan Province.
Materials and Methods
Leaf samples from 75 genotypes representing five populations were collected. After DNA extraction, PCR amplification was carried out using 10 SCoT primers. The polymorphic information content (PIC) and genetic diversity parameters, including the number of alleles, effective number of alleles, Shannon’s index, expected heterozygosity, and unbiased expected heterozygosity, were estimated using GenALEx 6.5. Nei’s genetic distances among populations were calculated using NTSYS‑2.10, and cluster analysis was performed using the UPGMA method. Analysis of molecular variance (AMOVA) and principal coordinate analysis (PCoA) were also conducted in GenALEx 6.5.
Results
Across the 10 SCoT primers, 78 alleles were detected, all of which were polymorphic. Primer SCoT26 produced the highest number of polymorphic alleles (14), while SCoT30 produced the lowest (4). The average PIC value was 0.429, with SCoT28 showing the highest PIC (0.468) and SCoT30 the lowest (0.357). Mean genetic diversity indices, including number of alleles, effective number of alleles, Shannon’s index, expected heterozygosity, and unbiased expected heterozygosity, were 1.50, 1.40, 0.366, 0.244, and 0.252, respectively. AMOVA indicated that 67% of the total genetic variation was distributed within populations and 33% among populations. UPGMA clustering grouped the genotypes into 11 distinct clades.
Conclusion
The Z. spina‑Christi populations in Khuzestan exhibit moderate to moderately high genetic diversity. This level of diversity represents a valuable genetic resource for the species, contributing to its adaptability under changing environmental conditions and supporting breeding and ecological restoration programs.