| چکیده انگلیسی مقاله |
Introduction: The Juniper tree is one of the most important tree species in the forests of southern Ardabil and plays a significant role in the province's reforestation programs. Providing standard seeds and seedlings is one of the primary concerns of natural resource managers. Seed orchards, along with seed production areas, are among the most important sustainable sources for supplying seeds and seedlings of forest trees and shrubs. The aim of this study is to assess the genetic diversity and structure of juniper seed production areas in Ardabil province.
Material and Methods: In this study, the intra- and inter-population genetic diversity of five different juniper populations, including 38 individual genotypes, was evaluated using the SCoT molecular marker. Initially, leaf samples were collected from the various genotypes, and after DNA extraction, PCR reactions were performed using six SCoT molecular primers. The polymorphic information content (PIC) of the markers was calculated using Excel, and genetic diversity parameters such as the number of alleles, effective number of alleles, Shannon's index, expected heterozygosity, and unbiased expected heterozygosity were estimated using GenALEx 6.5 software. Nei’s genetic distances between populations were calculated using NTSYS-2.10 software, and cluster analysis was conducted using the UPGMA method. Molecular variance analysis and principal coordinate analysis were also performed using GenALEx 6.5 software.
Results: Based on agarose gel electrophoresis, a total of 125 alleles were detected using these markers, all of which were polymorphic. The number of alleles ranged from 16 to 24. Among the primers, SCoT62 showed the highest number of polymorphic alleles (24), while SCoT41 had the lowest (16). The average PIC for the primers was 0.404. In this study, SCoT9 had the highest PIC value (0.440), indicating its important role in distinguishing different juniper genotypes, while the lowest PIC (0.384) was observed for SCoT41. The mean value for genetic diversity parameters, including number of alleles, effective number of alleles, Shannon's index, expected heterozygosity and unbiased expected heterozygosity were 1.69, 1.45, 0.420, 0.276, and 0.295, respectively.
Conclusion: Molecular variance analysis showed that 92% of the total variance is distributed within populations, and 8% is distributed between populations. Using the UPGMA algorithm, a phylogenetic tree was constructed for the juniper genotypes, placing them into five distinct clades. One of the most important points in the formation of a seed orchard is the use of trees that have less genetic affinity so that the progeny obtained from them has a high genetic diversity and prevents the genetic erosion of the forest in the future. As a result, it is suggested to use trees A1, A3, B4, B6, C2, B2, D3, C7, D1, D2, E2, D7, E4 and A5 to form a juniper seed orchard in Ardabil.
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