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Melon is one of the most important horticultural crops in Iran. There are a few studies on the genetic structure of Iranian melon. A set of 18 simple sequence repeat (SSR) primer pairs were used to assess the genetic diversity in a collection of 24 melon accessions representing different botanical groups of Iranian cultivated melons (vars. inodorus, cantalupensis and dudaim), along with 28 reference accessions from diverse geographic origin. All studied SSR loci were polymorphic that confirmed their usefulness for genetic analysis of melons. A total number of 141 alleles were detected, with an average of 7.8 alleles per locus for reference genotypes and 4.38 alleles per locus for Iranian accessions. The low variability within Iranian melon accessions is reflected by the low values of the observed heterozygosity (with an average of 0.119), indicating lack of intercrossing between accessions or a high rate of self-pollination. Values of observed homozygosity for 'Suski-e-Sabz' and 'Khatouni', as the most cultivated melon in Iran, were 0.98 and 0.99, respectively. Cluster analysis divided Iranian accessions into two major groups. The highest level of polymorphism was detected among the dudaim group. The analysis of molecular variance indicated that the majority of variation (87 %) was due to the difference within accessions. The average pairwise genetic distance among Iranian accessions was 0.674. Our results showed a distinct separation of dudaim group from the rest of Iranian accessions, even separated two different groups of var. dudaim with different traits. There was a wide genetic distance between Honey Dew, as the most popular member of inodorus group worldwide and 'Khatouni', a major Iranian winter melon (GD = 0.809). This genetic distance shows the importance of Iranian accessions for conservation and use in breeding programs. [ABSTRACT FROM AUTHOR]

Subgenus Cerasus species are useful genetic resources for cherry breeding programs. A total of 17 morphological traits together with 19 random amplified polymorphic DNA (RAPD) primers were used to study 39 accessions including 34 wild Cerasus subgenus genotypes belonging to Prunus avium L., P. cerasus L., P. mahaleb L., P. microcarpa Boiss., P. incana Pall., and P. brachypetala Boiss. species, along with an unknown wild Cerasus sample, two advanced cherry cultivars ('Lambert' and 'Bulgar'), and two rootstocks ('Colt' and 'Gisela 6'). Genotypes were separated into different groups according to their species and collection sites using cluster analysis performed by Ward's clustering method based on morphological data. Nineteen RAPD primers from 60 screened produced 304 polymorphic reproducible bands (98.15% polymorphism). According to the similarity matrix, the lowest similarity was obtained between P. avium and P. microcarpa samples. A dendrogram was prepared by the unweighted pair-group method with arithmetic average (UPGMA), and the accessions were separated according to their species and geographic origin. In both morphological and molecular results, the advanced cultivars and rootstocks were separated from wild genotypes, and the unknown genotype was grouped with P. mahaleb accessions. Grouping by morphological characteristics was compared with the results of RAPD analysis, with no significant correlations between morphological and molecular data being found. This is the first report of molecular (RAPD) genetic diversity study in wild Cerasus subgenus genotypes from Iran, and the results demonstrate the high potential of RAPD analysis for discrimination of Cerasus subgenus genotypes. [ABSTRACT FROM AUTHOR]

Abstract: Soft-seedness in pomegranate is a desirable trait for fresh consumption of this valuable fruit. At the main Iran pomegranate collection, 21 pomegranate accessions gathered from different parts of Iran are registered as soft-seed genotypes. The aim of this research was to study these soft-seed pomegranate accessions using fruit morphopomological traits and DNA markers to reveal their relatedness. Thirty-six fruit characteristics were measured in these accessions together with applying 29 random decamer primers already reported to be polymorphic on pomegranate. Factor analysis on mean values of fruit characteristics determined 10 main factors and applied for grouping of the accessions using Ward''s method. Also 14 of the random primers showed good amplification and polymorphism on these samples, and a total of 43 RAPD markers were produced. Estimates of genetic similarity, using Jaccard''s similarity coefficient, ranged from 0.13 to 1.0 using the RAPD data. Grouping based on the fruit traits compared with that based on RAPD data did not produce a significant correlation (r =−0.36). Morphometric measurements and sensory evaluation confirmed that some accessions are hard or semi-hard seeded. This study showed that information based on fruit characteristics and RAPD markers are complementary for genetic discrimination in soft-seed pomegranate accessions. This might be due to the high level of similarity between soft-seed pomegranate accessions. [Copyright &y& Elsevier]

Abstract: The genetic relationships among 41 Rosa damascena accessions from various cultivation areas of Iran and one accession from Bulgaria were analyzed using 31 RAPD (Randomly Amplified Polymorphic DNA) primers. Each primer exhibited 3–12 banding patterns for a total of 343 scorable and 184 polymorphic bands. The combination of 11 primers was found optimal for discrimination of 42 accessions with very low values of cumulative confusion probability (9.7×10−5); indicating that only one pair from over 10,000 distinct pairs of accessions would be indistinguishable. Unweighted pair group method cluster analysis based on similarity values revealed 10 groups at the distance of 0.85. The Bulgarian genotype grouped with the majority of the Iranian genotypes in a main cluster. Results of molecular variance analysis (AMOVA) indicated that the major proportion (65.7%) of the total genetic variation was within collecting provinces rather than between them. The wide genetic variation seen for R. damascena in Iran indicates that Iran is a center of genetic diversity for this species and that there is a promising future for the breeding. [Copyright &y& Elsevier]

Abstract: There is a high diversity among cultivated walnut trees in Iran due to its long time of seed propagation and vast area of cultivation. In this study some morphological characters as well as Simple Sequence Repeat (SSRs) markers were used to analyze the genetic diversity and relationships among 31 Iranian walnut genotypes along with four foreign cultivars. The nut weight ranged from 7.52 to 17.73g, kernel weight from 4.00 to 9.83g, and kernel percentage ratio from 38.78 to 67.05% among studied genotypes. In SSRs analysis, nine primer pairs were tested that produced 39 alleles ranging from 2 to 8, with a mean value of 5.10 allele per primer. The Iranian genotypes showed relatively high diversity both for their SSRs loci and morphological traits. Although the foreign cultivars (‘Serr’, ‘Vina’, ‘Franquette’ and ‘Lara’) clustered with each other, they also laid close and within the Iranian genotype. The results of the study provided us with valuable diversity among our genotypes which could be used for breeding studies and also showed the power of genetic markers for analysis and evaluation of this diversity. [Copyright &y& Elsevier]