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Persian walnut (Juglans regia L.) is a valuable economic plant used worldwide for its wood and nut fruit. In the current study, the genetic variation of 21 selected walnut genotypes from different regions of Iran was described using nut pomological properties, ISSR primers, and DNA analyses based on SSR primers. Nut pomology revealed nut weight of selected genotypes ranged from 12.1 to 17.5 g (OR23). Kernel weight varied from 5.3 to 10.3 g (OR23), and kernel fill percentage ranged from 43.4 to 62.7% (T12). PCR amplification with ISSR primers revealed 112 bands obtained with 91% polymorphism. Numbers of amplified bands ranged from 9 to 14. The highest primer resolving power (Rp), 7.71, was obtained with the UBC.884 primer and highlights the ability of the most informative primers to differentiate between the genotypes. The average band informativeness (AvIb) varied from 0.14 (UBC.886) to 0.62 (UBC.887 and UBC.888). Using the Jaccard coefficient, genetic similarity values among walnut genotypes varied from 0.52 to 0.88. The dendrogram of UPGMA analysis with ISSR primers classified walnuts genotypes in two main groups and three sub-groups. PCoA largely confirmed cluster analysis results. Genotypes collected from Shahrood displayed lower genetic variation and the Tuyserkan and Urmia genotypes were more genetically distant. Unique DNA profiles were established for all studied genotypes based on three distinct microsatellite loci. [ABSTRACT FROM AUTHOR]

ISSR molecular marker was used to investigate genetic diversity of 'Dare Gazi' genotypes of Mashhad Esteghlal orchard and its relationship with other commercial and native cultivars of pear. Among 'Dare Gazi' genotypes of Mashhad Esteghlal orchard 23 genotypes were selected base on difference in tree vigor, leaf color, shape and color of fruit and also 33 other commercial and native pear cultivars from Esteghlal orchard and other Mashhad commercial orchards were studied. A total number of 230 DNA fragments were obtained using 11 primers of which 225 were polymorphic. On average, each primer produced 20.9 bands. Dice similarity coefficient ranged from 0.27 (between 'Dom Kaj' and Asian pear) to 1 (between 'Dare Gazi' 1 and 2 genotypes). Sample cluster dendrogram indicated that 56 genotypes were divided into 12 distinct clusters. The dendogram generated on the principle of Unweight Pair Wise Method using Arithmetic Average (UPGMA) was constructed by Dice coefficient and the genotypes were grouped into 12 clusters. 'Dare Gazi' genotypes did not show 100% similarity due to seed propagation or mutation, as 'Dare Gazi' 3 and 18 genotypes had the lowest similarity coefficient (0.64). Asian pears were placed in a separate group from European pears. And 'Dare Gazi' genotypes from different orchards were grouped separately, but all of them are called as 'Dare Gazi' pear for convenience. ISSR molecular marker can well identify the genetic variability among genotypes and cultivars and found suitable for grouping them. [ABSTRACT FROM AUTHOR]