Genetic diversity of superior Persian walnut genotypes in Azadshahr, Iran.

Persian walnut (Juglans regia L.) is known to have originated in central and eastern Asia. Remnants of these wild populations can still be found in the Hyrcanian forest in north-eastern Iran. In this study, 102 individual walnut trees from four geographic populations in the Azadshahr province (Vamenan, Kashidar, Rudbar and Saidabad) were sampled. We characterized individual trees using 28 standard morphological traits. The range of traits varied widely for some economically important characteristics including nut weight (6.1-19.79 g), kernel weight (2.9-9.4 g), and kernel fill percentage (26.51-60.34%). After morphological evaluation, 39 superior individuals based on nut quality and kernel fill percentage were selected for further genetic analysis. Individual superior trees were genotyped using 10 simple sequence repeat markers (SSR) and genetic diversity. Number of alleles per locus ranged from 3 (WGA005) to 12 (WGA054). Clustering analysis of 10 SSR loci divided the genotypes into three main groups. PCoA analysis clearly sorted genotypes into one of four distinctive groups which aligned with the cluster analysis. All analyses showed that individuals from Saidabad were genetically distinct. Likewise, results indicated that the high level of genetic diversity in Azadshahr region walnuts may provide a diverse source for superior walnuts in walnut breeding programs.

Polymorphism of Myostatin Gene in Intron 1 and 2 and Exon 3, and Their Associations with Yearling Weight, Using PCR-RFLP and PCR-SSCP Techniques in Zel Sheep.

The aim of present study was to investigate myostatin gene polymorphism and its association with yearling weight records in Zel sheep using PCR-RFLP and PCR-SSCP methods. Blood samples were collected from 200 Zel sheep, randomly, and DNA was extracted using modified salting out method. Polymerase chain reaction was carried out to amplify 337, 222, and 311 bp fragments, respectively, comprising a part of exon 3, intron 1, and intron 2 of myostatin gene. In addition, exon 3 was digested by HaeIII enzyme under RFLP method, and introns 1 and 2 were studied using SSCP. Under RFLP method, all samples showed mm genotype. Under SSCP method, intron 1 was also monomorph but intron 2 was polymorph (AA, AB, and BB). The allelic frequencies for A and B were 75.5 and 24.5%, respectively. This locus was not in Hardy-Weinberg equilibrium (P < 0.05), and there was no significant effect of myostatin gene on yearling weights.