Isolation and Characterization of Novel Microsatellite Markers in Pomegranate (Punica granatum L.)

Pomegranate (Punica granatum L.) has been cultivated from ancient times for its economic, ornamental and medicinal properties globally. Here, we report the isolation and characterization of 12 polymorphic microsatellite markers from a repeat-enriched genomic library of Punica granatum L. The genetic diversity of these loci was assessed in 60 genotypes of Punica granatum L. All loci were variable: the number of polymorphic alleles per locus ranged from two to five (average 2.9). The observed and expected heterozygosities ranged from 0.15 to 0.87 and 0.29 to 0.65, respectively. The polymorphic information content ranged from 0.26 to 0.61 (average: 0.43). To the best of our knowledge, this is the first time that polymorphic microsatellite markers have been reported for P. granatum L. These new markers should allow studies of the population structure and genetic diversity of pomegranate to be performed in the future

Molecular characterization of almond cultivars and related wild species using nuclear and chloroplast DNA markers

6 pages.The genetic diversity of different accessions of several wild almond species including P. eleagnifolia, P. hausknechtii, P. scoparia and P. lycioides, endemic to Irano-Afghan plate, was investigated using nuclear and chloroplast DNA markers. In addition, five cultivated almond cultivars (Marta from Spain; Nonpareil and Mission from USA; Ferrangnes from France and Tuono from Italy) were included in the study. Diversity was analysed at the DNA level by means of 16 nuclear and 5 chloroplast pairs of primers flanking SSR sequences. In 45 accessions, the number of alleles per locus in nuclear microsatellites ranged from 7 to 16, and expected heterozygosity varied between 0.54 and 0.93 with average PIC value of 0.81. It showed that they represent rather polymorphic species. In the case of chloroplast SSR, the polymorphism observed was much lesser in agreement with higher level of conservation of the chloroplast DNA. Therefore, nuclear microsatellites have been the most abundant markers with a high polymorphism and level of transference across closely related species in comparison with the others. In addition, results indicated the high variability present in the S-locus. Hierarchical analysis using integrated nuclear and chloroplastic microsatellite data yielded best clustering with six logical clusters or groupings corresponding to the different subgenus and sections.Peer reviewe

Use of biotechnology for preserving rare fruit germplasm

15 pages.The application of recent biotechnological tools for conservation of rare fruit species from developing countries, including in vitro and hydroponic culture protocols, improved propagation techniques and molecular marker application, is described. Promising propagation methods include forcing germination of seeds, in-vitro protocols well adapted to these rare fruit species that allow the introduction, micropropagation and rooting of plant material, and developing hydroponic culture protocols that allow the early propagation of high-risk genotypes. In addition, the growth of seedlings in controlled environmental conditions in greenhouse and cold chamber provides a useful strategy for obtaining vigorously growing plants from seeds year round. A standard karyotyping protocol has been described working in several species as preliminary tool to start molecular (DNA) studies. In addition, different protocols for DNA isolation and quantification have been assayed in these rare fruit species. Molecular markers based on PCR amplification of the DNA have also become an essential tool for the characterization and conservation of these species. Regarding this PCR amplification of the DNA, two main strategies, RAPD (if the DNA sequence is unknown) and SSR markers (if the DNA sequence is known), have been assayed. These markers have been applied in the genetic characterization of this germplasm, the establishment of genetic relationships between cultivars and species, and the future construction of genetic maps of these rare fruit species. Additional advantages encouraging the utilization of these new technologies in breeding programs include the high levels of synteny between genomes of related species, and a well-established international network of cooperation among researchers.Peer reviewe