Phylogenetic relationships among nine species in the genus Pistacia were studied by randomly amplified polymorphic DNA (RAPD) analysis. The following species were included: P. atlantica, P. terebinthus, P. eurycarpa, P. vera, P. integerrima, P. mexicana, P. palaestina, P. lentiscus, and P. khinjuk. Genomic DNA was extracted from leaf tissue and RAPD analysis was performed using 20 primers. A total of 242 fragments were generated and 228 bands were polymorphic at the inter-specific level. Subjecting these data to phylogenetic analysis yielded a shortest cladogram that is 338 steps long, featuring two main groups. P. vera, P. khinjuk, P. eurycarpa, P. atlantica, and P. integerrima were included in one group, while P. terebinthus, P. palaestina, P. mexicana, and P. lentiscus formed the second group. The first group included species with single-trunked and big trees, whereas the species included in the second group mostly grow as shrubs or small trees. The cladogram showed that the closest pairs of species were P. terebinthus and P. palaestina, P. eurycarpa and P. atlantica, P. vera and P. khinjuk, and P. mexicana and P. lentiscus. We suggest that P. palaestina is in fact a variety of P. terebinthus in view of the small genetic distance between them. This study also showed that P. eurycarpa (syn. P. atlantica var. kurdica) is a distinct species from P. atlantica, rather than a variety within the same species.
Salih Kafkas and Rafael Perl-Treves
Salih Kafkas, Hakan Ozkan, and Mehmet Sutyemez
Turkey has more than 4 million walnut trees (Juglans regia L.), most of which are derived from seedlings, and are nongrafted trees. This characteristic leads to a huge opportunity to select superior walnut genotypes from natural populations for cultivation and for breeding programs. Several selection studies have been performed in the last decades and few genotypes were selected. The goal of this study was to characterize and determine genetic relationships among 21 walnut genotypes with potential in walnut production using amplified fragment length polymorphism (AFLP) and selective amplification of microsatellite polymorphic loci (SAMPL) techniques. Eight primer combinations (six for AFLP and two for SAMPL) were applied to 21 walnut genotypes and a total of 230 bands of which 50.4% of them were polymorphic were obtained. The SAMPL technique was more effective than AFLP in the separation of very closely related genotypes. Genotypes of the pairs `Maras-18' with `Maras-46', `KSU-5' with `Sutyemez-1', `Maras-12' with `Sutyemez-2,' `Kaman-3' with `Kaman-4', and `KSU-11' with `Maras-10' were the most closely related.
Salih Kafkas, Yıldız Doğan, Ali Sabır, Ali Turan, and Hasbi Seker
Genetic relationships among 18 Turkish hazelnut (Corylus avellana L.) cultivars were investigated using randomly amplified polymorphic DNA (RAPD), intersimple sequence repeat (ISSR), and amplified fragment length polymorphism (AFLP) markers. Twenty-five RAPD primers, 25 ISSR primers, and eight AFLP primer pairs generated a total of 434 polymorphic marker loci. The three marker systems were able to differentiate the cultivars. Genetic similarity index values ranged from a high of 0.96 for ‘Kan’ and ‘UzunMusa’ to a low of 0.73 for ‘Yassi Badem’ and ‘Kalinkara’. The genetic relationships were presented as an unweighted pair group method with arithmetic average (UPGMA) dendrogram and a three-dimensional principal coordinate analysis (PCoA) plot. The UPGMA dendrogram showed two main clusters, while PCoA analysis showed three groups. Cultivar-specific markers were produced by all marker systems for 10 cultivars. This study demonstrates the usefulness of molecular markers for identification of hazelnut cultivars.
Salih Kafkas, Sezai Ercişli, Yıldız Doğan, Yaşar Ertürk, Ayhan Haznedar, and Remzi Sekban
Individuals in most countries around the world drink tea (Camellia sinensis). Tea drinking has attained ceremonial status in many places as a social and medicinal beverage. Although tea is of great importance in Turkey's economy, little is known about the pattern of genetic variation among the various tea genotypes grown in Turkey. A total of 32 tea genotypes found at the Ataturk Tea and Horticulture Research Institute in the eastern Black Sea region of Turkey were sampled. Fluorescent dye amplified fragment length polymorphism (AFLP) markers and capillary electrophoresis were applied for molecular characterization. The AFLP analysis with six primer combinations generated 835 fragments of which 567 were polymorphic, corresponding to 69.8% polymorphism. Resolving powers of the AFLP primers ranged from 62.6 to 81.9, yielding a total of 437.8; the polymorphic information content (PIC) ranged from 0.76 to 0.83, with an average of 0.79. Genetic similarity values ranged from 0.68 to 0.92, with an average of 0.76. The dendrogram derived by unweighted pair group method with arithmetic mean algorithm (UPGMA) and principal coordinate analysis (PCoA) revealed that all tea genotypes could be clearly divided into four distinct clusters. The results of this study will provide valuable information to the tea cultivar breeding program for the purpose of parental selection.
Salih Kafkas, Hakan Ozkan, Bekir Erol Ak, Izzet Acar, Halit Seyfettin Atli, and Sonay Koyuncu
There are limited numbers of pistachio (Pistacia vera L.) cultivars in the world and their phenotypic appearance and productivity are variable. Understanding such variation would facilitate their use in cultivar breeding programs. Therefore, in this study, 69 pistachio cultivars and genotypes originating from seven countries were characterized by randomly amplified polymorphic DNA (RAPD), inter-simple sequence repeats (ISSR), and amplified fragment-length polymorphism (AFLP) markers. The results showed that all three marker systems were able to reveal variability between pistachio cultivars and genotypes. The correlation coefficients for genetic distances were statistically significant among all three molecular marker types. The correlation between RAPD and AFLP data was the highest (r = 0.73) and the value between RAPD and ISSR data was the lowest (r = 0.58). AFLP proved to be the best technique among them. ISSR and AFLP assays were reliable and produced reproducible bands. ISSR was preferred over RAPD, especially when financial investment and technical knowledge are limited. The constructed unweighted pair group method with arithmetic averages (UPGMA) dendrogram obtained from combined data separated the genotypes into two main clusters: one cluster (“Iranian”) included genotypes originating from Iran and the second cluster (“Mediterranean”) contained most other genotypes. The “Mediterranean” cluster further divided into three subclusters: one (“Siirt”) consisted of the cultivars Siirt and Hacireso with a few other selections; the second subcluster (“Turkish”) included Turkish cultivars; and the third subcluster contained Syrian, Italian, and the remaining cultivars. The closeness of the clusters was “Iranian” - “Siirt” - “Turkish”/“Syrian.” These findings reveal a new understanding in the diffusion of pistachio cultivation from its center of origin, the Iranian-Caspian region, via southeastern Turkey to Syria, the Mediterranean region of Europe, and northern Africa.
Kadir Uğurtan Yılmaz, Sezai Ercişli, Bayram Murat Asma, Yıldız Doğan, and Salih Kafkas
Inter-simple sequence repeat (ISSR) markers were used to study the genetic diversity and phylogenetic relationships among 16 genotypes from subgenus Prunus (six genotypes from section Prunophora, seven genotypes from section Armeniaca and two plumcot genotypes, and one genotype from subgenus Cerasus) in Prunus genus. From the polymerase chain reaction amplifications with 20 ISSR primers showing polymorphism among subgenera and sections, 180 polymorphic ISSR bands were detected and polymorphism ratio ranged from 57% to 100%. Based on the unweighted pair group method with arithmetic mean (UPGMA) analysis and principal coordinate analysis (PCoA) using the Jaccard coefficient, a dendrogram and three-dimensional plot were constructed including genotypes in Prunus genus. Two main groups formed in the dendrogram; one of them (Cluster I) included Cerasus, whereas Cluster II included Prunus. Cluster II also divided into three subgroups, including sections Prunophora, Armeniaca, and plumcot. Both UPGMA and the PCoA demonstrated that Armeniaca genotypes had lower genetic variation and plumcot genotypes are closer to the plums than the apricots. The ISSR-based phylogeny was generally consistent with Prunus taxonomy based on molecular evidence, suggesting the applicability of ISSR analysis for genotypic and phylogenetic studies in Prunus genus.
Salih Kafkas, Mustafa Özgen, Yıldız Doğan, Burcu Özcan, Sezai Ercişli, and Sedat Serçe
Mulberries (Morus L.) show a great deal of genetic variability and adaptability to various environments. There are more than 24 species of mulberries in cultivated and wild forms. In Turkey, three Morus species, M. alba L., M. nigra L., and M. rubra L., are grown. In this study, we attempted to characterize 43 Morus accessions originating from distinct regions of Turkey using fluorescent dye amplified fragment length polymorphism (AFLP) markers and capillary electrophoresis. The accessions belonged to M. alba, M. nigra, and M. rubra; M. alba consisted of white- and purple-fruited samples. Eight primer combinations generated a total of 416 bands, 337 of which were polymorphic (80.5%). Resolving powers of the AFLP primers ranged from 0.410 to 0.942 making a total of 5.015, whereas the polymorphic information content ranged from 0.662 to 0.898 with an average of 0.812. Unweighted pair-group method of arithmetic mean (UPGMA) clustering of the accessions showed three major groups representing M. nigra, M. rubra, and M. alba accessions. The M. alba group had two subgroups that were not correlated with fruit color. The UPGMA dendrogram of average taxonomic differences confirmed these results. The principle coordinate analysis demonstrated that M. nigra accessions had limited genetic variation. In conclusion, our study indicated that M. nigra and M. rubra are molecularly distinct from M. alba. Our results also suggest that M. nigra accessions having a low level of morphological variation are molecularly similar.