Detection and confirmation of diagnostic microsatellite loci in Populus nigra and Populus deltoides to identify their hybrids (P. × canadensis)

Authors: ASİYE ULUĞ

Abstract: Poplar cultivation has economic, social, ecological, and environmental importance in Turkey. Even though, Populus × canadensis hybrids play an important role for the commercial poplar cultivation with good growth performance and adaptability, hybrid clones introduced the different region of Turkey have started to replace the native stands of Populus nigra gradually. To continue sustainable cultivation of poplar and to conserve the native stands of P. nigra at the same time, genetic identification, and registration of the Populus cultivars from different origins are essential in breeding programs. Genetic identification and characterization of a natural population of P. nigra growing along the Melendiz River, Populus deltoides, and hybrid P. × canadensis trees were performed by 12 microsatellites loci. In addition, 18 P. nigra trees from EUFORGEN core collection were screened as reference samples. P. deltoides specific alleles were detected at four microsatellite loci previously reported as having diagnostic alleles. Several P. nigra trees from natural population and EUFORGEN core collection also included species-specific alleles of P. deltoides. It is concluded that there is an introgression event between the natural population and cultivated hybrids or P. deltoides clones in the surrounding area. Also, some members of the EUFORGEN core collection could have been mixed up or misidentified as P. nigra. The obtained results indicated that the application of the rigorous standards for reliable identification and registration with large sample size is a necessity for future breeding and conservation programs. Also, conservation of the native Populus nigra trees is an important requirement to prevent the genetic pollution of the species' gene pool and reduction of effective population size.

Keywords: Populus × canadensis, loci, diagnostic, breeding, conservation

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