SNP Diversity of Candidate Genes Encoding Cellulose and Lignin Biosynthetic Enzymes in Populus nigra Clone Bank in Turkey: Its Implications for Conservation and Breeding

European black poplar (Populus nigra) is economically important tree in Turkey. About twenty-five percent (4.3 m³) of the total wood production in Turkey is obtained from poplar. European black poplar plantations provide 45 % of total poplar wood production while the remaining 55% of production comes from hybrid poplar plantations. With the new irrigation projects, it is expected to have more lands will be available for poplar plantations. The important and major genetic resources of black poplar for future plantations consist of about 300 clones and located in Ankara nursery in Turkey. This clone bank is not fully explored yet, so far, only 5 commercially registered clones have developed.  With the current study, it was aimed to genotype the selected 288 clones with respect to cellulose and lignin biosynthetic enzymes and correlate these later with the growth and cellulose and lignin related enzymes. Here the SNP diversity has been provided. About 21 genes with 388 SNPs revealed that 234 of them were polymorphic. The observed heterozygosities (0.34) were much higher than the expected (0.24), indicating the excess of heterozygotes (Fis=-0.42) among studied clones. When, the 288 clones were grouped according to the geographic origins, the highest observed heterozygosity was found in the  Mediterranean population (0.37) while the highest excess of heterozygosity (0.67) was in the southeastern Turkey population though differentiation of the populations was low (Fst=0.05). The rapid decay of within gene-linkage disequilibrium (LD) with respect to distance among SNPs was observed for the studies genes of European black poplar. The implications of these findings with regard to European black poplar genetic resources and its breeding will be addressed further in the meeting.