A Study on Genetic Diversity of Populus tremula in China by Single-copy Nuclear Markers

ObjectiveThis paper aims at investigating the genetic diversity and genetic differentiation of Populus tremula distributed in Xinjiang, China. MethodSix single-copy nuclear gene markers of 72 P. tremula individuals from 4 populations in Xinjiang were amplified and sequenced. The parameters of genetic diversity and genetic differentiation were calculated. ResultAfter aligning, the length of the six genes ranged between 459 bp and 747 bp and the average number of polymorphism sites was 14. Diversity parameters, π and θw reached 0.004 8 and 0.004 4, respectively. The mean value of gene diversity was 0.73. These indicated high level of genetic diversity of P. tremula. The results of Neutral tests using Tajima's D were not significant, which indicated all the six genes did not violate from neutrality. The results of AMOVA analysis showed that 89.72% of the total variance existed within populations. The average genetic differentiation parameter Fst and gene flow among populations reached 0.10 and 3.235, respectively. ConclusionHigh level of outcrossing rate and nucleotide mutation rate as well as long distance dispersal seed contributed to the high level of genetic diversity and low genetic differentiation in P. tremula in Xinjiang, China.