承德光秃山不同海拔油松居群遗传多样性

为了解光秃山不同海拔下天然油松居群之间的遗传差异及探求遗传多样性与土壤因子的关联,为油松种源筛选和管理提供参考,本研究运用ISSR技术,对位于河北承德辽河源光秃山4个不同海拔油松天然居群共118个植株个体的遗传多样性进行分析。13个引物共扩增出177条清晰的条带,种群多态位点百分比(PPL)为60.2775%,Nei’s基因多样性指数(h)为0.2171,Shannon信息指数(I)为0.3222;不同种群遗传变异水平随海拔差异呈规律性变化,表现为沿海拔升高而呈低-高-低的分布规律,其中1354～1274 m范围的遗传多样性水平最高;在物种水平上油松具有较高的遗传多样性(PPL=98.33%,h=0.38142,I=0.5550),种群间的遗传分化系数Gst=0.6562。利用AMOVA软件对遗传变异的等级剖分结果表明,种群间有显著的遗传分化,约2/5的遗传变异存在种群间,种群内占3/5。Pearson相关分析表明,油松居群内遗传多样性与海拔、土壤养分(有机质、速效磷、速效钾含量)之间存在显著或一定的相关关系。Mantel检验结果显示,油松居群遗传距离与海拔差距、土壤养分因子的分异存在一定相关性。以上结果表明不同海拔区域的生态因子、低基因流等对油松居群间的遗传分化影响较大。

Genetic Diversity of Pinus tabulaeformis Populations at Different Altitudes in Guangtushan Mountains and Relationship to Environmental Changes

Inter Simple Sequence Repeat (ISSR) technique was used to evaluate the genetic diversity and population structure of 118 genets from four natural populations of Pinus tabulaeformis different altitudes in Liaoheyuan national Forest Park, Hebei Province, north of China. Thirteen random primers produced a total of 177 securable amplified fragments. The genetic diversity of Pinus tabulaeformis population level and species level was PPL=60.2775%,h=0.2171,I=0.3222 and PPL=98.33%,h=0.38142,I=0.5550, respectively. The level of genetic variation varied regularly with different altitudes, that is, the level of genetic variation of the population was the highest at the altitude of 1354-1274 m (Pop2), and it became dropping for the populations at the altitude of 1484-1430 m (Pop2), 1129-1091 m(Pop3) and 1002-901 m(Pop4). The high value of differentiation (Gst=0.6562) and analysis of molecular variance (AMOVA) indicated there was significant genetic differentiation among populations, and about two-five of the variations occurred among populations. Pearson correlation analysis further revealed that the genetic diversity within populations was significantly correlated with the altitude and soil nutrient factors (organic matter, available phosphorus and available phosphorus). Mantel tests showed that there was some correlation between the genetic distances among populations and the distance of elevation, and the divergence of soil nutrient factors. The results of the present study suggested that the genetic differentiation among populations of Pinus tabulaeformis different altitudes may be caused by the ecological factors of different altitudes and gene flow.