Study On Phenotypic Diversity Of Natural Populatiions In Quercus Liaotungensis

Six natural populations of Quercus liaotungensis were selected in this study according to it's distribution area in china and the investigation results using a natural population of Quercus mongolica as control(BaLiDian forestry centre in LiaoNing province).More than thirty indexes of phenotypic traits of Q.liaotungensis including leaf,bud and fruit were measured by detecting the quantitative traits,and the inflounce of different habits on morphology of leaf and bud in Q.liaotungensis population of Lingkong mountain in Shanxi province was also investigated.The results revealed that phenotypic differentiation degree,mode and law of variation in natural populations of Q.liaotungensis in China.The major conclusions were described as follows.(l)The vairance anlysis for morphologic traits of Q.liaotungensis at different direction and degree of slope showed that significant differences exited in depth of the tooth of leaf base,width of the middle apical bud,width of the tooth of leaf base and depth rate of the tooth of leaf base,moreover the tooth of leaf base and the middle apical bud in population half north facing slope was bigger than on half south facing slope and south facing slope.The study on Q.liaotungensis population at different slope positions indicated that the leaf and petiole at middle slope and lower slope was bigger compared to upper;number of the vien, angle of the vien, tooth angle of the widest part, the leaf area and the middle apcial bud gradually increased from mountaintop to valley,which resulted from the cooperative effect of ecological factors(soil moisture,temperature and light et al) with the difference of individual development.The variance analysis for morphologic traits at different altitudes exhibited that the ratio of petiole to leaf length and biomass were significantly different at α=0.01,while tooth depth of the widest part presented obvious variation at α = 0.05.(2)Nested analysis for all traits except length of the nut were significiantly different among populations and among individuals within population (α = 0.01).The mean phenotypic differentiation coefficient(Vst%) was 35.44% showing that the variation within population(62.73%) was higer than that among populations(37.27%).The nut became short,the shape of nut changed from long-oblong to oblong,and the cupule wasdeeper and deeper with the increase of longitude and latitude,while with the elevation of altitude the shape of nut varied from oblong to long-oblong,the volume of nut became small,and the cupule was shallower and shallower. The phenotypic variation included not only continuous components but also discontiguous ingredients. According to cluster analysis using Euclidean distance among populations the populations of Q.mongolica investigated may be divided into two groups and four subgroups.(3)The main difference between Q.liaotungensis and Q.mongolica was the bract shape of supule.According to morphological traits and cluster analysis,the Q.liaotungensis population of DongLing mountain in Beijing was classified a single group,exhibting the specificity. It was preliminarily presumed that the Q. liaotungensis population of DongLing mountain in BeiJing may be the especial type or ecological mutation appeared in movement of Quercus with movement to south of the climate band in the Late Pliocene and the Glacial Epoch in the Quaternary Periods,or the complex evolved in the process of overlapping distribution of these two species. It also possibly was the especial type formed in the process of diffusion to east and north of Q. liaotungensis after production in North China.