地理环境因素对天山云杉球果和针叶表型多样性的影响

The Effects of Geographical Environmental Factors on Cone and Needle Phenotypic Diversity of Picea schrenkiana var.tianschanica

以天然分布在天山北坡的天山云杉(Picea schrenkiana var.tianschanica)种群为研究对象,在天山北坡天山云杉生长范围内按一定间隔距离选择不同经度的4个区域,在区域内选择4个具有代表性的天山云杉天然林作为典型种群(吉木萨尔、乌鲁木齐、乌苏、巩留);以各种群天山云杉自然分布的下限至上限为基准,每隔50 m划分为1个海拔段,每个海拔段内随机选取3株直立、健康、叶片颜色基本一致的成年(结球果)天山云杉,每株均从树冠中部的东、西、南、北方向,采集球果20枚、针叶(主枝上2年生枝条)20枚,测定球果性状(球果干质量、球果长、球果宽、果形指数、种鳞长、种鳞宽、种鳞长宽比)、针叶性状(针叶长、针叶宽、叶形指数、叶厚度、叶面积);应用巢式方差分析法、多重比较法、多样性分析法、冗余分析法等方法,分析天山云杉球果和针叶表型分化水平、多样性特征及其与地理环境因素之间的相关性。结果表明:天山云杉球果和针叶表型分化系数均值为43.35%,表型变异的主要来源为种群内。表型性状重复力变幅为0.2007~0.5055、平均重复力0.3692,属于中等重复力水平;表型性状间球果干质量变异系数最大(14.59%),种群间乌苏的变异系数最大(8.964%)。表型性状香农-维纳(Shannon-Wiener)多样性指数均值为2.0347、辛普森(Simpson)多样性指数均值为0.8524,说明天山云杉具有较高的多样性。天山云杉不同种群间,表型分化水平、多样性特征存在一定的差异,海拔是影响天山云杉表型性状的主要影响因素,其次为降水、经度。

Taking Picea schrenkiana var.tianschanica populations naturally distributed on the northern slopes of the Tianshan Mountains as the study object,four areas with different longitudes were selected within the growing range of P.schrenkiana on the northern slopes of the Tianshan Mountains at certain intervals of distance,four representative P.schrenkiana natural forests were selected as typical populations in the region(Jimushar,Urumqi,Wusu,Gongliu).Using the lower and upper limits of the natural distribution of P.schrenkiana in each population as a reference,the altitude range was divided into intervals of 50 m.Within each altitude interval,three upright,healthy,and leaf color almost uniform adult(cone-bearing)P.schrenkiana trees were randomly selected.Each plant was collected from the middle of the canopy in the east,west,south,and north directions,with 20 cones and 20 needles(2 years old branches on the main branches),determination of cones traits(cone dry weight,cone length,cone width,cone shape index,seed scale length,seed scale width,seed scale length-width ratio),and needles traits(needle length,needle width,leaf shape index,leaf thickness,leaf area).Nested ANOVA,multiple comparisons,diversity analysis,and redundancy analysis were applied to analyze the level of phenotypic differentiation of P.schrenkiana cones and needles,the diversity characteristics,and their correlation with geographic environment factors.The results showed that the mean coefficient of phenotypic differentiation for cones and needles of P.schrenkiana was 43.35%,with the main source of phenotypic variation being within populations.The variability of repetition power of phenotypic traits ranged from 0.2007 to 0.5055,with an average repetition power of 0.3692,which is a medium level of repetition power;the coefficient of variation of cone dry weight was the largest among phenotypic traits(14.59%),and the coefficient of variation of Wusu was the largest among populations(8.964%).The mean Shannon-Wiener diversity index for phenotypic traits was 2.0347,and the mean Simpson diversity index was 0.8524,indicating a high level of diversity in P.schrenkiana.Between different populations of P.schrenkiana,there were some differences in the level of phenotypic differentiation and diversity characteristics,and altitude was the main influence factor affecting phenotypic traits of P.schrenkiana,followed by precipitation and longitude.