油松天然群体的种实性状表型多样性研究

为了揭示油松天然种群在不同地理环境条件下表型变异的程度和规律,在油松整个天然分布范围内选择了12个具有代表性的居群作为研究对象,对其球果、种子、种翅等12个种实性状的变异程度及其与环境因子间关系进行了比较分析。结果显示:(1)各个性状在居群内和居群间均存在较大的变异(CV>12%)。其中千山(QS),曾家镇(ZJ)和互助(HZ)3个居群表现出了较高的变异(CV>20%),而球果干重(CDW)和种子长(CL)是所有表型性状中变异幅度最大的(CV分别为31%和21%),但种翅性状与其他性状相比具有较高的稳定性。(2)巢式设计方差分析表明,在居群内表型分化系数(Vst)变化在3.18%~89.86%之间,而群体间的Vst为38.97%;与其他针叶树种相比,油松拥有较高的表型分化系数,且居群内的变异程度远高于居群间的变异,尤其是千山(QS)、曾家镇(ZJ)和互助(HZ)3个居群,这说明油松具有较高的环境异质性适应能力或恶劣环境耐受能力。(3)相关性分析表明,该研究的各形态特征与潜在蒸发量均为负相关,且大部分形态指标间及它们与潜在蒸发量间存在显著相关性,表明潜在蒸发量是油松形态特征变化的最重要环境影响因子,预示油松最适宜生长于温暖潮湿的环境中;并表明因各形态特征间相互紧密关联,所以它们受环境条件影响而共变。

Phenotypic Diversity of Cone and Seed in Natural Pinus tabuliformis Populations in China

Our objectives were to investigate phenotypic variations of cone and seed of Pinus tabuliformis in natural populations and to describe the relationship between morphological variations and geographic and climatic variables.Our field investigation of P.tabuliformis included four cone characters,four seed characters and four seed wing characters with 148 trees from 12 populations covering its entire natural distributional regions.We examined morphological diversity among/within populations based on the 12 life history traits.Variance analysis,correlation analysis,principal component analysis were used to analyze experimental results.Our results showed that each morphological character presented a large variation both within and among populations.Moreover,analysis of the coefficient of variation were higher in QS,HZ and ZJ (CV>20%).Furthermore,the cone dry weight(CDW) and cone length(CL) showed larger CV than that of other morphological traits.The wing traits were the lowest among all traits.Although the mean proportion of phenotypic variations of all measured traits was about 38.97% among populations of this species,it was much higher than those of other conifers,which further suggested that this species held the higher adaptive phenotypic variations or stress-tolerance ability under varying environmental conditions.According to the correlations between morphological traits and climatic factors,the significant negative correlations between potential evapotranspiration(PET) and most of morphological traits were detected.This study indicates that our research will provide important information for the reforestation and genetic conservation for this species in the changing climate.