山东元宝枫天然种群种实的表型多样性

Fruit and seed phenotypic diversity of natural populations of Acer truncatum in Shandong

【目的】通过分析山东各地不同种群元宝枫种实的表型性状,以期揭示元宝枫表型变异程度及变异规律,为元宝枫优良种质资源的遗传改良、优良选种、保护和开发利用提供理论基础。【方法】采用巢式方差分析、相关性分析、主成分分析和聚类分析等方法,对14个元宝枫种群的12个种实表型性状的变异特征、变异来源、表型分化、表型性状之间以及表型性状与地理环境因子之间的相关性、对种源的聚类特征进行统计和分析。【结果】元宝枫各种实表型性状均在种群间和种群内呈极显著差异,种群间的遗传分化显著。元宝枫平均表型变异系数为11.18%,变异范围为6.56%~17.51%,其中最小值为种仁千粒重(0.29%),最大为果实千粒重(41.85%)。12个种实表型性状的平均相对极差为44.23%,变化范围在0.53%~96.93%。元宝枫12个表型性状在种群间和种群内的平均方差分量百分比分别为7.74%和86.34%,元宝枫种群间的表型分化系数为86.34%,种群内的表型分化系数为13.66%。种实表型性状相关性结果显示,果实形态中除张开角之外,其余性状与种子形态之间呈现极显著的正相关。元宝枫各表型性状除翅果宽,其余性状与均经纬度呈显著或极显著的正相关,大部分表型性状与海拔和年降水量呈负相关。主成分分析结果表明,前三个主成分累积贡献率为67.441%,第1主成分主要反映果实和种子的形态大小,第2和第3主成分主要反映了果实形态特征。利用欧式平方距离将14个元宝枫种群分为两大类,YYSL单独归为一大类,其余种群聚为另一类。【结论】元宝枫14个种群种实表型性状变异丰富,能够进行基于表型性状的种质资源筛选;元宝枫果实性状与种子性状的遗传变异稳定性相当;元宝枫主要变异来源为种群间变异;翅果张开角与其余性状均呈负相关或不相关,推测其为独立因子;元宝枫种实表型性状受经纬度与海拔的影响,大体呈现随着经纬度的增大种实变大、海拔增高而种实变小的趋势;本研究中的聚类结果与地理分布相关性不强,种群间的表型性状的遗传变异未形成明显的规律性,呈现较为随机的变异趋势。

【Objective】To analyse the phenotypic traits of the seed fruits of Acer truncatum from different populations in different parts of Shandong,we aim to reveal the degree of phenotypic variation and variation pattern of A.truncatum,and provide a theoretical basis for genetic improvement,excellent selection,conservation and development and utilization of the excellent germplasm resources of A.truncatum.【Method】Nested ANOVA,correlation analysis,principal component analysis and cluster analysis were used to statistically and analytically analyse the variation characteristics of 12 phenotypic traits of 14 A.truncatum populations,the sources of variation,phenotypic differentiation,the correlation among phenotypic traits and between phenotypic traits and geographic factors,and the clustering characteristics of the seed sources.【Result】The phenotypic characters of fruit and seed of A.truncatum were significantly different among populations and within populations,and the genetic differentiation between populations was significant.The average phenotypic coefficient of variation of A.truncatum was 11.18%,ranging from 6.56%to 17.51%,of which the minimum value was the seed kernel mass(0.29%),and the maximum value was the fruit mass(41.85%).The average relative extreme variance of the 12 phenotypic traits was 44.23%,with a range of 0.53%to 96.93%.The average variance components of the 12 phenotypic traits in A.truncatum were 7.74%and 86.34%between and within populations,respectively,and the phenotypic differentiation coefficient was 86.34%between populations and 13.66%within populations of A.truncatum.The correlation results of seed phenotypic characters showed that there was a significant positive correlation between the fruit morphology and seed morphology,except for the opening angle.Except for samara width,the other phenotypic characters were significantly or extremely significantly positively correlated with average latitude and longitude,and most phenotypic characters were negatively correlated with altitude and annual precipitation.The results of principal component analysis showed that the cumulative contribution rate of the first three principal components was 67.441%.The first principal component mainly reflected the morphological characteristics of fruits and seeds,and the second and third principal components mainly reflected the morphological characteristics of fruits.Using Euclidean square distance,14 A.truncatum populations were divided into two groups,YYSL being individually grouped into one major group and the others were grouped into another group.【Conclusion】The phenotypic characters of 14 populations of A.truncatum were abundant,which could be used to screen germplasm resources based on phenotypic characters.The stability of genetic variation of fruit and seed traits was comparable.The main source of variation was inter-population variation.The opening angle of the samara was negatively correlated or not correlated with the rest if the characters,so it was presumed to be an independent factor.The phenotypic characters of A.truncatum were affected by latitude,longitude and altitude,with the increase of latitude and longitude,the fruit and seed increased and the altitude increased,but the fruit and seed decreased.In this study,the clustering results did not correlate well with geographic distribution,and the genetic variation of phenotypic traits among populations did not form an obvious regularity,showing a more random trend of variation.