7年生木荷生长和木材基本密度地理遗传变异及种源选择

Geographical Provenance Variation of Growth and Wood Basic Density of 7-Year-Old Schima superba and Its Provenance Selection

针对福建建瓯的7年生33个产地的木荷种源试验林,研究揭示其生长和木材基本密度的种源差异及地理变异模式,并依据聚类分析结果进行速生优质种源选择。结果表明,木荷胸径、树高、枝下高、材积指数和木材基本密度等存在显著或极显著的种源变异,其中以材积指数的种源变异最大。木荷生长和木材基本密度的种源变异主要受产地温度影响,呈典型的纬向变异模式,来自纬度较低、温度较高产地的木荷种源,其树高、胸径和材积指数等生长量较大,木材基本密度较小。木荷各性状间也存在相关性,其木材基本密度与生长性状呈显著负相关。除存在显著的种源效应外,不同重复间的微立地效应也非常显著,在较差立地条件下,木荷种源的生长量较小,但木材基本密度呈现增大趋势。基于生长和木材基本密度进行种源聚类,可大致将木荷划分为中心种源区、中部种源区和北部种源区3个种源区。同时,以高于材积指数和木材基本密度种源总体均值为选择标准,分别初选出17个速生型和11个速生优质型木荷优良种源,其中多数优良种源来源于南岭山脉—武夷山脉的中心种源区。

The provenance test including 33 seed sources of Schima superba at age seven was conducted at Jian＇ou of Fujian to study the provenance differences and geographic variation pattern for growth traits and wood basic density.Based on cluster analysis results,the provenances with superior growth and wood properties were selected.Significant variations in DBH,height,clear bole height,volume index and wood basic density among provenances were demonstrated,of which the variation in volume index was the largest.A typical latitude variation pattern was found for growth traits and wood basic density of S.superba,and the local temperature was the main climatic factor which led to the variation.The provenances from lower latitudes and higher temperature region were higher in height,diameter and volume index,with lower wood basic density.Also,there existed correlations among various traits,as the wood basic density was negatively correlated with growth traits.Besides the provenance effect,the effect of micro-environment of different repetition was also very significant,the increment of S.superba provenances was smaller under poorer site condition,but the wood basic density showed an increasing tendency.Based on clustering of growth and wood basic density,the S.superba provenances could be approximately divided into three provenance regions,i.e.central,middle and northern regions.Meanwhile,seventeen provenances with superior growth and eleven provenances with both superior growth and wood properties were preliminarily selected,which were above provenance mean of volume index and wood basic density,and most of which originated from central provenance region of the Nanling-Wuyi Mountains.