木荷地理遗传变异和优良种源初选

在2005年底,对福建建瓯、浙江淳安和庆元的3年生37个产地的木荷种源试验林进行了全面调查,系统研究了幼林生长和分枝性状的种源差异、种源与环境互作及地理变异模式.结果表明:木荷树高、当年抽梢长度、地径、冠幅及侧枝总数、侧枝长和侧枝粗等分枝性状都存在显著的种源效应,木荷地理种源分化明显.造林区立地生境和造林地立地条件对木荷种源生长影响显著,如福建建瓯点3年生种源平均树高较北缘区浙江淳安点和高海拔山地浙江庆元点分别提高了24.1%和18.0%.木荷树高、当年抽梢长度、冠幅、侧枝总数等存在显著的种源×地点和种源×重复/地点互作,不同种源在各区试点上的生长相对表现差异显著.相关分析表明,木荷生长和分枝性状的地理变异模式因区试点环境条件差异而迥异.在中心分布区的福建建瓯点,种源生长和分枝性状与产地纬度相关性显著,呈典型的纬向地理变异模式,速生种源主要来源于分布区的中南部;在北缘区的浙江淳安点,种源高径生长与产地经纬度相关性较小,仅发现侧枝总数和树冠浓密度与产地纬度呈一定程度的负相关,速生种源主要来源于分布区的中部;而在较高海拔区的浙江庆元点,由于环境相对恶劣,木荷种源生长和分枝性状与产地纬度呈显著的正相关,偏北部种源的早期生长表现较好.基于种源幼林测定结果,分别从中心分布区和北缘区初选了一批速生用材和生物防火优良种源.

Geographic Genetic Variation and Preliminary Selection of Superior Provinance in Schima superba

Schima superba provenance trails at age three including thirty-seven seed sources,located at Jian'ou of Fujian,Chun'an and Qinyuan of Zhejiang,were used to study provenance differences,provenance-environment interaction and geographic variation pattern for growth and branch traits.The result showed that there existed significant differences among provenances for height,shoot length,root collar diameter,crown width,total number of branches,length and diameter of branches.The growth of different provenances was found to be greatly influenced by the macro-condition and site-specific condition of plant locations.For example,the average height of provenances tested at Jian'ou of Fujian(the central distribution area)was 24.1% and 18.0% higher than those at Chun'an of Zhejiang(the northern zone) and Qinyuan of Zhejiang(the higher altitude mountainous region) respectively.The significant interaction of provenance by location and provenance by block within locations were found for height,shoot length,crown width and total number of branches.The relative growth performance of different provenances greatly varied with the experiment locations.Correlation analysis showed that geographic variation pattern for growth and branchtraits changed prominently with location environment.At Jian'ou of Fujian,a classical latitude clinal variation pattern was found forgrowth and branch traits which was negatively and significantly related to the latitudes of seed sources.Fast-growing provenances were primary from the middle and south distribution area.At Chun'an of Zhejiang,tree height and root collar diameter of provenances was not related to the longitudeand latitude of seed sources.Only total number of branches and crown density negatively wererelated to the latitude of seed source in a certain extent.Fast-growing provenances were primary from the middle distribution area.At Qinyuan of Zhejiang,provenance growth and branch traits was found to be positively and markedly related to the latitude of seed sources,due to relatively poor environment in the higher altitude mountainous region.Early growth performance of the northern provenance was better.Based on the provenance trial result at young stage,superior provenances used for fast-growing timber and biological fire-prevention were preliminarily selected for the central and northern distribution areas respectively.