木荷生长与形质地理变异和木制工艺材种源选择

利用设置在福建建瓯和浙江淳安的5年生木荷Schima superba种源试验林,系统研究生长和形质性状种源差异、地理变异模式和性状遗传相关,并利用选择指数开展木制工艺材优良种源选择。方差分析结果表明,木荷树高、胸径、树干通直度及一级侧枝总数、最大侧枝长和最大侧枝粗存在显著的种源效应,受到中等以上强度遗传控制,种源广义遗传力达0.34～0.61,而树干分叉干数和分枝角的种源效应较小。木荷生长和形质性状的地理变异模式因区试点不同而存在一定的差异,在木荷中心产区的福建建瓯点,主要生长和形质性状与产地纬度呈显著的负相关,相关系数达-0.313～-0.534,与产地经度相关性较小,呈典型的纬向变异模式,南部种源生长较快,树干通直,但分枝多而粗;在北缘区的浙江淳安点,除种源一级侧枝总数与产地纬度呈显著负相关外,其他生长和形质性状与产地纬度的负相关性较小。性状相关分析发现,木荷种源主要的形质与生长性状呈显著的正遗传相关,遗传相关系数达0.320～1.164,而树干通直度则与最大侧枝长互为独立。选用2个理想的等经济权重和以生长改良为主的选择指数分别为福建建瓯和浙江淳安点选出了10个生长和形质兼优的优良种源,前者多为南部种源,而后者多为中部种源。表6参16

Genetic variation of growth and form in Schima superba provenances with selection for wood processing materials

To aid in wood processing with superior Schima superba stock,provenance differences,geo-graphic variation patterns,and genetic correlation of growth and form traits in provenance trails of five-year-old trees located at Jian ou,Fujian Province and Chun an,Zhejiang Province were determined using the variance,simple correlation and genetic correlation analysis. A random block design with five replications was applied in the trials,and the traits survey was conducted in December of 2007. Provenance broad-sense heritability and selection index were estimated with the quantitative genetics methods. Results showed significant differences between provenances for height（P〈0.05）, D BH（P〈0.05）, stem straightness（P〈0.05）, total number of primary branches （P〈0.01） and length（P〈0.05）, and diameter of primary branches （P〈0.05）. These traits were under moderate or even strong provenance genetic control with a provenance broad-sense heritability that varied from 0.34 to 0.61. No significant differences for stem bifurcation or maximum branch angle were found. The correlation analysis at Jian ＇ou （the central distribution area） showed a classic latitudinal clinal variation pattern with main growth and form traits negatively （r = - 0.313 to - 0.534） and significantly （P〈0.05） related to seed source latitudes. At the more northern Chun＇an the total number of primary branches was negatively （r = - 0.380） and significantly （P〈0.05） related to seed source latitude. A significant （P〈0.05）, positive（r = 0.320 to 1.164） relationship was found for the main growth and form traits in both locations, whereas stem straightness was not correlated to primary branch length. Based on the two selection indexes of： 1） equal and 2） growth-emphasized economic weighting, 10 superior provenances were selected with most superior provenances for Jian＇ou in southern areas and for Chun＇an in central areas.