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马尾松年轮宽度和木材基本密度的种源变异及早期选择

花匠小妙招
2025-02-17 22:36

摘要：

针对浙江省淳安县姥山林场的24年生49个产地马尾松种源试验林，采集植株胸高处木芯，分析种源年轮宽度和木材基本密度的年龄效应。结果表明：除近髓部1～5轮年轮段的木材基本密度外，其他年龄段的年轮宽度和木材基本密度皆存在显著的种源差异，进一步说明通过种源选择可实现木材生产力和木材基本密度的遗传改良。不同年轮段木材基本密度的种源变异相对稳定，而年轮宽度的种源变异则易受环境的影响，幼龄材年轮宽度的种源变异较小，仅为成熟材的63.29%。来自不同种源区的种源年轮宽度的径向变异规律相似，皆表现出先增后减的变化趋势，在6～10轮达到最大值；年轮木材基本密度径向变化规律则与年轮宽度不同，表现为随年龄增长先增加后逐渐稳定的“S”型变化趋势，并据此筛选出广西横县、恭城、忻城，广东乳源和福建南靖5个木材基本密度径向均匀性高的纸浆材优良种源。不同年轮段年轮宽度和木材基本密度的相关分析显示，约在8年生选择径向生长快的种源会明显地降低其木材基本密度。基于性状早晚相关分析，认为可在7年生时先淘汰生长较差的种源，在12年生再开展种源生长和木材基本密度的联合选择。

关键词: 马尾松, 种源, 年轮宽度, 木材基本密度, 早期选择

Abstract:

Wood samples at 1.3 m height were collected from 24-year-old Masson Pine(Pinus massoniana) provenance trial including 49 seed sources located at Chun’an county of Zhejiang Province to study the age effect on ring width and wood density.The results indicated that there existed significant differences in ring width and wood density of every segment except the ring width of the first 1-5 rings between provenances,which suggested genetic improvement of wood productivity and density could be realized by provenance selection.The variation of wood density was relatively stable with cambial ages compared to ring width among provenances and the variation of ring width was susceptible to environment.Variability in juvenile wood was 36.71% less than that in mature wood.Pattern for the radial variation of ring width was similar for provenances in different zones,that is,the variation first increased and then decreased from pith to cambium and reached maximum in 6-10 rings.Pattern for the radial variation of wood density was S-type increment from the pith outward then followed by a leveling off period toward the cambium.Five superior provenances,including Hengxian,Gongcheng and Xincheng of Guangxi Province,Ruyuan of Guangdong Province,and Nanjing of Fujian Province,were selected for pulpwood according to wood density uniformity.Genetic correlation analysis between ring width and wood density suggested that provenance selection of fast radial growth would lead to low wood density in 8-year-old.The early-late correlation analysis showed that slower growth provenance could be eliminated in 7-year-old,then growth and wood basic density could be jointly selected for wood density in 12-year-old.

Key words: Pinus massoniana, provenance, ring width, wood basic density, early selection