杉木全同胞家系生长与木材基本密度性状的变异及选择

Variation and Selection of Growth and Wood Property Traits in Cunninghamia lanceolata Full-sib Families

【目的】创制新优杉木种质材料,进而筛选速生优质家系,推进杉木高世代育种进程。【方法】以杉木第二代改良种子园10个骨干亲本作为杂交亲本,采用人工控制授粉方式获得30个全同胞家系,并进行多地点全同胞子代测定,分析其8年生杉木的生长和木材基本密度遗传变异规律,进而开展优良家系选择。【结果】家系间树高、胸径(DBH)、单株材积和木材基本密度(WBD)存在广泛遗传变异,差异达显著(P<0.05)或极显著水平(P<0.01),其中单株材积变异较大,各地点表型变异系数和遗传变异系数分别达到21.56%~28.53%、12.18%~19.64%。树高、胸径、单株材积和木材基本密度家系遗传力分别为0.1594、0.2232、0.1799和0.5357,有利于家系选择。利用BLUP方法估算全同胞家系亲本生长和木材基本密度育种值,同时按亲本模型估算各杂交组合的特殊配合力(SCA)并进行排名,综合生长性状和木材基本密度表现,选获速生优质型家系2个(家系5和29)。其中,家系5具有更高的生长和材质增益,相比群体均值其树高、胸径、单株材积及木材基本密度增益平均为6.02%、8.21%、15.82%、7.25%,而相比对照(2.5代种子园混合种)增益平均为26.47%、14.25%、34.56%、5.35%,因此,家系5是更理想的速生优质家系。【结论】30个杉木全同胞家系的生长和木材基本密度存在丰富的遗传变异,筛选获得的家系可作为候选杉木速生优质良种。

【Objective】The study aims to prepare new and excellent Cunninghamia lanceolata(Lamb.)Hook germplasm materials and select superior families of C.lanceolata families,thus promoting the breeding process of higher generations of the species.【Method】Ten backbone parents of the second-generation improved seed orchard of C.lanceolata were used as hybrid parents,30 full-sib families were obtained by artificial pollination,and full-sib progeny determination was conducted in multiple sites.Genetic variations of the growth and wood basic density of 8-year-old C.lanceolata were analyzed,and then the superior families were selected.【Result】Significant differences(P<0.05)or extremely significant differences(P<0.01)in tree height,diameter at breast height(DBH),volume per plant and wood basic density(WBD)were observed among families.Among them,volume per plant had the highest variation with phenotypic and genetic variation coefficients of 21.56%-28.53%and 12.18%-19.64%.Family heritability values of tree height,DBH,volume per plant and WBD were 0.1594,0.2232,0.1799 and 0.5357,respectively,which were benefit for family selection.The best linear unbiased prediction(BLUP)method was used to estimate the breeding values of growth and WBD of parents from full-sib families,and the special combining ability(SCA)of each hybrid combination was estimated and ranked according to the parental model.Based on the growth traits and WBD,two fast-growth families with good wood quality(family 5 and family 29)were selected.Of the two families,family 5 showed more gain in growth and wood traits with average gain of 6.02%and 26.47%,8.21%and 14.25%,15.82%and 34.56%,7.25%and 5.35%in tree height,DBH,volume per plant and WBD when comparing to overall mean value and F2.5 population,respectively.There,family 5 should be an ideal fast-growth family with good quality.【Conclusion】The growth traits and WBD showed substantial variations among the 30 full-sib families of C.lanceolata.The selected families could be regarded as candidate families that are excellent both in growth and wood basic density.