乐昌油杉优树资源调查及收集区营建

对广东省乐昌地区杉木林分进行调查，共筛选出104份乐昌油杉优树资源。对优树生长、形质、材质等性状进行测定分析，结果表明：优树群体生长性状（树高、胸径、单株材积）均值明显高于样地群体值（P<0.01），性状表现水平（PL）皆在77.0以上；入选优树树高、胸径、单株材积现实增益分别为0.4%~97.1%、32.3%~131.8%、82.6%~712.5%；优树高径比、冠径比变幅分别为38.9~76.5、8.7~21.9；优树木材基本密度、红心材比率、木材干缩性、木材吸水性总体变幅则分别为0.251 1~0.3931g/cm3、29.2%~72.3%、0.8%~32.4%、189.0%~332.9%；其中，木材干缩性变异程度最大，CV值达100%，而木材基本密度变异程度较低，CV值仅为11%。以平均木材质测定值为阈值对优树进行分类，不同优树群体均可分选出一定数量生长材质皆优单株。研究还对乐昌油杉优树资源进行了有效保存（就地保存与异地保存），收集区资源合计保存率为98.1%。

Plus Tree Resource Survey and Genebank Construction for Cunninghamia lanceolata

Based on a large scale investigation into Cunninghamia lanceolata stands in Lechang area of Guangdong Province, a total of 104 plus trees of C. lanceolata were screened out, and the trait indexes including height, DBH, form index, standing volume, wood quality and growth properties of the plus trees were measured and analyzed. The results showed that the average values of tree height, DBH, and standing volume of the plus tree population were all significantly (P<0.01) higher than those of the sample plot population, whose phenotype level was above 77.0. Further analyses revealed that the real gain of tree height, DBH, and standing volume indexes of the plus trees could achieve to 0.4%-97.1%, 32.3%-131.8%, and 82.6%-712.5% respectively. The height DBH ratio and the crown DBH diameter ratio ranged from 38.9 to 76.5, and from 8.7 to 21.9 individually. The basic wood density(DEN), red heartwood ratio(RHR), shrinkage (SH) and hygroscopicity (HY) of the plus trees changed in amplitudes of 0.2511-0.3931g/cm3, 29.2%-72.3%, 0.8%-32.4%, and 189.0%-332.9% respectively. Notably, the trait of SH varied most significantly among the plus trees with phenotypic variation coefficient (CV) of 100%, while the DEN index varied much less with a CV of 11%. By using the mean trees as controls, a considerable number of plus trees with qualified wood were herein identified. Currently, the germplasm resources of C. lanceolata plus trees were well conserved by both in situ and ex situ methods. The compacted ex situ conservation ratio appeared to be 981%.