杉木半同胞子代胸径变异和大径材家系选择

Diameter Variation of Chinese Fir Half-sib Progenies and Selection for Large-size Timber Families

摘要:

为选择适宜培育大径材的优良家系，以广东杉木（Cunninghamia lanceolata）第二代种子园半同胞子代（28个半同胞家系）和2个对照（第一代、第一代改良种子园混合种）为对象，对林龄4、9、11、16和21 a的杉木胸径进行持续测定。结果表明，相同林龄家系间的胸径差异极显著（P<0.01），表型变异系数和遗传变异系数分别为4.43%~6.29%和2.95%~3.62%。家系胸径的遗传力较高（0.335 9~0.548 6），且随年龄的增长呈增大趋势，至林龄16 a时达到0.548 6，随后趋缓。林龄9 a的胸径与早期（4 a）、晚期（11、16和21 a）的胸径遗传相关性最为密切。基于多年度育种值和林龄21 a时家系各径级立木占比统计，共选择出F5、F9、F21等3个适于培育大径材的优良家系。

Abstract:

In order to select superior families for breeding large-size diameter of Chinese fir (Cunninghamia lanceolata), the diameter at breast height (DBH) of 28 half-sib progenies in second-generation seed orchard of Guangdong were continuously determined at 4, 9, 11, 16 and 21 years old, compared with 2 control families from primary seed orchard and 1.5 generation seed orchard of Guangdong. The result showed that DBH of Chinese fir had significant difference (P<0.01) among families at the same age, and the phenotypic and genetic coefficient ranged from 4.43% to 6.29% and from 2.95% to 3.62%, respectively. The family heritability of DBH increased from 0.3359 at 4 years old to a peak of 0.5486 at 16 years old, and then became stable at 21 years old. The genetic correlation of DBH at 9 years old was close to that at 4, 11, 16 and 21 years old, respectively. So, according to multi-year breeding values and the ratio of diameter-grade volume of family at age of 21, three families (F5, F9 and F21) were selected as the superior families for large-size timer cultivation.