Genetic Variation Analysis of Flowering Phenology in the 2.5 Generation Seed Orchard of Cunninghamia lanceolata

The flowering phenology observation was conducted from February to March in 2012 on 20 Cunninghamia lanceolata clones chosen from the 2.5 generation seed orchard, which was set up in 2009 in Xiaokeng Forest Farm. The results indicated that there ware extremely significant differences in the initial blooming stage (referred as phase 1), full blooming stage (referred as phase 2) and end blooming stage (referred as phase 3) among the clones. There was also extremely significant difference in phase 1 and phase 2 between the female and male strobilus of the same clone, but there was no significant difference in the phase 3 between the female and male strobilus of the same clone, suggesting there was a high overlay in phase 3 of the female and male strobilus, which.might lead to a very high level of selfpollination that would be one of the reasons to produce large proportion of shrunken seeds. The repeatability was amazingly high in phase 1 and phase 2, but relatively low in phase 3, revealing that phase 1 and phase 2 were under strong genetic control, and phase 3 of the species was more influenced by the environment. The high repeatability of the flowering phenology proved that it would be a very effective way to select the clones with synchronized flowering phenology for establishing new seed orchards of C. lanceolata.