Study on the Effects in the Second-Generation Orchard of Cunninghamia lanceolata

The growth and seeding situation of parental trees, the seed quality of sowing, the performance of progeny and the practical gains for the second-generation orchard were assessed. The results were summarized as follows. In 6 to 8 years after graft, the remaining rate of trees in the second-generation seed orchard was 74.34% and the rate of straight trunk was 87.65%. Trees in the orchard have grown well. Rate of seeding trees was 50.45%, and cone production index was 1.52. The seed rate of cone was 3.24%. The thousand-grain mass was 6.554 gram. The germination rate was 31.74%, and the germination capacity was 23.16%. The quality of sowing of the seed in the second-generation seed orchard was higher than those in the first-generation orchard with the same age, but was lower than those in the 1.5-generation orchard. The parents from Guangdong and Guangxi are better than those from Fujian, Guizhou and Hunan according to their seeding ability. The results from 4-year-old progeny tests indicated that the practical gain of volume in the second-generation seed orchard was 7.58%-10.60%, and the key targets of developing second-generation seed orchard and improving genetic quality of seeds were realized. The establishment of the second-generation seed orchard in Longshan state-own forest farm was basically successful.