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Scientia Silvae Sinicae ›› 2007, Vol. 43 ›› Issue (03): 20-27.doi: 10.11707/j.1001-7488.20070304

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A Study on Realized and Genetic Gains of Different Generations and Types in Seed Orchards of Chinese Fir (Cunninghamia lanceolata)

Zheng Yongping1,Sun Hongyou2,Dong Ruxiang3,Hua Zhaohui4,Tang Shuqin5,Zhang Jianzhang6,Fu Shunhua2   

  1. 1. Zhejiang Senhe Seed Company, Limited Hangzhou 310012; 2. School of Forestry and Biotechnology, Zhejiang Forestry College Lin'an 311300; 3. Forestry Seed and Stock Controlling Station of Zhejiang Province Hangzhou 310020; 4. Forestry Bureau of Suichang County Suichang 323300; 5. Laoshan Forest Farm of Chun'an County Chun'an 311700; 6. Forestry Bureau of Longquan County Longquan 323700
  • Received:2006-02-15 Revised:1900-01-01 Online:2007-03-25 Published:2007-03-25

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Abstract:

To fully understand the progress and trend of genetic improvement of Chinese Fir (Cunninghamia lanceolata) in seed orchards of different generations and types, and thus search for sustainable and efficient approaches for improving the genetic level of populations in trees, we collected seeds, grew and planted seedlings for two consecutive years in 17 clonal seed orchards in Zhejiang Province. Data on tree height, breast diameter, volume, crown diameter and lateral branch were measured twice in seed orchards of four different locations and five groups. The results showed that the average growth gain of progeny gradually improved from generation to next generation, I.e., from general unimproved seeds to seeds from orchards of the first, one and half, and second generations, however, the growth gain between different generations decreased significantly. The seeds from bi-clonal seed orchards showed the greatest growth gain, followed by those from provenance orchards. At six-year-old, compared with general unimproved seeds, the seeds from the first, one and half, and second generation orchards, provenance orchards and bi-clonal seed orchard showed height gain of 4.35%, 6.04%, 7.88%, 12.02% and 12.02%, representing genetic gain of 3.90%, 5.41%, 7.06%, 10.77% and 10.77%, respectively; breast diameter gain of 7.60%, 9.68%, 12.08%, 15.05% and 19.70%, representing genetic gain of 7.07%, 9.00%, 11.23%, 14.00% and 18.32%, respectively; and volume gain of 20.65%, 27.47%, 32.14%, 39.93% and 46.14%, representing genetic gain of 16.97%, 22.58%, 26.42%,32.82% and 37.93%, respectively. Based on these results, we suggest that the seed resources of fine provenances should be utilized to the fullest in advanced orchards in order to achieve sustainable genetic gain. We further suggest that it should be very important to build bi-clonal orchard for trees used for industrial materials while improving the genetic level of populations and maintaining genetic diversity.

Key words: Chinese Fir(Cunninghamia lanceolata), seed orchard, realized gain, genetic gain, progeny testing