Genetic Evaluation of New Exotic Resources of Slash Pine in Taishan Hongling Seed Orchard

seed lots of slash pine (Pinus elliottii) were introduced from United States,Australia and Zimbabwe,from 1989 to 1996. Among these seed lots,there were 6 provenances,188 half sib families,and 213 full-sib families.One provenance trial stand,6 gene resource stands were established with a total of 370 seed lots in Taishan Hongling Seed Orchard.And the seed lot from the primary slash pine seed orchard in Taishan was used as control (CK).The total area of these stands was 16.85 hm2.Based on data from these seven stands,the growth performance and selection potential of these new exotic materials were evaluated,and the reliability of early selection was studied.The results showed that the new materials had good adaptability and the survival rates of stands were above 90%.66.67% provenance and 82.14% families grown better than the CK did.The realized gains were 10.07% and 30.45% respectively for height and volume growth.It was estimated that the predicted genetic gains of plus trees from these new materials would be 28.51% and 60.79% respectively for height and volume,according to the combined selection method that the top 50% families were selected from these new resources,and then 2 plus trees within each selected family.Correlation coefficients between height growth at age 1,and height,diameter breast height and volume at age 3 and the increment at age 7 were greatly significant.Those families growing poorer at age 3 could not performance very well at age 7.