Abstract:

The genetic resource of Populus deltoides Bartr., a fast growing species of rich genetic variation, is poor in China and need to be introduced from foreign country. In 1980's 331 clones of Section Aigeiros consisting of 52 clones of P.deltoides, 56 clones of P.×euramericana and 6 clones of P.nigra were introduced from 17 foreign countries. In 1984 the first gene pool of Section Aigeiros in China was established in Changqing County, Shandong Province. The several characters in clones of Section Aigeiros had been measured and studied for ten years. The results showed that there were significant in phenology, growth, rooting, cold resistance, disease and pest resistance between different colnes, and the genetic variation was rich. The rules were as follows:(1)Growth showed significant negative correlation to the original latitude.(2)Cold resistance showed significant positive correlation to the original latitude.(3)Rooting ability tended to add little with the height of latitude.(4)Disease resistance showed slight significant positive correlation to the original latitude, as well as negative correlation to the original longitude.(5)Change of season showed significant correlation to growth of standing stock.(6)Cold resistance showed significant positive correlation to growth.(7)Disease resistance shows positive correlation to cold resistance.Basic wood properties such as wood basis density, fiber length, tree height, and DBH were also measued and analyzed. The results showed that a significant variance was observed in 4 traits among 46 clones and there was slight negative genetic correlation between the wood basic density and tree growth rate, as well as positive genetic correlation between the fiber length and tree growth rate. RAPD analysis was applied to the analysis of DNA polymorphism and genetic differentiation among the clones. The percent of polymorphism was up to 80%, which showed that genetic diversity of this gene pool was significant. The gene pool will provide rich breeding material for improvement of poplar in China.

Key words: Populus deltoides Bartr., Gene Pool, Main characters, Genetic analysis and evaluation