Study On The Stem Form Variation And Selection Of Paulownia

Take one hundred and fifty representative Paulownia trees in twevle-year-old Paulownia hybridization and thirty one eleven-year-old paulownia clones as trial materials, twenty three characteristics related stem form were studied, the results are as follows: Paulownia joint stem has three kinds: difficult joint stem, discontinuous joint stem, continuous joint stem. Nineteen characteristics among twenty-three ones are significantly differed. Stem form characteristics' three principal factors are volume of joint stem, volume of primary stem and the tapering grade of the primary stem. Continuous joint stem is the direction of Paulownia stem form selection.Three excellent Paulownia clones were selected according to three primary characteristics of stem form, they are7401-3-l,8508-2 and 744014-13. Genetic augment of joint stem volume,primary stem volume and the primary stem tapering grade of selected clones were respectively 108.92%, 17.19%, 12.29%.36'r- 2001Key words: paulownia;stem form characteristics;type of joint stem;stem form improvement...