The cDNA fragment encoding caffeic acid 3_O_methyltransferase (COMT) in Chinese white poplar ( Populus tomentosa Carr.) was isolated and cloned by RT_PCR technique. The size of the cDNA fragment is 1 080 bp, which alm...The cDNA fragment encoding caffeic acid 3_O_methyltransferase (COMT) in Chinese white poplar ( Populus tomentosa Carr.) was isolated and cloned by RT_PCR technique. The size of the cDNA fragment is 1 080 bp, which almost covers the whole cDNA_encoding region. Authors’ cDNA fragment in P. tomentosa shares 98.7% homology with the reported corresponding cDNA in the P. tremuloids at nucleotide level, 99.4% homology at amino acid level, respectively. The analysis of Northern dot hybridization showed that COMT is expressed specifically in the developing secondary xylem of stem during the season of xylem differentiation, which means the linkage between the gene expression for a monolignol biosynthetic enzyme and seasonal regulation of xylem development in woody plant.展开更多
We determined the calorific value of white poplar（Populus alba L.） woody biomass to use it as firewood. The value of 19.133 MJ kg-1obtained experimentally shows that the white poplar can be quite successfully used a...We determined the calorific value of white poplar（Populus alba L.） woody biomass to use it as firewood. The value of 19.133 MJ kg-1obtained experimentally shows that the white poplar can be quite successfully used as firewood. Being of a lower quality in comparison with usual beech firewood, the white poplar has similar calorific value. The white poplar has a calorific density of 30.7 % lower than that of current firewood. That is why the price of this firewood from white poplar is lower accordingly. Also, the prognosis of calorific value on the basis of the main chemical elements, being very close to the experimental value（＋2.6 %）, indicates an appropriate value can be achieved to be used for investigation with the chemical element analysis.展开更多
Cross breeding strategies are very efficient for gaining new and superior genotypes. Ninety-eight new white poplar hybrid clones produced from 12 cross combinations within the Section Leuce Duby were studied using gen...Cross breeding strategies are very efficient for gaining new and superior genotypes. Ninety-eight new white poplar hybrid clones produced from 12 cross combinations within the Section Leuce Duby were studied using genetic analysis and seedling tests. We exploited the wide variation that exists in this population and found that the differences among diameter at breast height （DBH）, root collar diameter （RCD） and height （H） were statistically extremely significant. The repeatability of clones of these measured traits ranged from 0.947-0.967, which indicated that these traits were strongly controlled by genetic factors. Based on multiple compari- sons, a total of 25 clones showed better performance in growth than the control cultivar. These 25 clones were from six different cross combinations, which can guarantee a larger genetic background for future new clone promotion projects. This study provides a simple overview on these clones and can guide us to carry out subsequent selection plans.展开更多
In the paper, differences between the juvenile Triploid Chinese White Poplar (TCWP) in saline soil and 5-year TCWP in normal soil are compared in terms of their APMP-pulping properties. The results show that the salin...In the paper, differences between the juvenile Triploid Chinese White Poplar (TCWP) in saline soil and 5-year TCWP in normal soil are compared in terms of their APMP-pulping properties. The results show that the saline planting environment does not show obvious effects on pulping properties of juvenile TCWP.展开更多
To investigate the levels of polymorphisms and Mendelian segregation ratio in clone “TB01” (P. tomentosa×P. bolleana) ×clone “LM50” (P. tomentosa) BC 1 population at the entire genome level, ampl...To investigate the levels of polymorphisms and Mendelian segregation ratio in clone “TB01” (P. tomentosa×P. bolleana) ×clone “LM50” (P. tomentosa) BC 1 population at the entire genome level, amplified fragment length polymorphisms (AFLPs) analysis was conducted for both parents and 120 progenies. Forty one pairs of selective primers were used to detect 2?707 bands, of which 712 (26.4%) were polymorphic. Chi\|square tests were performed to examine if the observed genotypic frequencies of AFLP loci deviated from expected 1∶1 Mendelian segregation ratio ( P <0.01) in BC 1 population. Among the 712 loci 571 (80.2%) fit to Mendelian 1∶1 segregation ratio, corresponding to DNA polymorphisms heterozygous in one parent and a null in the other. The result shows that the AFLP markers are very suitable for fingerprinting and genetic mapping in the Chinese white poplar (Populus tomentosa Carr.).展开更多
文摘The cDNA fragment encoding caffeic acid 3_O_methyltransferase (COMT) in Chinese white poplar ( Populus tomentosa Carr.) was isolated and cloned by RT_PCR technique. The size of the cDNA fragment is 1 080 bp, which almost covers the whole cDNA_encoding region. Authors’ cDNA fragment in P. tomentosa shares 98.7% homology with the reported corresponding cDNA in the P. tremuloids at nucleotide level, 99.4% homology at amino acid level, respectively. The analysis of Northern dot hybridization showed that COMT is expressed specifically in the developing secondary xylem of stem during the season of xylem differentiation, which means the linkage between the gene expression for a monolignol biosynthetic enzyme and seasonal regulation of xylem development in woody plant.
基金supported by the Doctoral Department of ‘‘Transylvania’’ University of Brasov for its material and financial support of Romaniathe Sectoral Operational Programme Human Resources Development(SOP HRD),ID134378financed from the European Social Fund and by the Romanian Government
文摘We determined the calorific value of white poplar（Populus alba L.） woody biomass to use it as firewood. The value of 19.133 MJ kg-1obtained experimentally shows that the white poplar can be quite successfully used as firewood. Being of a lower quality in comparison with usual beech firewood, the white poplar has similar calorific value. The white poplar has a calorific density of 30.7 % lower than that of current firewood. That is why the price of this firewood from white poplar is lower accordingly. Also, the prognosis of calorific value on the basis of the main chemical elements, being very close to the experimental value（＋2.6 %）, indicates an appropriate value can be achieved to be used for investigation with the chemical element analysis.
基金National Natural Sciences Foundation of China (Grant No.30571516)National Project of Science and Technology for the 11th Five-Year Plan (Grant No.2006BAD01A1502)
文摘Cross breeding strategies are very efficient for gaining new and superior genotypes. Ninety-eight new white poplar hybrid clones produced from 12 cross combinations within the Section Leuce Duby were studied using genetic analysis and seedling tests. We exploited the wide variation that exists in this population and found that the differences among diameter at breast height （DBH）, root collar diameter （RCD） and height （H） were statistically extremely significant. The repeatability of clones of these measured traits ranged from 0.947-0.967, which indicated that these traits were strongly controlled by genetic factors. Based on multiple compari- sons, a total of 25 clones showed better performance in growth than the control cultivar. These 25 clones were from six different cross combinations, which can guarantee a larger genetic background for future new clone promotion projects. This study provides a simple overview on these clones and can guide us to carry out subsequent selection plans.
文摘In the paper, differences between the juvenile Triploid Chinese White Poplar (TCWP) in saline soil and 5-year TCWP in normal soil are compared in terms of their APMP-pulping properties. The results show that the saline planting environment does not show obvious effects on pulping properties of juvenile TCWP.
文摘To investigate the levels of polymorphisms and Mendelian segregation ratio in clone “TB01” (P. tomentosa×P. bolleana) ×clone “LM50” (P. tomentosa) BC 1 population at the entire genome level, amplified fragment length polymorphisms (AFLPs) analysis was conducted for both parents and 120 progenies. Forty one pairs of selective primers were used to detect 2?707 bands, of which 712 (26.4%) were polymorphic. Chi\|square tests were performed to examine if the observed genotypic frequencies of AFLP loci deviated from expected 1∶1 Mendelian segregation ratio ( P <0.01) in BC 1 population. Among the 712 loci 571 (80.2%) fit to Mendelian 1∶1 segregation ratio, corresponding to DNA polymorphisms heterozygous in one parent and a null in the other. The result shows that the AFLP markers are very suitable for fingerprinting and genetic mapping in the Chinese white poplar (Populus tomentosa Carr.).
