In order to understand the structural characteristics of lignin in triploid clones ofPopulus tomentosa and its changes in the processes of pulping and bleaching, milled wood lignin (MWL), lignin carbohydrate complex...In order to understand the structural characteristics of lignin in triploid clones ofPopulus tomentosa and its changes in the processes of pulping and bleaching, milled wood lignin (MWL), lignin carbohydrate complex (LCC) and the residual lignin from kraft pulp (KP) and sulfite pulp (SP) were isolated and analyzed by Fourier transform infrared (FTIR) spectrum and ^13C nuclear magnetic resonance (NMR). The most diagnostic peaks were assigned and the differences were discussed. The spectral patterns reveal that triploid P tomentosa shows the specific features of hardwood from temperate areas, but in the spectrum of FTIR, the strength ratio orAl270 cm^-1 to A1226 cm^-1 is 0.88, higher than the average of hardwood from temperate areas, which will make the lignin delignification more difficult during pulping and bleaching. The LCC from triploid P tomentosa is mainly composed of xyloglucan and glucuronic acid, and other glucides have much lower ratio. In LCC FTIR, there are three peaks at 1 427, 1 329 and 1 046 cm^-1, indicating that both semi-cellulose and cellulose could exist in LCC, and that there might be relationships between cellulose and lignin. Compared with the residual lignin from KP and SP, the condensed structure in KP is more than that in SP.展开更多
The fiber morphology variation of triploid clone of Populus tomentosa Carr. and the supposed harvesting age for the paper industry were investigated in this paper. The results shows that in the first few years, 2-4 ye...The fiber morphology variation of triploid clone of Populus tomentosa Carr. and the supposed harvesting age for the paper industry were investigated in this paper. The results shows that in the first few years, 2-4 years for example, the fiber length at breast high grows faster than it does in the later years. But the standard deviation of distribution in fiber length at breast high in mature wood is larger than in the young tree. The technologically harvestable age of triploid clone of Populus tomentosa Carr., BL304 could be 4-7 year old to meet the requirement for paper industry. The distribution of fiber length become concentrated within an annual ring as the tree grows. The test results also show that the cloned poplar has a small Runkel ratio value (less than 0.4, generally about 0.3), and this ratio increases slightly with the tree grows.展开更多
An investigation was conducted to determine the extent of variations among nine provenances of Populus tomentosa Carr. in terms of leaf characteristics. A total of 263 accessions were studied under field conditions in...An investigation was conducted to determine the extent of variations among nine provenances of Populus tomentosa Carr. in terms of leaf characteristics. A total of 263 accessions were studied under field conditions in the National Gene Bank of P. tomentosa in 2003. All of the accessions were characterized by 17 indices from 1 to 2-dimension constructions. Variance analysis of all characteristics showed that there were significant differences among the nine provenances and among individuals within each provenance. This study reveals that the evaluated germplasm appears to have a wide genetic base and high potential for further genetic improvements and it also indicates that abundant gene resources of P. tomentosa have been collected and preserved in the National Gene Bank.展开更多
Microscopic examination and AFLP molecular markers were employed to determine the incidence and related markers of 2n pollen (unreduced pollen) in Populus tomentosa Carr. The parallel and tripolar spindle at metaphase...Microscopic examination and AFLP molecular markers were employed to determine the incidence and related markers of 2n pollen (unreduced pollen) in Populus tomentosa Carr. The parallel and tripolar spindle at metaphase Ⅱ and the absence of cytokinesis at telophase Ⅱ led to the formation of 2n pollen. A group of 298 clones came from their indigenous areas was investigated for the production of 2n pollen based on the pollen size differences, within a clone and between n and 2n pollen. Pollen grains of 224 clones were collected, six of them only produced normal pollen, and the rest produced 2n pollen at different frequencies (0.6% -21.9%). Clones producing six normal and 22 2n pollen were selected for AFLP analysis. Following an initial screening with 55 primer combinations, the E50-M38 (CAT/ACT) primer was identified, which generated a PCR fragment (246 bp) from the normal clones, but not from the 2n pollen producers. In addition, the E31-M50 (AAA/CAT) amplified DNA fragment (204 bp) that was present in 2n pollen producers, and absent in normal clones. Two polymorphic bands were found and they were distinguished between normal and 2n pollen clones. They are very useful as AFLP markers for molecular-assisted selection in triploid breeding of 2n gametes in P.tomentosa.展开更多
Leaf temperature of a plant is the result of heat transfer between the plant and its environment. There are many factors that can affect leaf temperature, such as the solar radiation energy, environmental temperature,...Leaf temperature of a plant is the result of heat transfer between the plant and its environment. There are many factors that can affect leaf temperature, such as the solar radiation energy, environmental temperature, wind velocity, evaporation on the leaf surface, photosynthesis, respiration and so on, which have different effects on the temperature of leaves. In first instance, we analyzed the heat transfer on leaves of Populus tomentosa Carr. theoretically and constructed a model of energy distribution. We then validated the model by analyzing seven different kinds of one-year-old P. tomentosa leaves experimentally. The result shows that solar radiation is the main energy input and the dominant ways of thermal diffusion are heat transfer between the upper and lower leaf surfaces and evaporation from the leaf surface.展开更多
Horizontal starch-gel electrophoresis was used to study crude enzyme extraction from young leaves of 234 clones of Populus tomentosa Cart. selected from nine provenances in North China. Ten enzyme systems were resolve...Horizontal starch-gel electrophoresis was used to study crude enzyme extraction from young leaves of 234 clones of Populus tomentosa Cart. selected from nine provenances in North China. Ten enzyme systems were resolved. One hundred and fifty-six clones showing unusual allozyme band patterns at locus Mdh-Ⅰ were found. Three allozyme bands at locus Mdh-Ⅰ were 9:6:1 in concentration. Further studies on the electrophoretic patterns of ground mixed pollen extraction of 30 male clones selected at random from the 156 clones were conducted and it was found that allozyme bands at locus Mdh-Ⅰ were composed of two dark-stained bands and a weak band. Only one group of the malate dehydrogenase (MDH) zymogram composed of two bands was obtained from the electrophoretic segregation of pollen leachate of the same clones. A comparison of the electrophoretic patterns one another suggested that the locus Mdh-Ⅰ coding malate dehydrogenase in diploid species of P. tomentosa was duplicated. The duplicate gene locus possessed three same alleles and was located in mitochondria. The locus duplication of alleles coding malate dehydrogenase in P.tomentosa was discovered and reported for the first time.展开更多
Transgenic lines were achieved by transforming the E. coli 1-phosphate mannitol dehydrogenase gene (mtl-D) into the Populus tomentosa Cart. genome. An Agrobacterium tumefaciens strain (AGL1), constructed by clonin...Transgenic lines were achieved by transforming the E. coli 1-phosphate mannitol dehydrogenase gene (mtl-D) into the Populus tomentosa Cart. genome. An Agrobacterium tumefaciens strain (AGL1), constructed by cloning mtl-D into the disarmed plasmid pBin438, was used to infect leaves of the clone YW2. The infected leaf discs were cultured on a medium containing 30 mg.L 1 kanamycin and 500 mg.L 1 cefotaxime. Transgenic plantlets regenerated from the infected leaves, rooted on the medium con- taining 30 mg.L 1 kanamycin. PCR and a Southern blotting test verified that the exogenous mtl-D gene had integrated into the trans- formation plants of the P. tomentosa genome. The mannitol content in control plant was 69 gg.gl FW, and the mannitol contents of the transgenic lines T1 to T5 ranged between 103.7 and 289.5 μg·g^-1 FW. Of the shoots of the control plants 20% survived; on the medium containing 0.6% NaCl, 60% and 70% of two transgenic shoots survived on a medium containing 0.8% NaCI.展开更多
In our study, two experimental plantations, respectively, with 24 and 32 new clones of P tomentosa, were established in Weixian County, Hebei Province and Wuzhi County, Henan Province using a completely randomized blo...In our study, two experimental plantations, respectively, with 24 and 32 new clones of P tomentosa, were established in Weixian County, Hebei Province and Wuzhi County, Henan Province using a completely randomized block design. A comparative study was conducted on the continuous 5-year-old height and diameter at breast height (DBH) of new clones in the two plantations. As well, based on genetic correlation over the years of testing of these clones, a preliminary study of early selection was carried out. Results indicate that the growth traits of the new clones in Weixian were better than those in Wuzhi. The traits show weak correlation between the two plantations. In some stands, the height, DBH and seedling volume of 5-year-old clones presented statistically significant differences among clones. In both plantations, the new clones showed over 0.6 repeatability of height, DBH and volume, as well as larger coefficients of variation (CV). The fact that these clones achieved the largest repeatability and CV in the second year suggests that these traits are highly controlled by heredity. Thus, based on the growth traits of the second year, the new clones B305, B307, B303, H75, BT18, BT17 and 21J-1 were considered suitable in Weixian. In Wuzhi, the new clones had variable repeatability and CVs in various years and their correlation of growth traits among different years was not high. We conclude that early selection of new clones was not feasible in Wuzhi.展开更多
The fiber morphology and pulping properties of triploid of populus tomentosa from plantation at different ages were investigated in the paper,also the main chemical compositions were determined. The results showed tha...The fiber morphology and pulping properties of triploid of populus tomentosa from plantation at different ages were investigated in the paper,also the main chemical compositions were determined. The results showed that the difference of chemical compositions is not significant, and the extractive contents become bigger in some sort with age, the difference of length weighted mean length of fiber also is not significant, and coarseness of fiber has trend of augment by degree, while the fines content increases obviously with age. That difference of pulping properties between chemical pulping (KP process and Soda-AQ process) and chemimechanical pulping (SCMP process and APMP process) is not significant, which is consistent with the analysis of chemical composition and fiber morphology. Considering comprehensively, the tree age of 5 years is better for paper making industry, also the mixed pulping with different ages of the triploid of populus tomentosa is feasible with steady pulp quality.展开更多
为探讨中高林龄杨树(Populus)光合生理特性对不同修枝强度的响应规律,以10年生三倍体毛白杨(triploid Populus tomentosa)无性系B301与S86为研究对象,采用轻度修枝(修去树冠下部1/3枝条)和重度修枝(修去树冠下部1/2枝条),以及未修枝杨...为探讨中高林龄杨树(Populus)光合生理特性对不同修枝强度的响应规律,以10年生三倍体毛白杨(triploid Populus tomentosa)无性系B301与S86为研究对象,采用轻度修枝(修去树冠下部1/3枝条)和重度修枝(修去树冠下部1/2枝条),以及未修枝杨树为对照,研究不同强度修枝对10年生毛白杨生长和生理特性的影响。结果表明:对于10年生中高龄杨树,修枝对树高、胸径、材积增长率无显著影响,但重度修枝能提高剩余叶片的净光合速率(P_(n))、蒸腾速率(T_(r))、气孔导度(G_(s)),增强单叶水平上物质合成的能力,而修枝对瞬时水分利用效率(WUE)影响不显著。从生长和光合角度综合分析,修去树冠下部1/2枝条能够改善10年生毛白杨生理状况,但对林木生长无明显促进作用。展开更多
[Objective] The experiment was aimed to select effective and economical media for container seedling of triploid clones of Populus tomentosa that was carried out. [Method] The sandy loam, peat, perlite, vermiculite, r...[Objective] The experiment was aimed to select effective and economical media for container seedling of triploid clones of Populus tomentosa that was carried out. [Method] The sandy loam, peat, perlite, vermiculite, riversand, sludge were taken as media of hardwood cutting and survival rate, seedling height were taken as indexes to select media for container seedling of triploid clones of Populus tomentosa. [Result] Different mixedmedia had great influence on survival rates of container seedlings. Taking peat and vermiculite with the proportion of 5∶2 (M10) or peat ,vermiculite with the proportion of 7∶2 (M11) or sandy loam (M1) as media would generate higher cutting survival rate that was higher than 90.0%. There were significant differece in height increments of container seedlings. Taking sandy loam, peat and vermiculite with the proportion of 6∶2∶2(M5)or sandy loam (M1), seedling height of 60-days the seedling was over 37.0 cm. [Conclusion] According to cost analysis of nursery medium, the optimum medium for hardwood cuttings container seedling-raising of triploid clones of Populus tomentosa was sandy loam.展开更多
The establishment of high frequency regeneration system is a foundation for Agrobacterium mediated genetic transformation. In this work, several important factors influencing the efficiency of regeneration of pla...The establishment of high frequency regeneration system is a foundation for Agrobacterium mediated genetic transformation. In this work, several important factors influencing the efficiency of regeneration of plants, such as concentration of plant growth regulators, leaf explant orientation, leaf growth sequence and leaf segment, were studied. The results indicated that the differentiation rate of adventitious shoots was 90% on basal MS medium only supplemented with 1 5?mg·L -1 BA (6 benzyladenine) and reached the highest level(95%) when 1 0?mg·L -1 BA and 0 3?mg·L -1 NAA (naphthaleneacetic acid) were added to MS medium. 90% of differentiation rate of adventitious roots were obtained when 0 3?mg·L -1 NAA was only added to MS medium. It was also found that more adventitious shoots were regenerated from the lower segment of leaf (with petiole) than the other segments, the number of adventitious shoots decreased from top to base of leaf growth sequence and the percentage of adventitious shoot induction with adaxial side downward was higher than that with adaxial side upward.展开更多
文摘In order to understand the structural characteristics of lignin in triploid clones ofPopulus tomentosa and its changes in the processes of pulping and bleaching, milled wood lignin (MWL), lignin carbohydrate complex (LCC) and the residual lignin from kraft pulp (KP) and sulfite pulp (SP) were isolated and analyzed by Fourier transform infrared (FTIR) spectrum and ^13C nuclear magnetic resonance (NMR). The most diagnostic peaks were assigned and the differences were discussed. The spectral patterns reveal that triploid P tomentosa shows the specific features of hardwood from temperate areas, but in the spectrum of FTIR, the strength ratio orAl270 cm^-1 to A1226 cm^-1 is 0.88, higher than the average of hardwood from temperate areas, which will make the lignin delignification more difficult during pulping and bleaching. The LCC from triploid P tomentosa is mainly composed of xyloglucan and glucuronic acid, and other glucides have much lower ratio. In LCC FTIR, there are three peaks at 1 427, 1 329 and 1 046 cm^-1, indicating that both semi-cellulose and cellulose could exist in LCC, and that there might be relationships between cellulose and lignin. Compared with the residual lignin from KP and SP, the condensed structure in KP is more than that in SP.
文摘The fiber morphology variation of triploid clone of Populus tomentosa Carr. and the supposed harvesting age for the paper industry were investigated in this paper. The results shows that in the first few years, 2-4 years for example, the fiber length at breast high grows faster than it does in the later years. But the standard deviation of distribution in fiber length at breast high in mature wood is larger than in the young tree. The technologically harvestable age of triploid clone of Populus tomentosa Carr., BL304 could be 4-7 year old to meet the requirement for paper industry. The distribution of fiber length become concentrated within an annual ring as the tree grows. The test results also show that the cloned poplar has a small Runkel ratio value (less than 0.4, generally about 0.3), and this ratio increases slightly with the tree grows.
文摘An investigation was conducted to determine the extent of variations among nine provenances of Populus tomentosa Carr. in terms of leaf characteristics. A total of 263 accessions were studied under field conditions in the National Gene Bank of P. tomentosa in 2003. All of the accessions were characterized by 17 indices from 1 to 2-dimension constructions. Variance analysis of all characteristics showed that there were significant differences among the nine provenances and among individuals within each provenance. This study reveals that the evaluated germplasm appears to have a wide genetic base and high potential for further genetic improvements and it also indicates that abundant gene resources of P. tomentosa have been collected and preserved in the National Gene Bank.
文摘Microscopic examination and AFLP molecular markers were employed to determine the incidence and related markers of 2n pollen (unreduced pollen) in Populus tomentosa Carr. The parallel and tripolar spindle at metaphase Ⅱ and the absence of cytokinesis at telophase Ⅱ led to the formation of 2n pollen. A group of 298 clones came from their indigenous areas was investigated for the production of 2n pollen based on the pollen size differences, within a clone and between n and 2n pollen. Pollen grains of 224 clones were collected, six of them only produced normal pollen, and the rest produced 2n pollen at different frequencies (0.6% -21.9%). Clones producing six normal and 22 2n pollen were selected for AFLP analysis. Following an initial screening with 55 primer combinations, the E50-M38 (CAT/ACT) primer was identified, which generated a PCR fragment (246 bp) from the normal clones, but not from the 2n pollen producers. In addition, the E31-M50 (AAA/CAT) amplified DNA fragment (204 bp) that was present in 2n pollen producers, and absent in normal clones. Two polymorphic bands were found and they were distinguished between normal and 2n pollen clones. They are very useful as AFLP markers for molecular-assisted selection in triploid breeding of 2n gametes in P.tomentosa.
基金the National Project of ScienceTechnology for the 11th Five-Year Plan in China (Grant No.2006BAD24B04)
文摘Leaf temperature of a plant is the result of heat transfer between the plant and its environment. There are many factors that can affect leaf temperature, such as the solar radiation energy, environmental temperature, wind velocity, evaporation on the leaf surface, photosynthesis, respiration and so on, which have different effects on the temperature of leaves. In first instance, we analyzed the heat transfer on leaves of Populus tomentosa Carr. theoretically and constructed a model of energy distribution. We then validated the model by analyzing seven different kinds of one-year-old P. tomentosa leaves experimentally. The result shows that solar radiation is the main energy input and the dominant ways of thermal diffusion are heat transfer between the upper and lower leaf surfaces and evaporation from the leaf surface.
文摘Horizontal starch-gel electrophoresis was used to study crude enzyme extraction from young leaves of 234 clones of Populus tomentosa Cart. selected from nine provenances in North China. Ten enzyme systems were resolved. One hundred and fifty-six clones showing unusual allozyme band patterns at locus Mdh-Ⅰ were found. Three allozyme bands at locus Mdh-Ⅰ were 9:6:1 in concentration. Further studies on the electrophoretic patterns of ground mixed pollen extraction of 30 male clones selected at random from the 156 clones were conducted and it was found that allozyme bands at locus Mdh-Ⅰ were composed of two dark-stained bands and a weak band. Only one group of the malate dehydrogenase (MDH) zymogram composed of two bands was obtained from the electrophoretic segregation of pollen leachate of the same clones. A comparison of the electrophoretic patterns one another suggested that the locus Mdh-Ⅰ coding malate dehydrogenase in diploid species of P. tomentosa was duplicated. The duplicate gene locus possessed three same alleles and was located in mitochondria. The locus duplication of alleles coding malate dehydrogenase in P.tomentosa was discovered and reported for the first time.
文摘Transgenic lines were achieved by transforming the E. coli 1-phosphate mannitol dehydrogenase gene (mtl-D) into the Populus tomentosa Cart. genome. An Agrobacterium tumefaciens strain (AGL1), constructed by cloning mtl-D into the disarmed plasmid pBin438, was used to infect leaves of the clone YW2. The infected leaf discs were cultured on a medium containing 30 mg.L 1 kanamycin and 500 mg.L 1 cefotaxime. Transgenic plantlets regenerated from the infected leaves, rooted on the medium con- taining 30 mg.L 1 kanamycin. PCR and a Southern blotting test verified that the exogenous mtl-D gene had integrated into the trans- formation plants of the P. tomentosa genome. The mannitol content in control plant was 69 gg.gl FW, and the mannitol contents of the transgenic lines T1 to T5 ranged between 103.7 and 289.5 μg·g^-1 FW. Of the shoots of the control plants 20% survived; on the medium containing 0.6% NaCl, 60% and 70% of two transgenic shoots survived on a medium containing 0.8% NaCI.
基金the National Project of ScienceTechnology for the 11th Five-Year Plan (Grant No.2006BAD01A1502)
文摘In our study, two experimental plantations, respectively, with 24 and 32 new clones of P tomentosa, were established in Weixian County, Hebei Province and Wuzhi County, Henan Province using a completely randomized block design. A comparative study was conducted on the continuous 5-year-old height and diameter at breast height (DBH) of new clones in the two plantations. As well, based on genetic correlation over the years of testing of these clones, a preliminary study of early selection was carried out. Results indicate that the growth traits of the new clones in Weixian were better than those in Wuzhi. The traits show weak correlation between the two plantations. In some stands, the height, DBH and seedling volume of 5-year-old clones presented statistically significant differences among clones. In both plantations, the new clones showed over 0.6 repeatability of height, DBH and volume, as well as larger coefficients of variation (CV). The fact that these clones achieved the largest repeatability and CV in the second year suggests that these traits are highly controlled by heredity. Thus, based on the growth traits of the second year, the new clones B305, B307, B303, H75, BT18, BT17 and 21J-1 were considered suitable in Weixian. In Wuzhi, the new clones had variable repeatability and CVs in various years and their correlation of growth traits among different years was not high. We conclude that early selection of new clones was not feasible in Wuzhi.
文摘The fiber morphology and pulping properties of triploid of populus tomentosa from plantation at different ages were investigated in the paper,also the main chemical compositions were determined. The results showed that the difference of chemical compositions is not significant, and the extractive contents become bigger in some sort with age, the difference of length weighted mean length of fiber also is not significant, and coarseness of fiber has trend of augment by degree, while the fines content increases obviously with age. That difference of pulping properties between chemical pulping (KP process and Soda-AQ process) and chemimechanical pulping (SCMP process and APMP process) is not significant, which is consistent with the analysis of chemical composition and fiber morphology. Considering comprehensively, the tree age of 5 years is better for paper making industry, also the mixed pulping with different ages of the triploid of populus tomentosa is feasible with steady pulp quality.
文摘为探讨中高林龄杨树(Populus)光合生理特性对不同修枝强度的响应规律,以10年生三倍体毛白杨(triploid Populus tomentosa)无性系B301与S86为研究对象,采用轻度修枝(修去树冠下部1/3枝条)和重度修枝(修去树冠下部1/2枝条),以及未修枝杨树为对照,研究不同强度修枝对10年生毛白杨生长和生理特性的影响。结果表明:对于10年生中高龄杨树,修枝对树高、胸径、材积增长率无显著影响,但重度修枝能提高剩余叶片的净光合速率(P_(n))、蒸腾速率(T_(r))、气孔导度(G_(s)),增强单叶水平上物质合成的能力,而修枝对瞬时水分利用效率(WUE)影响不显著。从生长和光合角度综合分析,修去树冠下部1/2枝条能够改善10年生毛白杨生理状况,但对林木生长无明显促进作用。
基金Supported by National Key Technology R&D Program during the 11th Five-year Plan Period(2006BAD32B01)~~
文摘[Objective] The experiment was aimed to select effective and economical media for container seedling of triploid clones of Populus tomentosa that was carried out. [Method] The sandy loam, peat, perlite, vermiculite, riversand, sludge were taken as media of hardwood cutting and survival rate, seedling height were taken as indexes to select media for container seedling of triploid clones of Populus tomentosa. [Result] Different mixedmedia had great influence on survival rates of container seedlings. Taking peat and vermiculite with the proportion of 5∶2 (M10) or peat ,vermiculite with the proportion of 7∶2 (M11) or sandy loam (M1) as media would generate higher cutting survival rate that was higher than 90.0%. There were significant differece in height increments of container seedlings. Taking sandy loam, peat and vermiculite with the proportion of 6∶2∶2(M5)or sandy loam (M1), seedling height of 60-days the seedling was over 37.0 cm. [Conclusion] According to cost analysis of nursery medium, the optimum medium for hardwood cuttings container seedling-raising of triploid clones of Populus tomentosa was sandy loam.
文摘The establishment of high frequency regeneration system is a foundation for Agrobacterium mediated genetic transformation. In this work, several important factors influencing the efficiency of regeneration of plants, such as concentration of plant growth regulators, leaf explant orientation, leaf growth sequence and leaf segment, were studied. The results indicated that the differentiation rate of adventitious shoots was 90% on basal MS medium only supplemented with 1 5?mg·L -1 BA (6 benzyladenine) and reached the highest level(95%) when 1 0?mg·L -1 BA and 0 3?mg·L -1 NAA (naphthaleneacetic acid) were added to MS medium. 90% of differentiation rate of adventitious roots were obtained when 0 3?mg·L -1 NAA was only added to MS medium. It was also found that more adventitious shoots were regenerated from the lower segment of leaf (with petiole) than the other segments, the number of adventitious shoots decreased from top to base of leaf growth sequence and the percentage of adventitious shoot induction with adaxial side downward was higher than that with adaxial side upward.