Lignin characterization of triploid clones of Populus tomentosa Carr.

In order to understand the structural characteristics of lignin in triploid clones of Populus 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 of A 1270 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.     

三倍体毛白杨新无性系木材气干密度和力学性质性状的遗传控制及对单板材育种的意义

该文利用 9个 9年生三倍体毛白杨无性系木材试样 ,研究了木材气干密度组成及力学性质的遗传变异规律 .结果表明 ,木材气干密度组成及力学性质在无性系间存在显著或极显著差异 ,并受到中等强度的遗传控制 ;气干密度的径向和纵向变异与多数研究结果一致 ;力学性质除抗弯弹性模量和端面硬度外其株内变异趋势也基本符合木材学理论 .在力学性质指标中 ,抗弯弹性模量和弦面硬度是遗传性很强的性状 ,其无性系重复力分别为 0 90和 0 80 ,抗弯强度、顺纹抗压强度和硬度的无性系重复力稍低 .遗传相关表明对单板材可通过木材密度与干形等形质指标进行优良无性系选择     

毛白杨无性系树体性状的关系分析

对１０年生毛白杨无性系５个树体性状组的关系分析结果表明，材积、枝下高、圆满度三个重要经济性状的改良潜力较大，通直度的改良效果较差。主干和侧枝两性状组与经济性状组的关系密切，分别解释了经济性状组５４７５％和２８７６％的相关变异。对经济性状实施选择时，可把树高、胸径、Ｈ／２径、冠幅、侧枝的数量与密度、主枝的长与粗以及新枝长和节数作为间接选择指标。     

Variation of Leaf Characteristics in Populus tomentosa Carr.

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.     

Effects of Planting Density on Growth of New Clones in Populus tomentosa

Effects of seven planting densities on the growth and tree form of nine 5-year-old new clones in Populus tomentosa were studied. The plantations, arranged with completely random block design, were located in Wuzhi County, Henan Province.Results indicated that effects of planting density on the diameter at breast height (DBH), individual volume and growing stock increment of all new clones in P. tomentosa were significant at the 1% level of probability, effects of planting density on the tree height increment of new clones B2 and B31 and on the live branches height (LBH) increment of new clones B5 and B30 were significant at the 5% level of probability, while the interaction between planting density and clone was not significant at the 5% level of probability. It was concluded that the degree of differences among new clones within the same planting density was different with different planting densities and traits. For short rotation industrial timber, clones B 1, B3, B4, B5, B7, B9, B31 were suitable with the density of 1 000-2 500 trees per hectare, while for bigger diameter timber, clones B1, B3, B4, B7, B9, B31 could be used with the planting density of 660-833 trees per hectare. Clonal repeatability was also different in different planting densities.     

三倍体毛白杨不同砧木嫁接试验

为探索不同砧木亲合力对三倍体毛白杨一条鞭芽接成活率的影响 ,试验分别采用赤峰杨、少先队杨、群众杨作砧木进行了一条鞭芽接试验。结果表明 ,在上述砧木上进行芽接 ,其亲合力对成活率影响差异不显著     

毛白杨无性系木材基本密度遗传变异研究(英文)

对河北、河南、山东、甘肃的４块毛白杨无性系测定林中约１００个无性系进行了木材基本密度的测定，对木材基本密度在地点和无性系间的遗传变异进行了研究．结果表明：毛白杨无性系的木材基本密度平均值为０．４３６３ｇ／ｃｍ３，木材基本密度在地点和无性系间均存在极显著差异．木材基本密度的无性系重复力为０．８２～０．９１，属于受遗传控制较强的材性性状．对生长和材性的相关研究表明，木材基本密度与生长性状（包括胸径、树高和材积）一般存在显著的负相关，但不同地点上表现为不同的正或负的相关关系     

Duplication of Locus Coding of Malate Dehydrogenase in Populus tomentosa Carr.

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.     

三倍体毛白杨配套造林技术研究

根据１０年来大规模的三倍体毛白杨春、秋、冬三季造林,总结出了通道工程绿化、农田林网和滩涂用材丰产林的整地、苗木质量标准、栽植八要诀、育造一体化和林木管理等系列配套造林技术。参照应用本技术,可使毛白杨造林成活率达到９５％以上,并使三倍体毛白杨产业的经济效益提高三倍以上,具有很高的推广价值。     

Effects of Fertilization Treatments on Plantation Growth of Triploid Clones in Populus tomentosa

With four clones of triploid Populus tomentosa as materials, the effects of fertilization treatment on growth and physiological characters in terms of leaf nitrogen content, phosphorous content, potassium content, net photosynthetic rate,transpiration rate, water utilization efficiency and chlorophyll content have been studied. Compared with the general fertilizer as a control, the long-effect fertilizer, especially for Populus, produce more favorable results, for P. tomentosa on sandy land.     

中幼龄毛白杨优良无性系生物量增长与分配规律研究

采用相对生长法研究了中幼龄毛白杨优良无性系生物量增长及其各器官相对生物量的积累和分配规律．结果表明：毛白杨生物量以干才占主导;6a生以前,各器官生物量分配不稳定,6～8a生以后,其分配趋势为干材＞根＞枝＞干皮＞叶;3个优良无性系每年单位面积的生物量和固定的太阳能均为对照的2～4倍;净光合效率比对照高24．41％～27．81％．并建立了各器官生物量增长的数学模型．     

Comparison and early selection of new clones in Populus tomentosa

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 sig-nificant differences among clones. In both plantations, the new clones showed over 0.6 repeatability of beight, 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, BTI7 and 21J-1 were considered suitable in Weixian. hi 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.     

Model of leaf energy distribution and its experimental validation of Populus tomentosa Carr

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 Cart. 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.     

白银地区三倍体毛白杨造林试验初报

分析了1998年引种的10个三倍体毛白杨系号在白银地区造林的生长适应性。结果表明：在同一立地类型和同等抚育条件下，A129、A128、B330、A125、B1008、BT85、A122等7个无性系杂种三倍体毛白杨幼林在白银地区速生、抗寒、耐盐碱、抗黄斑星天牛，对叶锈病、褐斑病和煤污病基本免疫，在白银市表现出较强的适应性和抗逆性，生长量显著高于普通毛白杨、群众杨、新疆杨；由于其速生性使黄斑星天牛不能完成生活史而不至于造成危害；在速生用材林、专用纸浆林、农田防护林和公路绿化等方面大力推广具有良好的发展前景。     

毛白杨无性系苗期生长参数分析

利用Logistic方程对6个毛白杨无性系苗高、地径的年生长动态进行拟合,并分析年生长动态规律及生长参数。结果表明:拟合效果显著,相关系数均大于0.900;苗高和地径的速生持续期分别为70~79 d和86~101 d,速生期内的苗高生长量占总生长量的58.9%~61.0%,地径生长量占总生长量的61.2%~65.1%;苗高、地径年生长极值与其实测值呈极显著正相关,相关系数均为0.990;苗高、地径的年生长极值均与各自的速生持续期、最大生长速度呈显著正相关。     

毛白杨苗期VA菌根菌与外生菌根菌接种的研究

1998～1999年在田间条件下布置了毛白杨VA菌根(包括根内球囊霉菌和单孢球囊霉菌)与外生菌根硬皮马勃混合接种试验.结果表明接种菌根菌对毛白杨苗高生长量有促进作用,且以根内球囊霉菌作用最明显,单孢球囊霉菌处理次之,硬皮马勃处理最差.水涝大大降低人工接种菌根菌的效果,严重影响VA菌根和外生菌根菌单独接种及混合接种的效应,根内球囊霉菌甚至会抑制毛白杨苗木的高生长,VA菌根和外生菌根间的负交互作用也不对苗高生长产生影响.菌根真菌的感染率随时间变化出现较大的波动和变化.     

不同年龄三倍体毛白杨纸浆林养分循环特征

以4个不同年龄的三倍体毛白杨纸浆林为对象,开展了养分积累及归还的研究,结果表明,随着年龄的增加,三倍体毛白杨纸浆林存留的N、P量相应增加,乔木层存留比例达95%以上;另外,通过地上凋落物、地下细根归还的N、P量也相应增加。地上凋落物归还的养分大于地下细根,需要在生产中采取措施加以保护并促进其分解。由于三倍体毛白杨归还的养分少于吸收存留的养分,因此林地土壤中N、P的总量呈现亏损状态,并随年龄的增加而增加,其中N的亏损从3年时亏损0.54%,到7年时亏损1.92%,P从3年时亏损0.35%,到7年时亏损0.52%,说明生产中要维持林木的生长,提高并改善立地生产力应补充养分来源;从不同年龄三倍体毛白杨林分的养分循环系数来看,年龄在3年、5年、6年、7年时N的归还率分别为0.347 5、0.458 5、0.488 1、0.467 8,P的归还率则分别为0.184 7、0.296 6、0.267 5、0.242 9。因此对三倍体毛白杨纸浆林来说,目前的经营措施有可能引起长期立地生产力下降,需要采取保护落叶、补充有机质来源和施肥等综合措施来提高生产力,确保纸浆林的可持续高产。     

杨树伐根嫁接毛白杨试验研究

试验结果表明：不同的白杨派品种对嫁接亲合力的敏感程度不同，敏感性最强的是白杨的７４１，敏感性最低的是河北毛白杨；选用生长健壮的种条作接穗，伐根生长旺盛，直径在１０ｃｍ以上，嫁接时间掌握在４月份，且边平茬边嫁接是提高嫁接成活率的主要措施；     

Interrelationships between leaf heat conductivity and tissue structures of different varieties of Populus tomentosa Carr.

Plant heat conductivity largely depends on tissue structure. Different structures lead to different heat conductivity. As well, water transfer also plays a very important role in heat transfer in plants. We have studied leaf heat conductivity and tissue structure of 3- and 30-year-old Populus tomentosa Carr. trees using mildred thermal imaging, steady state heat conductivity surveys and paraffin section and investigated the relationship between leaf heat conductivity, tissue structure and water content of leaves. The results show that the temperature on leaf surfaces among the various varieties of trees was almost the same. Leaf heat conductivity, temperature and water content of leaves are positively correlated. The thicker the leaf tissue structures, the larger the heat resistance. That is, the tighter the cells and the smaller the interspaces, the smaller the heat conductivity, which is not conducive for heat transfer.     

三倍体毛白杨新无性系木材干缩性的遗传分析

利用 9a生三倍体毛白杨测定林的 9个无性系为试材 ,着重研究了木材干缩率的遗传学问题。结果表明 :木材干缩率在无性系间的差异都达到了极显著水平 ,并受到强度遗传控制 ;木材干缩在株内纵向的变异模式是随树高增加而降低 ;全干体积 ,径向、弦向干缩率和气干体积 ,径向、弦向干缩率无性系重复力分别为 0 89,0 95 ,0 84 ,0 6 7,0 84和 0 6 8。