Establishment of cell suspension line of <Emphasis Type="Italic">Populus tomentosa</Emphasis> Carr.

Leaves of fine Populus tomentosa genotype TC152 were used as explants to establish cell suspension lines. The effects of plant growth regulators on callus induction and establishment of cell suspension lines were studied. The callus induction rate was the highest on a MS solid medium supplemented with 1.0 mg·L^-1 2,4-D. A cell suspension line could be obtained by inoculating calli which were not subcultured into a MS liquid medium supplemented with 1.5 mg·L^-1 2,4-D. The best subculture medium was MS ＋ 0.8 mg＇L-1 2,4-D ＋ 30 g·L^-1 sucrose with a subculture cycle of seven days.     

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.     

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；     

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。     

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.     

毛白杨叶片再生系统的建立

该文选用三倍体毛白杨的叶片作为外植体 ,MS作为基本培养基 ,采用不同组合的BA和NAA作为植物生长调节剂对毛白杨再生系统进行研究 .结果表明 ,在MS培养基中单独添加 1 5mg·L-1BA时 ,不定芽分化率为 90 % ,同时伴随一定程度的玻璃化现象 .单独添加 0 3mg·L-1NAA时 ,不定根产生率最高 (90 % ) ,但无不定芽生成 .采用 1 0mg·L-1BA + 0 3mg·L-1NAA组合搭配时 ,不定芽分化率最高 (95 % ) .在此基础上 ,采用M1(MS + 1 0mg·L-1BA + 0 3mg·L-1NAA)培养基 ,研究了不同着生位置的叶片、同一着生位置叶片的不同切段以及叶片在培养基上的放置方式对毛白杨叶片再生的影响 .结果表明带有叶柄的下切段比其余叶片切段不定芽再生率高 ,幼嫩叶片比老化叶片再生率高 ,叶片近轴端向下接触培养基比远轴端向下接触培养基再生率高 .叶片再生系统的建立为毛白杨的遗传转化奠定了基础     

Lignin Characterization of Triploid Clones of Populus tomentosa Carr.

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.     

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.     

毛白杨插条苗先生根原基形成的解剖学研究

作者解剖观察了毛白杨(Populut tomentosa Carr。)一年生插条苗的根原基形成时间、部位和分化的过程,以及培土措施对根原基分化的影响。结果表明,从样品苗木基部的第一、二节,连续作切片镜检,在673张切片中,有104个根原基。根原基自6月中旬开始分化,至7月上旬期间分化快,数量多。分布于苗茎4个部位。苗木基部数量多,上部少。培土比不培土的苗木基部,根原基形成得早、数量多。     

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.     

毛白杨遗传改良研究进展(英文)

毛白杨是中国一个十分重要的乡土树种，从“六·五”开始就被列为国家科技攻关研究的树种，分别在基因资源收集保存、无性系选育、回交和多交育种、三倍体育种、快速无性繁殖技术等方面进行了研究     

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     

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．     

毛白杨、银白杨嫁接育苗造林技术探讨

采用泰青杨和合作杨作砧木,进行毛白杨、银白杨育苗和造林试验。结果表明,用泰青杨作砧木,嫁接繁育毛白杨、银白杨,是培育毛白杨等较难生根杨树树种苗木的有效途径,并可提高育苗质量和造林成活率。     

毛白杨伐根嫁接繁殖技术研究

利用20 a生小叶杨伐根和1 a生小钻杨根桩嫁接毛白杨,进行嫁接繁殖技术研究。结果表明,伐根嫁接毛白杨的成活率是根桩嫁接成活率的231.2%;3 a生的伐根嫁接植株平均高生长量为8.2 m,是苗圃地根桩嫁接法的200.0%;平均胸径生长量为11.4 cm,是苗圃地根桩嫁接法的175.4%,两者差异极显著。该方法成本低,在低产林改造、农田防护林更新、城镇和村屯绿化、水土保持林及护路林更新改造等方面具有广泛的推广价值。     

三倍体毛白杨引种试验初报

三倍体毛白杨具有生长迅速、抗逆性强、材质优良等特性，在北方广为种植，是当前最有开发价值的10大杨树新品种之一。首次在江西开展引种栽培试验，当年平均苗高3．5m，平均地径3．2cm，病虫危害少，苗期生长基本正常。初步显示，三倍体毛白杨在江西也能引种栽培。     

Somatic embryogenesis from cell suspension cultures of aspen clone

Suspension cultures initiated from callus derived from petiole explants of aspen hybrid (Populus tremuloides × P. tremula) produced somatic embryos. Callus was induced on a MS medium supplemented with 5 mg·L–1 2,4-D and 0.05 mg·L–1 zeatin under light conditions. Embryogenic calli were obtained when a subsequent subculture of calli was suspended in the same basal me-dium with 10 mg·L–1 2,4-D. The highest number of globular embryos were induced from embryogenic calli by cell suspension cul-ture in a MS liquid medium supplemented with 10 mg·L–1 2,4-D. Genotype and 2,4-D concentration were vital to the induction of embryogenic calli producing competent cells. Embryogenic calli for each genotype were heterogeneous. Green calli with gel-like consistency could yield more competent cells than light yellow embryogenic calli. However, some globular embryos broke into slices and some developed abnormally after one month of culture under the same or other hormonal conditions.     

全国毛白杨优良无性系选育

经苗期对比试验,从全国１０省种源的１０４７株毛白杨优良基因资源中初选出３４个无性系进行中试,以比较速生的天然三倍体毛白杨雌株做对照。９年测定结果表明,鲁毛５０、５３１４、１４１４、５０１５和南×毛新五个无性系的材积增益高达３０％～５８．２％,且干形直,形态变异明显,易识别,适应性和抗逆性较强,有较高的推广利用价值。     

毛白杨苗木繁育技术试验

利用阜新地区的土壤、气候、水质等因子,采用毛白杨基部灌溉埋条法与扦插育苗法育苗,进行对比观察,发现毛白杨采用基部灌溉埋条法要比常用扦插育苗法成活率高20个百分点以上,每株苗木平均生根数埋条法比扦插法多10条。同时,埋条育苗方法能节省种条,提高苗木产量和土地利用率。     

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。