Natural Resistance of Two Plantation Woods Populus × canadensis cv. and Cunninghamia lanceolata to Decay Fungi and Termites

Natural durability of two plantation woods, Chinese fir and I-214 poplar, was investigated thoroughly by three testing methods, namely an accelerated laboratory decay test, a fungus cellar test and a field test. After the decay test using Postia placenta and Trametes versicolor, Chinese fir and the I-214 poplar showed 34% and 69% of mass loss, respectively, indicating they should be classified as slightly durable and non-durable wood. This conclusion was confirmed by the fungus cellar test and the field test. Like the performance in the decay test, I-214 poplar showed no resistance to termites either in the laboratory or in the field, whereas Chinese fir would be classified as moderately resistant. [Supported by Sino-Japanese Technical Cooperation Project Titled “Studies on Chinese Plantation Wood” (JICA PROJECT/033-1418-E-O)]     

Absorption and Accumulation of Heavy Metal from Soil by Leaves of Populus × euramericana cv.‘ Neva' Plantation

对北京市南郊房山区107杨绿化林地进行了土壤重金属吸收富集研究,林地周围有水泥厂、石材厂、污水和垃圾等不同污染源,结果表明:林地土壤受到了Pb、Cd、Cu和Zn不同程度的污染,Pb、Cu、Zn含量差异显著,Cd平均含量(0.077 6 mg·kg-1)低于北京市背景值,但Pb、Cu、Zn平均含量分别为37.61、26.25和90.3 mg· kg-1,均超过了背景值,3块林地107杨叶片的Pb、Cd、Cu和Zn含量不同,与土壤重金属含量的变化无明显规律性,107杨叶片对土壤Pb、Cd、Cu和Zn重金属元素均能吸收富集,但对不同重金属的吸收富集能力不同,呈现出Cd＞ Zn＞ Cu＞ Pb的变化趋势,尤其对Cd具有很强的富集能力,富集系数最高值大于16,表现出了低背景高富集,而对Pb、Cu的富集能力相对较小,富集系数均小于1;不同林地107杨叶片对同种重金属元素的吸收存在较大的差异.     

Absorption and Accumulation of Heavy Metal from Soil by Leaves of Populus x euramericana cv.‘Neva’Plantation

The absorption and enrichment of heavy metal elements by leaves of Populus×euramericana cv.’Neva’ were analyzed through content assessing of heavy metal elements in soils of three forest lands at Fangshan District in the southern suburb of Beijing. These forest lands with P.×euramericana cv. ’Neva’plantation were around with the various sources of pollution such as cement mill,stone mill, sewage and garbage.Some of heavy metal elements such as Cd,Pb,Cu,and Zn were found in the soil samples and leaves of P.×euramericana cv.’Neva’ grown on the three forest lands which were investigated.The results of investigation showed that the soils of three forest lands were polluted with Pb, Cd,Cu and Zn in varying degrees.The contents of Pb,Cu and Zn in soils were significantly different among the three forest lands,whereas the average content of Cd(0.077 6 mg·kg^-1) was less but that of Pb,Cu,and Zn(37.61,26.25 and 90.3 mg·kg^-1 ) were more than the average background value of Beijing.The contents of Pb,Cd,Cu and Zn in leaves of P.×euramericana cv.’Neva’ were different among three forestlands.With the changes of heavy metal contents in soil samples,there was no regularity on the changes of different heavy metal contents in leaves of P.×euramericana cv.’Neva’ grown on different forest land.P.×euramericana cv.’Neva’ can absorb and accumulate Pb,Cd,Cu and Zn in soil but showed different capacities of absorption and accumulation with the order of Cd>Zn>Cu>Pb.Especially,its absorption and accumulation capacity for Cd was strong with maximum enrichment factor higher than 16 and showed high accumulation on low background,whereas its enrichment capacities for Pb and Cu were relatively poorer with average enrichment factor of less than 1.At different forest lands,there existed great difference on absorption capacity of P.×euramericana cv.’Neva’ with the same heavy metal.     

Clones No 1333 of Populus alba×P.davidiana and No 1132 of P.davidiana×P.alba×P.daviana

IntroductionAspen(Populus~anaDode)isapioneeringspecieswhichiswidelydistributed,welIadapted,andhasgoodqualityoftimber.ItdistributesfromXimalayaMoun-tains,toDaxing'anMountainsandXiaoxing'anMoun-tainsandfromAhaiMountainstoWusulijiangriver,coVerin23provineeso…     

Analysis on Insecticidal Activity of Bt Transgenic Populus deltoides × P.euramericana cv‘ Nanlin895’ and Its Effects on Soil Microorganism

以转Bt基因南林895杨株系B1、B4、B17、B21扦插苗为试验材料,分析其在室内和野外自然条件下对靶标害虫杨小舟蛾幼虫的抗虫性.结果表明:转Bt基因杨树4个株系均有一定的杀虫活性,其中株系B21对杨小舟蛾1龄幼虫12d校正死亡率高达95.3％;虫试表明转Bt基因杨树各株系扦植苗在野外自然条件下的12 d幼虫校正死亡率8月份为35.0％～88.8％,9月份为40.5％～95.3％.用转Bt基因杨树叶片饲养杨小舟蛾,对照植株杨小舟蛾幼虫化蛹率为83.3％～96.0％,而转Bt基因株系幼虫化蛹率为8.0％～76.7％,二者有显著差异.转Bt基因杨树对杨小舟蛾幼虫的生长发育有抑制作用,饲喂8d后害虫取食量、体质量增长速率显著低于对照.此外,为了解转Bt基因杨树对土壤微生物的影响,对转Bt基因杨树株系及对照进行了根际土壤微生物可培养类群的分析,初步结果显示:转Bt基因杨树根际土壤微生物中细菌、真菌、放线菌的数量与对照比较无显著差异.     

Adaptation and morpho-physiology of three Populus deltoides Marsh.?×?P. nigra L. clones after preconditioning to prolonged waterlogging

The implementation of a management-protection program, using suitable cultivation practices, contributes to rehabilitating marginal areas prone to prolonged waterlogging and preserving biodiversity. Three hybrid poplar clones (‘I-488’, ‘Rimini’ and ‘D-64’) were tested to assess their degree of tolerance to waterlogging by imposing four water regimes over a 1?year period: control (C), non-preconditioned (NPr), and two levels of flood preconditioning (Pr₁₀ and Pr₂₀). During the 2nd?year, waterlogging (1.9?±?0.7?mg/l O₂) was imposed on plants from NPr, Pr₁₀ and Pr₂₀ treatments for 60?days followed by drainage. Survival rate, dry mass production, net photosynthesis and relative damage to membrane structural integrity were evaluated. The treatment response varied among clones and levels of preconditioning. Less pronounced damage to ‘I-488’ clones in comparison to those of ‘Rimini’ and ‘D-64’ indicates its superior tolerance to waterlogging. Preconditioning treatments (Pr₂₀) and, to a lesser extent (Pr₁₀), significantly improved the ability of the clones to tolerate flooding, suggesting that the application of a Pr₂₀ preconditioning treatment in the nursery before outplanting would give hybrid poplar clones the morpho-physiological advantages necessary to counteract the arduous conditions on inundated sites.     

Using SSR markers to study the mechanism of 2n pollen formation in Populus × euramericana (Dode) Guinier and P. × popularis

? Using cytological methods and SSR DNA marker analysis, this study revealed the formation mechanisms and the genetic constitutions of the 2n pollen in Populus × euramericana (Dode) Guinier and P. × popularis.

? In P. × euramericana (Dode) Guinier, four abnormalities in microsporogenesis were observed: parallel spindle, fused spindle, tripolar spindle and premature cytokinesis. The first three can lead to first-division restitution (FDR) 2n pollen formation and the last one can form second-division restitution (SDR) 2n pollen. The SSR marker analysis results of parents and their tetraploidy filial generation confirmed that the genetic constitution of 2n pollen produced by P. × euramericana (Dode) Guinier was FDR.

? In P. × popularis, three of these abnormalities were observed: parallel spindle, fused spindle and premature cytokinesis. The SSR marker analysis results showed the genetic constitution of 2n pollen produced by P. × popularis was SDR. Natural 2n female gametes in P. × euramericana (Dode) Guinier are reported for the first time. SSR analysis indicated that natural 2n female gametes of P. × euramericana (Dode) Guinier did exist and were fertile, which could be FDR genetic constitution.

? The results from this study showed a great potential for using 2n gametes to produce polyploid poplar clones, which can be used effectively for polyploid breeding for poplar species in the section Aigeiros.

     

Modulation of leaf physiology by age and in response to abiotic constraints in young cuttings of two Populus deltoides × P. nigra genotypes

? It is of importance, when comparing physiological responses of leaves to environmental constraints among different genotypes, to take into account any effect related to leaf position and age within the canopy that might interfere with the response to the constraints.

? To document such effects, photosynthetic capacity and tolerance to heat and to oxidation were measured on leaves from the top to the bottom of three-month-old single-stem rooted cuttings of Populus deltoides × P. nigra genotypes, ‘Dorskamp’ and ‘Luisa_Avanzo’, thus taking into account a gradient of ages from youngest and still expanding (top) to oldest and fully expanded (bottom) leaves.

? All recorded traits were tightly linked to the age of the leaves. Photosynthetic capacity gradually increased during leaf expansion, in parallel with chlorophyll content and relative nitrogen allocation to RuBisCO and to bioenergetics. On the contrary, dark respiration gradually decreased during leaf expansion until a minimum value was reached at maturity. Compared to expanding leaves, young mature leaves were characterized by a lower sensitivity to heat and a higher one to oxidations generated by methyl-viologen.

? Leaf characteristics appeared to vary along the stem to a larger extent than between the two genotypes that display largely different productivities in plantations.

     

Two novel eukaryotic translation initiation factor 5A genes from Populus simonii × P. nigra confer tolerance to abiotic stresses in Saccharomyces cerevisiae

The role of plant e IF5 A proteins in multiple biological processes, such as protein synthesis regulation,translation elongation, m RNA turnover, programmed cell death and stress tolerance is well known. Toward using these powerful proteins to increase stress tolerance in agricultural plants, in the present study, we cloned and characterized Psne IF5A2 and Psne IF5A4 from young poplar(P. simonii 9 P. nigra) leaves. The deduced amino acid sequences of Psne IF5A2 and Psne IF5A4 were 98 %similar to each other, and they are orthologs of e IF5A1 in Arabidopsis. In a subcellular localization analysis,Psne IF5A2 and Psne IF5A4 proteins were localized in the nucleus and cytoplasm. q RT-PCR analysis showed that Psne IF5A2 and Psne IF5A4 were transcribed in poplar flowers, stem, leaves, and roots. In addition, they were also induced by abiotic stresses. Transgenic yeast expressing Psne IF5A2 and Psne IF5A4 had increased salt, heavy metal, osmotic, oxidative tolerance. Our results suggest that Psne IF5A2 and Psne IF5A4 are excellent candidates for genetic engineering to improve salt and heavy metal tolerance in agricultural plants.     

Effects of warming basal ends of Carolina poplar (Populus × canadensis Moench.) softwood cuttings at controlled low-air-temperature on their root growth and leaf damage after planting

We investigated the effects of warming the basal ends of Carolina poplar (Populus × canadensis Moench.) softwood cuttings at controlled low-air-temperature on their root growth and leaf damage after planting. The warming treatment was applied to the cuttings by soaking 10 mm beyond the cut end in warmed water maintained at 30 °C in a cold chamber maintained at an air temperature of 10 °C and a photosynthetic photon flux density (PPFD) of 10 μmol m^?2 s^?1 (near the light compensation point at 10 °C) until rooting was observed. The warmed cuttings were then grown in a growth chamber at an air temperature of 30 °C, relative humidity 85–90 %, and a PPFD of 100 μmol m^?2 s^?1. Control cuttings were grown in the growth chamber throughout the experiment. Rooting occurred simultaneously for both warmed and control cuttings, irrespective of air temperature. Root development was greater and leaf damage, evaluated on the basis of extent of necrosis, was less for warmed cuttings than for control cuttings. The reduction of leaf damage for warmed cuttings probably resulted from reduced post-planting water stress and leaf senescence, because of improved root development as a result of the pre-planting warming treatment. This technique could improve the propagation of cuttings of woody plants, because it would ensure that the cuttings are ready to develop roots with minimum loss of carbohydrates, irrespective of weather conditions.     

RESISTANCE OF SCLEROTINIA SCLEROTIORUM TO CARBENDAZIM Ⅰ. Resistance and Its Development of Sclerotina Sclerotiorum to Carbendazim

INTRoDUCTIoNS.sclerotiorumissensitivetomanyfungicidalchemicals-Ofthesechemicals,carbendazimwasreportedtocontrolthediseaseofdifferentplantscausedbyS.sclerotiorumtl'2'3'43.However,likemostagrochemica1s,thisfungcideisfacingthechalIengeofre-sistance,especiallybecauseitisasystemicfungicide.AccordingtotheinvestigationofDelenandYildiz(l982),sinceintensivesprayingwithcarbendazim,threecucum-beriso1atesofS.scl`,rotiorumhavea1readydeve1opedresistance(althoughitisnotveryhigh)tothefungicide.theseiso1…     

Effects of Thidiazuron, basal medium and light quality on adventitious shoot regeneration from in vitro cultured stem of Populus alba×P. berolinensis

The effect of Thidiazuron (TDZ), basal media and light quality on adventitious shoot regeneration from in vitro cultured stem of Populus alba×P. berolinensis were determined to establish a high efficiency shoot regeneration system from stem explants of P. alba×P. berolinensis. Stems of Populus alba×P. berolinensis were collected from cultured shoots in vitro derived from dormancy buds of 3-year-old seedlings. The stem explants were cultured on MS medium containing 0.02-mg·L-1 NAA (naphthaleneacetic acid), and 0.1, 0.3, 0.5 and 1.0 mg·L-1 concentrations of TDZ to determine the effect of TDZ on shoot regeneration. Three basal media, i.e. MS, woody plant medium (WPM) and B5, were used to test their influences of different media on adventitious shoot regeneration. Green, red, blue and yellow plastic films in comparison with florescent light as control were used to observe their effects on shoot regeneration. The results showed that different concentrations of TDZ had an evident influence on shoot regeneration. Lower concentration of TDZ (0.1 mg·L-1) resulted in more adventitious shoot regeneration and higher concentration of TDZ (>0.1 mg·L-1) inhibited shoot regeneration. Among different media, MS medium exhibited a high efficiency for shoot regeneration, followed by WPM medium, while B5 medium inhibited shoot regeneration. Normal light and yellow light exhibited better effects on shoot regeneration, compared with other light.     

Growth and wood properties of a 38-year-old Populus simonii × P.nigra plantation established with different densities in semi-arid areas of northeastern China

To characterize the effects of plantation densities on the growth characteristics(diameter at breast level,tree height and volume) and the common wood properties,38-year-old Populus simonii 9 P.nigra clones planted with four levels of spacing(2 m × 2 m,3 m × 3 m,4 m × 4 m,and 5 m × 5 m) in a semi-arid area in northeastern China were examined.The results of ANOVA showed significant differences(P0.01) for all the investigated growth traits and wood properties under different plantation densities,except for the chemical composition of wood.The repeatability and phenotypic variations of all the traits varied from 0.34 to 0.99 and from 13.45 to 59.65%,respectively.Except for wood density,which was significantly negatively correlated with the growth traits,a positive correlation was observed between the growth traits and all the other wood mechanical properties.However,most of the correlations between the growth traits and the chemical composition of the wood were not significant.The path analysis for the wood mechanical characteristics and the growth in the prediction of volume were significant and ranged from 0.18 to 0.72 for wood density and diameter at breast height,respectively,while those for the chemical composition of wood ranged from 0.001 to 0.336,which showed a low impact on the volume.The highest stand volume(610 m~3) per hectare was observed with the 2 m × 2 m spacing,which consequently provided a high total price and income,while a high individual volume growth per tree was observed with the 5 m × 5 m spacing.The results suggested that for the poplar trees younger than 40 years in a semi-arid area in China,2 m × 2 m spacing is suitable for obtaining a high volume per hectare,while 5 m × 5 m spacing is best for obtaining a high individual volume per tree.     

Effects of ethylene and (Z)-hexen-3-al on production of volatiles in Populus simonii × P. pyramidalis ‘Opera 8277’ cuttings

We studied the effects of ethylene, (Z)-hexen-3-al, combinations of ethylene and (Z)-hexen-3-al, methyl jasmonate on the release of terpenoids and green leaf volatiles (GLVs) of Populus simonii × P. pyramidalis ‘Opera 8277’ by fumigation. The results show that exposure to ethylene alone did not induce volatiles. However, it was induced by exposure to combinations of (Z)-hexen-3-al and ethylene, a large amount of hexenal and hexen-3-ol as compared to sole (Z)-hexen-3-al exposure, which indicated that the release of wounding signals of P. simonii × P. pyramidalis ‘Opera 8277’ could be synergized by ethylene and (Z)-hexen-3-al. __________ Translated from Journal of Northwest Forestry University, 2008, 23(2): 143–146 [译自: 西北林学院学报]     

Phosphorus,copper and zinc supply levels influence growth and nutrition of a young Populus trichocarpa (Torr. & Gray) × P. deltoides (Bartr. ex Marsh) hybrid

Growth and nutrient responses of a P.trichocarpa × P. deltoides hybrid to phosphorus(P), copper (Cu) and zinc (Zn) were examined in a 4P× 3Cu × 3Zn factorial experiment conducted in anunheated greenhouse from 20 May until 25 August, 1997. Increase of growth medium P concentration from 37 to356 mg kg^-1 resulted in a mean increase in treedry weight of 53%, and increase of P concentrationfrom 37 to 500 mg kg^-1 was associated with a stemvolume increase of 47%. Increase from 0 to 0.32 µM Cu in solution applied thrice weekly wasassociated with a 61% increase in tree dry weight anda 59% increase in stem volume. There was also asmaller increase in stem volume (9.4%) resulting fromincrease in concentration of Zn from 0 to 0.31 µMin nutrient solution. Mean minimal leafconcentrations for satisfactory stem growth were foundto be 2.5 g kg^-1 P, 2.4 mg kg^-1 Cu and 74 mgkg^-1Zn. Visual deficiency symptoms wereassociated with mean leaf P concentrations below 1.6 gkg^-1, and Cu concentrations below 1.7 mgkg^-1. Increase in leaf P concentration wasassociated with decreases in leaf Cu and Znconcentrations, and high leaf Zn appeared tocompensate in some degree for low leaf Cu. Totalplant dry weight was satisfactorily predicted by stemvolume (r² = 0.85), but not by mean leaf weightor area.     

In vitro anther culture and Agrobacterium-mediated transformation of the AP1 gene from Salix integra Linn. in haploid poplar(Populus simonii × P. nigra)

A reliable,efficient anther culture system,the dominant technique for generating haploid plants in breeding programs,that can be used for generating transgenic poplar plants has been needed.In the present study,therefore,an anther culture system was developed using isolated mid-and late-uninucleate anthers of poplar(Populus simonii x P.nigra).From a combination of SSR and ploidy analyses,six double haploid and two haploid lines were characterized from 86 plants grown from 16 regenerated anther cultured lines.After 48 months of development,two plant lines from the regenerated plants maintained their haploid level in vitro for over 2 years.A number of haploid plants from the different lines weretransferred to soil.The leaves of these transplants were then used as explants for transformation with the APETALA1(AP1) gene using Agrobacterium tumefaciens.Overexpression of AP1 in haploid poplar induced early flowering with obvious petals when ectopically expressed.To our knowledge,this is the first report on changes in flowering time in AP1-trangenic poplar,which is important for elucidating the regulatory mechanism of tree flower development.     

Elevated temperature effects on germination and early growth of European aspen (Populus tremula), hybrid aspen (P. tremula × P. tremuloides) and their F2-hybrids

This study aimed to understand the interaction between temperature and genotype in terms of the effect on early seedling development of European aspen (Populus tremula) and various F₂-aspen hybrids. We evaluated the response of 16 different European aspen and F₂-hybrid families on seed germination, survival rate and seedling height in one- and two-family trials under three different temperature regimes. In one-family trials, higher germination and higher survival rates were observed in higher temperature (C1700), leading to taller seedlings. European aspen × hybrid aspen individuals (Asp × Hyb) had a higher survival rate and taller seedlings than Asp, Hyb × Asp or Hyb × Hyb individuals. The difference between Asp × Hyb and Hyb × Asp was pronounced. Both growth conditions and genotype (i.e., hybrid cross) had strong effects on germination, survival rate and height of European aspen and F₂-hybrid seedlings. However, the interaction of genotype and growth conditions also had a significant influence on survival rate and seedling height, but not on germination. Two-family trials involving European aspen and F₂-hybrids led to significant negative effects on germination and survival rate and also facilitation effects on seedling height. Similarly, genotype had strong effects on germination and survival rate. Different genotypes and traits affected survival rate and seedling height differently in different growth conditions. These differences were more pronounced in the warmest environment, i.e., 1,700 degree days. We conclude that introgression between F₂-hybrids and local European aspen is likely in the current climate, and any warming will likely favor certain F₂-hybrids, especially the most probable types (P. tremula × (P. tremula × P. tremuloides)).     

Interactive effects of irrigation and exponential fertilization on nutritional characteristics in Populus 3 euramericana cv. ‘74/76' cuttings in an open-air nursery in Beijing,China

Nutritional characteristics determine tree stock quality to a considerable extent. Exponential fertilization can induce nutrient reserves within juvenile trees, but its validity on poplar is contingent on interaction with a scientific irrigation regime due to limited water resources under global warming. In the present study, we raised 3200 Populus 9 euramericana cv. ‘74/76' cuttings under four irrigation regimes of 0(I0), 60 %(I60), 80 %(I80), and100 %(I100) of field capacity for soil moisture content with or without(control) the employment of nitrogen(N) addition delivered as exponential fertilization at the rate of 8 g N cutting~(-1)(E8) in an open-air nursery in Beijing, China. Both height and diameter increased with the increment of soil moisture ratio or in response to exponential fertilization(EF) without any interactive effects. In general, concentrations of N, phosphorus(P),and potassium(K) declined with time in stem but foliar N concentration did not change. Under the I100 regime, EF increased foliar N concentration relative to the control but failed to affect N concentration in stem in September, when both N concentration and N content were increased by EF under the I80 regime. Stem-K content and concentration by EF under the I80 regime also increased in September,therefore EF-treated cuttings had a higher ratio of K content in stem to that in whole plant(%ANAR). Vector diagnosis for nutritional status indicated that EF resulted in dilution of K concentration but induced a steady-state P uptake in leaves under all irrigation regimes. Therefore, EF of N addition could promote N uptake to leaves of P. 9 euramericana cv. ‘74/76' cuttings, but it had a null effect on N and P reserves in stem and impaired K reserves.In conclusion, the irrigation regime of 80 % field capacity of soil moisture content was suggested for the culture of juvenile P. 9 euramericana cv. ‘74/76' cuttings. As the interactive meaning, EF was also suggested for its excellent promotion on both N and K uptakes.