滴灌条件下4种树木生长发育规律的研究

通过对南疆干旱地区荒山绿化所采用的胡杨、沙枣、柽柳和白榆等4种主要造林树种在滴灌条件下的生长发育规律进行研究,结果表明:4种树木在滴灌条件下根系分布存在着明显差异;生长高峰期到达的时间不同,白榆生长高峰期最长,其次为沙枣、胡杨、柽柳;4种树木耐盐程度不同,柽柳耐盐性最强,在总盐含量2.26%的情况下,尚能生长。     

PHYSIOLOGY OF WOODY PLANT UNDER SALT CONDITION

INTRODUCTIoNBccauscofthetvidespreadofsalinityinthct`or1d-plantsareincreasinglybeingsub-Jcctedtothcadverseconditions.Theimpactofcxccssivcsalinit)'onxvOodyplantSistvide-sprcadandcost-ald1ougl1rePOrtsontheseis-sucsarcnotasnumerousasthoseofagricuI-taralcrops(Alle11ctaI.l994).Sincclbrcstsarcanin1portantcomPoncntofthccontincntalccoIogY.-Fhc}pla}anil11portantrolci11stabi-Il,lllgdcgradatIol1i11so111ct'uInerablearcas.Solncsalttolcra11ttrccscangrot`ttclIinarcasx`llcrcagriculturaicropscalll1ot…     

魔芋葡甘聚糖接枝共聚物的合成及其抗菌活性

考察了一种实验室自制的魔芋葡甘聚糖季铵盐衍生物(KGM-g-DMAE-BC)的合成以及抗菌性能。正交试验优选出的最佳合成条件为:反应温度70℃,单体质量比(mKGM∶mDMAE-BC)1∶5,引发剂用量0.7 mmol/L,反应时间3 h。悬菌定量实验结果表明:KGM-g-DMAE-BC(接枝率为38.5%)对大肠杆菌、金黄色葡萄球菌及白色念珠菌有较强的杀菌作用,在振荡作用15 m in后,平均灭杀率分别为99.99%、94.26%和99.99%。     

Salt distribution in response to optical stratification porosity and relative windspeed in a coastal forest in Niigata, Japan

Wind velocity, vertical stand structure and seasalt distribution were measured at various heights inside a plantation of coastal pine forest, with thinning and unthinning, to assess whether any relationships exist between the wind profile, stand structure and seasalt distribution in the coastal pine forest. The vertical stand structure, i.e., optical stratification porosity (OSP), which is defined as vertical distribution of the proportion of sky hemisphere not obscured by tree elements inside a forest stand, was determined for each height by computer analysis of digital images taken with a hemispherical lens. The distribution of OSP in the coastal forest follows the Lambert-Beer's law with absorbency coefficient (). The relative windspeed within canopy can be described using the exponential form with the attenuation coefficient (). The sea-salt was collected using salt gauze (a surgical dressing of loosely woven cotton) both inside and outside the coastal forest, and the distribution of sea-salt within canopy was also in accordance with an exponential function. The relationships among windspeed, OSP and sea-salt indicate that the distributions of both sea-salt and windspeed within canopy were very closely correlated with the distribution of OSP. A linear relationship between OSP and sea-salt has been found. Additionally, linear regression between coefficients and has been obtained as well. Based on these relationships between OSP, wind and sea-salt in the coastal forest, the sea-salt distribution and wind profile within the canopy of the coastal forest can be predicted according to OSP. These results may therefore be useful in analyzing the effects of sea-salt on vegetation and evaluating the filter functions of coastal forests.This revised version was published online in November 2005 with corrections to the Cover Date.     

花卉大棚土壤积盐规律的研究

在对寿光市花卉大棚土壤进行取样分析测定的基础上 ,通过对大棚栽培条件的积盐分析 ,进一步对大棚积盐规律、土壤内可溶性的盐分组成进行了分析     

Construction of cDNA Library from Populus euphratica

1 Introduction Populus euphratica is a salt tolerant tree species, which is mainly distributed in the desert regions in northwest China (Wei 1993). Moreover, it is the only large tree species, which can survive and develop into forest in these arid and saline-alkali areas. P. euphratica forest plays a very important role in restraining the expansion of desert, maintaining ecological environment in west China, protecting the biological diversity and raising the local people抯 living standard…     

Properties of red maple laminated veneer lumber impregnated with waterborne micronized and two soluble copper formulations

ABSTRACT

Certain important quality parameters of red maple (Acer rubrum) laminated veneer lumber (LVL) impregnated with three waterborne formulations: copper azole (CA-B), micronized copper azole (MicroCA or MCA) and alkaline copper quaternary (ACQ-D) bonded with phenol formaldehyde or cross-linked polyvinyl acetate (XPVAc) adhesives were evaluated. Pre-dipping of veneers before LVL production and two post-manufacturing procedures, viz., vacuum-pressure and post-dipping of LVL, were applied. Maximum copper retention in pre-dip-treated, vacuum-pressure and post-dip-treated LVL was 1.4, 9.7 and 1.7?kg/m³, respectively. Copper retention in MCA-treated LVL was relatively lower than soluble formulations. Various physical, mechanical and bonding properties of treated LVL such as density, water absorption, swelling, flexural properties, hardness, tensile shear strength, delamination and wood failure (%) were studied and compared with untreated LVL. Little to negligible deleterious effect was observed on properties of LVL due to these chemical treatments. Analysis of variance results showed that most of properties of red maple LVL were not significantly different compared with those of untreated LVL. Therefore, vacuum-pressure impregnation process can be used to treat the red maple LVL with novel micronized copper formulations for increasing the service life of such products against biodegradation without affecting techno-mechanical quality parameters.     

胡杨叶片基态渗透值的研究*

胡杨(Populus euphratica Oliv.)是我国西北干旱地区盐渍化土地上的主要造林树种之一。近十年来,我国有些学者通过野外调查、田间试验等方法,对胡杨独特的抗盐性进行了广泛研究,但有关胡杨抗盐性生理机制方面的研究还很少,为了探讨胡杨的抗盐性机理,我们在1989年采用初始质壁分离法,对胡杨叶片的基态渗透值进行了研究。     

盐胁迫和干旱胁迫条件下细胞内Ca2+水平的变化

Ca^2＋是植物必需的矿质元素之一，直接参与调节细胞内许多重要生理生化过程，同时Ca^2＋作为细胞内重要的第二信使，在植物感受和转导外界刺激等方面起着重要的作用。本文就国内外有关植物在盐胁迫和干旱胁迫条件下细胞内Ca^2＋水平的变化以及Ca^2＋与植物抗盐、抗旱性的关系作一慨述，并提出和讨论了有关该领域有待进一步探讨的问题。     

无机盐质量浓度及激素配比对四倍体刺槐组织培养苗生根的影响

在四倍体刺槐试管苗的生根培养阶段,诱导愈伤组织形成根原基,主要取决于6-BA和NAA的质量浓度配比。试验结果表明,在生根培养过程中,单加NAA0．3mg／L,可使组织培养苗发根早,根系发达,须根多,最终能形成完整的健壮植株;当培养基采用低无机盐质量浓度的Ms培养基即l／2MS时,试管苗发根早,且根多而粗壮。