常见杨树天牛分类管理系统（CPLTMS）的研建

在国内首次以杨树天牛为研究对象,研制其分类管理系统（ＣＰＬＴＭＳ）,对系统特征提取、特征编码、各水平分类检索表自动生成以及图形处理等技术问题进行了研究。系统集成环境可以实现信息处理、检索表自动生成、更新及图形显示等功能。     

百合内源激素与鳞茎休眠及花芽分化关系的研究

以切花百合品种"雪皇后"、"西伯利亚"和"哥德琳娜"为试验材料,采用石蜡切片和扫描电镜的方法对百合花芽在不同分化时期进行形态学观察,采用酶联免疫吸附法测定百合内源激素的变化,利用DPS数据分析系统对试验结果进行主成分分析。结果表明:ABA和GA1 3在解除休眠中起着关键作用,为进一步研究百合鳞茎的休眠机理提供了重要线索。     

Abscisic acid and the regulation of embryo dormancy in the genus Acer

Germination of Acer pseudoplatanus L. and Acer platanoides L. seeds was increased by moist storage of the intact fruits (seed + pericarp) at 5 degrees C, but not at 17 degrees C. In both species, germinative capacity of isolated embryos (seeds with testa removed) was increased by moist storage of fruits at either 5 or 17 degrees C. Thus dormancy loss by intact seeds and excised embryos was not necessarily correlated. Loss of dormancy in isolated embryos was associated with a reduction in free abscisic acid (ABA) content. Embryos from freshly harvested fruits of A. pseudoplatanus had a higher germinative capacity and a lower free ABA content than embryos from freshly harvested fruits of A. platanoides. Morever, germinative capacity increased, and free ABA content decreased, more rapidly with length of fruit storage in A. platanoides embryos than in A. pseudoplatanus embryos.     

Influence of temperature on the dynamics of ATP,ADP and non-adenylic triphosphate nucleotides in vegetative and floral peach buds during dormancy

The nucleotides test of endodormancy, which is based on the capacity of tissues to synthesize ATP and non-adenylic triphosphate nucleotides (NTP), cannot be used for floral buds, and it is of questionable use for vegetative buds. In an attempt to find an alternative test, we examined whether the dormancy state of vegetative and floral buds of trees exposed to different temperature conditions during the rest period is directly related to their ATP, ADP and NTP concentrations and ATP/ADP ratio. Once the buds had entered endo- or paradormancy, the nucleotide concentrations and the ATP/ADP ratio were low in the vegetative primordia and very low in the floral primordia. Only after the action of chilling, when the buds were considered to have completed the endodormancy and paradormancy phases, did the nucleotide concentrations increase, accompanied by a steep rise in ATP/ADP ratio. We conclude that the ATP/ADP ratio could be used to characterize the bud dormancy state by comparison with critical values of 1.5 for vegetative primordia and 1.0 for floral primordia.     

沙棘酸乳中抗坏血酸含量的检测

用2，4-二硝基苯肼法对沙棘酸乳中抗坏血酸的含量进行检测。检测结果看出，沙棘酸乳中抗坏血酸的含量与沙棘果中抗坏血酸的含量基本相同，说明在沙棘酸乳制造过程中抗坏血酸很少被破坏。     

Genotypic variation in drought tolerance of poplar in relation to abscisic acid

We investigated effects of water stress and external abscisic acid (ABA) supply on shoot growth, stomatal conductance and water status in 1-year-old cuttings of a drought-sensitive poplar genotype Populus x euramericana cv. I-214 (Italica) and a drought-tolerant genotype P. 'popularis 35-44' (popularis). Populus popularis was more productive and maintained higher leaf water potentials throughout the drought treatment than cv. Italica. Supply of ABA to the xylem sap caused a greater decline in growth and more leaf abscission in shoots of cv. Italica than in shoots of P. popularis. Immediately after initiation of the drought treatment in P. popularis, the ABA concentration ([ABA]) of the xylem increased rapidly and stomatal conductance declined; however, stomatal conductance had returned to control values by the third day of the drought treatment, coincident with a gradual decline in xylem [ABA]. In contrast, xylem [ABA] of cv. Italica initially increased more slowly than that of P. popularis in response to the drought treatment, but the increase continued for 3 days at which time a tenfold increase in xylem [ABA] was observed that was followed by abscission of more than 40% of the leaves. We conclude that sensitivity of poplar roots to variation in soil water content varies by clone and that a rapid short-term accumulation of ABA in shoots in response to water stress may contribute to drought tolerance.     

Pretreatment of poplar by acid and alkali for enzymatic hydrolysis

Summary The dilute acid pretreatment in a plug flow reactor and alkali pretreatments with caustic solutions at different conditions followed by enzymatic hydrolysis resulted in drastically improved glucose yields for aspen and hybrid poplar. The acid pretreatment conditions must be carefully chosen to open the cellulosic structure allowing rapid diffusion of enzyme. The effectiveness of pretreatment is chiefly based on the enlargement of the pore size suitable for enzyme molecules.This work was carried out at Thayer School of Engineering, Dartmouth College in New Hampshire. The author wishes to express his gratitude to Prof. H. E. Grethlein for all kind support and helpful discussions     

湿地松幼林主、侧枝弯曲成因及防治研究

湿地松幼林主、侧枝弯曲是由于土壤、植株缺铜引起的一种生理性病变。采用喷施、根施硫酸铜及喷施硼砂加硫酸铜混合液的方法进行防治，结果表明喷施硼砂加硫酸铜混合液的防治效果达80．56％－91．67％，明显优于喷施和根施硫酸铜的防治效果。     

Comparison of manure compost and mineral fertilizer for hybrid poplar plantation establishment on boreal heavy clay soils

• Introduction   

Clay soils are typically rich in nutrients but are often compact and hard during summer increasing planting shock by limiting root development. Recycling farm manure in hybrid poplar plantations may offer additional benefits to mineral fertilizer as organic amendment can create better conditions for the early development of roots in addition to nutrient release.     

Silicon promotes the control of Meloidogyne incognita in lettuce by increasing ascorbic acid and phenolic compounds

Journal of Pest Science - Silicon (Si) has a physical barrier effect on plant tissues, decreasing nematode infection in different crops. Notwithstanding, research on lettuce is lacking, especially...     

An efficient method for clonal propagation and in vitro establishment of softwood shoots from epicormic buds of teak （Tectona grandis L.）

Softwood shoots were produced from 40 cm long stem segments placed horizontally in flat trays containing sterilized sand under natural light or shade conditions for subsequent rooting and micropropagation studies in teak(Tectona grandis L.) . Higher number of shoots(6.17) per log was produced under natural light as compared to shade conditions. Forcing was also better in natural light as compared to shade in terms of shoot length,number of nodes or leaves. For rooting,2-4 cm long softwood shoots were excise...     

抗虫杨的组织培养

本研究报道采用茎切段生芽增殖方法繁殖抗虫杨。切段时采用一叶一段,在添加0.5-0.8mg／L IAA的改良MS培养基上生根、腋芽萌发长成完整植株。这种方法具有快速、变异率低、节约成本的优点。     

Preformation in vegetative buds of Prunus persica: factors influencing number of leaf primordia in overwintering buds

We investigated the influence of bud position, cultivar, tree age, tree carbohydrate status, sampling date, drought and light exposure on the number of leaf primordia formed in dormant vegetative peach buds (Prunus persica (L.) Batsch) relative to the number of primordia formed after bud break (neoformed). During winter dormancy, vegetative peach buds from California and Italy were dissected and the number of leaf primordia recorded. Between leaf drop and bud break, the number of leaf primordia doubled from about five to about 10. Parent shoot length, number of nodes on the parent shoot, cross-sectional area of the parent shoot, bud position along the parent shoot and bud cross-sectional area were correlated with the number of leaf primordia. Previous season light exposure, drought and tree carbohydrate status did not affect the number of leaf primordia present. The number of leaf primordia differed significantly among peach varieties and tree ages at leaf drop, but not at bud break. Our results indicate that neoformation accounted for all shoot growth beyond about 10 nodes. The predominance of neoformed shoot growth in peach allows this species great plasticity in its response to current-season conditions.     

Roles of gibberellins and abscisic acid in dormancy and germination of red bayberry (Myrica rubra) seeds

Intact seeds from freshly harvested fruits of Myrica rubra (Sieb et Zucc.) were dormant and required 8 weeks of warm stratification followed by 12 weeks of cold stratification for germination. Exogenous application of gibberellic acid (GA(3)) to intact fresh seeds was effective in breaking dormancy, with > 70% of seeds germinating when treated with 5.2 mM GA(3) and incubated at a day/night temperature of 30/20 degrees C for 20 weeks. Removing the hard endocarp or endocarp plus seed coat of fresh seeds promoted germination, and addition of GA(3) to the embryo accelerated germination. The gibberellins GA(1) and GA(4) were more effective than GA(3) in promoting germination of seeds with the endocarp removed. Endogenous contents of GA(1), GA(3), GA(4), GA(7) and GA(20) were quantified by gas chromatography-mass spectrometry-selected ion monitoring in the endocarps, seed coats and embryos of fresh seeds treated with 5.2 mM GA(3). The content of GA(3) decreased in the endocarp during incubation, whereas GA(1) contents increased in the endocarp and seed coat. A high GA(1) content was detected in the endocarps and embryos of newly germinated seeds. We speculate that GA(3) was converted to GA(1) during incubation and that GA(1) is involved in seed germination. Endogenous abscisic acid (ABA) contents were measured in fresh seeds and in warm and cold stratified seeds. The ABA content in fresh seeds was distributed in the order endocarp > seed coat > embryo, with the content in the endocarp being about 132-fold higher than in the seed coat and embryo. Total ABA content of seeds subjected to warm or cold stratification, or both, was 8.7- to 14.0-fold lower than that of fresh seeds. Low contents of endogenous GA(1), GA(3), GA(7) and GA(20), but elevated contents of GA(4), were found in the seed coats and endocarps of warm plus cold stratified seeds and in the seed coats and embryos of newly germinated seeds. These observations, coupled with the finding that GA stimulated germination of dormant Myrica seeds, provide evidence that endogenous ABA inhibited release of dormancy and that endogenous gibberellins, especially GA(4) or GA(1), or both, are involved in germination.     

洞庭湖区杨树引种试验

在170多个杨树无性系苗期选择的基础上,在湖区内垸进行了3次共有56个无性系参与的对比试验,主要依据4或5年生的材积生长量,提出中驻6、中潜3、NL-8012l等6个南方型黑杨无性系可与原有的中汉17等无性系-同在湖区推广应用。对引进的极具增产潜力的新l等5个杨树新无性系的早期速生性能进行了测定和比较。     

杨树派间远缘杂交研究

该文介绍了我国杨树派间杂交育种的成就,分析了杨树派间杂交育种存在的杂交不亲和以及杂种败育的原因及克服这些障碍的措施。     

Variable dormancy in seed of Pinus contorta

Seeds of lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) collected southwest of Grande Praire, Alberta at three different times and altitudes between August 20, 1984 and August 15, 1985 showed variable responses to stratification. The responses were related to seed ripeness, as judged through evaluations of cone moisture contents, and with the length of time that the cones had remained on the trees. Unripe seeds started to lose germination in the third year after pollination when on the tree. Mature seeds which lost germination by late fall 1984 regained it by the next fall, while most unripe seeds did not. Immature seeds increased their need for stratification over time while mature seeds did not. Seeds should be left on the tree until the end of the third year to insure maximum viability because they do not reach maturity until then.     

Effects of key growth conditions on endogenous hormone content in tillering stem bases,germination of lateral buds,and biomass allocation in Indocalamus decorus

Physiological responses and changes in growth of Indocalamus decorus Q.H.Dai under different ecological conditions are essential for further understanding growth regulation and adaptive mechanisms and establishing an evidence-based management system for optimal growth. In this study, the endogenous hormone content in tillering stem bases, germination of lateral buds, and biomass allocation of this bamboo species in different growth environments were investigated. Among the endogenous hormones in the basal stems of tillers, indole-3-pyruvic acid and zeatin riboside were highly correlated with lateral buds that germinated to form shoots, while gibberellic acid was highly correlated with lateral buds that germinated to form rhizomes. The best lateral bud germination characteristics were achieved with full sun, a density of six plantlets per pot, and watering every 6 days. I. decorus plantlets used different resource allocation strategies depending on treatment. Different ecological factors influenced endogenous hormones in the bamboo stem base,which affected lateral bud germination and biomass allocation.     

丘岗地区杨树造林技术

对丘岗地区杨树造林地选择、造林整地标准,栽植材料的选择,栽植季节,修枝、病虫害防治技术等方面进行了初步探讨,为在丘岗地区营造杨树提供了科学理论基础和依据。