Influence of water stress on the physiology and growth of red spruce seedlings

Two-year-old, container-grown red spruce (Picea rubens Sarg.) seedlings from a New Hampshire seed source were exposed to 10 or 11 drying cycles in which the seedlings were not watered until their midday (1400 h) xylem water potentials averaged -1.57 MPa. Control seedlings were kept well watered to maintain midday water potentials of about -0.73 MPa. After the final drying cycle, the water-stressed seedlings were rehydrated and osmotic potentials were determined by pressure-volume analysis. Gas exchange at ambient CO(2) concentration (338 ppm) and at an elevated CO(2) concentration (838 ppm) was measured on both groups of plants as they slowly dried down. No osmotic adjustment or photosynthetic acclimation occurred as a result of the water-stress treatment and both groups of seedlings maintained photosynthesis to water potentials as low as -3.0 MPa. Twenty-four hours after rehydration, the water-stressed seedlings had photosynthetic rates as high as the control seedlings. Estimated stomatal limitation to photosynthesis was approximately 30% down to water potentials of -1.4 MPa, but increased steadily as water potentials decreased further. At ambient CO(2) concentrations (338 ppm) and water potentials averaging -2.45 MPa, photosynthetic rates of water-stressed seedlings were 15% those of well-watered seedlings, whereas when the same water-stressed seedlings were measured in the presence of an elevated concentration of CO(2) (838 ppm) their photosynthetic rates were 73% those of well-watered seedlings measured at an ambient CO(2) concentration (338 ppm).     

高岭土/木质素磺酸钠-g-AA-AM复合高吸水树脂的制备

以木质素磺酸钠(LS-Na)、丙烯酸(AA)、丙烯酰胺(AM)为原料,高岭土(Kaolin)为无机添加剂,过硫酸钾(KPS)为引发剂,N,N’-亚甲基双丙烯酰胺(NMBA)为交联剂,通过溶液聚合制备高岭土/木质素磺酸钠-g-AA-AM复合高吸水树脂(LPAAM)。选用正交试验设计方法,以蒸馏水和0.9%NaCl溶液中的平衡吸液倍率为评价参数得到了较优配方:m(AM):m(AA)=1:1,m(KPS)=1.0%,m(NMBA)=0.1%,pH=3。将上述配方制备的LPAAM以不同浓度NaOH于90℃皂化2h,得到皂化后的LPAAM,该树脂在蒸馏水和0.9%NaCl溶液中的平衡吸液倍率分别为1003及89g·g-1。     

枸杞容器扦插育苗技术研究

通过单因素试验设计研究了不同类别促生根剂(W)对枸杞插穗生根率高低、生根条数多少的影响;还通过正交试验设计L8(27)方法来研究了促生根剂浓度(E)、母株采穗部位(C)、不同木质化插条(P)及插条下部径粗(Y)对枸杞扦插生根率高低、生根数多少的影响。结果证明:使用促生根剂ABT-1#(W2)来处理插条时扦插效果最好,平均生根率高达89.7%、生根数多达11.2条;采用糊状的浓度为700ppm(E2)促生根剂ABT-1#来粘母株下部(C2)所剪下部径粗为0.8~1.2mm(Y1)的未木质化的插条(P1)时,即采用E2C2Y1P1组合时对枸杞扦插效果最佳,平均生根率多达95.3%、生根数高达15.6条。     

松香基功能高分子金属离子配合物固定化淀粉酶(英文)

分别以聚马来松香己二醇酯、马来松香乙二醇丙烯酯聚合物和马来松香乙二醇丙烯酯-丙烯酸共聚物为载体,金属离子为桥键配位离子固定化淀粉酶。测定了固定化淀粉酶的性能,探讨了固定化酶反应机理。结果表明金属离子作为桥键配离子的固定化淀粉酶中,PMGAECa(Ⅱ)En和poly(MGAE-AA)Ca(Ⅱ)En效果较好,重复使用5次后,每5 min的活性分别为11.33、9.44 mg/g,相对保留活性为32.78%、37.59%,最适宜温度为60、50℃,最适宜pH值为6.03、5.00。     

Condensation reactions of phenolic resins IV: self-condensation of 2,4-dihydroxymethylphenol and 2,4,6-trihydroxymethylphenol (2)

Kinetics of the self-condensation of 2,4-dihydroxymethylphenol (2,4-DHMP) and 2,4,6-trihydroxymethylphenol (THMP) were investigated to elucidate the mechanisms of the condensation of hydroxymethylphenols (HMPs). Rate equations were derived on the assumptions of the formation of quinone methide intermediates as unimolecular reactions and the occurrence of bimolecular reactions between undissociated HMPs, between undissociated HMP and dissociated HMP, and between dissociated HMPs. Rate constants were determined numerically by comparing the calculated reaction rates with observed ones. The results of analyses are as follows: (1) Both unimolecular and bimolecular reactions occur as the rate-determining steps during the self-condensation of 2,4-DHMP and THMP with low concentrations. (2) Nothing but bimolecular reactions occur as the rate-determining steps during the self-condensation of THMP with high concentrations. (3) Differences in the activation energy and the reaction rate due to the unimolecular process between 2,4-DHMP and THMP are small. (4) Rates of bimolecular reactions of THMP are about five times as large as those of 2,4-DHMP. (5) The values of the rate constants and the activation energy for the bimolecular reactions of THMP of low concentrations differ from those of THMP of high concentrations, indicating the difference in reaction mechanisms.     

红凉伞扦插繁殖试验初报

研究了不同浓度吲哚丁酸、不同扦插基质、不同枝段3个试验因素对红凉伞扦插生根的影响.结果表明,用100mg/kg吲哚丁酸处理插穗生根率最高(53.3%)、生根数最多(4.3条)、根最长(9.0mm);用生红土作扦插基质生根率最高(76.7%)、生根数最多(19.7条)、根最长(13.3mm);用主茎梢部作插穗,生根率最高(56.7%)、生根数最多(9.7条)、根最长(12.0mm).     

A growth model of a single sugi (Cryptomeria japonica) tree based on the dry matter budget of its aboveground parts

Growth of a single sugi (Cryptomeria japonica (L.f.) D. Don.) tree was analyzed on the basis of a dry matter budget. The aboveground net production rate and death rate were defined as the anabolic rate and catabolic rate, respectively. Growth rate of aboveground tree weight, v(w) (kg(dw) year(-1)), was defined as follows: v(w) = v(p) - v(d) (1) where v(p) (kg(dw) year(-1)) is the aboveground net production rate and v(d) (kg(dw) year(-1)) is the aboveground death rate. The value of v(d) is obtained by measuring the monthly clippings of new dead leaves and branches attached to a sample tree. The value of v(w) was calculated as the annual difference in the estimated aboveground tree weight, w(T) (kg(dw)). Finally, the value of v(p) was estimated as the sum of the values of v(d) and v(w). The following allometric relationships were found between v(p) and w(T) and between v(d) and w(T): v(p) = aw(T) (alpha), v(d) = bw(T) (beta) (2). Combining Equations 1 and 2 gives a growth equation, Bertalanffy's equation, of the sample tree. dw(T)/dt = v(w) = aw(T) (alpha) - bw(T) (beta) (3). Because the growth curve of w(T) was derived from Equation 3, the analysis of the growth of w(T) is based on direct measurement of the dry matter budget.     

森林生物量空间知识挖掘方法应用研究——以河南西峡县为例

以河南省重点林业县西峡为研究对象,以2003年森林资源连续清查空间数据库为主要信息源,在地理信息系统软件ArcGIS 9.3、数据挖掘软件Clemintine 12.0支持下,通过空间热点探测、趋势面分析、地理加权回归、C5.0决策分析来进行西峡县森林生物量空间知识挖掘。研究表明:生物量的空间分布与海拔梯度有关,呈现一种从北向南阶梯状逐渐降低的带状分布格局;生物量与平均树高、坡度正相关,与土壤厚度、灯光亮度负相关;C5.0决策分析4个主要输入变量的重要性依次为平均树高(0.30)>灯光亮度(0.24)>坡度(0.23)>土壤厚度(0.22)。     

Growth and mineral nutrition of Gmelina arborea Roxb. seedlings fertilized with four sources of nitrogen on a latosolic soil

The growth and mineral nutrition of Gmelina arborea Roxb. seedlings were investigated in response to four nitrogen-based fertilizers applied at 0, 2.5, 5.0 or 7.5 g N per plant. Nitrogen sources included NH(4)-N as ammonium sulfate, NO(3)-N as potassium nitrate, NH(4)NO(3)-N as calcium ammonium nitrate, and urea-N as urea. Seedlings fertilized with NH(4)NO(3)-N or urea-N had greater height, collar diameter, dry weight, net assimilation rate, and relative growth rate than seedlings fertilized with NH(4)-N or NO(3)-N. For all sources of nitrogen, increasing the amount of exogenously supplied N per plant promoted shoot growth more than root development, hence the root to shoot ratios of all fertilized seedlings were smaller than those of the unfertilized controls. Applications of NO(3)-N increased the nitrogen, potassium, and phosphorus concentrations of fertilized seedlings. Regardless of source, a nitrogen application of 2.5 g N per plant was apparently optimal for the growth of Gmelina seedlings on a latosolic soil.     

滇东北4种典型筇竹林凋落物的持水性

以滇东北4种典型筇竹林为研究对象,对比分析不同类型筇竹林凋落物储量及持水性能,从而为滇东北筇竹林生态可持续经营提供理论依据和实践指导。研究结果表明,凋落物储量为人工筇竹-黄皮树混交林（7.61 t/hm²） > 天然筇竹-人工黄皮树混交林（6.61 t/hm²） > 天然筇竹-人工厚朴混交林（5.73 t/hm²） > 天然筇竹纯林（5.23 t/hm²）。凋落物最大持水量为天然筇竹-人工厚朴混交林（3.45 t/hm²） > 人工筇竹-黄皮树混交林（3.22 t/hm²） > 天然筇竹-人工黄皮树混交林（2.89 t/hm²） > 天然筇竹纯林（2.69 t/hm²）。4种类型筇竹林凋落物吸水速率均随着浸泡时间延长而逐渐趋于一致,筇竹混交林凋落物吸水速率高于筇竹纯林。凋落物的总有效拦蓄量为人工筇竹-黄皮树混交林（9.74 t/hm²） > 天然筇竹-人工厚朴混交林（8.95 t/hm²） > 天然筇竹-人工黄皮树混交林（7.73 t/hm²） > 天然筇竹纯林（6.23 t/hm²）。     

毒死蜱对舞毒蛾食物利用和解毒酶及AChE活性的影响

采用质量法和酶活性测定法研究了毒死蜱对舞毒蛾(Lymantria dispar)3龄幼虫食物利用的影响,并测定了其毒力及解毒酶、乙酰胆碱酯酶(AChE)的活性。用亚致死浓度(1.5 mg·L^-1)毒死蜱处理小黑杨叶片,饲喂舞毒蛾3龄幼虫,其幼虫生长率(RGR)、食物利用率(ECI)和食物转化率(ECD)均显著低于对照,而近似消化率(AD)显著高于对照,相对取食量(RCR)处理和对照间差异不显著。毒死蜱对舞毒蛾幼虫24 h致死中浓度(LC₅₀)为5.86 mg·L^-1,其毒力低于三氟氯氰菊酯而高于氧化乐果。毒死蜱对舞毒蛾3龄幼虫体内羧酸酯酶(CarE)、谷胱甘肽S-转移酶(GSTs)和AChE均有抑制作用,抑制程度为CarE＞AChE＞GSTs。毒死蜱通过影响舞毒蛾食物利用和抑制酶活性而表现出杀虫活性,为一种有效防治舞毒蛾的有机磷杀虫剂。     

湿加松在粤北山区早期生长表现初报

利用种植于粤北乐昌龙山林场的6年生湿加松测定林数据,分析了湿地松与洪都拉斯加勒比松杂种家系(PEE×PCH)、湿地松与巴哈马加勒比松杂种家系(PEE×PCB)、湿地松改良代种子园自由授粉家系(PEE(op))、洪都拉斯加勒比松1代种子园自由授粉家系(PCH(op))、马尾松初级种子园混合子代(PMA(p))、洪都拉斯加勒比松初级种子园混合子代(PCH(p))、古巴加勒比松初级种子园混合子代(PCC(p))、巴哈马加勒比松初级种子园混合子代(PCB(p))、湿地松改良代种子园混合子代(PEE(i))、湿地松1代种子园混合子代(PEE(o))、湿地松初级种子园混合子代(PEE(p))、火炬松初级种子园混合子代(PTA(p))间的造林成活率、保存率及生长量差异.结果表明:树种间及树种内类型间造林成活率、保存率存在差异,生长量间存在极显著差异,材积生长从大到小的顺序为:PEE×PCH＞PEE×PCB＞PCH(p)＞PMA(p)＞PCH(op)＞PEE(op)》PEE(i)＞PEE(p)＞PCB(p)＞PCC(P)＞PEE(o)＞PTA(p);湿加松当年造林成活率平均达96.2%,6年生时保存率平均达87.2%;21个家系间生长量存在极显著差异,从中初选出10个最优家系,其平均树高、胸径、材积分别为6.35 m、10.85 cm、0.035 48 m3,与PMA(p)、PCH(p)、PCB(p)、PEE(o)、PTA(p)比较,材积现实增益分别为59.39%、48.76%、134.97%、162.23%、172.29%.     

偶联剂对木塑复合材料拉伸性能与热膨胀性能的影响

以高密度聚乙烯(HDPE 6761)为基体,松木(Pine)粉为增强材料,以MAPE(EpoleneG2608)和MAPP(ExxelorVA1840)为偶联剂采用注塑法制备WPC,测定了不同配比WPC的热膨胀性能与拉伸性能,结果表明:在没有加入MAPE只加入木粉的情况下,WPC的拉伸强度较没有加入任何助剂的HDPE有所下降;偶联剂的加入量按不同配比加入对拉伸模量影响不大;对WPC热膨胀系数主要的影响因素应该是木粉的加入量及塑料基体的种类。     

拮抗菌株XZQ-20的鉴定及对多种植物病原细菌的拮抗 活性分析

利用拮抗微生物不仅能有效防治植物病原细菌,而且对环境友好。该研究中,拮抗菌株 XZQ- 20 分离自健康杨树根际土壤,基于形态学特征、生理生化特性和 16S rDNA 序列分析将该菌株鉴定为 深层类芽孢杆菌（Paenibacillus profundus）,XZQ-20 具有蛋白酶活性,其对 4 种植物病原细菌欧美杨细 菌性溃疡病菌（Lonsdalea quercina）、丁香假单胞菌（Pseudomonas syringae）、软腐欧文氏菌（Erwinia carotovora）和核桃黄极毛杆菌（Xanthomonas juglandis）均具有较强的拮抗活性,抑菌圈大小分别 为（11.75±1.06）mm、（13.3±2.26）mm、（16.75±0.07）mm 和（7.55±1.06）mm。 此 外, 对 拮 抗 菌 株 XZQ-20 的无菌培养滤液的拮抗活性进行测定,发现其无菌培养滤液也表现出了较强的拮抗活性,对 4 种植物病原细菌的抑菌圈直径分别达到（8.18±0.75）mm、（7.63±0.88）mm、（8.03±0.93）mm 和 （8.60±0.53）mm。研究结果表明拮抗菌株 XZQ-20 可用作为潜在的高效防治植物病原细菌的生防制剂。     

Lewis酸催化加氢合成天然茴香基丙酮及工艺优化

以天然亚茴香基丙酮为原料,Lewis酸为催化剂,环己烷为氢源,研究了天然茴香基丙酮的合成工艺,并探讨反应机理和反应的选择性。对不同Lewis酸催化剂与溶剂进行筛选,确定Al Cl3为催化剂,CH2Cl2为溶剂,采用正交试验方法对茴香基丙酮合成工艺进行优化,得到最佳工艺条件。在反应温度35℃,反应时间4 h,n(Al Cl3)∶n(亚茴香基丙酮)4∶1,n(环己烷)∶n(亚茴香基丙酮)4∶1的条件下反应稳定性较好,产物得率达95.1%。采用IR、GC-MS和1H NMR等分析技术对合成所得产物进行了表征。     

优系欧李茎叶愈伤组织诱导与植株再生

以欧李春季萌发的幼茎、叶片为外植体诱导愈伤组织的产生,结果表明:叶片愈伤组织培养以改良MS为基本培养基,附加NAA 1.0 mg/L IBA 0.5 mg/L BA 0.2 mg/L效果较好;茎段愈伤组织培养以改良MS附加2,4-D0.5 mg/L NAA 0.3 mg/L BA 0.15 mg/L诱导愈伤组织效果好;愈伤组织再诱导不定芽以1/3 MS附加BA2.0 mg/L IBA 0.01 mg/L培养基效果佳。     

时滞和平衡含水率直接估计法的有效性分析

通过对不同直径落叶松枯枝含水率和环境条件的室内连续观测,分别使用Nelson模型和Simard模型作为平衡含水率响应模型,估计可燃物时滞和平衡含水率响应函数,然后以参数估计值预测可燃物含水率,分析比较建模样本数和平衡含水率模型不同对参数估计和含水率预测误差的影响。结果表明:1)基于Nelson模型的直接估计法在建模样本数较大时(84个),结果稳健,预测误差小,方法是有效的。2)采用Simard模型直接估计可燃物时滞和平衡含水率时,在建模样本数较少时,其预测效果不如Nelson模型,但当建模样本数较多(超过84)时,2个模型预测效果没有显著差别。     

杉木不同指数级不同造林密度的经济效益分析

本文对邵武市卫闽林场的16和18指数立地上，不同密度15年生杉木立木蓄积量和可生产的不同规格杉木原条出材量，进行经济核算，结果表明；16指数立木造林密度1410株／hm~2的立木蓄积量比同指数630株／hm~2密度增产69．0％；比18指数密度630株／hm~2的林分增产36．3％。该林分的综合经济效益占第二位。     

四川桤木立木干材材积收获模型

根据 16 0株样木资料 ,以年龄 (X1)、胸径 (X2 )、树高 (X3 )、枝下高 (X4 )、冠幅 (X5)为说明变量 ,建立以立木干材材积 (Y)为基准变量的收获模型。     

Regulation of photosynthesis in interior spruce during water stress: changes in gas exchange and chlorophyll fluorescence

Photosynthetic response to water stress was analyzed in 1-year-old interior spruce (Picea glauca (Moench) Voss x P. engelmanni Parry hybrid complex) seedlings and emblings produced from somatic embryogenesis. Carbon dioxide uptake, oxygen evolution and chlorophyll fluorescence at 20 degrees C were monitored as predawn shoot water potential (Psi) decreased. Concurrently with stomatal closure, carbon assimilation declined rapidly as Psi decreased to -1.0 MPa. Oxygen evolution at 10,000 micro l CO(2) l(-1) declined continuously as Psi decreased to -1.6 MPa. At photon flux densities (PFD) above 50 micro mol m(-2) s(-1), photochemical efficiency of photosystem (PS) II observed during actinic light exposure (Phi(II), calculated as DeltaF/F(m)') decreased as Psi decreased. At the same PFDs, photochemical quenching (q(P)) declined with decreasing Psi and nonphotochemical quenching (q(N)) increased steadily. At PFDs below 50 micro mol m(-2) s(-1), major decreases in q(N) were not observed until Psi decreased below -1.6 MPa. We identified three phases of photosynthetic response to progressive water stress in interior spruce: a pronounced decline in gas exchange, subsequent photoprotective changes in chlorophyll fluorescence as primary photochemistry was down-regulated, and a decline in photochemical efficiency of dark-adapted needles.