贮藏温度和贮藏时间对垂柳种子生活力的影响

以成熟的垂柳种子为材料,测定了不同贮藏温度和不同贮藏时间下垂柳种子发芽率、发芽势、活力指数等生活力指标的变化,以探索贮藏温度和贮藏时间对垂柳种子生活力的影响。结果表明:适当的低温-10℃、-5℃、4℃可以延缓垂柳种子的劣变,延长其贮藏时间;常温20℃与极低温-20℃条件下会降低种子的生活力,表现为活力指数降低;随贮藏天数的增加,发芽率、发芽势、发芽指数表现出先升高后降低的趋势,发芽速则是先降低后升高。常温20℃贮藏7天种子发芽率显著下降,在-5℃贮藏3天的条件下种子生活力最强,可应用于垂柳种子萌发及人工种苗培育的实践中。     

箭根薯种子发芽试验

对箭根薯种子的室内发芽情况进行了试验.结果表明:在黑暗条件下,种子不能萌发;光照强度和光照时间对种子发芽率没有显著影响;每天光照14h,在15～35℃范围内,温度对发芽率无显著影响,但不同温度下发芽速率却有显著差异;在自然状况下风干的种子,种子含水率不同,其发芽率无明显差异;种子在4℃下贮藏1a,其发芽率不会下降,在-18℃下贮藏半年,其发芽率不会明显下降,贮藏半年以上,则下降明显.     

贮藏温度对川滇桤木种子发芽能力的影响

3种不同贮藏温度下川滇桤木种子发芽试验的结果表明:川滇桤木种子采收后冷藏(4±1℃)贮藏是最适宜的贮藏方法,对种子发芽能力的影响最小;冷冻(- 18±1℃)贮藏的种子发芽率与冷藏的种子没有显著差异,但发芽势随着贮藏时间的推移与冷藏的种子存在显著差异;常温贮藏下的种子发芽率与冷藏的种子差异显著,发芽势和高峰值差异极显著。用冷藏和冷冻的方法贮藏种子可以较好的保持其发芽率,但贮藏时间过长种子会出现一定程度的腐坏霉变。     

大叶椴种子不同贮藏方式对发芽和出苗率的影响

在大叶椴种子贮藏时期进行打破休眠对发芽率和出苗率影响的试验表明:即先从大叶椴坚硬果实内取出休眠种子在浓硫酸中脱皮10 min后,再在无基质(3℃)条件下层积催芽140～168 d(直到第1粒种子开始发芽为止).结果表明:经过处理后的种子当发芽试验中昼夜温度为3～15℃(16 h+8 h)时,几周后种子的发芽率达90%;...     

不同温度对刺榆种子发芽特性的影响

在实验室条件下对刺榆种子进行发芽试验的结果表明:刺榆种子在10~35℃均能发芽,最佳发芽温度为25℃,发芽率达90%以上,种子的发芽活力最强。不同温度处理对刺榆种子发芽特性的影响均差异显著,温度的升高能明显缩短种子的发芽时间,发芽率、发芽势、发芽指数、活力指数随温度升高而升高,达到最佳发芽温度后,随温度增加而降低。不同温度处理对种子发芽率的影响排序为25℃20℃与30℃35℃15℃10℃。10℃、15℃、20℃、30℃和35℃条件下种子的发芽活力较最佳温度条件分别下降92%、67%、33%、34%和57%。     

不同贮藏条件对米老排种子含水率和萌发特性的影响

通过设置真空铝箔袋、瓦罐和布袋3种封装材料和-20、-5、4、10℃和室温5种贮藏温度等15个组合,研究不同贮藏条件对贮藏6个月米老排(Mytilaria laosensis Lecomte)种子含水率和萌发特性的影响,以筛选最佳种子贮藏方案。研究结果表明,不同封装材料和贮藏温度对米老排种子含水率和萌发特性具有显著影响。布袋封装时,5种贮藏温度的种子含水率平均为9.61%,发芽率平均为21.5%;瓦罐封装时,种子含水率为11.48%,发芽率为15.8%;而真空铝箔袋封装时,种子含水率高达16.90%,发芽率基本为0。对于贮藏温度,4℃和10℃贮藏的种子发芽效果较好,-20℃和-5℃的效果一般,而常温贮藏的效果最差。不同封装材料和贮藏温度对种子含水率和种子萌发特性具有一定的交互作用,采用布袋或瓦罐封装在4℃和10℃进行冷藏的贮藏条件最佳,其贮藏6个月的种子发芽率约为30%,为新鲜种子发芽率的40%左右。种子含水率与种子发芽率具有较强的关联,其关系大致呈尖峰状分布,适宜的种子含水率有利于保持种子活力,从而促进种子发芽。综合分析,采用布袋或瓦罐封装在4℃和10℃进行冷藏的贮藏条件最佳,其贮藏效果最好。     

产地和萌发温度对胡枝子种子萌发的影响

以3个不同产地的胡枝子种子为材料,研究产地和萌发温度条件对种子萌发的影响,结果表明:产地对胡枝子种子的发芽指数无明显影响,但对种子发芽率和平均发芽时间均有极显著影响;其中黑龙江帽儿山产地种子的发芽率最高,发芽时间也最长;内蒙古扎兰屯产地种子发芽率和发芽时间居中;吉林蛟河产地种子发芽率最低,发芽时间却最短.萌发温度条件对胡枝子种子的发芽率、发芽指数和发芽时间均有极显著影响.15℃条件下种子的发芽率最高,20℃条件下种子的发芽指数最高,25℃条件下种子的平均发芽时间最短,30℃条件下种子各项发芽指标最差.产地与萌发温度的交互作用对种子发芽率和发芽指数影响不显著,但对种子发芽时间有极显著影响.     

不同处理对青冈栎种子发芽的影响

为了解青冈栎(Cyclobalanopsis glauca)种子萌发特性,采用实验室发芽方法,研究了不同的储藏方式、晾放时间、烘干时间、烘干温度对青冈栎种子发芽的影响,结果表明:不同储藏方式、不同烘干温度对青冈栎种子发芽率的影响差异显著,-4℃时低温冷藏的种子发芽率为0,明显低于沙藏的种子发芽率71.4±8.3%;不同晾放时间对青冈栎种子发芽率的影响很大,晾放5d后,发芽率只有未晾放的55.9%,15d后发芽率为0;在50℃时烘干时间对青冈栎种子发芽影响没有表现出规律性,不同处理的种子发芽率从60±7.1%到70.5±2.9%之间,差异不明显;不同烘干温度对青冈栎种子发芽率的影响差异显著,随着烘干温度从30℃增加150℃,青冈栎种子发芽率从69.2±5.9%降低到150℃时的7.5±3.5%,不同烘干温度之间差异显著。     

枸杞种子发芽特性的研究

研究贮藏年限对枸杞种子发芽的影响及其不同品种和不同种间的发芽特性,结果表明:枸杞种子发芽率随贮藏时间的增加而降低,4年内种子发芽率能保持在85%以上,4~10年种子发芽率大幅度下降,贮藏超过16年种子基本失去活力。贮藏年限与枸杞种子发芽率呈极显著负相关,相关系数r=0.988 7**,回归方程为y=-20.9x 123.45。依据不同品种枸杞种子间发芽率是否极显著,将所选枸杞品种分为3类,且基本上与田间形态观察相符。不同种枸杞种子发芽指标显著差异明显高于品种间,但黑果枸杞与其它种在发芽指标上表现极显著差异。     

贮藏温度和时间对木棉与美丽异木棉种子活力的影响

利用木棉 Bombax ceiba 和美丽异木棉Chorisia speciosa混合种子,在0、4、和8℃条件下贮藏135d,每隔45 d测定一次种子场圃发芽率和活力指标,用2,3,5-三苯基氯化四氮唑法(TTC法)测定种子的初始和贮藏135 d的生活力。结果如下:木棉种子在相同贮藏温度条件下,随贮藏时间的延长,发芽率、发芽势、活力指数存在显著差异(P<0.05),贮藏温度和贮藏时间有极显著的交互作用,种子活力逐渐下降,贮藏135 d后种子发芽率在8.33%以下,基本失去发芽能力;美丽异木棉种子在不同温度下,随着贮藏时间延长,发芽率、发芽势、活力指数没有显著差异,贮藏温度和贮藏时间没有显著的交互作用,种子发芽率为新鲜种子发芽率的67.46%以上;利用TTC染色法(1.0%浓度)能反映出木棉的种子生活力;木棉种子0℃贮藏90 d发芽率好于4和8℃,可在生产中推广应用TTC染色法检测木棉的种子生活力;美丽异木棉种子0、4、8℃贮藏135 d的发芽率差异很小,0℃贮藏发芽率和活力指数较优。     

Measurement of the dynamic modulus of elasticity of wood panels

This study investigated the dynamic modulus of elasticity (DMOE) of wood panels of Fraxinus mandshurica, Pinus koraiensis, and Juglans mandshurica using the natural frequency measurement system of fast Fourier transform (FFT). The results were compared with the static modulus of elasticity (E _S) tested by a mechanical test machine. The results show a significant correlation between E _S, transverse vibration DMOE (E _F), and longitudinal vibration DMOE (E _L). For all of these species, the correlation between E _S, E _F and E _L is more significant than the individual species, which indicated that the FFT method is universal. The correlations between E _S and sample’s density (ρ) are significant, but the correlation coefficient of E _S and ρ is lower than those between E _F, E _L and E _S. The E _S of wood is more accurately tested by the analysis based on FFT measurement than by the estimation based on density. __________ Translated from Scientia Silvae Sinicae, 2005, 41(6): 126–131 [译自: 林业科学, 2005, 41(6): 126–131]     

Susceptibility of species of Juglans to pathovars of Xanthomonas campestris

Bacterial blight is considered one of the most serious diseases affecting the genus Juglans. Artificial inoculations with Xanthomonas campestris pv. Juglandis were performed in the field by spraying seedlings of Juglans cinerea, Juglans hindsii, Juglans mandshurica, Juglans nigra, Juglans regia and Juglans sieboldiana. Juglans nigra, J. cinerea ana J. sieboldiana proved to be the most resistant. The multiplication ability of Xanthomonas campestris pv. corylina, X. c. pv. juglandis, and X. c. pv. campestris was evaluated by injecting 2-year-old seedling leaves of J. mandshurica, J. nigra and J. regia. The bacterial growth was monitored in the infected tissue over 12 days. Xanthomonas c. pv. juglandis exhibited a high growth rate and induced black greasy spots in J. mandshurica and J. regia; X. c. pv. campestris grew in leaf tissues without inducing symptoms, X. c. pv. corylina showed a very low growth rate. None of the tested bacterial strains multiplied in the leaves of J. nigra. This confirms the results obtained in the field tests. Juglans regia was the most susceptible among the walnut species tested.     

Effects of flooding on growth of seedlings of woody riparian species

The effects of flooding on growth of seedlings were compared over a 7-month period (April–November) among six different woody species: Aesculus turbinata, Cercidiphyllum japonicum, Fraxinus platypoda, Pterocarya rhoifolia, Pterostyrax hispida, and Quercus mongolica var. grosseserrata. Flooding reduced the shoot length of F. platypoda, P. rhoifolia, C. japonicum, P. hispida, and Q. mongolica var. grosseserrata seedlings but did not affect that of A. turbinata seedlings. Among control seedlings, shoot elongation occurred once in A. turbinata and twice in F. platypoda and Q. mongolica var. grosseserrata; the other species continued to grow from April to August. Among the flooded plants of all species, shoot elongation occurred only once at the beginning of the growing season. On August 25, flooding significantly reduced the number of developed leaves as compared with control plants except for A. turbinata. In the flooded plants except for F. platypoda, leaf fall began on June 30; in controls, by contrast, the number of developed leaves increased until August 25. Flooding reduced the total dry weight increment in all species. The survival ratio of flooded plants after the experiment differed with species. All of the F. platypoda and A. turbinata seedlings survived the flooding treatment, while only 20% of P. hispida and 30% of Q. mongolica var. grosseserrata survived. Flooding seriously affected the growth of riparian pioneer species including P. rhoifolia, C. japonicum, P. hispida, and Q. mongolica var. grosseserrata. The effects of flooding on growth of the seedlings differed with the tree species because of differences in leaf-emergence pattern and physiological flood tolerance. The responses of tree seedlings to flooding reflected species habitats and growth patterns.     

黄河小浪底库区山地栓皮栎人工林土壤呼吸的季节动态

[目的]分离并量化土壤自养呼吸和异养呼吸,探讨各自贡献率及其随季节变化的动态特征。[方法]采用壕沟法和气体红外分析法,研究黄河小浪底库区山地栓皮栎人工林土壤总呼吸、自养呼吸和异养呼吸速率的季节动态变化、贡献率和环境影响因子。[结果]表明:栓皮栎人工林总土壤呼吸、自养呼吸和异养呼吸均呈夏季速率高、冬季速率低。栓皮栎土壤总呼吸、自养呼吸及异养呼吸速率与5 cm土壤温度均呈极显著指数相关,温度敏感性系数Q_(10)值大小为自养呼吸(3.40)异养呼吸(2.90)土壤总呼吸(2.45);栓皮栎土壤总呼吸、自养呼吸、异养呼吸速率与0 10 cm土壤体积含水量均显著线性相关;土壤总呼吸、自养呼吸速率与0 10 cm土壤电导率显著相关。土壤总呼吸和异养呼吸的温度敏感系数Q_(10)值均在冬季最大,夏秋季最小;而自养呼吸的Q_(10)值则呈相反的变化趋势。栓皮栎人工林自养呼吸和异养呼吸对土壤总呼吸的月贡献率为13.23%37.33%和62.67%86.76%,且自养呼吸的贡献率与土壤温度的季节变化规律相似。土壤总呼吸、异养呼吸与自养呼吸的CO2年通量分别为1 616.41、1 199.39、417.02 g·m~(-2)·a~(-1)。[结论]经过区分与定量化土壤总呼吸及其组分,确定异养呼吸为本研究区栓皮栎人工林土壤总呼吸的主要组分,作用于异养呼吸的生物与非生物因子均能显著影响整个森林生态系统表层CO_2总排放通量的大小,进一步为该研究区森林生态系统碳循环与能量流动的进一步量化研究提供参考。     

Technologies of liquefaction of bamboo and preparation of adhesive

The technology of liquefying processed-waste bamboo with phenol is investigated by single factor trials and an orthogonal design. We studied the preparation technology and properties of adhesives from this phenol-liquefied bamboo with formaldehyde (BPF). The results show that temperature has a significant effect on liquefaction. The effect of the mass ratio of phenol to bamboo comes second and the catalyst dosage within the range of 2%–4% is the least effective. The optimum conditions of liquefaction are as follows: a mass ratio of phenol to bamboo 3.5, a catalyst dosage of 4%, liquefying temperature 145°C and liquefying time 60 min. The liquefaction rate of bamboo reached 99.1%. For the preparation of the adhesive, a mass ratio of liquefied bamboo products to formaldehyde (37%) is 100 to 164.8–199.5, while the ratio 100 to 108.2 is the best. This adhesive has a lower curing temperature than that of normal PF resin. At a hot-press temperature of 130 or 140°C, this new adhesive provides excellent bonding strength of plywood. The most favorable temperature for hot-pressing is 140°C. __________ Translated from Chemistry and Industry of Forest Products, 2007, 27(6): 65–70 [译自: 林产化学与工业]     

大花葵花色苷抑菌功能研究

本项研究通过采用固体培养和液体培养的试验方法,进行大花葵花(Malvasylvestris)色苷对金黄色葡萄球菌、大肠杆菌和黑曲霉的抑菌试验。结果表明:大花葵花色苷对金黄色葡萄球菌有很强的抑制作用,而对大肠杆菌和黑曲霉没有抑制现象发生。在固体培养试验中大花葵花色苷随着浓度的增加,对金黄色葡萄球菌的抑制程度越大,当大花葵花色苷浓度为10g/L时抑菌圈平均直径为6mm,当浓度增加至30g/L时,抑菌圈平均直径为16mm。而且,高浓度的大花葵花色苷溶液对金黄色葡萄球菌有长时间的抑制作用。     

Nondestructive test and prediction of modulus of elasticity of veneer-overlaid particleboard composite

The effects of grain angle, thickness of face veneer, and shelling ratio on dynamic modulus of elasticity (E) of veneer-overlaid particleboard composite (VOP) were examined by using nondestructive test. In this study, the possibility that E of VOP can be predicted by means of some empirical formula was also discussed. This study has shown that grain angle, thickness of face veneer, and shelling ratio have substantial effects on E of VOP. The E at 0° of grain angle of face veneer was the largest, decreasing rapidly with increase in the grain angle. The lowest value of E occurred at 90° of grain angle of face veneer. The relationship between grain angle of face veneer and E of VOP can be expressed in the form of Jenkin’s and Hankinson’s equations. The orthotropic properties of wood and VOP defined as the ratio E ₀/ E ₉₀ were 25.7 for wood and 4.7 for VOP. When the grain direction of face veneer was parallel to the length of the specimens, the E of VOP increased with increasing shelling ratio. VOP increased E from 125 to 179% over that of the particleboard and veneer thickness from 2.1 upto 3.6 mm. However, when the grain direction of face veneer was perpendicular to the length of the specimens, the E of VOP decreased with increasing shelling ratio. VOP decreased E from 23 to 41% over that of the particleboard and veneer thickness from 2.1 upto 3.6 mm. The relationship between E of VOP and face veneer thickness can be expressed in the form of a second-order parabolic equation. Rule of Mixture (ROM) can be used to predict E of VOP from the E of wood element and particleboard element.     

CONTROL TECHNIQUE OF BACTERIAL CANKER OF POPLAR

The poplar bacterial canker caused by Erwinia sp is a serious disease spreading inmost parts of Northeast China,where poplars are cultivalted.The disease seriously infects thosepoplars belonging to section Aigeiros or the intersection hybrids of section Tacamahaca and section Aigeiros and their clones.Five fine poplar cultivars resistant to the bacterial canker have been ob-tained by screening tests.They are Lz_2(Populus simonii×nigra var.italica),A_(15)(P.×sp.)613(P.×sp.),A_(102)and A_(98)(P.simonii×sp.)T following chemicals are obviously effective,such as:50％DT germicide ,40％ XF-136 and 10％ C.C.M.A.or 12.5％ ramphencol and 50,000 ppm/mlvalidamycin,with which the stems or roots can be watered.     

Inhibition of Armillaria by bacteria isolated from soils of the Boreal Mixedwood Forest of Ontario

Pseudomonas fluorescens, Pseudomonas spp., Bacillus spp., Enterobacter spp., Serratia spp. and Agrobacterium radiobacter were isolated from root-free soils of the Boreal Mixedwood Forest of Ontario a, nd found to be capable of inhibiting the linear growth of Armillaria ostoyae in vitro. Isolates of P. fluorescens, Bacillus spp. and A. radiobacter were the most effective inhibitors of mycelial growth. To test the ability of the bacteria to suppress rhizomorph formation, A. gallica, which produces rhizomorphs in culture more consistently than does A. ostoyae, was used; only a small fraction of P. fluorescens and Bacillus spp. isolates were capable of preventing in vitro rhizomorph formation by A. gallica.     

南北样带温带区栎属树种幼苗功能性状的变异研究

植物功能性状由生境条件和遗传因素共同决定,田间控制实验能够揭示植物功能性状在种内和种间的变异程度.采集南北样带温带区8个地点6种栎属树种的种子,通过田间栽培试验,以均一环境下1年生幼苗为对象,研究比较种内及种间比叶重、单位叶面积光合速率、单位叶重量光合速率、总干物质含量和根冠比5种功能性状的变化差异,并且分析幼苗功能性状与种子性状的关系.结果发现:栎属树种种间幼苗的功能性状变异系数高于种内,并且种内功能性状的差异较小,种间差异性较大,而比叶重和叶片光合速率无论在种间还是种内,其变异率都较小;总干物质量和根冠比与种子质量显著相关,随种子质量增加幼苗的总干物质量和根冠比呈现增加的趋势,比叶重和叶片光合速率与种子质量的相关性较小.