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1.
为加快对马尾松松花粉多糖的开发利用,探究提取多糖的最佳工艺组合。试验以贵阳成熟马尾松林松花粉为研究对象,采用超声破壁技术及苯酚-硫酸法测定多糖含量,通过探究料液比、提取时间、提取温度、提取次数4个不同因素对马尾松松花粉多糖提取率的影响,并结合单因素和正交试验,得出松花粉多糖的最佳提取条件。结果表明:提取次数对马尾松松花粉多糖提取量的影响最大,其次为料液比和温度,二者对多糖提取量的影响相差不大,提取时间对多糖提取量的影响最小;马尾松松花粉多糖最佳的提取工艺组合为料液比1∶10(g∶m L)、提取时间2.0 h、提取温度85℃、提取3次,提取率为11.246 3 mg/g。因此,通过此工艺组合,可提高松花粉多糖的提取率,对马尾松松花粉的开发利用具有重要意义。 相似文献
2.
采用CEPA、GA3、PP333、B9等植物生长物质,以不同浓度处理马尾松、黑松、湿地松、火炬松枝梢,比较药剂种类和处理浓度对枝梢生长的影响。结果表明: GA3(2 500 mg·L-1)对各供试树种均有显著促进作用(试验3中对湿地松除外);试验1中,5 000 mg·L-1 PP333显著抑制马尾松枝和黑松枝的伸长生长,具有最佳调节效果;试验2中,5 000 mg·L-1 PP333显著抑制湿地松和马尾松枝的伸长生长,具有最佳调节效果;试验3中,5 000 mg·L-1 PP333＋5 000 mg·L-1B9复合制剂显著抑制湿地松和火炬松枝梢的伸长生长,具有最佳调节效果。用"Y"型嗅觉仪测定微红梢斑螟成虫对松梢的嗅觉反应,结果表明处理组枝梢对微红梢斑螟成虫驱避效果明显;微红梢斑螟等松梢害虫危害率调查表明,处理枝梢的被害率也明显低于对照枝梢。 相似文献
3.
精制马尾松花粉的营养和加工储藏技术 总被引：8，自引：0，他引：8
本文对马尾松花粉合理适时采摘，及时在常温35℃以下进行干燥，使含水量迅速下降为10％以下，经紫外线处理1～2小时达到灭菌控菌。经过加工处理的马尾松花粉，使之能储藏1～3年质量不变，与冰箱0～5℃储藏质量一样好。松花粉营养丰富，蛋白质含量较高，Fe、P、Mn、Ca、Zn含量多，Mg更为丰富，多种的营养成分，对人体健康有利，能促使体内元素平衡．马尾松花粉又是民间食疗珍品和传统中药材，因此，对加快开发马尾松花粉是有重大意义的。 相似文献
4.
对闽南地区麻竹人工林地上部分生物量模型及现存生物量结构进行了研究。结果表明:以模型m=a·(D2H)b对麻竹地上部分总生物量和秆生物量进行估计较为可靠,而对枝、叶生物量的估计需引进枝下高因子h及模型m=a·Db·(H-h)C或m=a·Db·[(H-h)/h]C.闽南地区麻竹人工林地上部分平均现存生物量为39.518t·hm-2,按年龄分配为:3年生生物量最高,占59.17%,其次为2年生、4年生、5年生;按器官分配为:秆生物量最高,占62.81%,其次为枝、叶。地上部分总生物量与秆生物量随竹秆高度增加而递减,枝、叶生物量自6～8m区分段分别向秆基及秆梢递减。 相似文献
5.
[目的]利用不同于抗生素的PMI为选择标记基因的遗传转化体系,对杨树进行双抗虫基因(Bt和CpTI)的转基因研究.建立杨树以PMI为安全标记基因的转基因体系,为安全、高效的林木转基因育种研究提供实验依据.[方法]选择已有的转CpTI抗虫基因(利用Kmr选择标记获得)的美洲黑杨杂种优良无性系南林895杨(Populus ×euramericana ‘Nanlin895’)为受体材料,对杨树叶片、叶片分化芽、茎段生根的甘露糖敏感性等筛选优化,采用农杆菌介导的方法进行双抗虫基因的研究.[结果]较为适合的杨树叶片筛选培养基为:甘露糖8 g·L-1和蔗糖22 g·L-1;叶片分化芽筛选培养基为:甘露糖10 g·L-1和蔗糖20 g·L-1;茎段生根筛选培养基:甘露糖8 g·L-1和蔗糖22 g·L-1.在此基础上,获得了转Bt和CpTI双抗虫基因的植株8株.[结论]初步建立了以PMI为安全标记基因的杨树转基因体系:确定了PMI筛选的最适选择压,成功构建了含PMI选择标记基因的植物抗虫表达载体,通过农杆菌介导的遗传转化最终获得了转双抗虫基因植株. 相似文献
6.
在皖南春季越冬代马尾松毛虫防治时期,于安徽长江以南采用不同治虫策略的5个林场,选立地条件和林分状况类似的马尾松纯林,对节肢动物和虫生真菌群落的调查表明,常年释放白僵菌的林场和长期监测虫情、准确挑治虫源地的林场害虫种数约占群落总种数的50%,个体数约占70%,益害物种数比(Ns/Ps)为0.72～0.83,个体数比(Nn/Pn)为0.44～0.45,多样性指数(H′)波动小,松毛虫虫口≤2.0条·株-1.交替放菌和施药的林场,滥用农药、尤其不治虫的林场,害虫种数约占群落总种数的60%左右,个体数>74%,Ns/Ps0.46～0.54,Nn/Pn0.23～0.34,H′波动大,松毛虫虫口6.0～10.0条·株-1,超过防治指标(5条·株-1).长期的放菌或及时施药挑治利于优化群落结构,增大多样性指数,强化生态控制的力度 相似文献
7.
以江西吉水种源的白花树花粉为研究材料,进行了扫描电子显微镜下的花粉形态结构观察以及采用离体培养基法、I2-KI和TTC染色等花粉生活力测定方法的比较研究,探讨了不同贮藏条件对花粉萌发的影响。研究结果表明：白花树花粉粒为长球型,具3孔沟,外壁面具细网状纹饰;花粉平均极轴长52.33±0.577 μm,平均赤道轴长26.89±0.502 μm;3种花粉生活力测定方法中以离体培养基法最有效,花粉萌发的最佳组合为：10%蔗糖+0.05 g·L-1硼酸+100 mg·L-1 GA3+3 h;花粉最佳贮藏条件为-80 ℃密封保存,贮藏180 d后花粉的萌发率仍可达40.97%。 相似文献
8.
试验研究了大孔吸附树脂对白蜡虫粗多糖脱色效果的影响和脱色前后多糖抗氧化活性的变化。通过静态吸附法确定大孔吸附树脂NKA-9较适合白蜡虫粗多糖脱色,动态吸附法确定白蜡虫多糖脱色条件为30 ℃下10 mg·mL-1多糖溶液（pH值8.0）以1 BV·h-1流速上样1 BV后,以5 BV水洗脱,脱色率为71.4%、脱蛋白率51.9%、多糖收率为60%。体外细胞抗氧化结果表明：脱色前多糖溶液仅在1 000 μg·mL-1浓度时能提升过氧化氢损伤人神经母细胞瘤细胞的存活率,而脱色后多糖溶液在10 1 000 μg·mL-1范围内均能提升模型细胞存活率,其中,1 000 μg·mL-1的脱色白蜡虫多糖与模型组的差异显著（P<0.01）,结果表明,脱色后多糖抗氧化能力增加。 相似文献
9.
以杉木林和常绿阔叶林为对照,对闽北典型毛竹林(杉竹混交林、毛竹纯林、竹阔混交林)林下枯落物储量、持水特性及其对降雨的拦蓄能力进行研究,结果表明:(1)各林分未分解层、半分解层和已分解层枯落物储量、最大持水量和有效拦蓄差异较大,但均以半分解层最高,分解层次之,未分解层最小;杉木纯林枯落物总储量、最大持水量和有效拦蓄均最高,分别为14.6 t·hm-2、2.668 mm和1.43mm,竹阔混交林次之,分别为7.0 t·hm-2、1.298 mm和0.76 mm,毛竹纯林最低,分别仅为4.7 t·hm-2、0.916 mm和0.58 mm。(2)5种林分各层枯落物持水量与浸泡时间的关系为:S=k ln(t)+p,在0 - 2 h内,枯落物持水量迅速增加,此后增加速度逐渐减缓;其吸水速率与浸泡时间的关系为:V=at-1+b,在0 - 1 h内,枯落物吸水速率迅速下降,2 h后下降速度逐渐减缓。(3)竹阔混交林枯落物持水能力虽小于杉木纯林但在竹林中最强,对此,在竹林改造和竹林经营过程中应加以重视。 相似文献
10.
在自然条件下,采用Li-6400便携式光合作用测定系统研究了南方型和北方型美洲黑杨在5、7、9月的光合日变化。结果表明:南方型美洲黑杨在5月和9月的净光合速率日变化为单峰曲线,峰值分别为15.79、14.13 μmol·m-2·s-1,在7月为双峰曲线,最高峰值为22.03 μmol·m-2·s-1;北方型美洲黑杨在5、7、9月的净光合速率日变化一直为双峰曲线,最高峰值分别为13.46、18.08、12.91 μmol·m-2·s-1。南方型美洲黑杨仅在生长旺盛的7月存在光合"午休"现象;北方型美洲黑杨在整个生长季均存在光合"午休"现象;南北方型美洲黑杨净光合速率季节变化特点为:夏季(7月)>春季(5月)>秋季(9月);10月份,南方型美洲黑杨净光合速率达到12.70 μmol·m-2·s-1,北方型美洲黑杨已落叶。分别对南方型和北方型美洲黑杨5、7、9月的光合有效辐射、气温、空气相对湿度、空气CO2浓度与净光合速率进行逐步多元回归、偏相关及通径分析,影响净光合速率的主要生态因子是光合有效辐射。 相似文献
11.
Our study focuses on predicting the ultimate short-term load carrying capacity of timber-to-timber connections with dowel-type fasteners. The wide range of possible configurations in practice makes the resolution of these values by tests unrealistic. Moreover, different current regulations do not consider some specific failure mechanisms. In many countries, the reduction of resistance involved by this phenomenon is taken into account by considering an effective number of dowels (nef) smaller than the actual number of dowels (n) in the connection. However, these different regulations disagree on the values of nef and on other points (spacing, partial coefficient of security, formulas). These discrepancies in design rules invite the fundamental research on this topic and, therefore, new methods are sought in order to estimate the load carrying capacities of the connections. In the light of these, our approach consists of predicting the load carrying capacity with the neural network numerical tool. The results obtained by this analysis tool are satisfactory, although the model remains complex. Subsequently, we focus on the simplification of this numerical model with classical regression techniques in order to implement it in a design code. 相似文献
12.
Ophiostoma species were isolated from bark beetles and Abies mariesii, A. veitchii and A. homolepis attacked by the beetles in Nikko, Tochigi, central Honshu, Japan. One to two Ophiostoma species were frequently isolated from each species of bark beetle. Ophiostoma subalpinum was the most common associate of Cryphalus montanus. Ophiostoma sp. B as well as O. subalpinum was a common fungus associated with Polygraphus proximus. Ophiostoma europhioides was isolated from Dryocoetes hectographus and D. autographus as one of the common associates. Ophiostoma sp. J and Ophiostoma sp. S were frequently isolated from D. autographus and D. striatus, respectively. These fungi seem to have specific relationships with particular bark beetles. Ophiostoma sp. B, Ophiostoma sp. J and Ophiostoma sp. S have unique morphological characteristics and appear to be new species. Five trees of A. veitchii, approximately 43 years old, were inoculated with five Ophiostoma species to assess the relative virulence of the fungi. Ophiostoma subalpinum, Ophiostoma sp. B, and O. europhioides had relatively higher virulence than the other species studied. 相似文献
13.
Parasitic Hymenoptera from the suprafamily Ichneumonoidea attacking the horse chestnut leafminer Cameraria ohridella Deschka & Dimic (Lepidoptera: Gracillariidae) were studied in southwest Slovakia during 2000 and 2001. The search for such species resulted in the determination of eight ichneumonid species, Gelis agilis (Fabricius), Itoplectis alternans (Gravenhorst), I. clavicornis (Thompson), I. maculator (Fabricius), Scambus annulatus (Kiss), S. brevicornis (Gravenhorst), Zatypota percontatoria (Müller), Adelognathus sp. and a braconid Colastes braconius Haliday. The most abundant species was S. annulatus. All these species recorded are polyphagous and often facultative hyperparasitoids, except C. braconius, which departs from this norm in not being hyperparasitic. The presence of more diversified native parasitoids and hyperparasitoids from the Ichneumonoidea predicate a slow successive adaptation of the parasitoid fauna to the invasive host, Cameraria ohridella. 相似文献
14.
Contour hedgerows of multipurpose tree species in the sloping tea lands of Sri Lanka are expected to reduce soil erosion and
also add significant amounts of plant nutrients to the soil via periodic prunings. The objective of this experiment was to characterize the biomass decomposition pattern and quantify the
amount of nutrients added through prunings of six tree species (Calliandra calothyrsus, Senna spectabilis, Euphatorium innulifolium, Flemingia congesta, Gliricidia sepium and Tithonia diversifolia) currently being used in hedgerows associated with tea. Withered leaf and stem prunings (50 g) were enclosed in 2-mm litter
bags, placed at 5-cm depth and retrieved after one, three, six, nine and 12 weeks. Loss of initial dry weight, N, P and K
was measured. Single exponential decay function adequately described both dry weight and nutrient loss. Tree species differed
significantly in their rate of breakdown with decomposition constants (k) varying from 0.0299 to 0.2006 week−1 for leaves and from 0.0225 to 0.0633 week−1 for stems. Gliricidia showed the highest k for leaves with the rest in the following descending order: Senna > Tithonia ≥ Euphatorium > Calliandra > Flemingia. A similar pattern was observed for loss of all nutrients with Calliandra and Flemingia always having lower k values than the rest. Although N immobilization was not observed, immobilization of P and K was observed
during the first week of incubation in some species, particularly in stem prunings. Annual biomass of prunings differed significantly
between tree species in the following descending order: Calliandra > Senna > Flemingia > Tithonia > Gliricidia > Euphatorium. Calliandra added the greatest amount of nutrients annually to the soil with Euphatorium adding the least. Calliandra prunings provided the annual total K requirement and 49% of the N requirement of mature tea. However, none of the species
provided more than 5% of the P requirement. It is concluded that among the tree species tested, Calliandra and Flemingia are the most suitable for contour hedgerows in tea plantations of this agroclimatic region because of their higher soil nutrient
enrichment capacity and slower decomposition rates which would minimize leaching losses.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
15.
Trees and shrubs as sources of fodder in Australia 总被引：2，自引：0，他引：2
E. C. Lefroy P. R. Dann J. H. Wildin R. N. Wesley-Smith A. A. McGowan 《Agroforestry Systems》1992,20(1-2):117-139
Experience with browse plants in Australia is briefly reviewed in terms of their forage value to animals, their economic value to the landholder and their ecological contribution to landscape stability. Of the cultivated species only two have achieved any degree of commercial acceptance (Leucaena leucocephala and Chamaecytisus palmensis). Both of these are of sufficiently high forage value to be used as the sole source of feed during seasonal periods of nutritional shortage. Both are also leguminous shrubs that establish readily from seed. It is suggested that a limitation in their present use is the reliance on stands of single species which leaves these grazing systems vulnerable to disease and insects. Grazing systems so far developed for high production and persistence of cultivated species involve short periods of intense grazing followed by long periods of recovery. Similar management may be necessary in the arid and semi-arid rangelands where palatable browse species are in decline. 相似文献
16.
Pavela R 《Fitoterapia》2004,75(7-8):745-749
The methanol extracts of eight species of medicinal plants were tested for insecticidal activity in third instar larvae of Egyptian cottonworm (Spodoptera littoralis). All extracts showed a certain degree of larval toxicity. The extracts of Ocimum basilicum, Origanum majorana and Salvia officinalis appeared to be highly toxic. The extracts significantly affected the growth indexes [relative growth rate (RGR), efficiency of conversion of ingested food (ECI), efficiency of conversion of digested food (ECD)]. 相似文献
17.
Yu Mei Zhang Ning Hua Tan Guang Zhi Zeng Abiodun Humphrey Adebayo Chang Jiu Ji 《Fitoterapia》2009,80(6):361-363
A new norlignan, (2R,3R,4S,5S)-2,4-bis(4-hydroxyphenyl)-3,5-dihydroxy-tetrahydropyran (1), together with 9 known compounds were isolated from the branches and leaves of Taxodium ascendens. Their structures were mainly determined on the basis of MS, IR, 1D and 2D NMR spectral evidences. Methanol extract showed inhibitory activity on carbonic anhydrase II with an IC50 value of 4.27 µg/ml, acetone extract and methanol extract inhibited activity of cathepsin B with IC50 values of 2.12 and 3.71 µg/ml, respectively. 相似文献
18.
Steven Maranz Amadou Niang Antoine Kalinganire Djeneba Konaté Bocary Kaya 《Agroforestry Systems》2008,72(3):231-239
Baobab leaves form an important part of the local diet in Sahel countries and elsewhere in Africa. Existing leaf nutritional
data and agroforestry performance information are based solely on Adansonia digitata L., the baobab of continental Africa. The introduction potential of Adansonia species from the center of diversity in Madagascar and from Australia remains untapped. To assess this potential, the mineral
contents and B1 and B2 vitamin levels of dried baobab leaves were determined for five-year old trees of A. digitata, A. gibbosa (A. Cunn.) Guymer ex D. Baum, A. rubrostipa Jum. & H. Perrier (syn. A. fony Baill.), A. perrieri Capuron and A. za Baill. grown in an introduction trial in Mali. Nutritional data were evaluated against survival and vigor to identify promising
germplasm. Leaf vitamin and crude protein contents were highest in the Madagascar species, especially A. rubrostipa (B1 88 mg 100 g−1, B2 187 mg 100 g−1, protein 20.7% dry weight). However, the local species far outperformed the introductions in survival, tree height, basal
diameter and resistance to termites. We suggest grafting as a way of harnessing the vigor of well-adapted local baobab varieties
to the superior nutritional profiles of A. rubrostipa and others. Cross-species grafting tests in Adansonia were successful, thus creating new agroforestry possibilities with different scion/rootstock combinations. 相似文献
19.
Effects of soil water availability on seedling growth, dry matter production and allocation were determined for Gympie (humid coastal) and Hungry Hills (dry inland) provenances of Eucalyptus cloeziana F. Muell. and for E. argophloia Blakely (dry inland) species. Seven-month-old seedlings were subjected to well-watered (100% field capacity, FC), moderate (70% FC) and severe (50% FC) soil water regimes in a glasshouse environment for 14 wk. There were significant differences in seedling growth, biomass production and allocation patterns between species. E. argophloia produced twice as much biomass at 100% FC, and more than three times as much at 70% and 50% FC than did either E. cloeziana provenance. Although the humid provenance of E. cloeziana had a greater leaf area at 100% FC conditions than did the dry provenance, total biomass production did not differ significantly. Both E. cloeziana provenances were highly sensitive to water deficits. E. argophloia allocated 10% more biomass to roots than did E. cloeziana. Allometric analyses indicated that relative biomass allocation patterns were significantly affected by genotype but not by soil water availability. These results have implications for taxon selection for cultivation in humid and subhumid regions. 相似文献
20.
The aim of this study was to quantify the effects of different soil scarification methods on tree growth. Soil scarification influenced stem volume and stem biomass yield of lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) in a 17-year-old field trial in boreal Sweden. Soil scarification (disc trenching, mounding and ploughing) resulted in an average stem volume yield of 3.1 and 34.2 m3 ha–1 on the poor and intermediate sites, respectively, while corresponding values for no soil scarification were 0.9 and 16.7 m3 ha–1. In comparison to no scarification, ploughing increased volume yields by 500% on the poor site and by 200% on the intermediate sites. The ranking according to stem volume yield was ploughing > disc trenching = mounding no soil scarification. Averaged over the two sites, the mean annual increment of stem biomass was 219% and 145% higher (in d.w., 0.26 kg and 0.34 kg per sample tree) after ploughing compared with no soil scarification, for the average and dominant sample trees, respectively. Although not significant, the increased growth rate after soil scarification decreased the average stem basic wood density of the sample trees with 1.6% and 5.3%, at the poor and intermediate sites, respectively. In conclusion, soil scarification significantly increased the 17-year stem volume yield compared with no scarification. The results also indicate that the difference in stem biomass yield between ploughing and the other methods, especially no soil scarification, will increase even more in the near future. 相似文献