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1.
带箨冬笋的化学贮藏(1)   总被引:3,自引:0,他引:3  
利用固体保鲜剂对带箨的毛竹冬笋在常温(10~15℃)下进行贮藏试验,在为期5周的贮藏期内,以笋体外观及其营养成分含量的变化为指标,对试验结果应用正交试验方法筛选出了本实验条件下保鲜剂主要成分的最佳组合为25%Na2SO3、30%NaHCO3、10%CaO和40%大蒜抽出液。试验结果还表明,在贮藏开始的两周内冬笋的失水量可达到其自重的20%,因此,保鲜措施应以前期保水、后期防霉为重点。  相似文献   

2.
在大气CO2体积分数为700×10-6条件下,对油桐和烟草的光合CO2同化速率、光呼吸18O2吸收速率、光合色素、叶的脂类和脂肪酸组成等进行了比较分析.结果表明:大气CO2体积分数为700×10-6时油桐和烟草的光合速率有所增加,并抑制光呼吸18O2的吸收,但是,油桐对CO2浓度升高比烟草敏感,它的光合速率在700×10-6CO2时增加了2倍,而光呼吸18O2吸收则完全消失;油桐在700×10-6CO2下生长,光合色素合成量增加较多,其中叶绿素b及类胡罗卜素等属于捕光色素系统的色素增加尤其明显,叶绿素a/b值显著下降,在同样条件下,烟草的叶绿素含量还略有减少,类胡罗卜素含量则明显减少;高浓度CO2影响这两种植物叶的脂类和脂肪酸的组成,700×10-6CO2下生长的这两种植物叶的饱和脂肪酸和磷脂含量有所增加,但油桐叶的糖脂含量有所下降,烟草的糖脂含量则不受CO2浓度升高的影响.  相似文献   

3.
槐小卷蛾性诱剂的合成与林间诱蛾活性试验   总被引:4,自引:0,他引:4  
孟宪佐  李维维 《林业科学》1996,32(2):150-153
槐小巷蛾(CydiatradiasMeyrik)性诱剂的主要成分为(反、反)-8,10-十二碳双烯-1-醇(简式ESE10-12:OH)。从两个易得的C6原料出发,通过Grignard偶联反应合成了这种性诱剂。林间诱蛾试验结果表明,ESE10-12:OH对槐小卷蛾具有强烈的引诱作用,诱蛾量的变化能及时而准确地反映林间槐小卷蛾的发生与消长情况,从而为进行适时而有效的防治提供科学依据。  相似文献   

4.
不同保鲜剂对香石竹切花保鲜效果的研究   总被引:14,自引:0,他引:14  
用市售花鲜剂(Cut-flowernutriments)可利鲜(Chrysal)和自配保鲜剂对香石竹鲜切花瓶(泥)插的综合保鲜效果进行了对比试验。切花外部形态,生理效应及保鲜液变化的连续测定结果表明;3种保鲜剂对香石竹鲜切花均具有的保鲜效果,但两种市售剂优于自配剂,瓶插寿命和花径达到的最大值可利鲜稍强花鲜剂,促进开放速度和泥插寿命二者不相上下。连续使用效果和自然抗菌力花鲜剂优于可利鲜。  相似文献   

5.
1995年3月下旬从广东省广宁县引种5412株青皮竹(Bambusatextilis),采用ABT生根粉1~5号5种剂型,25×10(-6)、50×10(-6)、100×10(-6)的3种浓度处理,与清水对照,产苗量普遍增加,其中ABT-1号50×10(-6)、ABT-5号50×10(-6)效果显著。  相似文献   

6.
用市售花鲜剂(Cut-flowernutriments)、可利鲜(Chrysal)和自配保鲜剂对香石竹鲜切花瓶(泥)插的综合保鲜效果进行了对比试验。切花外部形态、生理效应及保鲜液变化的连续测定结果表明:3种保鲜剂对香石竹鲜切花均具有良好的保鲜效果,但两种市售剂优于自配剂;瓶插寿命和花径达到的最大值可利鲜稍强于花鲜剂;促进开放速度和泥插寿命二者不相上下;连续使用效果和自然抗菌力花鲜剂优于可利鲜。  相似文献   

7.
Nai李在常温条件下难以贮藏保鲜,经对Nai李的贮藏保鲜进行研究,用保鲜剂利用的Nai李冷藏保鲜30-45d,好果率达95%以上,果料风味较好。  相似文献   

8.
莲藕贮藏保鲜技术该技术解决了莲藕取挖后贮藏保鲜期短、易腐烂变质等突出问题,依据莲藕的生理生化特性,提出了贮藏保鲜的新方法:莲藕保鲜液浸泡法和薄膜袋贮藏保鲜法。筛选出两种配方的保鲜剂。经示范,在露地贮藏(12—2月份),莲藕保鲜期可达90天以上,好藕率...  相似文献   

9.
1 品种选择选择最晚熟的品系或单株上的果实为贮藏品种。2 采收在果实茸毛开始减少,彩色增多、果实硬、稍有弹性,八成熟时采收,采收时应选择健康果实,尽量保留果柄,采收后,果实要及时运输到贮藏地点。严格挑选剔除不符合贮藏要求的果实,并按果实大小分级。3 CaCl2和TBZ处理在水泥池或大缸中配制2%-3%的CaCl2和500×10-6-1000×10-6TBZ溶液。将挑选分级后的安丘蜜桃在池中浸一下,捞出晾干,或加鼓风机除去水滴,经处理,可增加果实硬度,防止腐烂,延长贮藏期。4 包装和乙烯的清除将…  相似文献   

10.
贮藏保鲜方法与再加工对毛竹笋营养成分的影响*   总被引:7,自引:0,他引:7       下载免费PDF全文
经试验分析表明,毛竹笋不同贮藏保鲜方法及再加工对笋产品的粗蛋白质、15种氨基酸及矿质元素等营养成分有影响,其中用盐汁(笋)法和用亚硫酸盐保鲜的笋,粗蛋白质及氨基酸含量较保鲜前明显减少,而用清水笋罐藏及用SM保鲜剂保鲜的熟笋,氨基酸含量变化较小,而且保鲜笋的色泽正常、无异味,各项检测指标符合食品卫生标准,是我国目前较好的贮藏保鲜方法。  相似文献   

11.

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.  相似文献   

12.

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.  相似文献   

13.

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.  相似文献   

14.

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.  相似文献   

15.
本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。  相似文献   

16.

The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided.  相似文献   

17.
18.

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken.  相似文献   

19.
In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts (stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea (Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea, largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols. Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its components are mixed.  相似文献   

20.
The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization, (2) milk sewage sludge at 40 kg N ha−1 target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha−1. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha−1) + Trifolium repens L. group Ladino (4 kg ha−1) + Trifolium pratense L. var. Marino (1 kg ha−1); (2) Lolium perenne L. var. Tove (25 kg ha−1) + Trifolium repens L. group Ladino (4 kg ha−1) + Trifolium pratense L. var. Marino (1 kg ha−1). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea (Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m2, with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral systems. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

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