蜀柏毒蛾核型多角体病毒毒力的生物测定

蜀柏毒蛾(Parocneria orienta)是近年来我省柏木林区发生和危害十分严重的食叶性害虫。为了探索一条柏木林区蜀柏毒蛾生物防治的有效途径,解决蜀柏毒蛾防治(主要是化学防治)与桑蚕业的冲突,1989年我们在金堂采集、分离到1株蜀柏毒蛾病毒新毒株,经中国科学院武汉病毒所鉴定为蜀柏毒蛾核型多角体病毒(Parocneria orienta Nunclear PolyedrosisVrius简称PoNPV)。为了研究该病毒的开发利用价值,1990年进行了PoNPV毒力的生物测定。现将研究结果报道如下。     

几种对蜀柏毒蛾核型多角体病毒增效的添加剂研究

蜀柏毒蛾(Parocneria orientia Chao)是四川省森林第一大食叶害虫,近年来每年都以较大面积的发生,严重威胁长江中上游柏木(Cupressus funebris Endl.)防护林的建设成果.用蜀柏毒蛾核型多角体病毒(Parocneria orientia Nulcear Polyhedrosis Virus,简称PoNPV)防治蜀柏毒蛾危害是我省蜀柏毒蛾生物防治的主要手段,但由于PoNPV产量的限制,使我省蜀柏毒蛾生物防治的发展受到制约.荧光增白剂Tinopal LPW、VBL、灭幼脲等作为增效剂可显著提高昆虫病毒的毒力,达到增效的作用~([1-5]),但利用荧光增白剂VBL、灭幼脲和敌百虫作为蜀柏毒蛾核型多角体病毒增效剂未见报道.     

用微核测定法评价蜀柏毒蛾核型多角体病毒杀虫剂对小白鼠的安全性

用微核测定法评价蜀柏毒蛾核型多角体病毒杀虫剂对小白鼠的安全性＊周建华郭亨孝（四川省林业科学研究院）本文用测定小白鼠骨髓嗜多染红细胞微核出现率的方法来分析蜀柏毒蛾核型多角体病毒杀虫剂对哺乳动物的安全性。口服４种剂量的蜀柏毒蛾核型多角体病毒杀虫剂感染小白...     

蜀柏毒蛾核型多角体病毒的初步研究

蜀柏毒蛾(Parocneria orienta)是我省柏木林区发生和危害十分严重的食叶害虫。1989年我们在四川省金堂县采集到一批自然病死虫,经分离、鉴定、室内毒力生物测定和林间初步应用表明:该病毒是1株新分离的蜀柏毒蛾核型多角体病毒(Parocneria orienta Nuclear Polyhedrosis Vrius,简称PoNPV),该病毒对蜀柏毒蛾有较强的毒力,有广泛的应用前景。现将研究结果报道如下。 感病幼虫的症状 幼虫吞食蜀柏毒蛾核型多角体病毒后,取食活动明显减弱,行动迟缓;一定时间后,幼虫死亡。幼虫刚死时,呈“倒悬”或倒“V”字型挂于柏桠上;腹部体色呈灰褐色,体壁易破,流出褐色脓液,无臭味。     

蜀柏毒蛾核型多角体病毒的增殖技术

蜀柏毒蛾(Parocneria orienta)是我省柏木林区的严重食叶害虫,发生面积高达200多万亩,给川中农区林业生产造成严重的损失。目前主要以大量使用化学农药为主,化学防治虽然对抗灾有较大的作用,但却存在着一些不可避免的矛盾和缺陷;如污染环境、易使目标害虫产生抗性、杀伤天敌,特别是影响桑蚕业的发展。因此,采用生物防治主要是病毒防治蜀柏毒蛾尤为重要和必要。1989～1991年我们对蜀柏毒蛾的活体增殖技术进行了探讨,研究出了3种增殖技术,为蜀柏毒蛾核型多角体病毒杀虫剂生产奠定基础。现将具体方法介绍如下。     

蜀柏毒蛾核多角体病毒的安全试验

应用蜀柏毒蛾多角体病毒制剂于１９９０年６月对实验动物、家禽、鸟类、水生动物和经济昆虫等进行一系列安全性试验，经２－３个月的试验，表明蜀柏毒蛾核多角体病毒对人畜及试验动物是安全的。     

温度和光周期对蜀柏毒蛾滞育的影响

蜀柏毒蛾(Parocneria orienta Chao)是四川省柏木林最重要的食叶害虫,其越冬代有明显的滞育现象.本文通过人工诱导的方法研究了温度和光周期对蜀柏毒蛾1龄幼虫滞育诱导和解除的影响.结果表明:1.温度对蜀柏毒蛾的滞育率影响极显著(P<0.01),蜀柏毒蛾的滞育率随温度的降低逐渐升高;2.温度和光周期协同作...     

蜀柏毒蛾的生物学特性与防治研究

蜀柏毒蛾(Parocneria orientaChao)属鳞翅目、毒蛾科、柏毒蛾属。蜀柏毒蛾危害柏木、桧柏、侧柏、千头柏等柏科树种,是我县柏木林中的主要食叶害虫。为了掌握蜀柏毒蛾的发生规律和防治方法,1981年至1984年,我们在央溪公社化林大队设立固定观察点,开展了室内室外的饲养工作,并在央溪、化林、江口等地设点进行了     

蜀柏毒蛾颗粒体病毒浸染致病初效

蜀柏毒蛾Parocneria ori enta分布我国云、贵、川等省,主要危害柏树,1979年四川省苍溪县普遍受其危害,在虫口密度大的柏木林地内发现蜀柏毒蛾幼虫自然感病死亡.用罹病死亡虫尸捣碎,用无菌水稀释,将配制成病毒液涂于清洁柏枝鲜鳞叶上,作健康幼虫取食的饵料,获得大批浸染致病幼虫尸,经武汉大学病毒研究所分离,是一种颗粒体病毒,这种病毒的颗粒体形态,呈椭圆形,两端钝园,较规则一致,但也可见到不少畸形CV(颗粒体),     

蜀柏毒蛾核型多角体病毒杀虫剂应用技术

蜀柏毒蛾核型多角体病毒(Parocneria orienta Nulear Polyhedrosis Virus,简称PoNPV)杀虫剂是以PoNPV为活性杀虫成份,添加其他惰性成份,经一定工艺加工而成的一种生物农药。通过1990～1991年林间应用研究:该杀虫剂具有不污染环境、对人畜蚕安全、专一性强、流行性好、有一定特效性等特点,通过研究,总结出了该杀虫剂的林间应用方法。现报道如下。 施药机械和施药方式 蜀柏毒蛾核型多角体病毒杀虫剂的施药机械用3MF——4型机动喷雾器或农用机动喷雾器。每公顷使用3600亿PIB,加水750公斤,常规喷雾。喷洒时,应仔细、全面地将药液喷到整个树株鳞叶上。     

Browsing Damage on Pine (Pinus sylvestris and P. contorta) by a migrating moose (Alces alces) Population in Winter: Relation to Habitat Composition and Road Barriers

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.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

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.     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

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.     

Growth and Terminal Bud Formation in Picea abies Seedlings Grown with Alternating Diurnal Temperature and Different Light Qualities

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.     

CAD与建筑设计的关系

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。     

Natural Regeneration in Clear-cuts: Effects of Scarification,Slash Removal and Clear-cut Age

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.     

Risk Perception Among Non-industrial Private Forest Owners

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.     

Interactions in decomposition and N mineralization between tropical legume residue components

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.     

Pasture production and tree growth in a young pine plantation fertilized with inorganic fertilizers and milk sewage in northwestern Spain

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.