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1.
马尾松毛虫质型多角体病毒替代寄主筛选的研究 总被引：4，自引：0，他引：4
用ＤｐＣＰＶ感染８种鳞翅目昆虫的试验结果表明，棉铃虫最敏感，感染率达９７％。ＤｐＣＰＶ对棉铃虫的毒力ＬＣ５０为７．６５×１０４ＣＰＢ／ｍｌ，浓度与感染死亡率相关性及回归方程均达到显著性。用该虫生产的Ｈａ－ＤｐＣＰＶ的产量平均为８．１２５亿ＣＰＢ／条，与用原寄主马尾松毛虫生产的平均为７．９４亿ＣＰＢ／条基本相等。Ｈａ－ＤｐｏＰＶ对马尾松毛虫的毒力ＬＣ５０为１．５×１０４ＣＰＢ／ｍｌ，而ＤｐＣＰＶ对马尾松毛虫的毒力ＬＣ５０为３．８６×１０５ＣＰＢ／ｍｌ，两者相比，毒力没有下降。 相似文献
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利用替代寄主生产马尾松毛虫质型多角体病毒的研究 总被引：7，自引：0，他引：7
ＤｐＣＰＶ对８种鳞翅目昆虫感染试验结果表明，棉铃虫最敏感，感染率达９７．０％。ＤｐＣＰＶ对棉铃虫的毒力ＬＣ５０＝７．６５×１０４ＣＰＢ／ｍｌ，浓度与感染死亡率相关性及回归方程均达到显著性。ＨａＤｐＣＰＶ与原毒种ＤｐＣＰＶ的形态特征相同；棉铃虫可用人工半合成饲料配方２在小塑料盒内单虫饲养，幼虫成活率达９８％以上、羽化率达９０％，平均蛹重０．４００６ｇ，平均产卵量７９７．７粒，卵孵化率达９８．２％；ＨａＤｐＣＰＶ对第一代４～５龄马尾松毛虫的毒力较强，ＬＣ５０＝１．１４×１０４ＣＰＢ／ｍｌ，与原毒种相比，毒力没有下降。用棉铃虫来生产ＤｐＣＰＶ，采用２３～２６℃、３龄虫、使用浓度１０５ＣＰＢ／ｍｌ以上，是比较理想的组合。将病毒喷在人工饲料表面喂虫，可获得较高的病毒产量，平均每条虫可产８．１３亿ＣＰＢ，与用原宿主生产的产量相接近。用ＨａＤｐＣＰＶ防治第一、二代４～５龄马尾松毛虫，防治效果达６０．２％～８４．０％。 相似文献
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马尾松毛虫质型多角体病毒单克隆抗体的制备和应用 总被引：1，自引：0，他引：1
纯化的马尾松毛虫质型多角体病毒（ＤｐＣＰＶ）云南文山株的病毒粒子经ＳＤＳＰＡＧＥ分析,其结构蛋白有１２０ｋｄ、１１６ｋｄ、１１０ｋｄ、６６ｋｄ和３３ｋｄ５个组分,而它的多角体蛋白含３０ｋｄ和２８ｋｄ两个主要组分。以纯化的ＤｐＣＰＶ粒子为抗原制备了２Ｄ５、２Ｄ１０、３Ｄ４和６Ｂ３共４种单克隆抗体,并测定了它们的亚类。制得的单克隆抗体用于ＤｐＣＰＶ的ＥＬＩＳＡ检测。对ＤｐＣＰＶ在棉铃虫卵巢细胞系ＳＦＥＨＡ８２１２和ＳＦＥＨＡ８３１中增殖动态的检测结果表明,ＤｐＣＰＶ感染培养细胞具有释放病毒量小和呈现持续感染等特点。用Ｗｅｓｔｅｒｎ印迹法在ＳＦＥＨＡ８３１细胞感染ＤｐＣＰＶ后第１８ｈ检测到病毒抗原的合成。运用所建立的免疫学检测方法,对几批采自ＤｐＣＰＶ防治林区的幼虫样品进行分析,结果表明,该方法适用于对ＤｐＣＰＶ的防治效果及其自然流行进行长时期、大规模的监测。 相似文献
4.
文山松毛虫质型多角体病毒的剂型研制 总被引：1，自引：0，他引：1
在采用天然饲料养虫，塑料围栏式集虫、林地集虫及林间高虫口密度接毒增殖病毒的方法，解决了病毒批量生产的基础眯适应云南大面积报应松毛虫的需要，进一步 ＤＰＷＣＰＶ剂型的研制。选用８种辅助剂进行文山松毛虫幼虫生活力试验及ＤＰＷＣＰＶ病毒毒力的影响试验。筛选出辅－１、辅－５、辅－６、辅－７等辅助剂作为ＤＰＷＣＰＶ病毒剂型研制的主要辅助原料；研制出ＤＰＷＣＰＶ－Ⅰ、ＤＰＷＣＰＶ－Ⅱ及ＤＰＷＣＰＶ－Ⅲ３种剂型 相似文献
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在采用天然饲料养虫，塑料围栏式集虫、林地集虫及林间高虫口密度接毒增殖病毒的方法，解决了病毒批量生产的基础上，为适应云南大面积防治松毛虫的需要，进一步开展了ＤＰＷＣＰＶ剂型的研制。选用８种辅助剂进行文山松毛虫幼虫生活力试验及ＤＰＷＣＰＶ病毒毒力的影响试验。筛选出辅—１、辅—５、辅—６、辅—７等辅助剂作为ＤＰＷＣＰＶ病毒剂型研制的主要辅助原料；研制出ＤＰＷＣＰＶ—Ⅰ、ＤＰＷＣＰＶ—Ⅱ及ＤＰＷＣＰＶ—Ⅲ３种剂型。经对文山松毛虫幼虫毒力比较试验，选择出ＤＰＷＣＰＶ—Ⅱ剂型为林间大面积应用推广剂型。经大面积防治松毛虫试验，防治效果达８５１％，比普通水液制剂提高９８％。通过剂型产品储藏效果测定及安全性检测表明剂型产品有效保存期为１年，不含对人畜有害的沙门氏菌、志贺氏菌及弧菌等致病菌，证明该剂型安全可靠。 相似文献
8.
应用CPV,Bt混配制剂飞机防治马尾松毛虫 总被引：2，自引：1，他引：1
应用Ｊ－Ｄｓ ＣＰＶ（日本赤松毛虫质型多体病毒）、Ｂｔ（苏云金杆菌）２种制剂混配，并加入适量化学农药进行飞机大面积防治马尾松毛虫，施药２５ｄ后校正虫口减退率达８４．７％。２种制剂混用具有显著的增效作用和持续防治效果。 相似文献
9.
虫死净对马尾松毛虫的毒力测定 总被引：1，自引：0，他引：1
虫死净是广州农药厂生产的一种新型昆虫生长调节剂，毒力测定结果表明：２０％虫死净可湿性粉剂、２０％胶悬剂和５％乳剂对马尾松毛虫均有较强的毒力，３种剂型的ＬＣ５０依次为１１５，８４．６，６４．４ｍｇｋｇ－１；ＬＣ９０依次为２２６，１７９，３８１ｍｇｋｇ－１；在使用浓度２５０ｍｇｋｇ－１下，ＬＴ５０分别为４．４，６．１，３．９天；在２５０—１０００ｍｇｋｇ－１浓度之间，施药后９天，松毛虫死亡率均达９０％以上。 相似文献
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《Scandinavian Journal of Forest Research》2012,27(5):427-435
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
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《Scandinavian Journal of Forest Research》2012,27(3):206-217
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
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《Scandinavian Journal of Forest Research》2012,27(1):53-61
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
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《Scandinavian Journal of Forest Research》2012,27(1):15-27
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
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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
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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
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Astra Zaluma Lauma Bruna Darta Klavina Natalija Burnevica Kristine Kenigsvalde Andis Lazdins Talis Gaitnieks 《Forest Pathology》2019,49(6)
Heterobasidion parviporum and Heterobasidion annosum are widely distributed root‐rot fungi that infect conifers throughout Europe. Infection of conifer stumps by spores of these pathogens can be controlled by treating fresh stumps with a competing non‐pathogenic fungus, Phlebiopsis gigantea. In this study, growth of three Latvian strains of P. gigantea and the biological control agent ‘Rotstop’ strain was evaluated in stem pieces of Norway spruce, Scots pine, lodgepole pine, Douglas‐fir, Weymouth pine, Siberian larch and Sitka spruce. The growth rates of one H. parviporum and one H. annosum isolate were also measured in the same stem pieces. The growth rate of P. gigantea varied greatly in wood of different conifer species. It was higher in the three pine species, lower in Norway spruce and lowest in Sitka spruce and Siberian larch, and in Douglas‐fir, this fungus did not grow. The largest area of wood occupied by P. gigantea was in lodgepole pine. Growth of Latvian isolates of P. gigantea in the wood of Pinus and Picea species was comparable to that of the Rotstop isolate. Consequently, stump treatment with local P. gigantea isolates should be recommended. However, our results suggest that Douglas‐fir stump treatment against Heterobasidion by P. gigantea may be ineffective and other stump treatment methods should be considered. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(2):118-130
The effects of seed weight and seed type on seedling growth of Pinus sylvestris (L.) were studied by seeding individually weighed orchard and stand seed in different mixtures under harsh (direct seeding in field) and optimal (seeding in nursery) conditions. In the nursery experiment an increase in the seed weight from 3 to 7 mg increased the seedling height by 10-27% and total weight by 27-113%, and decreased the height/diameter ratio by 5-6% after 2 yrs. With elimination of seed weight effects, orchard seedlings were 2% taller than stand seedlings in year 2. Without elimination of seed weight effects, orchard seedlings were 7-13% taller. In the field experiment an increase in the seed weight from 3 to 7 mg increased seedling height by 18-65%, stem volume by 81-274% and the number of top-buds by 23-34% in year 5. After elimination of seed weight effects, orchard seedlings were 7-13% taller than stand seedlings and without elimination of seed weight effects 20-21% taller after 5 yrs. Even after elimination of both seed weight and genetic effects orchard seedlings were 3-9% larger than stand seedlings in the field experiment. In conclusion, the influence of seed weight and seed type on growth traits and slenderness is highly significant and the influence seems to be greater in harsh conditions. 相似文献
19.
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
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《Wood material science & engineering》2013,8(2):76-84
Abstract Wood in general and wooden studs in particular are often distorted owing to uneven shrinkage during the drying process in the sawmill. Twist is often the most detrimental of all types of distortion, and it is caused by spiral grain in combination with variations in moisture content. For sawmills, the objective is to produce dried, straight boards, and one method of dealing with boards with excessive spiral grain is to sort them out and then dry them in a pretwisted position to obtain straight boards after drying. A model using the finite element (FE) method for the simulation of drying twist distortions was first calibrated against laboratory experiments in which boards were dried with and without restraints and pretwists. After the calibration, the FE results were compared with industrial test results for boards that were dried without restraints or with restraints with zero pretwist, i.e. straight restraints. The FE model used an elastic–ideally plastic material model to obtain permanent deformations. The calibration was to set the yield stresses so that there was a good match between FE results and results from the laboratory experiments. The comparison between the industrial test results and the FE results showed that the FE model is capable of realistic simulations of drying boards with and without restraints and presumably also pretwists. 相似文献