新疆不同种植区赞皇大枣品质的差异分析

为给新疆不同种植区赞皇大枣的栽培提供理论依据,选择位于新疆塔克拉玛干沙漠北部和南部2个种植区的赞皇大枣作为研究材料,分析2个产地赞皇大枣营养成分含量的差异。分析结果显示:(1)沙雅县赞皇大枣总糖含量和糖酸比相对较高,口感偏甜;224团枣果口感更偏向酸甜口味。综合分析各品质测定结果显示,224团赞皇大枣主要营养成分含量较高,枣品质较沙雅县好。(2)224团土壤养分含量总体较沙雅县偏低,但224团赞皇大枣Vc、Ca、Fe的含量都较沙雅县高且差异明显。测定结果进一步证明气候和土壤营养物质等诸多因子共同影响着枣果品质,在对不同产地枣营养成分进行深加工时,一定要注意枣果的来源和产地的生境差异。     

赞皇大枣主要害虫的生物学特性及综合防治方法

<正>赞皇大枣是我国枣品种中唯一自然三倍体,赞皇县大枣种植面积已达到15万hm2,年产大枣0.5亿kg以上,被国家林业局命名为“中国赞皇大枣之乡”。枣区人均收入已达到3000元,是赞皇县人民实现增收的支柱产业。由于近     

野生酸枣嫁接大枣技术

安阳市西部山区、丘陵地带野生酸枣资源丰富。为了充分利用这些资源并加快绿化荒山步伐，增加经济收入，龙安区龙泉乡、安阳县安丰、龙掌等乡1998年开始，引进赞皇大枣、骏枣、灰枣、梨枣、雪枣、冬枣等优良接穗，采用蜡封接穗技术，酸枣嫁接大枣800余万株，目前长势良好，已全部挂果。据2002年调     

野生酸枣嫁接大枣及其丰产栽培技术

朝阳市野生酸枣资源丰富，利用酸枣嫁接大枣，不仅提高枣的品质，而且嫁接后生长快，结果早，产量高，可迅速成园，使野生资源得到合理开发利用，加快了大枣生产的发展速度。自1997年以来，孙家湾乡代家店村利用野生酸枣就地嫁接优良品种大枣48.3万株，300.1hm2。嫁接的品种有平顶枣、凌枣、二十家子大枣、冬枣、梨枣、金丝小枣、赞皇大枣等。同时进行了大枣幼树丰产栽培试验，总结出了一套栽培管理经验，为山区荒山、丘陵治理开发提供了典型样板模式和经验。 1 嫁接技术 1．1 建园 建园时可按株行距2m×3m来选留酸枣树，每hm2选留的酸枣…     

大枣嫩枝扦插育苗技术研究

枣树为扦插难生根的树种,传统育苗为根孽育苗和嫁接育苗,育苗周期长,成本高,不能满足生产需要。利用自动间歇喷雾装置,在全光照条件下,研究了脱毒苹果枣在不同季节、不同的激素水平处理时嫩枝扦插育苗成活率。并对比了脱毒苹果枣和不脱毒的梨枣、桐柏大枣、赞皇大枣嫩枝扦插成活率差异。结果表明,脱毒苹果枣嫩枝扦插成活率明显高于其余几个品种,最高成活率97.84%;二次枝的生根率达86.31%,枣头枝生根率为73.80%,而且生长素处理对枣头枝生根率的作用要高于二次枝,使二者差异缩小,为科学选择嫩枝扦插育苗材料提供了依据。     

开发三倍体大枣资源 再创赞皇枣业辉煌

三倍体赞皇大枣来源于太行山区的河北省赞皇县,全县11个乡镇,212个行政村,23万人口,总面积181.5万亩,其中耕地25.3万亩,有林地68万亩(其中经济林41万亩)仅枣树面积31万亩,占经济林面积的75.6%。人均1.3亩枣园。全县果品总产9500万斤,其中赞皇大枣鲜枣产量6000万斤,占果品产量的63.2%,赞皇大枣已成为赞皇县主导产业及主要经济来源。同时,又绿化了太行山,形成了绿色大屏障。“赞皇大枣绿了太行,富了乡民,强了赞皇。我们的经验是:一、开发三倍体赞皇大枣资源,建优种化枣园基地赞皇金丝大枣是目前从全国110个品种中发现的惟一的自然三倍体(细胞…     

应用RAPD标记技术探讨枣与酸枣的分类学关系

我国枣树 (Ziziphusjujuba)、酸枣 (Ziziphusspinosa)资源丰富 ,枣树以无性繁殖为主 ,酸枣除有性繁殖外 ,也可进行根蘖繁殖 ,枣和酸枣均为多年生植物。赞皇大枣是目前发现的惟一的自然三倍体品种1) ,其他枣品种和酸枣均为二倍体。河北省赞皇县是赞皇大枣的原产地 ,于 2 0 0 0年对赞皇县及附近的枣品种和酸枣进行了普查 ,除酸枣外 ,还有赞皇大枣、榆底串杆、吕庄串杆、紫铃蛋、前台 1号、元氏串杆、小串杆 7个枣品种。群体遗传学以居群 (population)为研究对象 ,研究居群遗传组成变化 ,最终阐明生物进化的机制。RAPD技术在探测群体的遗传…     

朝阳4种大枣主栽品种苗期抗旱性分析

试验选取朝阳地区4个大枣主栽品种(大平顶枣、凌枣、三星大枣和大铃铛枣)的2年生盆栽苗为试材,对不同干旱胁迫程度下叶片相对含水量(LRWC)、叶绿素含量、叶片水势和水分利用率(WUE)等生理指标进行了测定和分析,并对4个大枣品种的抗旱性进行了比较。结果表明:4个大枣品种在干旱胁迫下均显示了良好的抗旱性,其中凌枣的抗旱性相对较弱,三星大枣的抗旱性最强。     

陕北枣树优质丰产栽培技术

自《陕北十万亩矮密丰产示范园建设》项目实施以来 ,我们课题组经过试验、示范 ,总结出一套陕北红枣高产优质技术 ,现总结如下 ,以供参考。1　品种选择　　陕北黄河沿岸是全国优良制干枣的优生区。该区品种配置应以当地红枣品种为主 ,适当发展一些外引优良品种。适宜发展的优良品种为中阳木枣及其优良变异类型 (如佳县油枣、绥德大枣、清涧条枣、延川木条枣等 )、赞皇大枣、方木枣、骏枣等 ;适当发展一些优良兼用和鲜食品种 ,如狗头枣、脆枣、梨枣等。通过优良品种及优良变异类型的优树选择 ,建立了采穗和示范园 ,加大优良品种的推广。2　优…     

特大枣优良新品种--泗洪大枣

泗洪大枣是江苏省国营泗洪县五里江农场果树良种场 1 985年选育的新品种。 1 994年该场与中国枣树研究所合作在该场 1 0ｈｍ2 泗洪大枣生产试验园 ,用我国梨枣、南阳大王枣、国光枣等国内 35个大枣品种作对照试验。结果表明泗洪大枣综合性状尤为突出 ,其果型之大为参试品种之首。 (注 :现已由南京农业大学、江苏省农林厅及中国枣树研究所专家论证泗洪大枣果型之大为全国目前已知70 0余个枣品种之首。)该品种对枣疯病表现免疫 ,缩果病、炭疽病抗病性也优于参试品种。该品种1 995年荣获江苏省优质水果金奖。 1 999年泗洪大枣被江苏省农林厅选…     

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.     

Decomposition and nutrient loss from prunings of different contour hedgerow species in tea plantations in the sloping highlands of Sri Lanka

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.     

Effects of Seed Weight and Seed Type on Early Seedling Growth of Pinus sylvestris under Harsh and Optimal Conditions

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.     

Potential to harness superior nutritional qualities of exotic baobabs if local adaptation can be conferred through grafting

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.     

Modelling of adequate pretwist for obtaining straight timber

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.     

Growth of Phlebiopsis gigantea in wood of seven conifer species

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.     

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。