4个石榴品种果实品质的差异性分析

为给石榴品种的品质评价和果实贮藏加工利用提供理论参考,以新疆维吾尔自治区叶城县的石榴主栽品种‘叶城1号’和‘叶城2号’以及河南省郑州市的石榴主栽品种‘突尼斯’与‘中农红’作为研究对象,测定和比较了4个石榴品种的果实表型特征指标、果实经济性状指标、果实内在品质指标及果实中8种营养元素的含量。结果表明:4个石榴品种在果实品质上存在不同水平的差异性,其中,‘突尼斯’的果形指数接近1,其果皮较薄,果皮质量也最低,果实可食率反而最高(66.54%±6.12%),比‘中农红’和‘叶城1号’‘叶城2号’分别高约10%、25%、20%,其果汁中的可溶性固形物和维生素C、钾和钙含量均较高;‘中农红’果实籽粒的含水量最多,其糖酸比也较高,果汁中锰、锌、铁和铜等微量元素的含量均较高;‘叶城1号’果实的纵横径均最高,果形指数却最低,其单果质量最高,为(435.33±75.97)g,但因其果皮厚度大和质量重,故其果实的可食率反而最低,为(41.582%±6.785%),其可溶性固形物和可溶性糖含量及磷和镁含量均最高;‘叶城2号’虽其单果籽粒颗数最多,因其籽粒较小,故其单果籽粒质量最低,其籽粒含水量也最低,而其可滴定酸含量较高,为(0.577%±0.110%)。4个石榴品种中,‘突尼斯’和‘中农红’均不耐贮运,均较适用于加工果汁或就地就近处理;‘叶城1号’和‘叶城2号’均较耐贮运,均较适于远地贮藏和运输。     

蒙枣1号、蒙枣2号、蒙枣3号果实品质测试分析

以内蒙古自治区林木品种审定委员会审定和认定的红枣良种蒙枣1号、蒙枣2号、蒙枣3号脆熟期果实为供试材料,对氨基酸、营养成分、矿质元素等含量进行测试分析。蒙枣1号果实总氨基酸(TAA)、人体必需氨基酸(EAA)、果实总酸(以柠檬酸计)、粗纤维、维生素C、粗脂肪、Fe和Zn含量最高,分别为0.979 g·100 g^-1、0.178 g·100 g^-1、0.61 g·100 g^-1、1.54 g·100 g^-1、0.39 g·100 g^-1、0.70 g·100 g^-1、7.82 mg·kg^-1和7.30 mg·kg^-1。蒙枣2号果实可溶性总糖、糖酸比和Ca含量最高,分别为19.76 g·100 g^-1、56.46和294.65 mg·kg^-1。蒙枣3号果实还原糖、可溶性固形物含量最高,分别为11.98 g·100 g^-1和34.50 g·100 g^-1。Pb、Cd、Hg、As的含量极少或未检测出。通过测试分析,为蒙枣1号~3号品质评价和进一步深加工提供科学依据。     

19个油茶无性系的酶活性及蛋白质含量分析

本试验通过采集19个油茶优良无性系的叶片,测定其过氧化物酶（POD）活性、超氧化物歧化酶（SOD）活性、细胞色素氧化酶（COX）活性及蛋白质含量,比较不同品种油茶的酶活性、蛋白质含量,并进行主成分分析和聚类分析。结果表明：（1）17号品种油茶叶片POD活性最高,达2.3493U·g-1FW,15号最低,仅有0.0215U·g-1FW,品种间POD活性差异极显著;2号品种油茶叶片SOD活性最高,达341.0256U·g-1FW,7号品种最低,仅有159.8928U·g-1FW,品种间POD活性差异显著;18号品种COX活性最高,达0.5406μmol cytc·min-1·g-1FW,11号最低,仅有0.0121μmol cytc·min-1·g-1FW,各品种间无明显差异;16号品种蛋白质含量最高,有39.9854mg·g-1,4号品种最低,仅有5.4296mg·g-1,各品种间差异极显著;（2）在各品种油茶叶片中,POD、SOD、蛋白质这三项指标均不是影响各品种间差异的明显主成分;（3）对各品种叶片的POD活性、SOD活性、蛋白质三项指标进行ward最小平均法聚类分析,可区分为五类,同类群中大部分品种均来自同一种源地。     

潮州市7个杨梅品种果实营养成分评价

为给杨梅的品种选育提供依据,以潮州市主栽7个杨梅品种为试材,测定了各杨梅品种果实的主要性状及营养品质。结果表明:不同杨梅品种间所含营养成分存在差异,不同区域栽培的同一品种果实的营养品质也有所不同。鸭背村生产的东魁杨梅单果质量为17.918 g,果实最大,远高于潮阳乌、酥核、玫瑰红、饶平红、葫芦蒂、潮阳红等6个杨梅品种,也比银潭村生产的东魁杨梅(单果质量仅15.366 g)大;7个杨梅品种果实含有丰富的可溶性固形物、蛋白质、有机酸、维生素C以及Fe、Mg和Zn等矿质元素,东魁杨梅在7个被测品种中无论从单果质量还是品质方面均具有较大的优势,值得推广。     

不同花粉源对仙蜜6号火龙果坐果、产量及品质的影响

研究不同花粉源对仙蜜6号火龙果坐果率、产量、单果重及内在品质的影响,试验结果表明,自花花粉处理的坐果率显著低于对照及其它处理;花粉源为异品种、同品种处理的产量、果实纵横径、平均单果重、可食率显著高于对照(自然坐果),而内在品质(可溶性固形物)与对照相当;表明仙蜜6号火龙果具备一定的自花亲合性,自然条件下能取得一定的经济产量,采集异品种或同品种的花粉进行人工授粉,有利于提高仙蜜6号火龙果的产量,而对其品质无明显影响。     

山东主栽石榴品种果实Vc含量及品质指标差异研究

以山东9个主栽石榴品种为试材,分析其果皮、隔膜、种子、果汁中的Vc含量及果实中可溶性固形物、可溶性糖、可滴定酸等品质指标,结果表明：石榴果皮和隔膜中Vc含量较高,果汁中含量较低,种子中最少;青皮岗榴果皮中Vc含量最高,种子中最低;三白石榴果皮和隔膜中Vc含量最低;青皮软籽种子和果汁中Vc含量最高;泰山红单果重和皮厚度最高,三白最低,青皮马牙甜百粒重最大;青皮岗榴可溶性固形物含量最高,青皮马牙甜最低。大青皮甜果实中可溶性糖含量和糖酸比均最高,是供试品种中果实品质最佳的优良品种;大青皮酸果实中可滴定酸含量最高,适合加工。     

不同品种核桃在鄂北引种栽培的品质分析

调查了鄂北引种栽培的10个核桃品种坚果的外观品质,并分析测定部分品种核仁的脂肪、蛋白质、矿质养分含量。结果表明:元丰、晋龙3号和辽核4号综合品质较优,其外观品质、蛋白质和脂肪含量均达到国家标准;中林5号坚果较小,脂肪含量较低,但出仁率高、口感好,可以作为授粉品种使用;当地野核桃果径小、单果质量小、壳厚、内隔壁骨质、出仁率极低,无直接经济利用价值,但蛋白质含量高达26.1%,可用野核桃与核桃进行杂交,选育抗性强、高蛋白含量的核桃新品种。     

丹东地区主栽蓝莓品种果实品质分析

为了解丹东主栽蓝莓品种的果实品质,便于蓝莓种植户选择,对丹东地区主栽的8种蓝莓品种果实内在品质和外观形态进行分析。结果表明:钱德勒平均单果重最大,公爵最小;果实硬度以卡拉、大果蓝金、蓝丰为好,伊丽莎白、伯克利稍差;耐贮性卡拉较差;各蓝莓品种果粉厚度差异不大。冻果总酸含量卡拉最高,可达13.28 mg·g-1,伯克利最低为5.84 mg·g-1;伊丽莎白总糖含量最高为23.59 mg·g-1,钱德勒总糖含量最低为10.67 mg·g-1。8个蓝莓品种的糖酸比为1.14~3.33,可以满足喜酸、喜甜和酸甜适中口味的各类消费者。     

不同产地‘澳洲青苹’果实形态及品质特征的比较分析

为了掌握不同产地‘澳洲青苹’的果实形态及品质特征,从而为‘澳洲青苹’生态区划研究奠定基础,分别从11个产地采集了‘澳洲青苹’果实样品,并就其横径、纵径、果形指数、单果质量、硬度、可滴定酸、可溶性固形物、糖酸比、维生素C含量和出汁率等形态与品质指标进行了测定与差异性分析。结果表明:不同产地‘澳洲青苹’的果实形态和品质特征间均存在一定的差异,其中,果实横径、纵径和果形指数间的差异均相对较小,各产地‘澳洲青苹’的果形指数普遍在0.8~0.9之间,其果实接近于圆形或近圆形;而其单果质量和果肉硬度间的差异均较大,其中,单果质量以辽宁绥中产地的为最大(221.0 g);果肉硬度和果实中可溶性固形物的含量,均以甘肃清水县产地的为最高,分别为10.8 kg·cm-2和12.95%;可滴定酸含量,宁夏银川产地的最高(0.9%),山东栖霞市产地的最低(0.63%);VC含量,甘肃清水县产地的最高(达157.1 mg·g-1),陕西眉县产地的最低(115.1 mg·g-1);各产地的‘澳洲青苹’其出汁率间的差异相对较小,其出汁率在68.9%~76.8%之间。     

不同区域黄冠梨品质对比试验

采集皇冠梨和雪花梨样本,分析矿质元素、可溶性固形物、可溶性糖、可滴定酸等品质指标。结果表明,黄羊镇皇冠梨矿质元素含量最高,其中Na、Mg、K、Ga、Mn、Cu、Zn、Fe等矿质元素含量分别为0.54、26.45、1 296.47、27.98、0.38、0.27、0.28、7.91mg/kg;黄羊镇皇冠梨可溶性固形物含量最高为11.92%,清源镇皇冠梨可溶性糖含量最高为10.47%,清源镇皇冠梨糖酸比最高为156.26。     

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.     

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.     

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.     

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。     

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.