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1.
《福建林业科技》2020,(2)
2019年9月对福建省64株香椿(Toona sinensis Roem.)候选优树进行生长与材性测定,对各个性状进行正态分布检验、系统聚类分析和主成分分析。结果表明:不同候选优树的生长性状和木材材性存在着不同程度的变异;芯材率与胸径和立木材积分别呈显著正相关,说明生长性状和材性性状之间存在着一定的关联性。利用聚类分析方法最终可以将64株候选优树分为生长与材性综合表现优、良、差3类,而主成分分析从4个主成分所代表的主要性状角度可将它们细分为12个类别,综合2种分析的生长性状与材性综合表现较优的候选优树为FA_3、MH_2、FA_6和JC_4,它们的树高、胸径、立木材积、芯材率、偏心率和木材基本密度整体均值分别为15.6 m、29.7 cm、0.4988 m~3、92.64%、2.98%和0.5428 g·cm~(-3)。该研究结果可为福建省香椿的遗传育种研究和良种推广应用提供理论支撑和优质材料。 相似文献
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本文对香杨×黑杨F_1有关性状的遗传参考进行了初步研究。从香杨×黑杨F_1中初选出5个无性系进行随机区组试验,据5年生胸径、树高和材积的方差、协方差理论成分估算有关遗传参数,结果表明,三个性状均可作为选择性状,但以材积为结果性状时,胸径做为选择性状较树高更为可靠。为此以胸径为选择性状进行选择并估算了遗传增益和杂种优势。 相似文献
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《林业实用技术》2019,(12)
通过对5年生杉木(Cunninghamia lanceolata)全双列杂交试验林的调查与分析,研究杉木若干性状的遗传与变异规律,以期为杉木育种提供科学依据,为建立少数几个系的杂交种子园提供亲本材料。通过对杉木若干性状进行系统地研究,获得了不同性状的遗传变异性大小:通常杉木研究性状具有中度以上的遗传力和窄的变异性;生长与形质性状间具有复杂的遗传相关。构建主成分选择指数,配合力分析揭示杉木主成分指数,这一综合性状的基因作用方式是非加性基因效应超过了加性基因效应,虽然加性基因效应也有一定作用;最后评选出4个优良的杂交组合和3个一般配合力高的亲本。鉴于杉木全双列杂交试验的遗传分析,特别是主成分指数的配合力结果,揭示选用经过单亲和双亲测定与评选的亲本,再进行双列杂交试验时,非加性遗传方差会大大超过加性方差;杉木应以杂交育种的方式进行多性状、多世代连续改良,以杂交种子园来利用杉木多性状遗传改良成果。 相似文献
4.
以杜仲35个无性系为研究材料,以5 a的性状测定数据为基础,对杜仲无性系叶片性状、树皮性状、果实性状、产量进行了遗传参数估计和改良效果分析.结果表明:叶片性状、树皮性状、果实性状、产量性状的重复力均较高,为0.54～0.97.表型变异系数叶片性状和树皮性状的较低,而果实性状和产量性状的相对较高.分别根据叶片含胶率、树皮含胶率、果实含胶率和产量筛选出了4个高产胶无性系,其遗传改良效果分析结果表明,叶片含胶率、树皮含胶率、果实含胶率和产量的遗传增益分别为21.10%、54.95%、12.17%和55.22%.说明这些性状的遗传改良效果均较好,所筛选出来的无性系可以大大提高产胶量和果实产量,该研究为杜仲高产胶优良无性系的进一步栽培和推广提供了重要的理论依据. 相似文献
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表型性状遗传多样性是植物遗传多样性的重要组成部分,研究植物表型性状遗传多样性对于开展植物遗传资源的保护与利用具有重要意义.本文对红山茶组12个物种的6个质量性状、5个数量性状以及茶果3个品质性状进行分析,结果显示各质量性状重要程度是果实质量性状>叶片质量性状;各数量性状变异程度较大,具有较高的遗传多样性,多样性指数1.43~1.91,其中3个果实经济性状(仁含油率、油酸含量、亚油酸含量)的多样性值占数量性状多样性总值的37.12%.聚类分析结果表明物种聚类与原种地理分布存在关联. 相似文献
9.
为了解南方型黑杨种质材料的表型及生长性状遗传多样性,丰富黑杨种质资源遗传基础,并进一步为南方地区黑杨种质资源定向选育提供参考,选取地径、苗高、叶面积、叶长、叶宽、叶柄长、叶绿素、侧枝数、叶厚、单株总叶片、叶片干质量共11个树体性状及生理指标,同时观测记录了每个无性系的生长期和抗性,对62份南方型黑杨种质资源的13个性状进行了遗传多样性分析。结果表明:62份黑杨资源分成7个类群,各类群材料根据不同性状的相似性进行聚类,整体比较分散,具有较高的分化强度。13个性状的多样性指数H′变化范围介于0.587~1.550之间,平均值为1.098,叶片相关性状以及生长期遗传多样性较丰富。主成分分析将相关变量转化为叶片形态、单株叶片数量、抗性及生长期、侧枝数4个主成分,涵盖了13个测定性状80.953%的遗传信息。本研究首次从表型及生长相关性状等方面探明了南方型黑杨的遗传多样性,对于充分发掘黑杨资源优良基因型,进一步开展南方型黑杨遗传改良工作具有重要意义。 相似文献
10.
利用ISSR标记分析了马尾松测交亲本遗传距离与11年生子代生长性状的相关性,发现亲本遗传距离在0.158 - 0.657范围时与子代各生长性状的相关性较低,而当遗传距离在0.264 - 0.529区间时与子代胸径、材积性状的相关系数分别为0.493和0.469, 一元线性回归拟合效果均达显著水平,表明随着亲本间遗传距离的增大,马尾松胸径、材积等性状呈显著线性增加。当遗传距离位于0.357 - 0.529区间时,遗传距离与生长性状的相关系数比其在0.264 - 0.529区间时的相关系数增加,与材积性状相关系数为0.635。本研究证实马尾松亲本间ISSR分子遗传差异对于子代生长预测和杂交亲本选配具有一定参考价值,但由于相关系数较小,尚不能提供决定性作用,而在本研究基础上建立更完善的分子标记实验模型,将利于有效进行马尾松杂种优势辅助聚合。 相似文献
11.
《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
12.
《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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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
14.
《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
15.
《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
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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
17.
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(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
19.
《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
20.
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