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1.
Gunnar Jansson Jon Kehlet Hansen Matti Haapanen Harald Kvaalen Arne Steffenrem 《Scandinavian Journal of Forest Research》2017,32(4):273-286
Plantations of genetically improved forest trees are critical for economic sustainability in forestry. This review summarizes gains in objective traits and the resulting economic impact of tree breeding programmes in Scandinavia and Finland. Genetic improvement of forest trees in these countries began in the late 1940s, when the first phenotypically superior plus-trees were selected from natural environments. The main findings from this review are that (i) tree breeding can increase volume growth in the range 10–25%, and (ii) the bare land value associated with genetically improved trees gives a better return on investment and a shorter rotation period compared to the unimproved forests. As some Nordic countries are quite dependent on the forest industry, breeding programmes that have resulted in economic gains have been beneficial for society. Growth and wood quality traits are often adversely correlated, and the weighting of traits from an economic perspective could provide an index for determining maximum profit from breeding. Tree breeding faces an array of challenges in the future, such as changes in silviculture, climate, new pests and diseases, and demand for wood-based products. 相似文献
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我国是全球第一大木材进口国和第二大木材消费国,木材对外依存度已连续多年超过50%。然而,我国每公顷森林年均生长量约为林业发达国家水平的一半,这说明我国林木育种水平与林业发达国家相比仍有较大差距。因此,加强林木的规模化试验与精准遗传评估,通过林木良种的精确选育与推广对提高我国人工林的生产力水平具有重要意义。基因型与环境互作是林木规模化试验与精准遗传评估的重要环节之一。基因型与环境互作(G×E)是指基因型的相对表现在不同环境下缺乏稳定性,表现为不同环境下基因型排序变化或基因型间差别不恒定。现有研究证实,林木G×E很普遍且通常很大,要找到具有广泛适应性的优良基因型往往较困难。由于G×E会减小遗传力和遗传增益,因此了解G×E效应及其驱动环境因子,对育种设计、良种选育和种苗配置至关重要。本文归纳了目前研究G×E的主流分析方法(包括因子分析法、BLUP-GGE联合分析法)和遗传力的估算方法,也比较了这些G×E分析方法(包括稳定性分析、B型遗传相关、AMMI分析、GGE双标法、因子分析法和BLUP-GGE联合分析法)的优缺点,其次综述了全球重要经济树种(湿地松、火炬松、欧洲云杉、巨桉、辐射松、花旗松,等)近年来在生长性状(胸径、树高、材积,等)、形质性状(通直度、分枝角度、分枝大小,等)和材性性状(木材密度、弹性模量,等)的G×E研究进展,进而讨论了林木G×E的环境驱动因子及其应对策略,最后针对林木G×E研究新方法开发、加强多性状的G×E分析以及将基因组选择融入G×E分析方面对未来研究方向提出建议:1)新的林木遗传分析模型与G×E分析的联合应用;2)林木多环境、多性状的G×E的模式和幅度;3)特定环境的林木基因组育种值的精准估计。 相似文献
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我国东北、内蒙古国有林区经过40年的建设和发展, 已步入了重要的转折时期, 其主要表现为: 森工企业的森林资源危机和经济危困。本文从森林资源的内涵意义入手, 阐述了"两危"的本质特征、表现形式; "两危"形成的必然性及其发展前景, 分析了林业经济建设必须遵循自然规律和经济规律, 协调资源、人口与社会经济的发展, 为缓解东北、内蒙古国有林区"两危"提供理论依据。 相似文献
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常规林木育种研究现状与发展趋势 总被引：12，自引：1，他引：11
常规林木育种最重要的途径是利用树种现有的自然遗传变异以及利用育种手段创造遗传变异,通过选择获得优良品种,使目的性状在遗传上得到改良。把常规育种的分阶段遗传试验如种源试验、子代测定等整合到同一试验,以及对多个性状的综合选择,使传统的田间试验所需时间大大缩短,缩短育种周期,加速育种进程,为育种项目带来巨大的经济效益。另一方面,随着计算机技术的迅速发展,进行复杂模拟和运算的能力不断提高,使育种值估计和预测的精确度越来越高,也使采用复杂的试验设计成为可能。随着许多林木育种项目进入高世代,多世代育种受到日益广泛的重视。在育种群体或种子园内,通过建立优化育种模型对遗传材料进行优化配置。未来林木育种策略和育种目标将会把育种成本等经济因素考虑在内,根据育种项目的经济效果来确定育种方法。育种新技术必须以常规育种项目为依托,才能真正发挥作用。 相似文献
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工业人工林发展与材性育种 总被引：8，自引：1，他引：7
文中介绍了世界上因工业人工林发展的需要所开展的材性变异和改良研究的现状及基本成就,并针对我国即将兴起的材性育种的需要提出了材性育种中的一些原则性考虑。 相似文献
6.
分子标记辅助选择在林木育种中的应用 总被引：8，自引：0，他引：8
历史上,数量遗传学被认为是指导林木育种的唯一有效工具,这有两个方面的原因：第一,在林木上具有重要经济价值的性状,如树干材积生长、木材纤维长度及适应性等,均是以数量方式遗传的性状,并且控制这些性状的每一个过程是假设受微效多基因所控制的;第二,林木具有很长的世代间隔,很高的遗传杂合性和很高的遗传负荷,这些特性限制了一些经典的遗传材料,如近交系,突变体及特异类型的产生。然而,传统的数量遗传学方法用于指导林木育种的实践并不是完美无缺的。林木个体高大,占地面积大,且大多栽植在非农用耕地上,这样的环境异质性在很大程度上影响性状遗传力的提高,有些林木树种人工杂交比较困难,很难获得足够大的家系,从而产生不平衡的交配设计。Ｎａｍｋｏｏｎｇ 和Ｒｏｂｅｒｄｓ（１９７６） 认为,不平衡的交配设计很难获得准确的遗传参数估计。到目前为止,大多数成功的林木育种方案往往都是基于对表型的简单选择。这种表型选择不能利用林木固有的非加性效应,以及对异质环境的反应潜能,因而育种效果是极为有限的。分子标记技术为现代数量遗传学的发展提供了新的方向。通过利用中性标记与影响数量性状的位点（ＱＴＬ） 之间的连锁关系,人们已经提出了一套统计方法用来鉴定重要的Ｑ 相似文献
7.
杨树工业用材林的定向培育 总被引：8，自引：0，他引：8
本文列泽了国外利用杨树作为工业用材和采取定向培育所取得的成功经验。讨论了我国杨树人工林发展的现状及存在的问题,为杨树人工林朝着具有“定向、速生、丰产、优质、稳定、高效”等目标发展提供了参考性建议。 相似文献
8.
[目的]在保证遗传力估算精确度较高的前提下,探讨对已有湿地松测定群体遗传力评估最经济有效的调查取样数量(样本量),为遗传选择提供最佳的遗传参数和选择策略。[方法]以61个湿地松22年生半同胞家系的胸径、树高等生长性状和木材基本密度、弹性模量等材性性状测定值为试验数据,利用ASReml-R软件混合线性模型的限制性极大似然估计法(REML)估算各性状在不同参试样本量下的遗传力及其标准误。通过比较分析在不同样本量下各性状遗传力及其标准误估算值的收敛性,讨论样本量对性状遗传力估算的影响,进而确定各性状遗传力评估所需的最少样本量。[结果]对于61个湿地松自由授粉家系测定林,当测定的家系数少于39个或者随机测量的单株数小于600株时,估算的遗传力极不稳定,标准误偏大,随着样本容量或家系容量的增加其精度与准确性逐渐增加;遗传力较低的性状其遗传力估计所需样本量普遍大于遗传力较高的性状。[结论]对本研究的测定群体而言,要获得精确度较高的遗传力估算值,所需测定的湿地松家系数应该大于39个或者随机测量的单株数大于600株;由于材性性状遗传力相对较高,其需要测定的样本量可相对少一些。本文为大型用材树种遗传力估算提供了一个具有参考价值的实例研究,结果及相应的研究方法对于类似遗传测定群体遗传参数估算具有参考意义。 相似文献
9.
[目的]研究广西国有东门林场25年生大花序桉种源生长与形质性状的遗传变异,筛选优良种源及单株,为大花序桉良种繁育及中大径材培育提供优质遗传材料。[方法]采用方差分析、构建性状选择指数方程综合分析等方法,对11个大花序桉种源进行生长与形质性状遗传变异分析及选择。[结果]表明:大花序桉胸径(DBH)、树高(H)、单株材积(V)、树干通直度(ST)和树干圆满度(SF)在种源间呈极显著差异;上述5个主要性状的种源遗传力(H2)为0.634 0.895,单株遗传力(h2)为0.136 0.342;以DBH、H、V、ST和SF 5个性状指标构建大花序桉种源/单株选择指数方程,按标准选择出4个优良种源和13株优良单株,优良种源平均材积遗传增益达11.2%,优良单株平均材积遗传增益达29.7%,选择效果尚好。[结论]大花序桉5个主要性状遗传变异在种源水平受中度至较强遗传控制,在单株水平受弱度遗传控制。优良种源D47、S14127、B47和S12195生长材性兼优,可用作培育优质中大径材。 相似文献
10.
我国经济林用材树种的材性和培育 总被引：3，自引：0，他引：3
发展经济林类用材树种是经济林与用材林的交叉领域,在我国潜力很大。文中就对该交叉领域的认识、发展的必要性、木材性质特点以及应采取的措施等方面做了介绍,目的在于推进人工经济林木材性质和定向培育的研究进程,加快发展步伐。 相似文献
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12.
关于发展人工林与建立人工林业问题探讨 总被引：13，自引：1，他引：12
全世界森林面积为 34 5 4× 1 0 8hm2 ,其中 3%是人工林。人工林是重要的森林生态系统 ,在木材生产、环境保护和景观建设中具有重要功能和作用。人工林在生产功能方面的补偿作用 ,使天然林可以更好地发挥生态环境价值、森林娱乐和生物多样性保护功能。人工林可持续经营的前提是遗传材料的正确选择与营林实践艺术的结合以及保证这种结合的林业政策。愈来愈多地使用外来树种营建人工林是全球趋势。人工林对于环境和生物多样性的影响 ,可以通过合理的规划和经营措施得到解决。林木育种与遗传改良和经营制度的技术创新是不断提高人工林生态系统生产力的动力。人工林的可持续经营是一个十分复杂的问题 ,中国人工林实现可持续经营面临技术和体制两方面的挑战 ,但是 ,根本出路在于林业经济体制的改革 ,象农业那样 ,在市场经济环境中实行人工林产业化经营 ,建立人工林业 (Forestplantationindustry)。 相似文献
13.
Washington J. Gapare Brian S. Baltunis Miloš Ivković Harry X. Wu 《Annals of Forest Science》2009,66(6):606-606
14.
林木遗传育种基础研究热点述评 总被引：1，自引：0，他引：1
林木由于世代周期长、个体高大、遗传负荷高等自身固有的一些特性,一直被认为是一种非常难以操作的遗传学材料,导致林木遗传育种在基础研究方面远远滞后于模式动、植物和其他重要作物,成为限制林木遗传改良进程的主要因素。分子育种是突破林木育种周期长的关键技术,通过基因组学研究,分析和阐明林木基因的功能是进行林木分子育种设计的前提。近年来随着生命科学领域新技术的快速发展,林木遗传育种基础研究也出现一些新的热点。本文主要阐述林木基因组和功能基因组学、连锁与关联分析、木材形成机制及分子育种技术的研究进展,虽然目前相关研究成果实际应用的条件还不成熟,但作为技术储备是急需加强的研究方向。 相似文献
15.
试论发展我国工业人工林的若干对策 总被引：4，自引：1，他引：4
本文从我国林业面临的“生态和资源危机”是由于我国是个少林国家而为满足工业和农村发展需要,长期以来不得不大量采伐木材生产力低而生态效益高的天然林所造成的这一现实出发,支持只有有计划地发展专用工业人工林才能缓解“两危”的论点。提出了发展我国工业人工林的若干对策:制订可行的长、短期配合的发展计划;根据工业需要进行造林树种的调整;进行工业用材林地所有制的改革;林业投资集中于工业用材林;生态效益林由国家投资;发展无性系林业等。 相似文献
16.
《Scandinavian Journal of Forest Research》2012,27(2):161-170
Wood density and tracheid length are two traits that significantly affect wood products. Genetic correlations were estimated to evaluate the effect on these traits from a selection for traits included in the Swedish Pinus sylvestris L. breeding programme. Measurements from a non-contiguous single-tree plot progeny trial with controlled matings between 30 parent trees was used. Heritabilities were high for the wood traits, intermediate for the growth capacity traits and low for the stem traits, with the exception of branch angle. Wood density showed no or non-significant negative genetic correlations with the growth capacity traits and a positive correlation with relative branch diameter. Tracheid length showed positive genetic correlations with height and a positive correlation with relative branch diameter. A selection that increased height growth at the age of 13 yrs by 10% was expected to decrease mean wood density at 33 yrs by 1%. The expected correlated response to tracheid length from the same selection was a 3% increase in the juvenile and mature wood. 相似文献
17.
Fikret Isik 《New Forests》2014,45(3):379-401
Using large numbers of DNA markers to predict genetic merit [genomic selection (GS)] is a new frontier in plant and animal breeding programs. GS is now routinely used to select superior bulls in dairy cattle breeding. In forest trees, a few empirical proof of-concept studies suggest that GS could be successful. However, application of GS in forest tree breeding is still in its infancy. The major hurdle is lack of high throughput genotyping platforms for trees, and the high genotyping costs, though, the cost of genotyping will likely decrease in the future. There has been a growing interest in GS among tree breeders, forest geneticists, and tree improvement managers. A broad overview of pedigree reconstruction and GS is presented. Underlying reasons for failures of marker-assisted selection were summarized and compared with GS. Challenges of GS in forest tree breeding and the outlook for the future are discussed, and a GS plan for a cloned loblolly pine breeding population is presented. This review is intended for tree breeders, forest managers, scientist and students who are not necessarily familiar with genomic or quantitative genetics jargon. 相似文献
18.
Wood density,phytomass variations within and among trees,and allometric equations in a tropical rainforest of Africa 总被引：1，自引：0，他引：1
M. Henry A. Besnard W.A. Asante J. Eshun S. Adu-Bredu R. Valentini M. Bernoux L. Saint-André 《Forest Ecology and Management》2010
The development of tree allometric equations is crucial to accurate forest carbon assessment. However, very few allometric equations exist for sub-Saharan Africa and as a result generalized allometric equations, often established for forests in other continents, are used by default. The objectives of this study were (1) to propose a sampling methodology and calculation procedures to assess biomass for tropical tree species of contrasted tree shapes in Africa, (2) to identify factors affecting within and between trees wood density, (3) to propose an allometric model that integrates these factors and (4) to evaluate the reliability of using generalized allometric equations in this type of forests. Models were developed to predict wood density and phytomass of the trees based on the harvesting of 42 trees from 16 species, representing three guild status in the wet evergreen forest of Boi Tano in Ghana. Results indicated that the wood density was highly influenced by the tree species, guild status, size of the tree and pith to bark distance. Dry mass of a tree was influenced by diameter at breast height, crown diameter and wood density. The wood density depends on the position of the wood within the tree and the guild status considered. The use of generalized allometric models in literature is limited by the specific climate zone, the consideration of tree height and species specific wood density. In considering those factors, using generalized allometric equations could result in an error of 3%. Further research should better consider the bigger trees and the influence of the topography and ecosystem history. 相似文献
19.
Luis A. Apiolaza 《New Forests》2014,45(3):439-448
This article uses the breeder’s equation, which predicts genetic gain in breeding programs, to frame a general discussion on breeding objectives, new phenotypic techniques for selection criteria and statistical models as applied to short rotation species. Short-rotation breeding programs are increasingly working on wood quality traits; however, we keep on treating them as if they were growth traits. Understanding tree-level patterns of variation can lead to alternative strategies for evaluation, analysis and inclusion in breeding objectives; which I describe in a pilot application in Pinus radiata in New Zealand. Finally I discuss the relationship between the breeder’s equation and formulations of linear mixed models, using genotype by environment interaction as example, to show the interplay between genetic evaluation and breeding strategies. There is tension between increasing complexity (and the implicitly promised flexibility), information recovery (as more parameters are poorly estimated) and computational demands. The latter can be tackled through much more computer power (a never-ending endeavor), exploiting features of the problem or moving back to a lower complexity level. 相似文献
20.
Simon P. Whittock Gregory W. Dutkowski Bruce L. Greaves Luis A. Apiolaza 《Annals of Forest Science》2007,64(3):239-246
A system where carbon sequestration was directly dependent upon biomass production in a plantation was modelled to assess whether economic breeding objectives for the genetic improvement of Eucalyptus globulus were sensitive to potential revenues from carbon sequestration. Carbon dioxide equivalent accumulation in the biomass (CO2e) of the Australian E. globulus plantation estate established between 2004 and 2012 was estimated. Total carbon dioxide equivalent (CO2e) accumulation was in the order of ～146 t CO2e ha?1, of which 62 t CO2e ha?1 were tradable in 2012 (the 1st Kyoto Protocol commitment period) and a further 30 t CO2e ha?1 were tradable in 2016 (a hypothetical second Kyoto protocol commitment period). The correlated response of breeding objectives with and without carbon revenues (ΔcG h 1) never fell below 0.86 in sensitivity analysis, and the mean was 0.93. Where economic breeding objectives for the genetic improvement of Eucalyptus globulus for pulpwood plantations are based on maximizing net present value by increasing biomass production, the consideration of carbon revenues in economic breeding objectives will have no significant effect on the relative economic weights of the key economic traits, wood basic density and standing volume at harvest. 相似文献