分子标记技术在桉树遗传育种中的应用

分子标记技术作为现代育种手段已广泛应用于桉树育种,常用的标记包括RAPD、ISSR、EST等.我国桉树分子育种在绘制指纹图谱、构建连锁图谱、数量性状定位等方面取得了丰厚的成果,展望了分子标记技术在提高桉树育种效率、缩短桉树育种周期方面的应用前景.     

油桐DNA快速提取以及RAPD扩增初步研究

油桐（AleuritesfordiiHemsl）是我国重要的工业油料树种。在不断进行的遗传育种过程中,筛选是一项耗时费力的主要工作内容。传统的筛选工作主要依据的遗传标记是成年期的经济性状及其连锁住状,包括外观形态指标和生理指标。由于这些遗传标记往往是模糊的,信息量极少,同时林木育种周期太长,阻碍了油桐等经济树种的品种选育。随机扩增多态性DNA（RAPD）标记技术是一种新兴的分子遗传标记技术,通过提供大量的DNA标记信息迅速推动了生物群体遗传学研究及遗传育种选育的发展［’1。与同工酶标记、RFLP标记技术等相比,具有征作简单…     

林木遗传图谱构建研究进展*

综述了利用分子标记技术构建杨树、松树和桉树等速生树种遗传连锁图的研究进展，并提出了当前林木遗传作图中存在的主要问题。     

桉树分子育种研究进展

桉树是全球广泛引种栽培的优良的用材、能源、纸浆材等树种,为工业发展提供高质量的木质原材料,目前世界桉树人工林的面积2000万hm^2.对桉树分子育种的研究、应用和前景等进行了综述.介绍了桉树现代育种的主要的特征以及分子标记在育种上的主要应用,概述了桉树基因组、包括数量性状座位遗传图谱构建、转基因研究进展,并就分子育种技术在桉树品种改良应用中存在的问题和发展前景进行了阐述.     

生物技术在按树遗传育种中的应用

为全面了解现代生物技术在桉树遗传育种中的作用，本文概述了桉树组织培养，基因工程转化，桉树遗传图谱构建，数量性状位点（QTL）的定位，桉树DNA指纹图谱分析，分子水平系统发育研究，遗传结构和遗传多样性等方面的研究现状，探讨了生物技术方法和手段在改良桉树种质资源，培育新品种等方面的重要作用。     

分子标记技术在林木遗传育种中的应用

分子标记是一种新型的遗传标记,它为包括林木在内的植物遗传育种研究提供了新的手段,在缩短育种周期、提高育种效益等方面展现了广阔的应用前景。本文着重介绍分子标记技术在林木遗传育种中的应用：（１）指纹图谱绘制和基因型鉴定;（２）种质资源和育种群体的遗传结构分析;（３）遗传连锁图谱构建;（４）数量性状定位;（５）分子标记辅助选择;（６）目的基因定位与分离。     

生物技术在桉树遗传育种中的应用

为全面了解现代生物技术在桉树遗传育种中的作用,本文概述了按树组织培养、基因工程转化、桉树遗传图谱构建、数量性状位点(QTL)的定位、桉树 DNA 指纹图谱分析、分子水平系统发育研究、遗传结构和遗传多样性等方面的研究现状,探讨了生物技术方法和手段在改良桉树种质资源、培育新品种等方面的重要作用。     

SRAP标记及其在林木遗传育种研究中的应用前景

相关序列多态性（SRAP）是近年发展起来一种基于PCR的新型DNA分子标记技术。该文介绍了SRAP的原理与方法,阐述了SRAP标记在植物遗传育种研究中的应用进展,展望了其在林木遗传育种上的应用前景。     

松树分子标记辅助育种研究进展

松树是世界上森林生态系统和人工林的重要树种,松树的遗传改良开展早,进展快,成效大.分子标记技术为缩短育种周期,提高育种效率提供了有力的工具.本文回顾了世界上松树分子标记遗传图谱构建、比较遗传作图、数量性状位点定位和标记辅助选择的研究进展.已经构建遗传连锁图的林木有13个属,近40个树种,其中松树占40%,而大多数松树遗传图谱仍然是不完整的,不能覆盖全基因组;比较遗传作图显示松属树种具有高度的遗传保守性;数量性状位点(QTL)定位表明,大多数性状的遗传基础存在着主效基因,为开展分子标记辅助选择提供了良好的基础.杂种松部分重要性状的遗传控制中存在着树种效应,对标记辅助选择和育种策略的制订具有指导意义.     

DNA分子标记在蓝莓遗传育种研究中的应用

论述和分析了DNA分子标记技术在蓝莓亲缘关系、遗传多样性、遗传图谱构建、基因定位及品种鉴定等方面的应用,并概述了DNA分子标记在蓝莓遗传育种中的作用和应用前景,以期为蓝莓生物技术育种提供一定的理论依据。     

Application of Molecular Marking Technologies in Heredity Breeding of Eucalyptus

Two clonal trial stands of Chinese Fir （Cunninghamia lanceolata） were used in this study, one was 19-year-old stand which included 38 clones, and the other was 17-year-old stand including 102 clones.The statistical analyses showed that there were very significant genetic variations in height, DBH,volume and ratio of heartwood(R_hw),wood basic density（ρ_b ） of the clones in the two stands. The repeatability of clones was in median to high level,and the genetic CV was different over the all five traits.There were very significant phenotypic and genetic correlations among height,DBH and volume,and negative correlations among growth, R_hw andρ_b.The selection method experiment indicated that index selection could improve volume, R_hw andρ_b,showing synthetically superior selection effects compared to any individual trait selection methods.     

柽柳属植物遗传改良研究进展

柽柳属植物具有抗旱、抗寒、抗盐碱、耐水湿等特性,作为干旱区、半干旱区大面积沙荒地和盐碱化土地上广泛分布的一类重要灌木植物,以其独特的生物、生态学特征和重要的生态、社会经济价值成为学者的研究热点。文中综述了柽柳属植物种质资源遗传多样性、相关抗逆基因研究、育种技术以及良种繁育等方面的研究进展,指出在柽柳属植物分子生物学研究和品种培育工作中存在的问题,并提出柽柳遗传资源开发利用的建议,旨在为包括柽柳在内的干旱区主要植物资源遗传育种研究提供参考。     

Herbivory, pathogens, and epiphylls in Araucaria Forest and ecologically-managed tree monocultures

Over the last centuries, natural forests have been replaced by extensive and homogeneous tree monocultures that cause strong impacts on ecological interactions and ecosystem processes. We expect, however, that ecologically-sustainable management practices can help to mitigate these effects. This study investigates how the replacement of Araucaria Forest by ecologically-managed tree monocultures affects leaf damage patterns produced by external chewers, internal chewers, leaf miners, galling insects, and pathogens, as well as the incidence of epiphylls. The study was performed in the São Francisco de Paula National Forest (southern Brazil) on 12 1-ha plots of Araucaria Forest and ecologically managed plantations of Araucaria, Pinus and Eucalyptus. Overall, 9955 leaves of the understory community (up to 1 m tall) were sampled and analyzed. The mean and the frequency distribution pattern of leaf damage were very similar between Araucaria Forest and all three tree monocultures. Also, there was no difference between habitats in the percentage of leaves attacked by different feeding guilds of insect herbivores and by pathogens. Araucaria Forest had a higher percentage of leaves with epiphylls than Eucalyptus plantation, probably due to its shadier and moister microclimate. Ecologically managed tree monocultures sustain a wide variety of herbivorous insects, pathogens and epiphylls which helps the maintenance of key ecological interactions and the functioning of the ecosystem.     

Growth and production varies between pair-wise mixtures and monoculture plantations in North Viet Nam

The potential benefits of species mixture were investigated using pair-wise comparisons of four timber tree species in northern Viet Nam. Chukrasia tabularis, Canarium album, Michelia mediocris and Eucalyptus urophylla were grown in monocultures and in pair-wise mixtures. The trial was established as a randomized block design with each treatment replicated four times. Volume production gain or loss in mixtures was assessed by calculating a mixture index, which is defined as Relative Yield Total (RYT). At age 48 months, the trial indicated mixed performance with both positive and negative impacts of growing some species in mixtures compared to monocultures. The largest gain was shown in the mixture of a shade-intolerant species, Chukrasia with a more shade-tolerant species, Michelia (47% gain in relative yield), and Eucalyptus with Michelia (45% gain in relative yield) at the first 38 months. The other three mixtures tested, and which were not successful (i.e. had lower relative yields) at 38 months, was the mixture of all shade-intolerant species, including Chukrasia with Canarium, Canarium with Eucalyptus and Chukrasia with Eucalyptus. This suggests that species with different shade tolerances can form complementary pair-wise mixtures, but this changed significantly (P < 0.05) over the following 10 months. At age 48 months the RYT of Chukrasia with Michelia increased by 12%, those of Michelia with Eucalyptus decreased by 20% at 48 months compared to 38 months, suggesting that Eucalyptus should be thinned at around year 5 years. Likewise, the RYT of Michelia with Canarium declined significantly by 23% at 48 months. The RYT of other tested mixtures remained almost unchanged over time.     

Why do Pinus species have different growth dominance patterns than Eucalyptus species? A hypothesis based on differential physiological plasticity

It has been observed that Eucalyptus stands show high growth dominance levels while Pinus stands show null or low growth dominance levels. We hypothesized that this differential behaviour is linked to a higher degree of physiological-biochemical plasticity in Eucalyptus than in Pinus species related to photosynthetic capacity. This leads to an increment in growth efficiency (GE) difference between the largest and the smallest trees of a stand, and therefore to high growth dominance levels in Eucalyptus. To test our hypothesis we carried out a bibliographical survey and reanalyzed data from Pinus ponderosa and Pinus taeda plantations in Argentina. We found that some species within the genus Eucalyptus present higher growth dominance levels, physiological plasticity and GE differentiation than Pinus species. The mean maximum values of these traits reported for any Eucalyptus species were: growth dominance coefficient, 0.48; photosynthetic capacity increment when resource availability increases, 175%; GE difference between the largest and the smallest trees of a stand, 300%. Mean maximum values for the same traits reported for any Pinus species were 0.13, no phostosynthetic plasticity as the most frequent pattern, and 51%, respectively. In Pinus species the most frequent response to an increase in resource availability is characterized by an increase in leaf area or biomass, maintaining a similar photosynthetic capacity per unit area. However, it appears that in P. ponderosa there are some situations, characterized by a high degree of intraspecific competition, leading to a very high degree of GE differentiation which deserve future research. Although we did not find any study reporting simultaneously all variables concerning our hypothesis (growth dominance, growth efficiency differentiation and physiological plasticity) any of the circumstantial evidence found in the bibliography contrasts our hypothesis.     

金合欢属植物组织培养研究进展

金合欢属植物生长速度快、产量高、材质好、适应性强、用途广,在我国南方林业生产中占据重要地位。掌握该属植物的组织培养技术,对促进其产业发展具有重大意义。文中从外植体、基本培养基、培养条件、植物生长调节剂、组培苗移栽等方面简述20世纪80年代以来金合欢属植物组织培养技术的研究进展,并就组培快繁中存在的主要问题提出相应的解决方法,同时提出今后的研究展望,以期为建立金合欢属植物高效组培体系及工厂化育苗提供参考。     

木荷1代育种群体遗传多样性分析

木荷为我国亚热带地区主要的珍贵优质阔叶用材树种和生态防护树种.利用筛选的14对多态性强的SSR引物,对木荷1代育种群体中来自15个产地133个亲本进行遗传多样性分析,为其优异种质资源保存、杂交亲本选配及新种质创制提供科学依据.结果表明:14对引物共扩增86个位点,每对引物检测到的等位基因数(Na)变异范围为2～11个,平均等位基因数(Na)为6.14个,平均有效等位基因数(Ne)为3.23个,平均观察杂合度(Ho)为0.572 0,平均Shannon信息指数(I)和平均Nei's基因多样性指数(Nei)分别为1.224 7和0.599 0,说明木荷1代育种群体具有丰富的遗传多样性,其中,福建建瓯产地遗传多样性最高,浙江遂昌产地遗传多样性最低.木荷1代育种群体中成对亲本间遗传距离为0.023 3～1.633 8,平均为0.6067.不同产地遗传多样性与纬度呈显著的负相关关系(r=-0.5162,p=0.048 9).通过UPGMA聚类,可将133个育种亲本分成3个类群,其中,类群3又分为4个亚类群.木荷亲本选配时,应充分考虑优树的产地来源.     

Plant regeneration by somatic embryogenesis in Eucalyptus spp.: current status and future perspectives

Forest tree improvement programs benefit from the emergence of new biotechnological strategies that complement plant developmental biology and discovery of genes associated with complex multigenic traits. Recently, significant progress has been made in the area of plant regeneration via somatic embryogenesis (SE) for economically important tree species (e.g. pines). These advances have opened up new scenarios for deployment of new high-performance clonally replicated planting stock to forest plantations and may also be a valuable tool for the development of efficient gene transfer techniques. Although high rates of plant propagation from axillary shoot proliferation can be achieved easily in many Eucalyptus species, even higher multiplication rates through SE have been recorded in other tree species. If the clonal propagation of Eucalyptus through SE proves to be an effective propagation method, it has the potential to meet the increasing industrial demands for high-quality uniform materials and to rapidly capture the benefits of breeding programs. Since 2002 a reproducible protocol for SE induction from mature zygotic embryos of E. globulus has been available. However, for SE to be useful in E. globulus improvement programs, the frequency of SE initiation, maturation, germination and acclimatisation needs to be improved and controlled. If this technology could be extended to elite germplasm, it would become an economically feasible tool for large-scale production and delivery of improved planting stock. This is one of the greatest current challenges in Eucalyptus tissue culture. In this review we update the most important aspects of SE in Eucalyptus with particular emphasis on E. globulus. We highlight both genetic control and the influence of different environmental factors in the SE process (e.g. medium composition, antioxidants, light and plant growth regulators), from induction to plant acclimatisation in both primary and secondary SE.     

山桐子自然群体表型性状变异分析

山桐子(Idesia polycarpa Maxim.)属大风子科(Flacourtiaceae)山桐子属(Idesia Maxim.)植物,主要分布于我国长江流域、华北和西北南部的17个省区。另外,朝鲜、日本的南部也有分布[1]。山桐子树干通直,树形美观,生长迅速,适应性强,材质优良,3年生实生苗木即可挂果,是我国南方主要城市园林绿化和用材树种之一.研究发现,山桐子果实含油率及油中不饱和脂肪酸含量较高,而不饱和脂肪酸中尤以亚油酸含量最高[2-3].