林木全基因组选择研究现状和应用

全基因组选择（GS）是利用覆盖全基因组的高密度遗传标记对复杂数量性状进行预测的育种方法。在林木种苗阶段根据基因组估计育种值（GEBV）可以利用GS进行个体选择,相比常规育种能增强遗传增益、加快选育进程。该方法无需定位与性状相关的数量性状位点（QTL）,相比分子标记辅助育种能极大地提高对微效位点的捕获功效,是具有巨大潜力的林木育种策略。文中系统介绍了GS的概念和优势,及其在林木中的研究现状和应用。我国林木GS研究处于初期阶段,可优先在常规育种较成熟的树种中开展研究,建立林木GS程序为其他树种提供范式。该综述有助于系统了解全基因组选择育种策略和研究进展,并为全基因组选择在林木育种中的应用提供理论和技术信息。     

关于山东林木遗传育种研究的思考与建议

根据国内林木遗传育种发展的现状与趋势，结合山东少年省的林木改良情况，讨论了育种策略、育种群体、有性与无性结合、育种区和区域试验、早期选择、多性状指数选择等问题，并提出一些建议。     

英国林业和林木育种研究现状及对我国林木改良的启示

本文概述了英国林业、林地利用、木材生产的过去和将来，林木育种研究内容，研究方法和主要研究成果，讨论中英两国在林木育种上差异。英国林木改良仍然以常规育种为主，同时综合林业生物技术育种，极力提倡由群体选择到个体选择的多层利用，最后就我国林木遗传改良工作提出几点建议。     

分子设计育种研究进展及其在林木育种中的应用

阐述了分子设计育种的概念、研究进展及其在动植物遗传育种中的应用。结合当前林木育种发展现状和育种目标, 介绍了开展林木分子设计育种的研究基础, 包括林木多基因转化技术研究、林木的分子标记辅助选择研究以及林木的生物信息学研究。针对林木分子设计育种现状, 分析了开展林木分子设计育种存在的相关问题, 并对今后的应用前景进行了展望。     

林木分子标记研究及其在育种中的应用

林木分子标记研究主要包括林木遗传连锁图谱构建、比较基因组研究、数量性状位点定位、标记辅助选择、系统演化及群体遗传变异和多样性等内容。迄今已有近 2 0个树种构建了基因组遗传连锁图谱 ,少数树种进行了目标性状位点定位研究 ,定位了为数不多的与分子标记连锁的数量性状位点。林木分子标记已在育种策略制定、辅助选择育种、基因型鉴别 ,以及目的基因的分离和克隆等分子育种研究中广泛应用。     

国际林木抗病育种的基本经验

文章概述了近４０年来国际林木抗病育种研究的经验。突出地介绍了作为抗病性育种主体的寄主和病原菌两个对立系的遗传和变异。认为从现有林分中选择高抗性个体是当前行之有效的抗病育种途径，而制定快速、有效和大批量人工接种鉴定入选个体抗性的方法又是抗病育种的中心。建议强化我国林木抗病育种的研究，以为发展集约人工林服务。     

浅谈林木育种的作用及发展策略

本文根据辽宁省林木衣种研究和良种生产的状况,阐述林木育种在林业建设中的作用及存在的问题,并提出今后发展策略或措施。     

常规林木育种研究现状与发展趋势

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。     

贵州马尾松高世代育种的问题与思考及遗传育种回顾

林木遗传育种进程中,有一个高世代遗传选择与育种的过程。在这个过程中,不同种类与不同性质的树种有着各自不同的特点。乔木、灌木、针叶、阔叶、用材、经济等等树种在进入高世代育种过程中,都会遇到一些具共性或特殊性的问题。本文以马尾松为例,基于对贵州马尾松遗传育种几十年的工作经验及出现的问题,提出高世代育种应该将多世代选择育种、多目标育种、种内(间)杂交育种、特异形状选择等贯穿于全过程中;提出完备的遗传育种研究体系中4个组成部分(4个群体)完整协调组建的重要性。通过这些工作,尽可能多的为不断推进的林木遗传育种研究与实践提供科学有效的物质基础与技术储备。     

高世代种子园营建研究的进展

作者综述了国际林木育种界近十多年就高世代种子园组建理论提出的第一代种子园发展有所不同的新见解，以及在若干重要树种改良项目中设计和采用的方法。其内容包括各种育种群体的优缺点评价，高世代种子园的类别，组成材料的来源和选择方法，种子园的组成成分和设计原则等。     

湿地松改良种子园无性系的遗传评价及新一轮育种亲本选择*

台山湿地松（Pinus elliottii）改良种子园营建于1988—1997 年，为评价该种子园无性系的遗传品质，项目组在种子园内采集无性系的自由授粉种子并营建子代测定林。文章根据1 块营建在台山市红岭种子园的湿地松子代测定林4、13、18 a 的生长性状数据，分析了改良种子园的现实增益，评价建园无性系的选择效果，选择新一轮的育种亲本，结果如下：3 个年份数据分析结果均显示，在生长量方面，改良种子园子代显著甚至极显著大于湿地松一代种子园子代，18 a 生时，树高、胸径、单株材积的平均现实增益分别为3.09%、4.70%、15.08%；根据单株材积育种值选择出优良亲本无性系6 个，其育种值介于0.050 5~0.186 1 m3，其中有5 个亲本无性系的遗传品质已得到多次验证，可以作为新一轮的育种亲本甚至是核心育种亲本；新选优树15 株，其单株材积育种值介于0.114 9~0.276 9 m3，可充实到新一轮的育种群体中。     

韦塔桉母本选择与控制授粉技术

桉树为纸浆材重要树种,其新品种培育已成为研究热点,韦塔桉作为桉树中的速生和适生种而备受育种家的关注.总结了韦塔桉常规育种程序和技术,内容包括选择韦塔桉为亲本的原因,亲本选择原则,亲本物候观察,亲本育种前高度控制方法,花粉收集、处理及保存方法,用于授粉的花粉活力测定、控制授粉中去雄处理及套袋授粉方法,割柱授粉法,种子的采收和贮藏方法等.韦塔桉育种总结可为其它桉树人工杂交及乔木树种的控制授粉提供技术及方法上的借鉴.     

Efficiency of breeding strategy where grandparents — but not parents — contribute equally to the breeding population

? The objective was to optimise the strategy for maintaining the genetic balance in long-term breeding where the grandparents contribute equally to the breeding population, but the parents do not.

? The annual genetic progress under a budget constraint was compared for a number of scenarios. The factors considered were: genetic parameters, recruitment population size, mating number per grandparent, cost of plants and parents, selection age and time components. Phenotypic selection forward was assumed. Using more parents than grandparents affects the testing population only, thus, gene diversity loss and breeding population size remain constant.

? Using larger number of parents than grandparents was a superior strategy at all scenarios tested. The strategy with 6 parents per grandparent and 1% of the tested plants selected on their phenotype at age 15 for further mating is recommendable. The strategy to choose 6 parents per grandparent was robust over a heritability range 0.05 to 0.2. At a higher heritability, the optimum number of parents per grandparent was 2 to 4.

? Using larger number of parents than grandparents has the potential to improve annual genetic gain in the magnitude of 50% compared to the strategies currently used for Scots pine in Sweden.

     

Increased forest production through forest tree breeding

Forest tree breeding started in the middle of the twentieth century and since then the use of improved forest regeneration material has become an essential part of forestry in many countries. This review describes methods and achievements of tree breeding programmes, which aim at increasing the quantities and improving qualities of wood-based raw materials through selection, field testing and controlled crossings. Most improved materials currently deployed are seed crops from first-generation phenotypic or tested seed orchards, which offer 10–25% gains in yield depending on the selection intensity of parent trees. Methods of vegetative propagation are developed intensively so that it could be applied to a larger range of species, because it offers high genetic gain and uniformity of the material. Genomic tools are also developed to enhance the efficacy of selection. Applications of genetic engineering are currently limited to research purposes. Forest tree breeding will be an integral part of bioeconomy in securing the production of good quality raw materials in large quantities and will have a significant economic impact on the profitability of forestry in the long term.     

Gains from selecting Pinus sylvestris in southern Sweden for volume per hectare

Abstract

An overall objective of the Swedish Scots pine (Pinus sylvestris L.) tree breeding programme is to increase volume production. Selection is based on height at young age as an indicator of future volume production. This study examined the relationship between height at young age and volume production in block-plots at older ages, and the sustainability of increased growth in volume per unit area using parent breeding values. The study included five trials with controlled pollinated progenies from 71 phenotypically selected plus-trees. Height and diameter were measured in the trials at ages ranging from 7 to 36 years. The genetic correlation between height at 9 years and volume growth per unit area at 30 years of age was 0.8. The additive genetic coefficient of variation for growth per area unit was 17% at the age of 30 years, i.e. first thinning. Based on the estimated parameters, selection of the best 25% genetic entries according to their height at age 9 years resulted in 13% volume gain at age of 30 years, while selection of the 10% best resulted in 18% volume gain. The plus-tree progenies had 12% higher volume growth per unit area than the unimproved commercial check lots, and this difference needs to be added to obtain the total gains. This means that selection of the 25% best parents gave a gain of 25% in volume per hectare compared with unimproved check lots.     

Variation analyses of controlled pollinated families and parental combining ability of Pinus koraiensis

To evaluate and select elite Pinus koraiensis parent combinations and offspring families, 34 full-sib families were evaluated. Variance analysis of tree height, diameter at breast height and volume showed no significant differences among each block, the interaction of block, male and female. The family heritability of all traits were high( 0.9). Phenotypic and genotypic coefficients of variance of height, diameter at breast height, and volume showed that the phenotypic coefficient of variation of volume in the same combination was higher than height and diameter at breast height, indicating that volume was the main factor determining excellent single plant selection. The female and male trees with the best general combining ability indicated that the optimal parental hybridization was not necessarily the optimal combination. In addition, the least parents of hybrid offspring performance were always relatively poor and should not be selected as hybrid parents. Additionally, we found there was no significant difference among the effects of female and male parents by random modelling, but there were significant differences by fixed modelling. The most significant effect of female-and male interaction, and the selection of better female or male parents in the test parent group should be efficient as well as the results of significant variation among them by fixed modelling. For the evaluated breeding population of P. koraiensis, the backward selection of excellent parent combinations or forward selection of excellent individuals as progeny should be the major breeding strategies.     

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。