葫芦科瓜类作物分子标记辅助育种研究进展

综述了几种常用分子标记在葫芦科瓜类作物遗传图谱构建、重要性状基因定位、遗传多样性及亲缘关系分析、分子标记辅助选择及在葫芦科遗传育种中的应用,对目前葫芦科遗传育种中应用分子标记技术存在的问题和解决方案进行了探讨,并对葫芦科分子标记辅助育种的前景做了展望。     

作物分子标记辅助选择的研究进展、影响因素及其发展策略

随着分子标记技术及其检测手段的发展,开发和应用成本的降低,分子标记辅助选择(MAS)在作物育种上的应用优势日益明显。本文综述了近年来MAS在基因聚合、基因转移和数量性状改良上的研究进展。总结了MAS的影响因素,包括标记与基因间的距离、目标性状的遗传率、群体大小、所用分子标记的数目、类型和相位等。并提出育种和定位同步进行、选择合适分子标记类型和数量、简化DNA提取方法、背景选择的逐步选择法、确定合适选择方案等MAS发展策略。     

农作物育种向分子设计育种迈步——访中国农业科学院作物科学研究所所长万建民

——分子设计育种的核心内容是什么？ 万：设计育种（breeding by design）的概念最早由Peleman J D于2003年提出．其策略是在基因定位的基础上,构建近等基因系,利用分子标记聚合有利等位基因．实现育种目标。其后,Varshney R K（2005年）提出基因组学辅助育种（genomics—assisted breeding）．旨在利用作物基因组学、蛋白质组学和代谢组学的生物数据,发掘和整合遗传资源的有利基因．借助生物信息学的力量让人们从全基因组分子水平上加快控制作物重要农艺性状的聚合,     

分子标记的种类及其在作物遗传育种中的应用

分子标记技术近年来发展很快,目前,常用的分子标记主要可以分为基于杂交的分子标记、基于PCR的分子标记、基于限制性酶切和PCR结合的分子标记以及新一代分子标记.本文对这几类分子标记中常用类型的基本原理进行介绍,并从分子标记在作物种质遗传多样性、基因定位和基因克隆以及分子标记辅助选择育种和分子设计育种中应用进行了阐述.     

小麦抗赤霉病研究现状与展望

小麦是我国最重要的口粮作物之一。在小麦生产所面临的各种病害中,赤霉病的发生具有愈来愈严重的趋势,引起小麦产业界的高度关注。近几十年来,科研人员在小麦抗赤霉病遗传育种以及防控技术领域进行了持续不懈的努力,在赤霉病病原菌致病基因、小麦赤霉病抗性基因定位、克隆及功能研究以及抗赤霉病分子育种等方面取得了重大进展。本文主要从赤霉病抗性基因资源的发掘和鉴定、不同抗源遗传基础解析、小麦赤霉病抗性基因、抗赤霉病分子标记辅助选择育种与基因聚合以及小麦抗赤霉病基因的克隆和功能研究等方面进行了综述,分析了目前小麦抗赤霉病研究中存在的问题,并提出应加强基因克隆、功能分子标记开发以及应用单体型辅助选择(HAS)和标记组辅助选择(MSAS)等小麦抗赤霉病研究的相关建议。     

SSR分子标记在作物遗传育种中的应用

SSR(simple sequence repeat)是建立在PCR技术上的一种广泛应用的分子标记,具有含量丰富、多态性高、共显性等优点。本文简要介绍了SSR分子标记技术的原理和特点,重点介绍了SSR分子标记技术在作物遗传育种中的应用,主要在作物遗传多样性、基因定位、分子辅助标记、遗传图谱构建、品种鉴定和纯度鉴定等方面进行阐述。     

高粱遗传转化研究进展

高粱（Sorghum bicolor）是一种重要的多用途作物, 其遗传转化研究对于高粱的分子育种和分子遗传学基础研究都具有重要意义。该文对高粱遗传转化的方法、标记基因、遗传转化的启动子和受体系统进行了综述, 并提出了今后高粱遗传转化应当集中研究的问题。     

西瓜甜瓜质量性状的分子标记与定位研究进展

分子标记在作物育种、资源遗传多样性分析、遗传图谱构建等方面有着广泛的应用,常见的分子标记方法主要有RFLP、RAPD、SSR、AFLP、SCAR、CAPS、SNP等.迄今为止,国内外学者已经利用分子标记技术对西瓜和甜瓜的20多个质量性状进行了标记和定位.本文主要对西瓜和甜瓜质量性状的分子标记和定位研究进展进行了综述,发现RAPD标记使用最多,而更具优势的SSR标记使用较少;对抗病虫等育种相关的基因研究较多,且多数标记遗传距离偏大,达不到图位克隆的要求,而对西瓜和甜瓜遗传基础相关的基因研究较少.     

观赏植物分子标记研究进展

分子标记是继形态学标记、细胞学标记和生化标记之后发展起来的一种新的遗传标记。简要综述了分子标记技术在观赏植物种质资源遗传多样性评价、种质鉴定、亲缘关系的演化及分类、系谱分析、遗传图谱构建、基因定位、分子标记辅助选择育种等领域的研究进展,探讨了分子标记在观赏植物遗传育种上存在的问题。     

黄瓜分子标记辅助育种研究进展

本文综述了不同分子标记技术在黄瓜遗传连锁图谱构建、重要性状相关基因的定位、种质资源遗传多样性分析和亲缘关系鉴定、分子标记辅助选择、种子纯度与活力鉴定及其在黄瓜遗传育种等方面的应用,讨论了目前黄瓜遗传育种中应用分子标记技术存在的问题和今后育种工作的重点,并对黄瓜分子标记辅助育种的前景作了展望。     

分子标记辅助聚合两个棉纤维高强主效QTLs的选择效果

利用长江流域推广品种泗棉3号和优异纤维种质系7235为育种亲本,配置了系统育种和修饰回交聚合育种两套群体。基于来自7235的2个高强纤维主效QTL的分子标记,在上述育种群体中进行了分子标记辅助选择效率研究。高强纤维主效QTLfs1是利用(7235×TM1)F2分离群体,通过集团混合分离法检测到的,它可解释纤维强度表型变异的30%以上。高强纤维主效QTLfs2最初是利用(HS42710×TM1)F2分离群体检测到的,它可解释纤维强度表型变异的12.5%以上。进一步的研究表明,该QTL也位于7235优质系中,但与QTLfs1非等位。2套育种分离群体的2个高强纤维主效QTL的分子标记辅助选择效果表明:QTLfs1在不同环境条件下均稳定表达,它对不同遗传背景的育种群体均有显著的选择效果。尽管QTLfs2的选择效果低于QTLfs1,它在高世代育种群体中也表现较高的选择效率。利用分子标记辅助选择具有一定遗传距离的QTLfs1区间,其纤维强度的选择效率将大大增强。通过分子标记对位于不同连锁群上的2个QTL聚合选择,其中选单株的纤维强度显著提高。研究结果为利用分子标记辅助聚合优质QTL提供了成功实例。     

Potential for marker-assisted selection for forest tree breeding: lessons from 20 years of MAS in crops

For the most part, molecular markers and detection of quantitative trait loci have been developed for forest tree species in view to performing marker-assisted selection (MAS). However, MAS has not been applied to forest trees until now. In parallel, some success stories of MAS in crop breeding have been reported. Recently, genotyping techniques have undergone a tremendous increase in throughput, moving the trend from MAS to genomic selection. We analyzed 250 papers reporting the use of MAS in plant breeding and found that the most popular schemes used were gene pyramiding and marker-assisted backcross manipulating a single or very few genomic regions which have a major impact on crop value. We reviewed theoretical and simulation studies to identify the parametric space in which MAS is expected to bring about significant advantages over phenotypic selection. Then, we tried to explain why MAS has not been applied to forest trees and discuss the opportunities offered by recent advances in these species.     

基于单片段代换系的水稻穗长QTL加性及其上位性效应

穗长是影响水稻(Oryza sativa)产量的重要因子之一, 研究水稻穗长QTL间的上位性效应对于发掘水稻产量潜力具有重要意义。该研究以16个单片段代换系(single segment substitution lines, SSSLs)和15个双片段聚合系(double segment pyramiding lines, DSPLs)为材料研究了水稻穗长QTL的加性及上位性效应。以P<0.01为阈值, 共检测到6个穗长QTL和9对基因互作座位。其中2个(Pl-2和Pl-10)是尚未报道的穗长QTL。穗长QTL互作后, 一些互作对的上位性效应与单个QTL的作用方式及效应大小各不相同, 预示着基因聚合后会产生不同的互作效应。该研究结果对于通过分子聚合育种手段改良穗长具有重要意义。     

小麦白粉病抗性基因的聚合及其分子标记辅助选择

采用了在早代进行抗性鉴定、淘汰感病株、保留抗病株继续种植、较晚世代（F4代）进行抗性鉴定结合分子标记辅助选择的策略,提高了选到聚合抗性植株的效率。利用与Pm2、Pm4α、Pm8、Pm21紧密连锁或共分离的RFLP标记和PCR标记（SCAR标记）,对含有这些基因的优良品系间配制的杂交组合的F4代进行了分子标记辅助育种选择,并结合抗性鉴定,筛选到14株Pm4α Pm2I的植株,16株Pm2 Pm4α的植株,6株Pm8 Pm21的植株。应该引起注意的是,Pm2 Pm4α对混合白粉病菌的抗性达到高抗至免疫水平,而Pm2和Pm4α单独存在时抗性较差,表明聚合抗病基因植株的抗性提高了,为培育具有持久性抗性的品系或品种提供了新思路,它在实践和理论研究上都将具有重要意义。     

Inducing drought tolerance in plants: Recent advances

Undoubtedly, drought is one of the prime abiotic stresses in the world. Crop yield losses due to drought stress are considerable. Although a variety of approaches have been used to alleviate the problem of drought, plant breeding, either conventional breeding or genetic engineering, seems to be an efficient and economic means of tailoring crops to enable them to grow successfully in drought-prone environments. During the last century, although plant breeders have made ample progress through conventional breeding in developing drought tolerant lines/cultivars of some selected crops, the approach is, in fact, highly time-consuming and labor- and cost-intensive. Alternatively, marker-assisted breeding (MAB) is a more efficient approach, which identifies the usefulness of thousands of genomic regions of a crop under stress conditions, which was, in reality, previously not possible. Quantitative trait loci (QTL) for drought tolerance have been identified for a variety of traits in different crops. With the development of comprehensive molecular linkage maps, marker-assisted selection procedures have led to pyramiding desirable traits to achieve improvements in crop drought tolerance. However, the accuracy and preciseness in QTL identification are problematic. Furthermore, significant genetic × environment interaction, large number of genes encoding yield, and use of wrong mapping populations, have all harmed programs involved in mapping of QTL for high growth and yield under water limited conditions. Under such circumstances, a transgenic approach to the problem seems more convincing and practicable, and it is being pursued vigorously to improve qualitative and quantitative traits including tolerance to biotic and abiotic stresses in different crops. Rapid advance in knowledge on genomics and proteomics will certainly be beneficial to fine-tune the molecular breeding and transformation approaches so as to achieve a significant progress in crop improvement in future. Knowledge of gene regulation and signal transduction to generate drought tolerant crop cultivars/lines has been discussed in the present review. In addition, the advantages and disadvantages as well as future prospects of each breeding approach have also been discussed.     

Whole-genome strategies for marker-assisted plant breeding

Molecular breeding for complex traits in crop plants requires understanding and manipulation of many factors influencing plant growth, development and responses to an array of biotic and abiotic stresses. Molecular marker-assisted breeding procedures can be facilitated and revolutionized through whole-genome strategies, which utilize full genome sequencing and genome-wide molecular markers to effectively address various genomic and environmental factors through a representative or complete set of genetic resources and breeding materials. These strategies are now increasingly based on understanding of specific genomic regions, genes/alleles, haplotypes, linkage disequilibrium (LD) block(s), gene networks and their contribution to specific phenotypes. Large-scale and high-density genotyping and genome-wide selection are two important components of these strategies. As components of whole-genome strategies, molecular breeding platforms and methodologies should be backed up by high throughput and precision phenotyping and e-typing (environmental assay) with strong support systems such as breeding informatics and decision support tools. Some basic strategies are discussed in this article, including (1) seed DNA-based genotyping for simplifying marker-assisted selection (MAS), reducing breeding cost and increasing scale and efficiency, (2) selective genotyping and phenotyping, combined with pooled DNA analysis, for capturing the most important contributing factors, (3) flexible genotyping systems, such as genotyping by sequencing and arraying, refined for different selection methods including MAS, marker-assisted recurrent selection and genomic selection (GS), (4) marker-trait association analysis using joint linkage and LD mapping, and (5) sequence-based strategies for marker development, allele mining, gene discovery and molecular breeding.     

中国肉牛分子与基因修饰育种研究进展

随着世界肉牛产业科技的快速发展,我国肉牛产业的整体水平得到明显提高并取得丰硕成果。肉牛育种技术实现了由常规杂交育种向分子标记辅助育种、全基因组选择育种和基因组修饰育种的技术跨越,揭示出大量与生长发育、肉质品质、繁殖与疾病等相关的候选基因与分子标记,并逐步应用于肉牛育种实践。与生长发育性状相关的基因或分子标记主要集中在生长激素基因、生肌调节因子家族、肌肉生长抑制因子和胰岛素样生长因子等;参与肉质形成的基因主要集中在脂肪酸运输与沉积相关信号通路、钙蛋白酶信号通路、生肌调节因子家族与肌肉生长抑制因子等;繁殖性状相关基因或分子标记主要集中在GnRH-FSHR-LH、生长分化因子9、催乳素受体和FoxO1等;抗病相关基因主要有MHC基因家族、TOLL样受体4基因等。目前,利用精准基因编辑技术已培育出促生长发育与提高肉品质的肉牛育种新材料。本文总结了近年来我国在肉牛分子与基因组修饰育种领域取得的研究进展,以期为我国肉牛遗传育种技术研究提供参考和借鉴。     

小麦抗白粉病基因Pm23的RAPD标记

小麦抗白粉病基因Pm23对世界上很多麦区流行的白粉病表现高抗或免疫.本研究以Pm23和Chancellor为抗感亲本,用集群分离分析法对抗性基因Pm23进行了RAPD分析,从320个十碱基随机引物中筛选到一个与Pm23紧密连锁的相引相标记OPE051100. 对F2分离群体进行RAPD分析表明,该标记与Pm23基因之间的连锁距离为10.65±3.25 cM.该标记可以有效用于小麦育种分子标记辅助选择中.     

抗稻瘟病水稻资源抗性基因Pita、Pib、Pi9以及Pikm的分布研究

利用抗稻瘟病水稻资源品种杂交,聚合多个抗性基因是培育持久抗稻瘟病水稻新品种的主要育种途径.利用分子标记技术对水稻抗性资源进行基因型鉴定是分子辅助聚合育种的基础.通过以亚华种业科学院稻瘟病病圃抗病水稻资源为材料,利用特异性分子标记对Pi9、Pita、Pib以及Pikm基因在水稻抗稻瘟病资源的分布进行了鉴定,初步建立了抗性基因数据库.同时对抗性基因及与抗性反应的相关性进行了探讨,结果表明以Pi9为主效基因,同时聚合Pita和Pib抗性基因能提高持久抗稻瘟病能力.