从遗传学、基因组学回顾与展望杂种优势的应用

早在3 000年前人类就发现了杂种优势现象,但在农业生产上较大面积种植杂交种,是在20世纪30年代.经过大半个世纪的发展,杂种优势已在多种作物上推广,为解决人类的食品供给发挥了重大作用.回顾孟德尔遗传学的研究历史,从正向遗传学的方法所得结果,来研讨杂种优势利用的成效和机理.DNA分子结构的发现,使遗传学得到升华;基因组学又把遗传学带入崭新的领域,极大地促进了生物科学的创新.从现有分子生物学的研究和基因组分析所获得的知识将成为理解杂种优势的重要基础.同时,分析了杂种优势的研究方向和突破途径.     

双壳类功能基因和蛋白质组学研究进展

近十年来,双壳类在水产业中的地位日趋重要。由于对赤潮的发生存有预警作用,其在环境科学中的价值日益受到重视。有关双壳类基因组学和蛋白质组学的研究进展很快。上世纪,双壳类基因组结构、功能和进化等方面的研究才刚刚开始,现在已经开始研究双壳类基因连锁图谱、基因转录和蛋白质组学。与双壳贝类生产性能相关的分子生物学特性研究报道越来越多。主要的研究热点是双壳类重大疾病的易感性、双壳类对环境压力的耐受力以及生长状况的分子基础等。太平洋牡蛎（Crassostreagigas）是目前双壳类基因组关注的焦点,被推荐为首选的双壳类基因组学模式动物,正在筹划对其进行全基因组测序。明确了双壳类在污染监测中的作用,可以从双壳类细胞和机体与共息生物之间的关系来进一步研究,由此扩展到浮游植物的毒理效应领域的基因组研究。从养殖增殖考虑,今后需重点对双壳类的生长、性别决定和生殖腺发育等方面的基因调控以及幼虫阶段的某些基本过程的基因控制方面进行研究,进而推广到实际生产应用中。     

Evolutionary analysis of herbivorous insects in natural and agricultural environments

Herbivorous insects offer a remarkable example of the biological diversity that formed the foundation for Darwin's theory of evolution by natural selection. The ability of insects to evolve resistance rapidly to insecticides and host‐plant resistance present a continual challenge for pest management. This paper considers the manner in which genetic constraints, host‐plant availability and trade‐offs affect the evolution of herbivorous insects in natural and agricultural environments, and the extent to which lessons learned from studying natural systems may be applied to improve insect resistance management in agricultural systems. Studies on the genetic architecture of adaptation by herbivores to host plants and to insecticides are reviewed. The genetic basis of resistance is an important component of simulation models that predict the evolution of resistance. These models often assume monogenic resistance, but available data suggest that this assumption may be overly narrow and that modeling of resistance as oligogenic or polygenic may be more appropriate. As omics (e.g. genomics and proteomics) technologies become more accessible, a better understanding of the genetic basis of resistance will be possible. Trade‐offs often accompany adaptations by herbivores. Trade‐offs arise when the benefit of a trait, such as the ability to feed on a novel host plant or to survive in the presence of an insecticide, is counterbalanced by fitness costs that decrease fitness in the absence of the selective agent. For resistance to insecticides, and resistance to insecticidal transgenic crops in particular, fitness costs may act as an evolutionary constraint and delay or prevent the evolution of resistance. An important observation is that certain ecological factors such as host plants and entomopathogens can magnify fitness costs, which is termed ecological negative cross‐resistance. The application of omics technologies may allow for more efficient identification of factors that will impose ecological negative cross‐resistance, thereby bolstering insect resistance management. Copyright © 2009 Society of Chemical Industry     

病毒诱导的基因沉默（VIGS）研究进展

病毒诱导的基因沉默（Virus-induced gene silencing,VIGS）是一种RNA 介导的植物抗病毒机制,近年来已被用作研究植物基因功能的反向遗传学手段。与转基因、基因敲除、反义抑制等基因功能研究方法相比,VIGS 技术研究周期短,不需要遗传转化,具有低成本、高通量等优势。因此,VIGS已被广泛应用于植物抗病抗逆、生长发育以及代谢调控等生理途径相关基因的功能鉴定。综述了VIGS 的机制、技术发展、沉默效率的影响因素及其在植物基因功能鉴定中的应用,并对VIGS 在植物性状改良及植物保护方面的应用前景进行了展望。     

Genetics and biology of cytoplasmic male sterility and its applications in forage and turf grass breeding

Hybrid breeding can exploit heterosis and thus offers opportunities to maximize yield, quality and resistance traits in crop species. Cytoplasmic male sterility (CMS) is a widely applied tool for efficient hybrid seed production. Encoded in the mitochondrial genome, CMS is maternally inherited, and thus, it can be challenging to apply in breeding schemes of allogamous self‐incompatible plant species, such as perennial ryegrass. Starting with a general introduction to the origin and the function of mitochondria in plants, this review focuses on the genetics and biology of CMS systems in plants to identify conserved and system‐specific mechanisms. We examine prospects of comparative mitochondrial genomics to identify candidate genes and causative polymorphisms associated with CMS across species and discuss specificities, obstacles and potentials of CMS as a breeding tool for maximizing heterosis in forage grasses. The purpose of the review is to highlight the importance of CMS and hybrid breeding in grasses, with the aim of facilitating research and development of novel breeding strategies to address the future needs for food, feed and biomass production.     

生物实验流程管理系统模型及其在水稻基因组测序中的应用

生物实验流程管理是生物实验室信息管理系统的核心,我们针对生物实验室实验流程灵活,数据流网络复杂等特点,设计了一套生物实验流程管理模型（Biological experiments flow management model,简称BioEFM）,为生物实验室信息管理系统软件（Biology Laboratory Information Management System Software,缩写为BioLIMS）的开发提供了理论基础,大大提高了BioLIMS的开发效率。在此基础上开发的生物实验室信息管理系统软件（BioLIMS）应用于水稻基因组测序实验的信息管理中,为水稻基因组测序实验提供了灵活、便捷、高效的实验信息管理工具,为水稻基因组测序及后续的生物信息学分析奠定了良好的基础。     

海底深部生物圈菌株泛酸枝芽孢杆菌19R1-5的来源和代谢特征分析

河流输送大量的陆源有机物、无机物和微生物到海洋,沉积到近海海盆。随着陆源和海源沉积物在盆地的逐渐堆积,这些陆源微生物被埋藏,进而逐渐演变为沉积物中固有微生物群体的一部分,是研究微生物环境适应与进化的理想生态系统。本课题组从国际大洋钻探计划(IODP) 337航次的一个西太平洋煤层岩芯(1 999 mbsf, meter below the seafloor)中,成功分离到一株革兰氏阳性细菌泛酸枝芽孢杆菌19R1-5(19R)。研究发现,19R与分离自陆源土壤的泛酸枝芽孢杆菌DSM 26(26^T)相比,16S rRNA基因序列相似性为100%,DNA杂交同源性高达91.7%。我们将19R和26^T作为研究对象,从比较基因组的角度对19R的来源和代谢潜能进行研究。结果表明,分离自海底深部的19R来源于陆地;同时,19R较26^T拥有3个额外的磷酸葡萄糖转移酶系统(PTS),提示19R具有更强的糖利用能力,使之能够适应原位中特殊的营养环境,研究结果对探索海底深部生物圈微生物的来源及其在深海物质循环中的作用具有重要意义。     

植物病原细菌Pseudomonas syringae pv. tomato DC3000致病基因比较基因组及原核表达分析

番茄细菌性叶斑病是由Pseudomonas syringae pv. tomato引起的一种世界范围内广泛发生的植物细菌性病害,其模式菌株DC3000已完成全基因组测序。试验通过比较基因组学方法将该模式菌株基因组中的致病基因与其他已完成全基因组测序的植物病原细菌的基因组序列进行比对,得到3个DC3000菌株特有的致病基因PSPTO_4707、PSPTO_4708、PSPTO_4711,并对PSPTO_4711基因进行原核表达和蛋白活力检测,发现其表达的活性蛋白对拟南芥具有很强的毒性。     

Pseudomonas stutzeri|A1501基因组结构及功能注释

采用全基因组“shotgun”方法完成了固氮斯氏假单胞菌A1501的全基因组序列测定,并进行了基因组结构与功能注释分析。A1501基因组全长4 567 418 bp,含有4 146个ORFs。该基因组中已鉴定了42个编码转座酶的重复序列,这些序列的存在预示着转座现象在A1501菌中非常活跃,预示该菌与其他生物之间基因交流可能比较频繁。比较基因组表明,为了适应特定的生存环境,假单胞菌在基因组结构和遗传信息容量上产生了明显的分化。此外,基因组分析鉴定了A1501环境适应的遗传基础,包括物质转运、信号传导和趋化系统等,这些系统是细菌能够在根际土壤环境中保持竞争力以及能够与水稻形成高效联合固氮体系的关键。A1501基因组的完成为进一步开展功能基因组学和蛋白质组学研究奠定了基础。     

Genomics,genetics and breeding of tropical legumes for better livelihoods of smallholder farmers

Legumes are important components of sustainable agricultural production, food, nutrition and income systems of developing countries. In spite of their importance, legume crop production is challenged by a number of biotic (diseases and pests) and abiotic stresses (heat, frost, drought and salinity), edaphic factors (associated with soil nutrient deficits) and policy issues (where less emphasis is put on legumes compared to priority starchy staples). Significant research and development work have been done in the past decade on important grain legumes through collaborative bilateral and multilateral projects as well as the CGIAR Research Program on Grain Legumes (CRP‐GL). Through these initiatives, genomic resources and genomic tools such as draft genome sequence, resequencing data, large‐scale genomewide markers, dense genetic maps, quantitative trait loci (QTLs) and diagnostic markers have been developed for further use in multiple genetic and breeding applications. Also, these mega‐initiatives facilitated release of a number of new varieties and also dissemination of on‐the‐shelf varieties to the farmers. More efforts are needed to enhance genetic gains by reducing the time required in cultivar development through integration of genomics‐assisted breeding approaches and rapid generation advancement.