作物抗旱相关性状的QTLs定位研究进展

提高作物品种的抗旱性、获得高产稳产是抗旱育种的最终目标。作物分子连锁图谱的构建及其它分子遗传学研究进展为改良作物抗旱性提供了新机遇。Ｔａｎｋｓｌｅｙ等[1]指出,通过ＲＦＬＰ或其他分子标记进行标记辅助选择,为难以测量的性状提供了一条重要的选择途径。通过对抗旱相关性状的数量性状位点(ＱＴＬｓ)的标记,就可以把复杂的性状作为一套单基因性状进行分析和选择。一旦找到紧密连锁的标记(1-5ｃＭ),就可以在育种工作中进行标记辅助选择[2]。分子标记使育种家无需测定表型就能够追踪调控抗旱性状的遗传位点,可免去多年多点的大量田间…     

水稻抗稻瘟病基因Pi-2(t)物理图谱的构建

应用ＢＡＣ文库,采用基于分子标记的染色体着陆（ｍａｒｋｅｒ－ｂａｓｅｄ ｃｈｒｏｍｏｓｏｍｅ ｌａｎｄｉｎｇ）和染色体步查（ｃｈｒｏｍｏｓｏｍｅ ｗａｌｋｉｎｇ）等手段,建立了包含有裟抗稻瘟病基因Ｐｉ－２（ｔ）的物理图谱,该物理图谱由２２个ＢＡＣ克隆组成,遗传跨度８ｃＭ,而物理距离为９２５ｋｂ,该物理图谱的构建不仅为进一步分离和克隆该基因打下了基础,同时也可为分子标记辅助选择育种选择抗稻瘟病新材料     

DNA分子标记、基因组作图及其在植物遗传育种上的应用

本文总结了现代分子生物学所发展的各类分子标记及其在遗传图谱构建中的作用,还综述了遗传图谱与物理图谱的构建、数量与质量性状定位及分子标记在作物育种中的应用。     

作物抗旱相关分子标记及其辅助选择的研究进展

分子标记辅助选择育种给作物抗旱育种提供了新的途径。本介绍了国内外在小麦、玉米、水稻、大豆等重要农作物抗旱相关分子标记方面的研究进展。对作物抗旱相关QTL分子标记辅助育种进行了探讨,并对其发展策略提出了一些思考。     

遗传标记及其在作物品种鉴定中的应用

本文评述了用于作物品种鉴定的形态标记（morphological markers）、细胞标记（cytological markers）、生化标记（biochemical markers）、分子标记（molecular markers）的优缺点。重点评述了分子标记在作物品种鉴定中的应用。文中除对蛋白质电泳指纹图谱——同工酶和贮藏蛋白（包括醇溶性蛋白、清蛋白、谷蛋白、球蛋白等）电泳产生的指纹图谱的应用外,较详细地介绍了近年来DNA指纹图谱技术;包括限制片段长度多态性（restriction fragment length polymorphism,简称RFLP）、随机扩增多态性DNA (random amplified po lymorphic DNA,简称RAPD)、小卫星DNA（minisatellite DNA）、微卫星DNA（microsatellite DNA）,简单重复序列间扩增（intersimple sequence repeats,简称ISSR）,扩增片段长度多态性（amplified fragment length polymorphism,简称AFLP）以及CAPS (cleaved amplified polymorphic sequences)和SNPS (single nucleotide polymorphisms)对作物品种鉴定和新品种登记,品种纯度和真实性的检验以及品种间亲缘关系的探讨和在分类研究中的贡献等。     

传标记及其在作物品种鉴定中的应用

本文评述了用于作物品种鉴定的形态标记（morphological markers）、细胞标记（cytological markers）、生化标记（biochemical markers）、分子标记（molecular markers）的优缺点。重点评述了分子标记在作物品种鉴定中的应用。文中除对蛋白质电泳指纹图谱－－同工酶和贮茂蛋白（包括醇溶性蛋白、清蛋白、谷蛋白、球蛋白等）电泳产生的指纹图谱的应用外,较详细地介绍了近年来ＤＮＡ指纹图谱技术;包括限制片段长度多态性（restriction fragment length polymorphism,简称ＲＦＬＰ)、随机扩增多态性ＤＮＡ（random amplified polymorphic DNA,简称ＲＡＰＤ）、小卫星ＤＮＡ（minisatellite DNA）、微卫生ＤＡＮmicrosatellite DNA）,简单重复序列间扩增（intersimple sequence repeats,简称ＩＳＳＲ）,扩增片段长度多态性（amplified fragment length polymor-phism,简称ＡＦＬＰ）以及ＣＡＰＳ（cleaved amplified polymorphic sequences）和ＳＮＰＳ（single mucleotide polymor-phisms）对作物品种鉴定和新品种登记,品种纯度和真实性的检验以及品种间亲缘关系的探讨和在分类研究中的贡献等。     

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。     

DNA标记和分子育种

ＤＮＡ标记和分子育种钱惠荣郑康乐（中国水稻研究所生物工程系杭州３１０００６）生物技术的发展给作物遗传育种研究带来了巨大的变化,ＤＮＡ分子标记技术的应用是其中最显著的变化之一［９,４８］。由于分子标记相对于经典遗传育种研究中的形态性状具有无可比拟的优越性,它的使用也越来越广泛。许多以前无法进行的研究,比如环境因素的影响,数量性状的多重效应等等,在分子标记的帮助下已经开展。同时分子标记直接应用于...     

桃基因组及全基因组关/联分析研究进展

桃(Prunus persica [L.] Batsch)是蔷薇科重要的核果类果树, 适应性强, 栽培范围广, 果实口感好, 深受消费者喜欢。提高桃果实品质及增加抗病、抗虫性一直是桃遗传育种者关注的焦点。文章对近年来桃遗传分子标记连锁图谱和物理图谱构建、分子标记开发应用、全基因组和转录组测序工作中所取得的最新成果进行综述, 同时阐述了高密度SNP芯片标记技术在桃以及其它作物上所开展的全基因组关联分析应用实例, 为桃进一步开展全基因组关联分析, 挖掘目标性状QTLs以及高效育种选择标记提供理论基础     

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。     

生物炭影响作物生长及其与化肥混施的增效机制研究进展

利用秸秆型生物炭进行还田改土不仅具有提升作物产量的潜力,而且能够产生明显的环境效益,现已成为当今国内外农业领域的研究热点.本文综述了近年来国内外有关生物炭添加影响作物生长的分子调控机制研究,尤其关注了生物炭与作物根系的互作效应;介绍了生物炭与化肥混施的生物学效应及可能的增效机制;展望了今后的研究方向,以期促进我国相关领域的研究.国内外的最新研究表明:生物炭土壤添加改善植物生长的关键是生长素相关信号转导分子,通过促进植物细胞扩增、细胞壁松弛、水及营养的转运等相关基因的表达,有利于植物的新陈代谢及生长.生物炭及其与根系的相互作用能够直接或间接地影响土壤物理、化学、生物因子,从而在炭、肥互作增效过程中起主导调控作用.     

Emerging tools,concepts and ideas to track the modulator genes underlying plant drought adaptive traits: An overview

Crop vulnerability to multiple abiotic stresses is increasing at an alarming rate in the current global climate change scenario, especially drought. Crop improvement for adaptive adjustments to accomplish stress tolerance requires a comprehensive understanding of the key contributory processes. This requires the identification and careful analysis of the critical morpho-physiological plant attributes and their genetic control. In this review we try to discuss the crucial traits underlying drought tolerance and the various modes followed to understand their molecular level regulation. Plant stress biology is progressing into new dimensions and a conscious attempt has been made to traverse through the various approaches and checkpoints that would be relevant to tackle drought stress limitations for sustainable crop production.     

African crop yield reductions due to increasingly unbalanced Nitrogen and Phosphorus consumption

The impact of soil nutrient depletion on crop production has been known for decades, but robust assessments of the impact of increasingly unbalanced nitrogen (N) and phosphorus (P) application rates on crop production are lacking. Here, we use crop response functions based on 741 FAO maize crop trials and EPIC crop modeling across Africa to examine maize yield deficits resulting from unbalanced N : P applications under low, medium, and high input scenarios, for past (1975), current, and future N : P mass ratios of respectively, 1 : 0.29, 1 : 0.15, and 1 : 0.05. At low N inputs (10 kg ha^?1), current yield deficits amount to 10% but will increase up to 27% under the assumed future N : P ratio, while at medium N inputs (50 kg N ha^?1), future yield losses could amount to over 40%. The EPIC crop model was then used to simulate maize yields across Africa. The model results showed relative median future yield reductions at low N inputs of 40%, and 50% at medium and high inputs, albeit with large spatial variability. Dominant low‐quality soils such as Ferralsols, which are strongly adsorbing P, and Arenosols with a low nutrient retention capacity, are associated with a strong yield decline, although Arenosols show very variable crop yield losses at low inputs. Optimal N : P ratios, i.e. those where the lowest amount of applied P produces the highest yield (given N input) where calculated with EPIC to be as low as 1 : 0.5. Finally, we estimated the additional P required given current N inputs, and given N inputs that would allow Africa to close yield gaps (ca. 70%). At current N inputs, P consumption would have to increase 2.3‐fold to be optimal, and to increase 11.7‐fold to close yield gaps. The P demand to overcome these yield deficits would provide a significant additional pressure on current global extraction of P resources.     

A Rice Semi-Dwarf Gene,Tan-Ginbozu (D35), Encodes the Gibberellin Biosynthesis Enzyme,ent-Kaurene Oxidase

A rice (Oryza sativa L.) semi-dwarf cultivar, Tan-Ginbozu (d35Tan-Ginbozu), contributed to the increase in crop productivity in Japan in the 1950s. Previous studies suggested that the semi-dwarf stature of d35Tan-Ginbozu is caused by a defective early step of gibberellin biosynthesis, which is catalyzed by ent-kaurene oxidase (KO). To study the molecular characteristics of d35Tan-Ginbozu, we isolated 5 KO-like (KOL) genes from the rice genome, which encoded proteins highly homologous to Arabidopsis and pumpkin KOs. The genes (OsKOL1 to 5) were arranged as tandem repeats in the same direction within a 120 kb sequence. Expression analysis revealed that OsKOL2 and OsKOL4 were actively transcribed in various organs, while OsKOL1 and OsKOL5 were expressed only at low levels; OsKOL3 may be a pseudogene. Sequence analysis and complementation experiments demonstrated that OsKOL2 corresponds to D35. Homozygote with null alleles of D35 showed a severe dwarf phenotype; therefore, d35Tan-Ginbozu is a weak allele of D35. Introduction of OsKOL4 into d35Tan-Ginbozu did not rescue its dwarf phenotype, indicating that OsKOL4 is not involved in GA biosynthesis. OsKOL4 and OsKOL5 are likely to take part in phytoalexin biosynthesis, because their expression was promoted by UV irradiation and/or elicitor treatment. Comparing d35Tan-Ginbozu with other high yielding cultivars, we discuss strategies to produce culm architectures suitable for high crop yield by decreasing GA levels.     

Economic consequences for UK farmers of growing GM herbicide tolerant sugar beet

Weed control is important and one of the more expensive inputs to sugar beet production. The introduction of genetically modified herbicide tolerant (GMHT) sugar beet would result in a major saving in weed control costs in the crop for growers, including control of problem weeds such as perennial weeds and weed beet. However, there would be other economic consequences of growing GMHT beet, some of which would manifest themselves in other parts of the rotation, such as the previous crop, the cereal stubbles that proceed most beet crops, soil tillage and spray application. The average national saving for UK sugar beet growers if they could use the technology would be in excess of £150 ha^?1 yr^?1 or £23 million yr^?1, which includes reductions in agrochemical use of c. £80 ha,^?1 yr^?1 or £12 million yr^?1. However, for some growers, the gains would be much larger and for a few, less than these figures. The possible cost savings are sufficiently large that they could ensure that sugar beet production, with its regionally important environmental benefits as a spring crop, remains economically viable in the UK post reform of the EU sugar regime.     

Tandem constructs to mitigate transgene persistence: tobacco as a model

Some transgenic crops can introgress genes into other varieties of the crop, to related weeds or themselves remain as 'volunteer' weeds, potentially enhancing the invasiveness or weediness of the resulting offspring. The presently suggested mechanisms for transgene containment allow low frequency of gene release (leakage), requiring the mitigation of continued spread. Transgenic mitigation (TM), where a desired primary gene is tandemly coupled with mitigating genes that are positive or neutral to the crop but deleterious to hybrids and their progeny, was tested as a mechanism to mitigate transgene introgression. Dwarfism, which typically increases crop yield while decreasing the ability to compete, was used as a mitigator. A construct of a dominant ahasR (acetohydroxy acid synthase) gene conferring herbicide resistance in tandem with the semidominant mitigator dwarfing Delta gai (gibberellic acid-insensitive) gene was transformed into tobacco (Nicotiana tabacum). The integration and the phenotypic stability of the tandemly linked ahasR and Delta gai genomic inserts in later generations were confirmed by polymerase chain reaction. The hemizygous semidwarf imazapyr-resistant TM T1 (= BC1) transgenic plants were weak competitors when cocultivated with wild type segregants under greenhouse conditions and without using the herbicide. The competition was most intense at close spacings typical of weed offspring. Most dwarf plants interspersed with wild type died at 1-cm, > 70% at 2.5-cm and 45% at 5-cm spacing, and the dwarf survivors formed no flowers. At 10-cm spacing, where few TM plants died, only those TM plants growing at the periphery of the large cultivation containers formed flowers, after the wild type plants terminated growth. The highest reproductive TM fitness relative to the wild type was 17%. The results demonstrate the suppression of crop-weed hybrids when competing with wild type weeds, or such crops as volunteer weeds, in seasons when the selector (herbicide) is not used. The linked unfitness would be continuously manifested in future generations, keeping the transgene at a low frequency.     

中国转基因水稻的研究进展及产业化问题分析

水稻在我国粮食生产和消费中占有重要地位,也是世界上最重要的粮食作物之一。水稻转基因研究已成为当前国内外植物分子生物学和作物育种研究的热点。目前我国转基因水稻研究处于国际领先水平,有望成为转基因抗虫棉之后又一个进入产业化的转基因粮食作物,这可能将在确保我国粮食安全中发挥重要贡献。从国内外转基因水稻研发概况、我国Bt抗虫水稻生物安全评价两方面综述了我国转基因水稻产业化的前景,并在此基础上对产业化提出相关建议与对策。     

Domestication rewired gene expression and nucleotide diversity patterns in tomato

Plant domestication has led to considerable phenotypic modifications from wild species to modern varieties. However, although changes in key traits have been well documented, less is known about the underlying molecular mechanisms, such as the reduction of molecular diversity or global gene co‐expression patterns. In this study, we used a combination of gene expression and population genetics in wild and crop tomato to decipher the footprints of domestication. We found a set of 1729 differentially expressed genes (DEG) between the two genetic groups, belonging to 17 clusters of co‐expressed DEG, suggesting that domestication affected not only individual genes but also regulatory networks. Five co‐expression clusters were enriched in functional terms involving carbohydrate metabolism or epigenetic regulation of gene expression. We detected differences in nucleotide diversity between the crop and wild groups specific to DEG. Our study provides an extensive profiling of the rewiring of gene co‐expression induced by the domestication syndrome in one of the main crop species.     

Developing specific leaf promoters tools for genetic use in transgenic plants towards food security

Significant yields enrichments are necessitated for meeting the rapid global growth population together with the expected demanding for food, particularly major crops. Photosynthesis improvement is an unexploited opportunity in research on improving crop yields. However, the lack of sufficient molecular promoters tools leads to the need to explore and analyze native leaf-specified promoters for manipulating photosynthesis activities in plants. Two B. distachyon promoters, sedoheptulose-1, 7-bisphosphatase (SBPase) and fructose-1, 6-bisphosphate aldolase (FBPA), were isolated and cloned into an expression vector upstream of the eYFP reporter gene. The results demonstrate that both promoters actively function in N. benthamiana leaves in both agro-transiently assays, successfully regulating expression specifically to leaf-tissues. Exploring these active promoters could potentially provide new well genetic tools for any transgene expression in plants or leaves to genetically manipulate photosynthesis for yield improvement.     

Sugarcane biotechnology: The challenges and opportunities

Summary Commercial sugarcane, belonging to the genus Saccharum (Poaceae), is an important industrial crop accounting for nearly 70% of sugar produced worldwide. Compared to other major crops, efforts to improve sugarcane are limited and relatively recent, with the first introduction of interspecific hybrids about 80 yr ago. Progress in traditional breeding of sugareane, a highly polyploid and frequently aneuploid plant, is impeded by its narrow gene pool, complex genome, poor fertility, and the long breeding/selection cycle. These constraints, however, make sugarcane a good candidate for molecular breeding. In the past decade considerable progress has been made in understanding and manipulating the sugarcane genome using various biotechnological and cell biological approaches. Notable among them are the creation of transgenic plants with improved agronomic or other important traits, advances in genomics and molecular markers, and progress in understanding the molecular aspects of sucrose transport and accumulation. More recently, substantial effort has been directed towards developing sugarcane as a biofactory for high-value products. While these achievements are commendable, a greater understanding of the sugarcane genome, and cell and whole plant physiology, will accelerate the implementation of commercially significant biotechnology outcomes. We anticipate that the rapid advancements in molecular biology and emerging biotechnology innovations would play a significant role in the future sugarcane crop improvement programs and offer many new opportunities to develop it as a new-generation industrial crop.