大麦基因组和分子育种研究进展

大麦(Hordeum vulgare L.)是世界上重要的谷类作物之一,其二倍体特性使其成为麦类作物基因组研究的重要材料。随着大量分子标记图谱、BACs文库、突变集合和DNA阵列技术的应用,大麦基因组测序工作已不断深入,越来越多的大麦基因组信息使综合分析大麦基因组结构和功能,了解基因表达网络同重要农艺性状之间的关系成为可能。就大麦基因组研究内容,如ESTs系统、物理图谱的构建、功能基因组学研究和大麦分子育种研究作简要综述,为进一步阐述大麦基因组结构和功能特性,提高大麦分子育种能力提供理论依据。     

大麦杂种F2群体主要农艺性状遗传力和遗传进度的初步研究

大麦的主要农艺性状大都属于数量性状, 受微效多基因控制,易受环境条件的影响,在杂 种分离世代中,个体性状呈现连续分布,这给正 确地配组和有效地选择带来了一定的困难。运 用数量遗传研究方法对大麦农艺性状的遗传力 和遗传进度进行估测,可以衡量遗传和环境影 响对于表型总变异的相对重要性及在一定选择 压力下的选择效果,可为杂种后代的选择和处 理提供参考依据。国外对大麦的研究甚多,而 国内较少。我们试图通过大麦杂种Fz群体主 要农艺性状的遗传力和遗传进度的初步研究, 为大麦育种提供一些依据。     

禾本科作物芒遗传研究进展

芒是许多禾本科作物穗部的重要结构, 不仅可以作为区分不同品种以及基因定位的重要形态标记, 而且在禾谷类作物的种子传播、籽粒灌浆、蒸腾作用及产量形成等方面起重要作用。该文综述了小麦(Triticum aestivum)、大麦(Hordeum vulgare)和水稻(Oryza sativa)芒的结构、功能与遗传调控机制研究进展, 以期为芒性状遗传机理的进一步研究及其在育种中的应用提供参考。     

家蚕遗传育种:从传统杂交到分子设计

蚕桑丝绸是我国人民的伟大发明,是中华民族的重要文化标识,我国也长期保持着世界产业中心的地位。家蚕早期遗传育种研究高度发达,形成了完善、科学的蚕种繁育和保存体系,但是也提前进入了育种技术的发展瓶颈,如传统遗传资源已被充分挖掘,品种同质化程度高等。进入21世纪以来,我国蚕桑丝绸产业面临着前所未有的巨大挑战。近年来,随着分子生物学、基因组学、转基因、基因组编辑技术的蓬勃发展及其快速应用,家蚕遗传育种迎来了良好的发展势头。本文综述了家蚕遗传育种的发展历程,尤其是转基因和基因组编辑技术在现代家蚕品种改良中的应用潜力和现状,展望和讨论了家蚕遗传育种未来研究和应用的重点。     

生物技术与我国猕猴桃育种

猕猴桃是原产我国的重要果树之一。随着现代生物技术的发展,以野生和实生选优为主的传统猕猴桃育种方法与以基因组学和转基因为核心的分子育种技术相比,挑战和机遇并存。与其他果树相比,猕猴桃生物技术及其转基因研究较为滞后。就现代生物技术在猕猴桃遗传育种中的方法、应用及研究进展进行了综述,并对我国猕猴桃育种现状进行浅析,旨在为我国猕猴桃育种和产业发展提供方法参考及思路借鉴。     

欢迎订阅《麦类作物学报》

《麦类作物学报》是由教育部主管、西北农林科技大学和国家小麦工程技术研究中心联合主办的专业性学术期刊,也是全国唯一的一份麦类作物专刊。主要刊载麦类作物(小麦、大麦、燕麦、黑麦等)遗传育种、     

六棱大麦种质表型遗传多样性评价

为探究六棱大麦种质资源的遗传多样性,提高六棱大麦育种组合选配的针对性和育种效率。以来自国内外的89份六棱大麦种质为材料,考察了3个不同环境下参试材料的株高、穗下节间长、穗长、主穗粒数、单株穗数、千粒重、单株粒重、单株生物重等8个性状,综合参试材料3个不同环境的表现,通过变异系数及遗传多样性指数分析参试材料的遗传多样性,通过主成分分析、聚类分析等方法对参试六棱大麦种质进行了综合评价。结果表明:(1)六棱大麦的穗长、单株粒重2个性状变异较丰富,株型性状与穗粒数变异系数较小,六棱大麦育种的增益效应主要体现在穗长和粒重的适度增加;(2)六棱皮大麦与六棱裸大麦仅在千粒重性状上差异显著,六棱皮大麦各性状多样性指数普遍高于六棱裸大麦;(3)参试六棱大麦种质分为5类,其中第4类基本均为中国地方种质,分布广泛,但遗传距离较近;其他4类为国内外选育的种质,各具特性;(4)利用主成分二维排序分析筛选到以高产为基础,分别兼具矮秆、长穗且分蘖能力强、大粒及高生物重的4类优异种质;基于主成分构建了六棱大麦种质资源的综合评价方程。     

大麦主要农艺性状的遗传相关剖析

提高产量是大麦育种的最终目标之一。由于产量性状是复杂的数量性状,受多种因素的影响和制约,同时诸因素间又存在着不同程度的相关,某一性状的变化必然导致其它性状的相关改变,这给正确而又有效的选择带来了一定的困难。笔者曾用两个多棱大麦杂交组合和3个二棱大麦杂交组合研究了大麦主要农艺性状的遗传力和遗传进度,对大麦杂种后代的直接选择和处理提出了一些指标^[3], 但未能涉及到各性状间的遗传相关变化。本研究着重分析长江下游大面积推广使用的一些高产二棱大麦新品种主要农艺性状间的遗传相关,进行各性状的通径分析,剖析产生这些相关的原因及估测各性状的相对重要性,为利用这些高产品种作为原始群体,从中选择出更高产品种或某些性状有所改良的新品种提供参考依据。     

贵州野生大麦麦芽品质性状的SSR标记分析

采用6对啤酒大麦的麦芽浸提和糖化力紧密连锁引物对103份采自贵州的野生大麦材料进行SSR标记。结果表明,贵州野生大麦麦芽品质性状存在丰富的变异,6对SSR引物共检测出38个等位变异,每个位点平均6.33个等位变异,其中GMS001位点对贵州野生大麦基因组DNA变异检测最有效。UPGMA聚类图显示,该6对与麦芽品质紧密连锁的SSR引物对区分野生大麦在贵州不同的资源产地和棱性是有效的,表现为遵义地区野生大麦遗传多样性丰富,而来自贵州凯里地区的野生大麦资源遗传多样性狭窄。麦芽品质性状标记结果表明贵州野生六棱大麦较四棱大麦的遗传差异更显著,表明进行贵州啤酒大麦人工育种的亲本应在亲缘关系较远的六棱大麦之间选择。     

彩色小麦基因发掘和种质资源育种利用北大核心CSCD

随着人类对彩色营养功能小麦需求越来越大,彩色小麦遗传研究越来越深入,彩色小麦品种越来越多,但我国彩色小麦种质资源家底不清。为了满足国内外对彩色小麦营养遗传育种方面的迅猛需求,本文综述了彩色小麦基因和种质资源育种利用进展,首先介绍了彩色小麦基因来源的种质资源,其次介绍了彩色小麦染色体组及系谱,第三是首次全面总结了我国彩色小麦育种和种质资源创新的进展。我国近24年来审定了61个彩色小麦品种,其中紫(黑)粒品种50个,蓝粒小麦品种10个,绿粒小麦品种1个,还育成了19个彩色小麦种质新资源,其中近4年是我国彩色小麦品种审定最多的年份。河南省、山东省、河北省、山西省是我国4大彩色小麦育种和产业化基地。彩色小麦品种大部分来源于彩色小麦和普通小麦杂交,彩色小麦基因主要来自于小麦与野生一粒小麦、野生二粒小麦、偃麦草、黑麦、赖草等远缘杂交。有48个彩色小麦品种籽粒蛋白质含量超过14%,4个彩色小麦品种籽粒蛋白质含量超过18%,4个彩色小麦品种面团稳定时间超过10 min。针对彩色小麦遗传育种和产业化存在的问题,建议作物种质资源保护与利用要遵循“有差异,就选择;能遗传,可定向;有价值,就保藏;需鉴定,要精准;扬其长,广利用”的基本原则。以上资料将为我国彩色小麦遗传育种研究提供大量有用信息和基因种质资源,推动我国彩色小麦遗传育种研究深入发展。     

The Current Status of Culture Collections and Their Contribution to Biotechnology

Abstract

Cereals are the most important group of plants for human nutrition and animal feed. Partially due to the commercial value of crop plants, there has been an ever-increasing interest in using modern biotechnological methods for the improvement of the characteristics of cereals during the past decade. The rapid progress in molecular biology, plant cell culture techniques, and gene transfer technology has resulted in successful transformations of all the major cereals—maize, rice, wheat, and barley. This brings the biotechnological methods closer to the routine also in barley breeding. In this article, the current status of barley genetic engineering, including the patent situation, is reviewed. The needs, aims, and possible applications of genetic engineering in barley breeding are discussed.     

Improvement of anther culture methods for doubled haploid production in barley breeding

There is potential to accelerate cultivar development with a doubled haploid system for breeding line production. Anther culture methodology was evaluated for U.S.A. spring barley (Hordeum vulgare L.) breeding applications. Gelrite was found to be an acceptable replacement for ficoll in the induction medium to reduce costs while maintaining embryoid and plant production levels. Beneficial effects of 28 d cold pretreatment of donor spikes for anther culture were confirmed with Pacific Northwest USA barley genotypes. A 3 d mannitol solution pretreatment of fresh anthers was shown to be less effective for green plant production compared to 28 d cold pretreatment of donor spikes. Extended donor spike cold pretreatment from 28 to 42 d did not reduce anther culture productivity. Based on this research, anther culture techniques show promise for economical and convenient application in spring barley breeding.Abbreviations DH doubled haploid - LS Linsmaier and Skoog basal medium - BAP benzylaminopurine - GLM Generalized Linear Model - SAS Statistical Analysis System     

Prospects for molecular breeding of barley

Data from UK Recommended List Trials showed that the introduction of new cultivars of spring and winter barley has maintained a significant increase in yield over time, whereas there has been no significant improvement in hot water extract, the major determinant of good malting quality, in either crop. Commercial barley breeding is based upon phenotypic selection, and the introduction of molecular breeding methods must either increase the rate of advance, or offer an improvement in the cost‐effectiveness of breeding programmes. Molecular breeding can be applied to either single gene or polygenic characters but is not widely used in commercial barley breeding, other than as a marker for resistance to the Barley Yellow Mosaic Virus complex. There are many reports of potential targets for use in molecular breeding but the few validation studies that have been carried out to date are disappointing. Results from genomics studies are likely to lead to the identification of key candidate genes, which can be associated with economically important characters through co‐location on certain chromosomal regions. Associations between candidate gene sequence haplotypes and phenotypic characteristics is expected to identify allelic combinations, which are most frequently observed in successful cultivars, that can be used in molecular breeding of barley on a commercial scale.     

Hybridisation‐based target enrichment of phenology genes to dissect the genetic basis of yield and adaptation in barley

Barley (Hordeum vulgare L.) is a major cereal grain widely used for livestock feed, brewing malts and human food. Grain yield is the most important breeding target for genetic improvement and largely depends on optimal timing of flowering. Little is known about the allelic diversity of genes that underlie flowering time in domesticated barley, the genetic changes that have occurred during breeding, and their impact on yield and adaptation. Here, we report a comprehensive genomic assessment of a worldwide collection of 895 barley accessions based on the targeted resequencing of phenology genes. A versatile target‐capture method was used to detect genome‐wide polymorphisms in a panel of 174 flowering time‐related genes, chosen based on prior knowledge from barley, rice and Arabidopsis thaliana. Association studies identified novel polymorphisms that accounted for observed phenotypic variation in phenology and grain yield, and explained improvements in adaptation as a result of historical breeding of Australian barley cultivars. We found that 50% of genetic variants associated with grain yield, and 67% of the plant height variation was also associated with phenology. The precise identification of favourable alleles provides a genomic basis to improve barley yield traits and to enhance adaptation for specific production areas.     

The efficiency of inducing spring barley haploids depending on the method of haploid production and on the genotype of the initial diploids

The comparative assessment of the combining application of bulbosum technique and anther culture in vitro for spring barley haploid production has been presented. It has been shown that the yield of haploids depended on genotype of initial material and genotype and method interaction. The advantages of the use of these two techniques complemented each other in barley breeding program are discussed.     

基于诊断标记的LOX-1活性缺失大麦种质鉴定评价

在啤酒酿造和储藏过程中,所含脂类物质代谢是影响啤酒风味稳定性和啤酒货架期长短的主要原因。研究表明,大麦脂肪氧化酶1(LOX-1)是导致籽粒中脂类代谢的关键酶,筛选和创制LOX-1活性缺失(null LOX-1)的大麦种质是促进啤酒大麦品质育种的有效途径。为提高检测效率,针对前期鉴定出的中国null LOX-1大麦稀有SNP功能变异,开发出特异性KASP快速诊断标记,并利用该标记对来源于河南和山东两省的633份大麦地方品种进行鉴定评价,共计筛选出8份LOX-1活性缺失新种质,同时明确了该变异的地理分布及其在不同地方品种中的变异频率。本研究不仅为啤酒大麦分子辅助育种提供了优异种质和快速检测手段,也为大麦种质资源遗传完整性保护与利用提供了参考。     

Genetic Diversity and Population Structure Analysis of Barley Landraces from Shanghai Region Using Genotyping-by-Sequencing

Barley (Hordeum vulgare L.) is an important economic crop for food, feed and industrial raw materials. In the present research, 112 barley landraces from the Shanghai region were genotyped using genotyping-by-sequencing (GBS), and the genetic diversity and population structure were analyzed. The results showed that 210,268 Single Nucleotide Polymorphisms (SNPs) were present in total, and the average poly-morphism information content (PIC) was 0.1642. Genetic diversity and population structure analyses suggested that these barley landraces were differentiated and could be divided into three sub-groups, with morphological traits of row-type and adherence of the hulls the main distinguishing factors between groups. Genotypes with similar or duplicated names were also investigated according to their genetic backgrounds and seed appearances. This study provided valuable information on barley landraces from the Shanghai region, and showed that all these barley landraces should be protected and used for future breeding programs.     

Development of DNA markers associated with beer foam stability for barley breeding

Traits conferring brewing quality are important objectives in malting barley breeding. Beer foam stability is one of the more difficult traits to evaluate due to the requirement for a relatively large amount of grain to be malted and then the experimental costs for subsequent brewing trials. Consequently, foam stability tends to be evaluated with only advanced lines in the final stages of the breeding process. To simplify the evaluation and selection for this trait, efficient DNA makers were developed in this study. Previous studies have suggested that the level of both of the foam-associated proteins Z4 and Z7 were possible factors that influenced beer foam stability. To confirm the relationship between levels of these proteins in beer and foam stability, 24 beer samples prepared from malt made from 10 barley cultivars, were examined. Regression analyses suggested that beer proteins Z4 and Z7 could be positive and negative markers for beer foam stability, respectively. To develop DNA markers associated with contents of proteins Z4 and Z7 in barley grain, nucleotide sequence polymorphisms in barley cultivars in the upstream region of the translation initiation codon, where the promoter region might be located were compared. As a result, 5 and 23 nucleotide sequence polymorphisms were detected in protein Z4 and protein Z7, respectively. By using these polymorphisms, cleaved amplified polymorphic sequence (CAPS) markers were developed. The CAPS markers for proteins Z4 and Z7 were applied to classify the barley grain content of 23 barley cultivars into two protein Z4 (pZ4-H and pZ4-L) and three protein Z7 (the pZ7-H, pZ7-L and pZ7-L2) haplotypes, respectively. Barley cultivars with pZ4-H showed significantly higher levels of protein Z4 in grain, and those with pZ7-L and pZ7-L2 showed significantly lower levels of protein Z7 in grain. Beer foam stability in the cultivars with pZ4-H and pZ7-L was significantly higher than that with pZ4-L and pZ7-H, respectively. Our results indicate that these CAPS markers provide an efficient selection tool for beer foam stability in barley breeding programs.     

Molecular mapping of genes determining height, time to heading, and growth habit in barley (Hordeum vulgare).

A combination of random amplified polymorphic DNA (RAPD) and restriction fragment length polymorphism (RFLP) markers has been used to locate genes controlling important developmental characters in barley. The denso dwarfing gene has been mapped to the long arm of chromosome 3H. Stepwise multiple regression was also used to identify another region of the barley genome (on chromosome 7H), which contributed to variation in height. The denso locus was shown to be associated with delaying time to heading. A protein (WSP2) and an RAPD marker on barley chromosomes 5H and 6H, respectively, were also associated with time to heading. These results are discussed in relation to the genetic analysis of developmentally important traits and the development of dwarfing genes in barley breeding programs.