Genetic dissection of seminal root architecture in elite durum wheat germplasm

Although root architecture has been shown to play an important role in crop performance, particularly under drought conditions, no information is available on the genetic control of root traits in durum wheat, a crop largely grown in rainfed areas with low rainfall. In our study, a panel of 57 elite durum wheat accessions were evaluated under controlled conditions for root and shoot traits at the seedling stage. Significant genetic variability was detected for all the root and shoot traits that were investigated. Correlation analysis suggested that root and shoot features were only partially controlled by common sets of genes. The high linkage disequilibrium (up to 5 cM) present in the germplasm collection herein considered allowed us to use simple sequence repeat‐based association mapping to identify chromosome regions with significant effects on the investigated traits. In total, 15 chromosome regions showed significant effects on one or more root architectural features. A number of these regions also influenced shoot traits and, in some cases, plant height measured in field conditions. Major effects were detected on chromosome arms 2AL (at Xgwm294), 7AL (at Xcfa2257 and Xgwm332) and 7BL (at Xgwm577 and Xcfa2040). The accessions with the most remarkable differences in root features will provide a valuable opportunity to assemble durum wheat mapping populations well suited for ascertaining the effects of root architecture on water use efficiency and grain yield.     

Genetic diversity in a collection of Italian long storage tomato landraces as revealed by SNP markers array

Tomato (Solanum lycopersicum L.) is one of the most important crops worldwide. In this study, we used 7720 genome-wide SNPs to characterize the genetic diversity within a tomato germplasm collection enriched with 64 accessions from southern Italy of the so called “da serbo” type i.e. drought-tolerant and long storage landraces. Notwithstanding the relatively small collection area, 1575 (20.4%) polymorphic SNPs, mostly on Chr11, detected considerable levels of genetic variation. Maximum parsimony analysis of genetic distance revealed four main clusters and clearly separated most “da serbo” landraces from the outgroups. One of the clusters grouped the landraces from the Mount Vesuvius area, though no further indications of a geographic-specific structure were found. STRUCTURE analysis confirmed the presence of four genetic groups within the collection, with admixture between them. A survey of non-synonymous SNPs highlighted several mutations in genes related to stress tolerance and fruit maturation/quality. Overall, our results suggest possible exchange of “da serbo” genetic material between southern Italy regions and indicate that the long storage “da serbo” germplasm could be a promising reservoir of peculiar alleles for traits of interest.     

High-throughput root phenotyping screens identify genetic loci associated with root architectural traits in Brassica napus under contrasting phosphate availabilities

Background and Aims

Phosphate (Pi) deficiency in soils is a major limiting factor for crop growth worldwide. Plant growth under low Pi conditions correlates with root architectural traits and it may therefore be possible to select these traits for crop improvement. The aim of this study was to characterize root architectural traits, and to test quantitative trait loci (QTL) associated with these traits, under low Pi (LP) and high Pi (HP) availability in Brassica napus.

Methods

Root architectural traits were characterized in seedlings of a double haploid (DH) mapping population (n = 190) of B. napus [‘Tapidor’ × ‘Ningyou 7’ (TNDH)] using high-throughput phenotyping methods. Primary root length (PRL), lateral root length (LRL), lateral root number (LRN), lateral root density (LRD) and biomass traits were measured 12 d post-germination in agar at LP and HP.

Key Results

In general, root and biomass traits were highly correlated under LP and HP conditions. ‘Ningyou 7’ had greater LRL, LRN and LRD than ‘Tapidor’, at both LP and HP availability, but smaller PRL. A cluster of highly significant QTL for LRN, LRD and biomass traits at LP availability were identified on chromosome A03; QTL for PRL were identified on chromosomes A07 and C06.

Conclusions

High-throughput phenotyping of Brassica can be used to identify root architectural traits which correlate with shoot biomass. It is feasible that these traits could be used in crop improvement strategies. The identification of QTL linked to root traits under LP and HP conditions provides further insights on the genetic basis of plant tolerance to P deficiency, and these QTL warrant further dissection.     

Evaluation of Genetic Diversity of Chilli Landraces from North Eastern India Based on Morphology, SSR Markers and the Pun1 Locus

The chilli (Capsicum sp.) germplasm found throughout North Eastern (NE) India exhibits wide variability in fruit morphology, pungency, bearing habit and crop duration. As the genetic resources of chilli landraces from this region are not well documented, it is likely that they have hitherto unknown alleles and/or genes for economically important traits. In this study, 53 chilli accessions from different areas of this NE region were evaluated for genetic diversity using various morphological characters and 50 simple sequence repeat markers. It was found that erect and campanulate fruit types are grouped in separate clusters. The number of alleles per locus ranged from 3 to 9 with an average of 5.36. The average polymorphic information content value was 0.52. Percentage variation among populations, within individuals of population and within individuals was found to be 34, 57.9 and 8.05 %, respectively, indicating diversity in the landraces sampled. Allele mining across acyltransferase 3 (AT3) gene in a set of landraces led to identification of new single nucleotide polymorphisms (SNPs). Sequence analysis of the 2,349 bp AT3 region revealed the presence of a total of 79 SNPs and 3 indels. This overview of diversity of chilli landraces from NE India paves the way for conservation and utilisation of germplasm and contributes to the development of systematic breeding strategies.     

Patterns of genetic diversity in the Andean gene pool of common bean reveal a candidate domestication gene

Most studies on the genetic diversity of common bean (Phaseolus vulgaris L.) have focussed on accessions from the Mesoamerican gene pool compared to the Andean gene pool. A deeper knowledge of the genetic structure of Argentinian germplasm would enable researchers to determine how the Andean domestication event affected patterns of genetic diversity in domesticated beans and to identify candidates for genes targeted by selection during the evolution of the cultivated common bean. A collection of 116 wild and domesticated accessions representing the diversity of the Andean bean in Argentina was genotyped by means of 114 simple sequence repeat (SSR) markers. Forty-seven Mesoamerican bean accessions and 16 Andean bean accessions representing the diversity of Andean landraces and wild accessions were also included. Using the Bayesian algorithm implemented in the software STRUCTURE we identified five major groups that correspond to Mesoamerican and Argentinian wild accessions and landraces and a group that corresponds to accessions from different Andean and Mesoamerican countries. The neighbour-joining algorithm and principal coordinate clustering analysis confirmed the genetic relationships among accessions observed with the STRUCTURE analysis. Argentinian accessions showed a substantial genetic variation with a considerable number of unique haplotypes and private alleles, suggesting that they may have played an important role in the evolution of the species. The results of statistical analyses aimed at identifying genomic regions with consistent patterns of variation were significant for 35 loci (~20 % of the SSRs used in the Argentinian accessions). One of these loci mapped in or near the genomic region of the glutamate decarboxylase gene. Our data characterize the population structure of the Argentinian germplasm. This information on its diversity will be very valuable for use in introgressing Argentinian genes into commercial varieties because the majority of present-day common bean varieties are of Andean origin.     

Genetic diversity,population structure,and linkage disequilibrium of elite and local apple accessions from Belgium using the IRSC array

The identification of molecular markers associated with economic and quality traits will help improve breeding for new apple (Malus × domestica Borkh.) cultivars. Tools such as the 8K apple SNP array developed by the RosBREED consortium allow for high-throughput genotyping of SNP polymorphisms within collections. However, genetic characterization and the identification of population stratification and kinship within germplasm collections is a fundamental prerequisite for identifying robust marker–trait associations. In this study, a collection of apple germplasm originally developed for plant architectural studies and consisting of both non-commercial/local and elite accessions was genotyped using the 8K apple SNP array to identify cryptic relationships between accessions, to analyze population structure and to calculate the linkage disequilibrium (LD). A total of nine pairs of synonyms and several triploids accessions were identified within the 130 accessions genotyped. In addition, most of the known parent-child relations were confirmed, and several putative, previously unknown parent-child relations were identified among the local accessions. No clear subgroups could be identified although some separation between local and elite accessions was evident. The study of LD showed a rapid decay in our collection, indicating that a larger number of SNPs is necessary to perform whole genome association mapping. Finally, an association mapping effort for architectural traits was carried out on a small number of accessions to estimate the feasibility of this approach.     

Association analysis of fiber quality traits and exploration of elite alleles in Upland cotton cultivars/accessions （Gossypium hirsutum L.）

Exploring the elite al eles and germplasm acces-sions related to fiber quality traits wil accelerate the breeding of cotton for fiber quality improvement. In this study, 99 Gossypium hirsutum L. accessions with diverse origins were used to perform association analysis of fiber quality traits using 97 polymorphic microsatel ite marker primer pairs. A total of 107 significant marker-trait associations were detected for three fiber quality traits under three different environments, with 70 detected in two or three environments and 37 detected in only one environment. Among the 70 significant marker-trait associations, 52.86% were reported previously, implying that these are stable loci for target traits. Furthermore, we detected a large number of elite al eles associated simulta-neously with two or three traits. These elite al eles were mainly from accessions col ected in China, introduced to China from the United States, or rare al eles with a frequency of less than＆amp;nbsp;5%. No one cultivar contained more than half of the elite al eles, but 10 accessions were col ected from China and the two introduced from the United States did contain more than half of these al eles. Therefore, there is great potential for mining elite al eles from germplasm accessions for use in fiber quality improvement in modern cotton breeding.     

Identification of loci controlling adaptation in Chinese soya bean landraces via a combination of conventional and bioclimatic GWAS

Landraces often contain genetic diversity that has been lost in modern cultivars, including alleles that confer enhanced local adaptation. To comprehensively identify loci associated with adaptive traits in soya bean landraces, for example flowering time, a population of 1938 diverse landraces and 97 accessions of the wild progenitor of cultivated soya bean, Glycine soja was genotyped using tGBS^®. Based on 99 085 high‐quality SNPs, landraces were classified into three sub‐populations which exhibit geographical genetic differentiation. Clustering was inferred from STRUCTURE, principal component analyses and neighbour‐joining tree analyses. Using phenotypic data collected at two locations separated by 10 degrees of latitude, 17 trait‐associated SNPs (TASs) for flowering time were identified, including a stable locus Chr12:5914898 and previously undetected candidate QTL/genes for flowering time in the vicinity of the previously cloned flowering genes, E1 and E2. Using passport data associated with the collection sites of the landraces, 27 SNPs associated with adaptation to three bioclimatic variables (temperature, daylength, and precipitation) were identified. A series of candidate flowering genes were detected within linkage disequilibrium (LD) blocks surrounding 12 bioclimatic TASs. Nine of these TASs exhibit significant differences in flowering time between alleles within one or more of the three individual sub‐populations. Signals of selection during domestication and/or subsequent landrace diversification and adaptation were detected at 38 of the 44 flowering and bioclimatic TASs. Hence, this study lays the groundwork to begin breeding for novel environments predicted to arise following global climate change.     

重庆地区玉米种质资源调查与收集

"第三次全国农作物种质资源普查与收集行动"重庆项目组于2015-2016年在重庆市石柱县、巫山县、巫溪县、城口县、奉节县、武隆县、秀山县、云阳县、潼南区、合川区、江津区和万盛经济技术开发区这12个重点区县75个乡镇的181个村开展了农作物资源的系统调查与收集,并向重庆市其他区县以普查的形式进行了优异资源的征集,通过这两种方式共收集到资源1379份,其中玉米地方品种122份。本文对收集到的重庆玉米地方品种资源的分布区域、特点和特异资源进行了整理和分析。从玉米资源的水平分布来看,收集的资源多分布于重庆的东北、南部和武陵山地区,中西部地区资源分布较少;从玉米资源的垂直分布来看,收集的资源多分布于800~1000 m的中山和1200~1600 m的高山地区。收集的玉米资源籽粒多为硬粒型,籽粒颜色多为白色。收集的特异玉米地方品种中,大籽黄高抗穗粒腐病;野鸡爪根系发达,具有极强的耐瘠性;铁籽白、青壳早、金黄早食用品质良好,具有良好的淀粉加工特性。这些资源对现代玉米品种在品质、抗逆性、适应性和营养高效利用等性状方面的改良具有较强的利用价值。     

水稻一多拷贝微卫星DNA多态性分析

用一个多拷贝微卫星 DNA标记分析了238份栽培水稻的遗传多样性及遗传多样性从农家品种到现代栽培品种的动态变化。共检测出16种长度变异类型和32种表现型,但长度变异类型数、表现型数和表现型多样性水平在农家品种和现代栽培品种间没有显著差别。该标记在遗传资源评价和DNA指纹图谱建设中有重要的应用价值,也是研究环境或人工对多拷贝基因选择作用的一个良好模型。 Abstract:The genetic diversity of 238 cultivated rice and its difference between landraces and modern cultivars have been assayed using a multiple copy microsatellite DNA marker.Although 16 length variants and 32 phenotypes were found in all accessions,no significant differences in number of length variants,number of phenotypes and phenotypic diversity were detected between landraces and modern cultivars.This marker is of great value in evaluating genetic germplasm and constructing DNA fingerprints of rice and provides an elite model for tracing effectiveness of natural and artificial selection on multiple copy genes.     

Dissection of the genetic architecture of three seed‐quality traits and consequences for breeding in Brassica napus

Genome‐wide association studies (GWASs) combining high‐throughput genome resequencing and phenotyping can accelerate the dissection of genetic architecture and identification of genes for plant complex traits. In this study, we developed a rapeseed genomic variation map consisting of 4 542 011 SNPs and 628 666 INDELs. GWAS was performed for three seed‐quality traits, including erucic acid content (EAC), glucosinolate content (GSC) and seed oil content (SOC) using 3.82 million polymorphisms in an association panel. Six, 49 and 17 loci were detected to be associated with EAC, GSC and SOC in multiple environments, respectively. The mean total contribution of these loci in each environment was 94.1% for EAC and 87.9% for GSC, notably higher than that for SOC (40.1%). A high correlation was observed between phenotypic variance and number of favourable alleles for associated loci, which will contribute to breeding improvement by pyramiding these loci. Furthermore, candidate genes were detected underlying associated loci, based on functional polymorphisms in gene regions where sequence variation was found to correlate with phenotypic variation. Our approach was validated by detection of well‐characterized FAE1 genes at each of two major loci for EAC on chromosomes A8 and C3, along with MYB28 genes at each of three major loci for GSC on chromosomes A9, C2 and C9. Four novel candidate genes were detected by correlation between GSC and SOC and observed sequence variation, respectively. This study provides insights into the genetic architecture of three seed‐quality traits, which would be useful for genetic improvement of B. napus.     

Analysis of a diverse global Pisum sp. collection and comparison to a Chinese local P. sativum collection with microsatellite markers

Twenty-one informative microsatellite loci were used to assess and compare the genetic diversity among Pisum genotypes sourced from within and outside China. The Chinese germplasm comprised 1243 P. sativum genotypes from 28 provinces and this was compared to 774 P. sativum genotypes that represented a globally diverse germplasm collection, as well as 103 genotypes from related Pisum species. The Chinese P. sativum germplasm was found to contain genotypes genetically distinct from the global gene pool sourced outside China. The Chinese spring type genotypes were separate from the global gene pool and from the other main Chinese gene pool of winter types. The distinct Chinese spring gene pool comprised genotypes from Inner Mongolia and Sha'anxi provinces, with those from Sha'anxi showing the greatest diversity. The other main gene pool within China included both spring types from other northern provinces and winter types from central and southern China, plus some accessions from Inner Mongolia and Sha'anxi. A core collection of Chinese landraces chosen to represent molecular diversity was compared both to the wider Chinese collection and to a geographically diverse core collection of Chinese landraces. The average gene diversity and allelic richness per locus of both the micro-satellite based core and the wider collection were similar, and greater than the geographically diverse core. The genetic diversity of P. sativum within China appears to be quite different to that detected in the global gene pool, including the presence of several rare alleles, and may be a useful source of allelic variation for both major gene and quantitative traits.     

The genetic basis of drought tolerance in the high oil crop Sesamum indicum

Unlike most of the important food crops, sesame can survive drought but severe and repeated drought episodes, especially occurring during the reproductive stage, significantly curtail the productivity of this high oil crop. Genome‐wide association study was conducted for traits related to drought tolerance using 400 diverse sesame accessions, including landraces and modern cultivars. Ten stable QTLs explaining more than 40% of the phenotypic variation and located on four linkage groups were significantly associated with drought tolerance related traits. Accessions from the tropical area harboured higher numbers of drought tolerance alleles at the peak loci and were found to be more tolerant than those from the northern area, indicating a long‐term genetic adaptation to drought‐prone environments. We found that sesame has already fixed important alleles conferring survival to drought which may explain its relative high drought tolerance. However, most of the alleles crucial for productivity and yield maintenance under drought conditions are far from been fixed. This study also revealed that pyramiding the favourable alleles observed at the peak loci is of high potential for enhancing drought tolerance in sesame. In addition, our results highlighted two important pleiotropic QTLs harbouring known and unreported drought tolerance genes such as SiABI4, SiTTM3, SiGOLS1, SiNIMIN1 and SiSAM. By integrating candidate gene association study, gene expression and transgenic experiments, we demonstrated that SiSAM confers drought tolerance by modulating polyamine levels and ROS homeostasis, and a missense mutation in the coding region partly contributes to the natural variation of drought tolerance in sesame.     

Quantitative trait loci and candidate genes underlying genotype by environment interaction in the response of Arabidopsis thaliana to drought

Drought stress was imposed on two sets of Arabidopsis thaliana genotypes grown in sand under short‐day conditions and analysed for several shoot and root growth traits. The response to drought was assessed for quantitative trait locus (QTL) mapping in a genetically diverse set of Arabidopsis accessions using genome‐wide association (GWA) mapping, and conventional linkage analysis of a recombinant inbred line (RIL) population. Results showed significant genotype by environment interaction (G×E) for all traits in response to different watering regimes. For the RIL population, the observed G×E was reflected in 17 QTL by environment interactions (Q×E), while 17 additional QTLs were mapped not showing Q×E. GWA mapping identified 58 single nucleotide polymorphism (SNPs) associated with loci displaying Q×E and an additional 16 SNPs associated with loci not showing Q×E. Many candidate genes potentially underlying these loci were suggested. The genes for RPS3C and YLS7 were found to contain conserved amino acid differences when comparing Arabidopsis accessions with strongly contrasting drought response phenotypes, further supporting their candidacy. One of these candidate genes co‐located with a QTL mapped in the RIL population.     

Genome‐wide association analyses reveal complex genetic architecture underlying natural variation for flowering time in canola

Optimum flowering time is the key to maximize canola production in order to meet global demand of vegetable oil, biodiesel and canola‐meal. We reveal extensive variation in flowering time across diverse genotypes of canola under field, glasshouse and controlled environmental conditions. We conduct a genome‐wide association study and identify 69 single nucleotide polymorphism (SNP) markers associated with flowering time, which are repeatedly detected across experiments. Several associated SNPs occur in clusters across the canola genome; seven of them were detected within 20 Kb regions of a priori candidate genes; FLOWERING LOCUS T, FRUITFUL, FLOWERING LOCUS C, CONSTANS, FRIGIDA, PHYTOCHROME B and an additional five SNPs were localized within 14 Kb of a previously identified quantitative trait loci for flowering time. Expression analyses showed that among FLC paralogs, BnFLC.A2 accounts for ~23% of natural variation in diverse accessions. Genome‐wide association analysis for FLC expression levels mapped not only BnFLC.C2 but also other loci that contribute to variation in FLC expression. In addition to revealing the complex genetic architecture of flowering time variation, we demonstrate that the identified SNPs can be modelled to predict flowering time in diverse canola germplasm accurately and hence are suitable for genomic selection of adaptative traits in canola improvement programmes.     

东北春大豆样本的代表性及其SSR位点的遗传多样性分析

从3226份东北春大豆总体中选择283份春大豆种质,用质量性状和数量性状进行检测,对总体的代表性为80%.利用筛选出61对SSR核心引物对具代表性的东北春大豆样本进行分析,共检测到534个等位变异,平均每个位点的等位变异为8.75个,变幅为2～16个;遗传多样性指数变化范围在0.406～0.886,平均为0.704;东北春大豆样本在大多数位点上有优势等位变异,从而降低了其遗传多样性.其中35份种质具有特异等位变异,分布在29个位点上;各个位点上分化系数均较小,遗传多样性分化程度较低.东北春大豆中3个省种质的共有等位变异较多,以吉林省和辽宁省种质的遗传多样性表现较为一致,均高于黑龙江省种质的遗传多样性.地方品种的遗传多样性高于育成品种.东北春大豆种质资源的遗传多样性分布特点为有目的选择杂交亲本拓宽遗传基础以培育新品种提供了理论依据.     

Inheritance and QTL mapping of related root traits in soybean at the seedling stage

Key message

This study provides a foundation for further research on root genetic regulation and molecular breeding with emphasis on correlations among root traits to ensure robust root growth and well-developed root systems.

Abstract

A set of 447 recombinant inbred lines (RILs) derived from a cross between Jingdou23 (cultivar, female parent) and ZDD2315 (semi-wild, male parent) were used to analyze inheritance and detect QTLs related to root traits at the seedling stage using major gene plus polygene mixed inheritance analysis and composite interval mapping. The results showed that maximum root length (MRL) was controlled by three equivalent major genes, lateral root number (LRN) was controlled by two overlapping major genes, root weight (RW) and volume (RV) were controlled by four equivalent major genes. Hypocotyl length (HL) was controlled by four additive main genes, and hypocotyl weight (HW) was controlled by four additive and additive × additive epistatic, major genes; however, polygene effects were not detected in these traits. Shoot weight (SW) was controlled by multi-gene effects, but major gene effects were not detected. Twenty-four QTLs for MRL, LRN, RW, RV, SW, HL, HW were mapped on LG A1 (chromosome 5), LG A2 (chromosome 8), LG B1 (chromosome 11), LG B2 (chromosome 14), LG C2 (chromosome 6), LG D1b (chromosome 2), LG F_1 (chromosome 13), LG G (chromosome 18), LG H_1 (chromosome 12), LG H_2 (chromosome 12), LG I (chromosome 20), LG K_2 (chromosome 9), LG L (chromosome 19), LG M (chromosome 7), LG N (chromosome 3), LG O (chromosome 10), separately. Root traits were shown to have complex genetic mechanisms at the seedling stage, SW was controlled by multi-gene effects, and the other six traits were controlled by major gene effects. It is concluded that correlations among root traits must be considered to improve the development of beneficial root traits.     

Mixed model association scans of multi-environmental trial data reveal major loci controlling yield and yield related traits in Hordeum vulgare in Mediterranean environments

An association panel consisting of 185 accessions representative of the barley germplasm cultivated in the Mediterranean basin was used to localise quantitative trait loci (QTL) controlling grain yield and yield related traits. The germplasm set was genotyped with 1,536 SNP markers and tested for associations with phenotypic data gathered over 2?years for a total of 24?year?×?location combinations under a broad range of environmental conditions. Analysis of multi-environmental trial (MET) data by fitting a mixed model with kinship estimates detected from two to seven QTL for the major components of yield including 1000 kernel weight, grains per spike and spikes per m², as well as heading date, harvest index and plant height. Several of the associations involved SNPs tightly linked to known major genes determining spike morphology in barley (vrs1 and int-c). Similarly, the largest QTL for heading date co-locates with SNPs linked with eam6, a major locus for heading date in barley for autumn sown conditions. Co-localization of several QTL related to yield components traits suggest that major developmental loci may be linked to most of the associations. This study highlights the potential of association genetics to identify genetic variants controlling complex traits.     

Comparative analysis of microsatellite DNA polymorphism in landraces and cultivars of rice

Genetic polymorphisms of ten microsatellite DNA loci were examined among 238 accessions of landraces and cultivars that represent a significant portion of the distribution range for both indica and japonica groups of cultivated rice. In all, 93 alleles were identified with these ten markers. The number of alleles varied from a low of 3 or 4 at each of four loci, to an intermediate value of 9–14 at five loci, and to an extra-ordinarily high 25 at one locus. The numbers of alleles per locus are much larger than those detected using other types of markers. The number of alleles detected at a locus is significantly correlated with the number of simple sequence repeats in the targeted microsatellite DNA. Indica rice has about 14% more alleles than japonica rice, and such allele number differences are more pronounced in landraces than in cultivars. The indica-japonica differentiation component accounted for about 10% of the diversity in the total sample, and twice as much differentiation was detected in cultivars as in landraces. About two-thirds as many alleles were observed in cultivars as in landraces; another two-thirds of the alleles in the cultivar group were found in modern elite cultivars or parents of hybrid rice. The majority of the simple sequence repeat (SSR) alleles that were present in high or intermediate frequencies in landraces ultimately survived into modern elite cultivars and hybrids. The greater resolving power and the efficient production of massive amounts of SSR data may be particularly useful for germplasm assessment and evolutionary studies of crop plants.     

Unlocking the Genetic Diversity of Maize Landraces with Doubled Haploids Opens New Avenues for Breeding

Landraces are valuable genetic resources for broadening the genetic base of elite germplasm in maize. Extensive exploitation of landraces has been hampered by their genetic heterogeneity and heavy genetic load. These limitations may be overcome by the in-vivo doubled haploid (DH) technique. A set of 132 DH lines derived from three European landraces and 106 elite flint (EF) lines were genotyped for 56,110 single nucleotide polymorphism (SNP) markers and evaluated in field trials at five locations in Germany in 2010 for several agronomic traits. In addition, the landraces were compared with synthetic populations produced by intermating DH lines derived from the respective landrace. Our objectives were to (1) evaluate the phenotypic and molecular diversity captured within DH lines derived from European landraces, (2) assess the breeding potential (usefulness) of DH lines derived from landraces to broaden the genetic base of the EF germplasm, and (3) compare the performance of each landrace with the synthetic population produced from the respective DH lines. Large genotypic variances among DH lines derived from landraces allowed the identification of DH lines with grain yields comparable to those of EF lines. Selected DH lines may thus be introgressed into elite germplasm without impairing its yield level. Large genetic distances of the DH lines to the EF lines demonstrated the potential of DH lines derived from landraces to broaden the genetic base of the EF germplasm. The comparison of landraces with their respective synthetic population showed no yield improvement and no reduction of phenotypic diversity. Owing to the low population structure and rapid decrease of linkage disequilibrium within populations of DH lines derived from landraces, these would be an ideal tool for association mapping. Altogether, the DH technology opens new opportunities for characterizing and utilizing the genetic diversity present in gene bank accessions of maize.