Drought is one of the major factors limiting wheat yield in many developing countries worldwide. Parameters of chlorophyll a fluorescence kinetics under drought stress conditions have been used to characterize dehydration tolerance in wheat. In the present study, a set of 94 doubled haploid lines obtained from Chinese Spring × SQ1 (CSDH), mapped with 450 markers, was evaluated for yield (grain dry weight/main stem ear), number of grains/main stem ear (NG) and chlorophyll a fluorescence parameters (FC) under moderate and severe drought stress, and compared with results for well-watered plants. quantitative trait loci (QTLs) were identified using Windows QTLCartographer version 2.5 software and the results were analysed using single-marker analysis (SMA) and composite interval mapping (CIM). Analysis using SMA and CIM showed mostly similar QTLs for all traits, though more QTLs were identified by SMA than by CIM. The genetic control of yield, NG and FC varied considerably between drought-stressed and non-stressed plants. Although no major QTL co-locations were found for yield and FC using CIM, the co-location of QTLs for NG, yield and Fv/Fm in drought-stressed plants was observed on chromosome 5A using SMA.

Snow mould caused by Microdochium nivale (Fr.) Samuels & Hallett is the most widespread seedling disease in winter cereals. Due to the complexity of the resistance mechanisms, a poorly understood genetic background and strong interaction with winter weather conditions, it is difficult to assess the resistance of triticale cultivars via conventional inoculation methods. Genetic resistance is the most economical and environmental friendly way to control M. nivale infection; therefore, the objective of this study was to detect the quantitative trait loci (QTLs) associated with resistance components of winter triticale in a mapping population derived from a cross of the ‘Modus’ (partly resistant) and ‘SaKa 3006’ (sensitive) varieties. High-resolution mapping was conducted by using 1518 molecular markers (diversity arrays technology, simple sequence repeat and amplified fragment length polymorphism). Partial resistance components assessed in this study, i.e. candidate QTLs, were detected on chromosomes 1B, 2A, 3A, 3B, 5A, 5B, 6A, 6B and 7B, whereas QTLs describing overall seedling vitality in non-infected control plants were located on chromosomes 1B, 2B, 3A, 5A, 7B and 7R.

Rice is a salt-sensitive species with enormous genetic variation for salt tolerance hidden in its germplasm pool. The EcoTILLING technique allows us to assign haplotypes, thus reducing the number of accessions to be sequenced, becoming a cost-effective, time-saving and high-throughput method, ideal to be used in laboratories with limited financial resources. Aiming to find alleles associated with salinity tolerance, we are currently using the EcoTILLING technique to detect single nucleotide polymorphisms (SNPs) and small indels across 375 germplasm accessions representing the diversity available in domesticated rice. We are targeting several genes known to be involved in salt stress signal transduction (OsCPK17) or tolerance mechanisms (SalT). So far, we found a total of 15 and 23 representative SNPs or indels in OsCPK17 and SalT, respectively. These natural allelic variants are mostly located in 3′-untranslated region, thus opening a new path for studying their potential contribution to the regulation of gene expression and possible role in salt tolerance.

A coiled coil-nucleotide binding site-leucine-rich repeat gene RB/Rpi-blb1 isolated from Solanum bulbocastanum confers broad-spectrum resistance to Phytophthora infestans and is currently employed in potato breeding for durable late blight (LB) resistance. RB homologues were reported in several Solanum species; some of them retained defence function. Here, we report additional evidence on RB-like sequences in 21 Solanum species of the section Petota. The panel of Solanum species was screened with three RB-related PCR markers. RB-like sequences were found in every tested Solanum accession, suggesting universal distribution of RB structural homologues among Solanum genomes, while locus-specific RB-629 was found only in 15 species. Phylogenetic analysis of RB-629 sequences suggested a highly conservative pattern of polymorphisms that was neither species- nor series-specific. Apparently, duplication and evolution of RB-like loci preceded Solanum speciation. Marker presence and particular haplotypes were not immediately associated with high LB resistance.

New races of Phytophthora infestans rapidly defeat potato late blight (LB) resistance based on Solanum demissum germplasm, and breeders search for new sources of durable LB resistance. We developed and verified six sequence characterized amplified region markers recognizing the race-specific genes R1 and R3 of S. demissum and the broad-spectrum resistance gene RB of S. bulbocastanum and the germplasms of these species and used them to screen 209 accessions of 21 wild Solanum species. In addition to S. demissum, homologues of R1 and R3 were found in several species of series Demissa,Longipedicellata and diploid Tuberosa; R3 homologues were also detected in S. bulbocastanum,S. cardiophyllum and S. ehrenbergii. The RB homologues were found in a wider range of Solanum species. The markers of R1 and R3 genes reliably discerned between germplasms of S. tuberosum ssp. tuberosum and wild sources of LB resistance. Following introgression, the species-specific markers of demissum and bulbocastanum germplasm were rapidly lost, whereas the markers of R1 and R3 genes lasted through several meiotic generations and were maintained at high frequencies in modern potato cultivars. The presence of these markers in demissoid potato cultivars was significantly associated with LB resistance, presuming that both genes contribute to overall defence response.

Hordeum chilense Roem. et Schultz. is a diploid wild barley native to Chile and Argentina. The high crossability of this species with other members of the Triticeae tribe promoted the development of the new species × Tritordeum Ascherson et Graebner. Hexaploid tritordeum was developed from the hybrid derived from the cross between H. chilense (used as female parent) and durum wheat. The interest of H. chilense is based on the presence of traits potentially useful for wheat breeding, including high endosperm carotenoid content, septoria tritici blotch resistance and abiotic stress tolerance. Besides, the variability at cytoplasm level is also important in this species. The development of common wheat–H. chilense alloplasmic lines (nucleus from wheat and cytoplasm from H. chilense) results in fertile or male sterile genotypes, depending on the accession donating the cytoplasm. Furthermore, these alloplasmic lines constitute an ideal system for deepening our knowledge on nuclear–cytoplasm interactions. In conclusion, H. chilense is an interesting source of variability for wheat breeding.

Successful development of new sorghum cultivars and hybrids to ensure sustainable production depends largely on the availability of genetic resources with desirable traits such as pest resistance. Our recent research has focused on improvement of crop protection against greenbugs using the worldwide germplasm collection and genomics-based approaches. First, we conducted the systematic evaluation of a worldwide germplasm collection in order to identify new sources of greenbug resistance. Twenty-one resistant lines were identified, which offered new sources of resistance to sorghum breeding. Molecular markers used to assess the genetic diversity among those resistant lines suggested relatively diverse resistant sources in the sorghum germplasm collection. More recently, a mapping project was executed to associate the resistance genes with sorghum chromosomes. The mapping data indicated one major and a minor quantitative trait loci reside on chromosome 9 and are responsible for resistance to greenbug. In addition, cDNA microarrays were used to monitor greenbug-induced gene expression in sorghum plants. This study has developed a transcriptional profile for sorghum in response to greenbug attack, which provides us with useful molecular information for discovery of greenbug resistance genes and a better understanding of the genetic mechanisms controlling host defences in sorghum.

The importance of plant genetic resources for the future of agricultural production and for achieving food security necessitates the study of the factors affecting their most efficient exploitation, particularly in breeding programmes. The established negative correlation between competitive and yielding ability is emerging as an important, yet overlooked cause of seed and variety degradation. Because of this negative correlation, the low yielding, strong competing plants within the variety or the germplasm under study acquire a survival advantage over the high yielding, weak competing plants when propagated under dense stands, leading to a gradual cultivar degeneration and identity loss. Moreover, this gradual degeneration prevents selecting for the positive and novel adaptive variation that is endlessly released by the genome in response to biotic (e.g. mutating pathogens) and abiotic stresses. The application of nonstop selection on individual plants grown in the absence of competition using a novel selection equation demonstrates an effective means to counteract the negative effects and accelerate progress through selection.

In this study, several genotypes of cultivated (Solanum tuberosum subsp. andigena, S. phureja) and wild, tuber-bearing Solanum species (S. chacoense, S. pinnatisectum) were examined for concentrations of antioxidants, soluble phenols and proteins in their tuber tissue. The potato genotypes differed considerably in all these traits. Amounts of antioxidants ranged from 0.06 to 4.22 μg/mg fresh weight (fw) when the ascorbic acid equivalent was measured and from 0.08 to 3.98 μg/mg fw for the trolox equivalent. The wild species S. pinnatisectum exhibited on average higher levels of both types of antioxidants than the other Solanum species, and it also had the highest quantities of soluble phenols and proteins in its tuber tissue. Among the species, S. phureja ranked on the lowest level of antioxidant potential.

Mineral nutrient deficiencies are a worldwide problem that is directly correlated with poverty and food insecurity. The most common of these is iron deficiency; more than one-third of the world's population suffer from iron deficiency-induced anaemia, 80% of which are in developing countries. The consequences of iron deficiency include increased mortality and morbidity rates, diminished cognitive abilities in children and reduced labour productivity, which in turn stagnates national development. The developed world has made tremendous success in alleviating nutrient deficiencies through dietary diversification, food product fortification, improved public health care and supplementation. In developing countries, these strategies are often expensive and difficult to sustain, especially in rural areas. The rural poor typically consume what they grow and are dependent upon a small number of staple crops for the vast majority of their nutrition. Therefore, genetic improvement of staple crops (biofortification) is the most cost-effective and sustainable solution to this global health problem. In this study, we describe a strategy to enhance iron nutritional quality in maize using a human cell culture (Caco-2)-based bioassay as a phenotyping tool to guide genetic analysis of the trait. We also report validation of this approach using an animal feeding study.

Hulled wheats are neglected crops that have potential in plant breeding programmes of modern durum and common wheat. Among these wheats, three species were widely cultivated in Spain until the mid 20th century: Triticum monococcum ssp. monococcum (einkorn), Triticum turgidum ssp. dicoccum (emmer) and Triticum aestivum ssp. spelta (spelt). One important aspect of wheat grain quality is starch composition, which is related to the action of waxy proteins. A collection of 536 accessions of Spanish hulled wheats was analyzed for waxy protein composition using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Polymorphism was found for the Wx-A1, Wx-B1 and Wx-D1 proteins, including new and null alleles in the three species. An allelic variant with an electrophoretic mobility not previously described was found in einkorn wheat. In emmer and spelt, some alleles with different mobility were also found. A Wx-B1 null allele was detected in emmer wheat, and null alleles for Wx-A1, Wx-B1 and Wx-D1 were found in spelt wheat. The variations found could be used to enlarge the gene pool available to breeders, and to design new cultivars with different levels of amylose content.

Triticum urartu Thum. ex Gandil. is a wild species identified as A-genome donor for polyploid wheats, which could be used as gene source for wheat breeding. The high-molecular weight glutenin subunits are endosperm storage proteins that are associated with bread-making quality. In T. urartu, these proteins are encoded by the Ax and Ay genes at the Glu-Au1 locus. The Ay gene of 17 Glu-Au1 allelic variants previously detected in this species has been analysed using PCR amplification and digestion of the PCR products with two endonucleases (DdeI and PstI). The combination of two restriction patterns has revealed variations between the active and inactive alleles, and within each type. This variation, especially that detected among the active alleles, could enlarge the high-quality genetic pool of modern wheat and be used for bread-making quality improvement in durum and common wheat.

Protein disulphide isomerase (PDI) catalyses the formation, reduction and isomerization of disulphide bonds in the newly synthesized secretory proteins. Plant PDIs have been shown to be involved in the folding and deposition of seed storage proteins, which makes this enzyme particularly interesting in wheat, as flour quality is strongly affected by composition and structure of seed storage proteins. In hexaploid wheat cultivar (AABBDD) Chinese Spring (CS), the genomic, complementary DNA and promoter sequences of the three homoeologous gene encoding PDI had been isolated and characterized in a previous study revealing high levels of sequence conservation. In this study, we report the isolation and sequencing of a ~700 bp region, comprising ~600 bp of the putative promoter region and 88 bp of the first exon of the typical PDI gene, in five accessions each from Triticum urartu (AA), Aegilops speltoides (BB) and Aegilops tauschii (DD). Sequence analysis indicated large variation among sequences belonging to the different genomes, while close similarity was found within each species and with the corresponding homoeologous PDI sequences of Triticum aestivum cv. CS (AABBDD) resulting in an overall high conservation of the regulatory motifs conferring endosperm-specific expression.

Eight genes encoding protein disulphide isomerase (PDI)-like proteins in bread wheat were cloned and characterized and their genomic structure was compared with that of homoeologous genes isolated from other plant species. Fourteen wheat cDNA sequences of PDI-like genes were amplified and cloned; eight of them were relative to distinct PDI-like genes, whereas six corresponded to homoeologous sequences. Also, the genomic sequences of the eight non-homoeologous genes were amplified and cloned. Phylogenetic analysis, which included eight genes encoding PDI-like proteins and the gene encoding the typical PDI, assigned at least one of them to each of the eight major clades identified in the phylogenetic tree of the PDI gene family of plants. The close chromosome synteny between wheat and rice was confirmed by the location of the homoeologous genes of the PDI family in syntenic regions of the two species. Within the same phylogenetic group, a high level of conservation, in terms of sequence homology, genomic structure and domain organization, was detected between wheat and the other plant species. The high level of conservation of sequence and genomic organization within the PDI gene family, even between distant plant species, might be ascribed to the key metabolic roles of their protein products.

The deduced amino-acid sequences of 17 protein disulphide isomerase (PDI) and PDI-like cDNAs of wheat assigned to nine homoeologous groups were searched for conserved motives by comparison with characterized sequences in different protein databases. The wheat protein sequences encoded by genes of different homoelogous groups showed a high level of structural similarity with the corresponding protein sequences of other species clustering into the same phylogenetic group. The proteins of five groups (I–V) share two thioredoxin-like active domains and show structural similarities with the corresponding proteins of higher eukaryotes, whereas those of the remaining three groups (VI–VIII) contain a single thioredoxin-like active domain. The expression analysis of the nine non-homoeologous wheat genes, which was carried out by quantitative RT-PCR in developing caryopses and in seedlings subjected to temperature stresses, showed their constitutive although highly variable transcription rate. The comprehensive structural and transcriptional characterization of the PDI and PDI-like genes of wheat performed in this study represents a basis for future functional characterization of the PDI gene family in the hexaploid context of bread wheat.

Deploying whole and dissected nuclear genome of wild Triticeae species in the homoeologous wheat genetic background through inter-specific hybridization and introgression is a lower cost and effective option to prepare wheat germplasm with unexploited genes for disease resistance and enhanced grain yield and quality traits. The whole nuclear genomes of Dasypyrum villosum (Dv) and T. turgidum var durum have been combined, and an homoploid derivative of the original amphiploid displayed typical ‘farro’ spike morphology, tough rachis and the adaptive traits of Dv such as high resistance to diseases (caused by Tilletia tritici, Blumeria graminis f. sp. tritici, Puccinia triticina and P. graminis f. sp. tritici), heading earliness and fortified caryopses (high protein and micronutrient contents). The dissection of the Dv genome by either ‘Triticum aestivum cv Chinese Spring (CS) × hexaploid amphiploid’ or ‘(CS × Dv) × CS’ hybridization and backcrossing provided wheat introgression breeding lines (IBLs) expressing one or more of the Dv adaptive traits. Molecular analyses revealed that either cryptic or Genomic In-situ Hybridization (GISH) detectable Dv chromatin introgression occurred in those IBLs. The IBLs, after 2 years of low-input field tests and genetic analyses in Italy and Hungary, showed simple inheritance, dominance and stability of the adaptive and disease resistance traits.

In this study, a forward-genetics analysis was performed on a portion of TILLMore, a chemically mutagenized population of barley cv. ‘Morex’ (http://www.distagenomics.unibo.it/TILLMore/), to identify root morphology alterations by comparison with ‘Morex’ wild-type. For this purpose, a simple paper-roll approach was performed to identify phenotypic variants at the seedling stage. The analysis of c. 1000 M4 families allowed us to identify c. 70 lines with altered root morphology. A more accurate phenotypic characterization of a portion of the mutant lines has been performed using stereomicroscopy and a scanning electron microscopy approach.