Genetic and Phenotypic Evaluation of European Maize Landraces as a Tool for Conservation and Valorization of Agrobiodiversity.

The ECPGR European Evaluation Network (EVA) for Maize involves genebanks, research institutions, and private breeding companies from nine countries focusing on the valorization of maize genetic resources across Europe. This study describes a diverse collection of 626 local landraces and traditional varieties of maize (Zea mays L.) from nine European genebanks, including criteria for selection of the collection and its genetic and phenotypic diversity. High-throughput pool genotyping grouped the landraces into nine genetic groups with a threshold of 0.6 admixture, while 277 accessions were designated admixed and likely to have resulted from previous breeding activities. The grouping correlated well with the geographic origins of the collection, also reflecting the various pathways of introduction of maize to Europe. Phenotypic evaluations of 588 accessions for flowering time and plant architecture in multilocation trials over three years confirmed the great diversity within the collection, although phenotypic clusters only partially correlated with the genetic grouping. The EVA approach promotes conservation of genetic resources and opens an opportunity to increase genetic variability for developing improved varieties and populations for farmers, with better adaptation to specific environments and greater tolerance to various stresses. As such, the EVA maize collection provides valuable sources of diversity for facing climate change due to the varieties' local adaptation.

Traditional Foods From Maize (Zea mays L.) in Europe.

Maize (Zea mays L.) is one of the major crops of the world for feed, food, and industrial uses. It was originated in Central America and introduced into Europe and other continents after Columbus trips at the end of the 15th century. Due to the large adaptability of maize, farmers have originated a wide variability of genetic resources with wide diversity of adaptation, characteristics, and uses. Nowadays, in Europe, maize is mainly used for feed, but several food specialties were originated during these five centuries of maize history and became traditional food specialties. This review summarizes the state of the art of traditional foodstuffs made with maize in Southern, South-Western and South-Eastern Europe, from an historic evolution to the last research activities that focus on improving sustainability, quality and safety of food production.

The starch-bound alpha-amylase/trypsin-inhibitors in Avena.

Oat kernels exhibit an extra-soft texture, a trait recently demonstrated to be largely modulated by starch-bound tryptophan-rich 2S proteins, the vromindolines. In this study, fractionation by two-dimensional electrophoresis of starch-bound proteins in 25 oat (Avena sativa) cultivars and 11 diploid or tetraploid Avena species revealed novel 2S proteins called Avena α-amylase/trypsin-inhibitors (AATI) because of their sequence similarity with wheat α-amylase/trypsin inhibitors. Thirty-seven AATI polypeptides, about 14 kDa in size, were split into three families named AATI-1, AATI-2, and AATI-3 with different primary structures and isoelectric points. AATI-1 and AATI-2 proteins showed 55.5-60.0 % sequence similarity with wheat α-amylase inhibitors CM1, CM2, and CM16, which have been found to cause innate immunity responses in celiac disease and non-celiac gluten sensitivity. Diploid A-genome and tetraploid AC-genome oat species possess three and five genes encoding for the AATI proteins, respectively, whereas hexaploid A. sativa exhibits 12 genes dispersed over the A-, C-, and D-genomes. Some AATI proteins expressed in hexaploid oats were assigned to the A-genome based on similarity to their counterparts in diploid species, contributing to further clarify the genetic origin of hexaploid oats. Moreover, AATI may interact with starch-bound vromindolines in determining the extra-soft texture of oat kernels and, due to their balanced amino acid compositions, may contribute to the biological value of oat proteins in a positive manner.

Development of a NIRS calibration for total antioxidant capacity in maize germplasm.

The feasibility of predicting total antioxidant capacity (TAC) in maize flours by NIRS was assessed in a set of 391 samples, comprising Italian and public inbred lines, F1 seeds, commercial hybrids and traditional varieties, using ABTS direct assay as reference value. A subset of 81 samples were also used to test the development of a calibration model for soluble phenolic content (SPC), whereas 101 samples were analysed by DPPH assay. The models obtained for TAC by ABTS in different genetic materials were characterized by a good stability of the regression coefficients and showed a RER>2, allowing to develop both global and specific predictive models for this trait. On the contrary, only specific models were developed for SPC, and no predictive models were obtained for TAC by DPPH assay. These results demonstrated that NIR spectroscopy could be applied efficiently to the screening of the genotypes currently selected for the food industry.

Biochemical and molecular characterization of Avena indolines and their role in kernel texture.

Among cereals, Avena sativa is characterized by an extremely soft endosperm texture, which leads to some negative agronomic and technological traits. On the basis of the well-known softening effect of puroindolines in wheat kernel texture, in this study, indolines and their encoding genes are investigated in Avena species at different ploidy levels. Three novel 14 kDa proteins, showing a central hydrophobic domain with four tryptophan residues and here named vromindoline (VIN)-1,2 and 3, were identified. Each VIN protein in diploid oat species was found to be synthesized by a single Vin gene whereas, in hexaploid A. sativa, three Vin-1, three Vin-2 and two Vin-3 genes coding for VIN-1, VIN-2 and VIN-3, respectively, were described and assigned to the A, C or D genomes based on similarity to their counterparts in diploid species. Expression of oat vromindoline transgenes in the extra-hard durum wheat led to accumulation of vromindolines in the endosperm and caused an approximate 50 % reduction of grain hardness, suggesting a central role for vromindolines in causing the extra-soft texture of oat grain. Further, hexaploid oats showed three orthologous genes coding for avenoindolines A and B, with five or three tryptophan residues, respectively, but very low amounts of avenoindolines were found in mature kernels. The present results identify a novel protein family affecting cereal kernel texture and would further elucidate the phylogenetic evolution of Avena genus.

Use of near infrared reflectance and transmittance coupled to robust calibration for the evaluation of nutritional value in naked oats.

A rapid accurate and precise method for simultaneous determination of ß-glucan and protein content in naked oat samples, based on the coupling of near-infrared spectroscopy and chemometrics, is presented. In particular, three different spectroscopic approaches [near infrared reflectance (NIR) and transmittance (NIT) on flour and NIT on whole grains] and various spectral pretreatments were considered. To account for the possibility of outlying samples, a robust version of the PLS algorithm (namely partial robust M-regression) was used. All the models resulted as accurate as the reference methods, reflectance spectroscopy being the technique providing the best outcomes. Variable reduction by inclusion of the most relevant predictors only (as evaluated by VIP scores) resulted in simpler and, in one case, more parsimonious models, without loss in accuracy.

Characterization of maize germplasm for the chemical composition of the grain.

The aim of this research was the evaluation of food grain quality-related traits in a collection of maize populations of different origins, currently used in the framework of breeding and genetic programs. A total of 1245 maize samples were scanned by near-infrared (NIR) spectroscopy to develop calibration equations to evaluate the content of crude protein, crude lipid, starch, and floatation area. The performances of the NIR equations developed in our study were assessed using the determination coefficient of cross-validation r(2) (ranging from 0.66 to 0.91) and the ratio of performance deviation (1.71-3.31) in flour starch and grain crude protein, respectively. Among the genotypes considered, 93 landraces belonging to the European Union Maize Landraces Core Collection (EUMLCC) were also analyzed for their content of lutein, zeaxanthin, and total carotenoids. Among the populations of the collection, several accessions, interesting from a nutritional point of view, were identified: VA25, VA158, VA282, VA284, VA285, VA567, VA572, VA814, VA950, VA1057, and VA1179. They showed protein and lipid contents ranging between 12.52 and 15.16% and 5.26 and 7.17%. The range of variation observed for antioxidants in the EUMLCC was quite large. Lutein varied between 1.03 and 21.00 mg kg(-1) dm, zeaxanthin varied between 0.01 and 35.00 mg kg(-1) dm, and total carotenoids ranged from 1.09 to 61.10 mg kg(-1) dm. Recently, a single cross-hybrid was developed from the ITA0370005 population; this hybrid had a high carotenoids content and is currently being used by the Italian food industry.