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.

Open access peer-reviewed chapter

Maize (Zea mays L.) landraces are an important source of genes for improving commercial germplasm. Today, drought tolerance and grain quality are major challenges in maize cultivation due to climatic changes and population growth. The Maize Research Institute genebank has a drought tolerant collection, which includes 13 landraces (from the former Yugoslavia) and 12 introduced populations (from different countries). These accessions were analyzed for protein, oil, starch and tryptophan contents, in order to identify drought tolerant accessions with high grain quality. Also, simple sequence repeat (SSR) analysis with specific primers for opaque2 recessive allele (o2) was carried out. All analyzed accessions showed high levels of protein. Oil content ranged from 3.75 % to 5.40 % and starch content from 67.5 % to 71.30 %. Average protein content was not different (p < 0.01) between landraces and introduced populations. Starch and oil contents were higher in introduced populations at 0.84 % and 0.39 %, respectively (p < 0.01). Twenty-three accessions had high levels of tryptophan content. A high percentage of kernel type 1 and 2 indicated the presence of endosperm hardness modifier genes. Recessive o2 allele was found in most of the accessions. Absence of o2 in some high tryptophan accessions indicated action of another mutation. In two high tryptophan accessions an unknown band was detected. Absence of negative correlations between proteins, tryptophan and oil makes certain accessions suitable for use in the simultaneous improvement of target genotypes for these traits. Identified drought tolerant, high quality accessions can be used in breeding programs aimed at nutritional improvement of maize grown under drought conditions

Plants reconfigure their metabolic pathways to cope with water deficit. The aim of this study was to determine the status of the physiological parameters and the content of phenolic acids in the upper most ear leaf of maize inbred lines contrasting in drought tolerance in terms of improved plant productivity e.g., increased grain yield. The experiment was conducted under irrigation and rain-fed conditions. In drought-tolerant lines, the effect of water deficit was reflected through a chlorophyll and nitrogen balance index increase followed by a flavonols index decrease. The opposite trend was noticed in drought susceptible inbreds, with the exception of the anthocyanins index. Moreover, in comparison to irrigation treatment, opposite trends in the correlations between grain yield and physiological parameters found under water deficit conditions indicated the activation of different metabolic pathways in defense against water deficit stress. Concerning phenolic acid content, water deficit caused the reduction of protocatechuic, caffeic, and sinapic acid in all inbreds evaluated. However, the highly pronounced increase of ferulic and especially cinnamic acid content under water deficit conditions indicated possible crucial role of these secondary metabolites in preventing the harmful effects of water deficit stress, which, in turn, might be useful in maize breeding selection for drought tolerance.

Taste and nutritional value make sweet corn a valued plant and an important component of the human diet worldwide. Kernel nutritive composition of sweet corn has been reported in various papers, but a description of carotenoid and tocopherols profile, especially after cooking is scarce. Therefore, the present study was carried out to compare the carotenoid and tocopherol content in sweet corn before and after cooking. Contents of b-carotene, lutein+zeaxanthin and tocopherols (d-T, b+g-T, a-T) in the kernels of twelve sweet corn hybrids were determined by High-Performance Liquid Chromatography (HPLC) and were expressed as the mean value of three independent measurements. Both genotype and cooking affected the content of the carotenoids and tocopherols in the kernel. The highest content of total carotenoids before and after cooking was found in hybrid ZP486/1su (27.77/45.28 µg/g) whereas the lowest content was in hybrid ZP 355su (10.27 µg/g) before cooking i.e. in hybrid ZP 347su (24.55 µg/g) after cooking. The cooking resulted in a significant increase in the content of total carotenoids and tocopherols, lutein+zeaxanthin, and b-carotene in all hybrids, except the ZP504su in which the b-carotene content decreased. An increase in a-tocopherol after cooking was observed in hybrids ZP485/1su and ZP484/1su, while a decrease was in hybrids ZP481/1su, ZP486/1su and ZP477/2su. The results showed that increasing micronutrient content is genotype-dependent. This study confirmed that cooking increases the nutritional value of sweet corn and gives it additional value in terms of functional food.