The flag leaf can be an important vehicle for high grain yield due to its position and photosynthetic characteristics. To identify the most adaptive and stable yielding genotype, three winter wheat genotypes were studied during two experimental years under field conditions to quantify the influence of flag leaf removal in different phenological stages on the grain yield and grain quality. To quantify the influence of the flag leaf on the main yield components, the flag leaf was removed every 7 days, starting from the booting stage to ripening. Chlorophyll a, chlorophyll b, and carotenoids were determined from the removed leaves. As a complex trait, the number of grains/spikes and the weight of the grains/spikes were highly influenced by the flag leaf removal during the early generative stages, causing a yield loss from 9% to more than 40%, depending on the variety. It was established that the photosynthetic pigments were highly influenced by the plant phenology stages and the environmental conditions, especially carotenoids, which act as photoprotective and antioxidant agents under stress conditions. Regarding grain quality, flag leaf removal had a significant influence on the accumulation of grain protein and the wet gluten content, the variability of these quantitative traits being also influenced by the climatic conditions.

Cultivated potato (Solanum tuberosum) is a major crop worldwide. It occupies the second place after cereals (corn, rice, and wheat). This important crop is threatened by the Oomycete Phytophthora infestans, the agent of late blight disease. This pathogen was first encountered during the Irish famine during the 1840s and is a reemerging threat to potatoes. It is mainly controlled chemically by using fungicides, but due to health and environmental concerns, the best alternative is resistance. When there is no disease, no treatment is required. In this study, we present a summary of the ongoing efforts concerning resistance breeding of potato against this devastating pathogen, P. infestans. This work begins with the search for and selection of resistance genes, whether they are from within or from outside the species. The genetic methods developed to date for gene mining, such as effectoromics and GWAS, provide researchers with the ability to identify genes of interest more efficiently. Once identified, these genes are cloned using molecular markers (MAS or QRL) and can then be introduced into different cultivars using somatic hybridization or recombinant DNA technology. More innovative technologies have been developed lately, such as gene editing using the CRISPR system or gene silencing, by exploiting iRNA strategies that have emerged as promising tools for managing Phytophthora infestans, which can be employed. Also, gene pyramiding or gene stacking, which involves the accumulation of two or more R genes on the same individual plant, is an innovative method that has yielded many promising results. All these advances related to the development of molecular techniques for obtaining new potato cultivars resistant to P. infestans can contribute not only to reducing losses in agriculture but especially to ensuring food security and safety.

Maize will continue to expand and diversify as an industrial resource and a feed and fuel crop in the near future. The United Nations estimate that in 2050 the global population will reach 9.7 billion people. In this context, food security is increasingly being discussed. Additionally, another threat to food security is global warming. It is predicted that both the quantity and the quality of crops will be seriously affected by climate change in the near future. Scientists and breeders need to speed up the process of creating new maize cultivars that are resistant to climate stress without diminishing yield or quality. The present paper provides a brief overview of some of the most important genomics tools that can be used to develop high-performance and well-adapted hybrids of maize and also emphasizes the contribution of bioinformatics to an advanced maize breeding. Genomics tools are essential for a precise, fast, and efficient breeding of crops especially in the context of climate challenges. Maize breeders are able now to develop new cultivars with better traits more easily as a result of the new genomic approaches, either by aiding the selection process or by increasing the available diversity through precision breeding procedures. Furthermore, the use of genomic tools may in the future represent a way to accelerate the processes of de novo domestication of the species.

Cultivated potato (Solanum tuberosum L.) is one of the most important crops worldwide. Phytophthora infestans (Mont.) de Bary is the oomycete pathogen responsible for the famous Irish famine (1840s). It is still the most important pathogen affecting potato crops, causing the late blight disease on potato and tomato. It is mainly controlled by fungicides. Breeding for disease resistance is the best alternative to chemical control of the disease. One of the strategies used is to stack many resistance genes in the same genotype. Here, we wanted to test the effect of the stacked resistance gene (R) from S. demissum on the infection process by the virulent race EU_13_A2. Four potato genotypes were tested, each one harboring, respectively, one, two, three or four R genes. All the tested genotypes were sensitive. However, the sensitivity degree was negatively correlated with the number of genes harbored by each genotype. There was a delay of two days of symptoms manifestation for the genotype with 4Rs, and the pathogen produced less spores on the detached leaf test. In addition, the amount of phenolic compounds produced is higher in the genotypes with multiple R genes.

To ensure food and feed security, modern maize hybrids must not only perform well under changing climate conditions but also consistently achieve higher and stable yields, exhibit maximum tolerance to stress factors, and produce high quality grains. In a study conducted in 2022 and 2023, 50 maize hybrids were developed from crosses of five elite (highly productive) inbred lines and ten lines possessing favorable genes for carotenoid content. These hybrids were tested under particularly unfavorable conditions for maize cultivation. The aim was to identify which lines effectively transmit the desired traits to the offspring (general combining ability—GCA), and to identify superior hybrids in terms of productivity, adaptability, and quality (specific combining ability—SCA). The study revealed that total carotenoids ranged from 2.30 to 40.20 μg/g for the inbred lines and from 7.45 to 25.08 μg/g for hybrids. A wider distribution of values was observed in the inbred lines compared to the hybrids for key carotenoids such as lutein, zeaxanthin, β-cryptoxanthin, and β-carotene. Among the hybrids, notable performers in yield, adaptability, and carotenoid content included E390×D302, A452×D302, and A447×D302. The paternal inbred line D302 exhibited a high general combining ability for yield (1446 kg ha⁻¹) and, when crossed with several inbred lines, produced hybrids with enhanced yields and higher levels of zeaxanthin, lutein, and β-carotene, as well as improved unbroken plants percent.

The chapter “Challenges in Wheat Breeding in the 21st Century” explores the profound impact of climate change and population growth on wheat cultivation, emphasizing the urgent need to develop high-performing cultivars. The depletion of natural resources, such as water and soil, further complicates this process. The role of wheat in the circular economy is highlighted, providing insights into the efficient use of agricultural resources. New genomic techniques and next-generation sequencing are revolutionizing wheat breeding, accelerating the identification of favorable genes for adaptability and constant high yield, which are vital for future food security. To address current and future challenges, an integrated approach combining new breeding techniques, sustainable agricultural practices, and circular economy principles is essential. Wheat breeding programs should focus on developing varieties that are resilient to abiotic stresses, resource-efficient, and adapted to local conditions. International collaboration and interdisciplinary research are essential to supporting innovation and ensuring global food security. Furthermore, lobbying for the extensive adoption of improved, cost-effective cultivars will ensure accessibility for farmers. By aligning breeding goals with market demands and environmental sustainability, the foundation for a resilient and sustainable agricultural future can be established.