The primary purpose of this study was to explore yield stability of pea (Pisum sativum L.) cultivars based on stability index, with specific aim at studying cultivar behavior regarding yield of peas under both conventional and low-input cultivation systems. Five cultivars of peas were used in a strip-plot design. Correlations showed a significant positive relation between seed yield and some other traits. Indirect seed yield improvement may be implemented by improving pod length, which generally showed high stability indices in Greek mega-environment. Comparisons between conventional and low-input farming systems generally did not affect stability estimations, but revealed cultivars that exhibited stable performance, even in low-input farming systems. The additive main effects and multiplicative interaction (AMMI) biplot analysis, genotype by environment interaction (GGE) biplot analysis and analysis of variance (ANOVA) showed statistically significant differences between genotypes and environments, and also the farming system. This way, we have certain cultivars of peas to recommend for specific areas and farming system, in order to achieve the most stable performance. Vermio proved to be a stable cultivar for seed yield performance, in Giannitsa, Trikala and Kalambaka area, in low-inputs farming systems, while Olympos was the best in Florina area and low-input farming.

Alfalfa (Medicago sativa L.) is used to support livestock. A stability study was carried out over three years. The stability indices for yield and main quality characteristics such as plant height, number of nodes, the yield of green mass and dry matter, crude protein and fiber (%), and ash (%), were examined. Statistical analysis revealed significant differences that indicated the presence of high genotype–year interactions. Heritability was higher in the case of qualitative traits than quantitative traits. The most intriguing correlation was between green mass yield and crude protein content because positive correlations may lead to indirect and simultaneous selection. According to the statistical biplot models AMMI and GGE, the best genotypes for almost all traits to use, regardless of the environment and cultivation type, were the G8 (Population 2) followed by cultivar G3 (Yliki). Despite the high index values shown by the parameter number of nodes, the latter and yield showed low heritability.

The purposes of this study were to define the kind of trait inheritance through stability estimations of various traits in maize, to define the relationship between different environments and maize hybrids, and to propose the best environments and hybrids for farmers. Field experiments were conducted in two years (2011 and 2012) at four different locations in Greece: Florina, Trikala, Kalambaka and Giannitsa which were selected as they represent different environments. The genetic materials tested in a Randomized Complete Block (RCB) design, were 15 F1 commercial maize hybrids and 15 open-pollination lines developed from 4-cycle Honeycomb evaluation. Materials were sown and harvested by hand at different dates according to local conditions. Trait stability index ${\left(\overline{x}∕s\right)}^2$ across environments was computed for each maize trait studied: yield, specific weight, 1000-kernel weight, axis (spindle) weight, spike weight, number of kernels per spike, spike length and diameter, number of kernel rows, spindle diameter, main spike and plant height, prolificacy and number of kernels per row. The findings showed great differences in stability index between traits and also for the same trait across environments or between maize genotypes. GGE biplot for yield distributed genotypes in a different way for Florina on the basis of one main factor and managed to depict Trikala’s differential response on the basis of two factors. Almost the same trend was found for 1000-kernel weight and specific weight, where there was a wide core for similar responding genotypes. Basic conclusions of this research are summarized in great differences of various traits, indicating qualitative, medium or quantitative inheritance. Estimations for trait stability can be easily performed in a multi-genotype experiment using trait stability index. The most stable hybrids were proved to be 31Y43, COSTANZA and FACTOR. The environment favouring a general stable performance proved to be Florina.

Barley (Hordeum vulgare L.) seed quality traits were evaluated to investigate the relative genetic and environmental contributions to their variation, the stability of genotypes across environments, and the interrelationships among traits. Fifteen genotypes, including classical pedigree-derived lines (G1–G5), PYI-selected lines (G6–G10), YC-selected lines (G11–G12), cultivars (G13–G14), and a local population (G15), were assessed for crude protein content, fat content, ash content, starch content, crude fiber content, carbohydrate content, soluble fraction, and non-starch fraction. Field trials were conducted across six environments under a randomized complete block design with four replications per environment. Combined ANOVA revealed significant differences among genotypes for all evaluated traits, while environmental effects and genotype × environment interactions also contributed significantly to trait variation. Stability analysis using the Stability Index (SI) showed that classical pedigree lines (G1–G5) demonstrated the highest overall stability across most traits. Lines selected via the Plant Yield Index (PYI) and Yielding Coefficient (YC) criteria exhibited greater stability compared to the local population, while cultivars showed intermediate and trait-dependent stability. Broad-sense heritability (H²) was high for all traits (>92%), with crude protein, fat, ash, and crude fiber content showing particularly strong genetic control. Genetic advance (GA) and genetic advance as a percentage of the mean (GA%) indicated a favorable expected response to selection for protein- and fiber-related traits. Traits such as starch content, carbohydrate content, soluble fraction, and non-starch fraction were more strongly influenced by environmental variation, highlighting the need for multi-environment testing. Correlation analysis revealed significant associations among traits, highlighting both trade-offs and coordinated accumulation patterns. Crude protein content was negatively correlated with carbohydrate content, soluble fraction, and non-starch fraction, whereas fat content showed positive correlations with ash content and fiber-related components, indicating potential targets for breeding programs. Overall, advanced barley lines combine high performance and stability, providing material suitable for further breeding under Mediterranean conditions.

Grain quality traits in wheat (Triticum aestivum L.), including protein content, gluten strength, and carbohydrate composition, are key determinants of end-use performance and breeding potential. This study assessed the genetic variability, stability, and multivariate relationships of seed quality traits among elite F7 pure lines derived from six long-term cultivated wheat cultivars. Field trials were conducted across six contrasting environments to evaluate genotype, environment, and genotype × environment (G × E) effects on crude protein, fat, ash, starch, crude fiber, Zeleny sedimentation, carbohydrates, non-starch carbohydrates, and moisture. Combined ANOVA revealed that genotypic effects accounted for the largest proportion of variation, though significant environmental and G × E effects were also observed. Broad-sense heritability was high for protein, Zeleny, and carbohydrate content. Stability analysis using the Stability Index (SI) highlighted A1, A2, A4, C2, E1, and F2 as genotypes combining high mean performance with a consistent expression across all environments. Principal component analysis (PCA) illustrated key trait relationships and trade-offs, particularly the negative association between protein-related traits and carbohydrate accumulation, while revealing the partial clustering of genotypes with similar quality profiles. AMMI and GGE biplots further supported broad adaptation for some genotypes (e.g., E1, F4, E2 for crude protein; F3, F4, E2 for Zeleny) and trait- or environment-specific performance for others. Correlation analyses confirmed positive associations between protein and gluten strength, and negative correlations with carbohydrate traits. Overall, targeted pure-line selection effectively exploits intracultivar genetic variation, offering a practical strategy for identifying superior, resilient wheat lines for breeding programs across diverse environments.

Maize seed quality and kernel morphological traits are important determinants of grain utilization and are influenced by both genetic factors and growing-season conditions. This study evaluated the stability of seed quality and kernel morphological traits in two commercial maize hybrids (Costanza and LG 3535) across four growing seasons, three row spacing systems, and two plant density levels. Seed quality traits (protein, fat, ash, starch, crude fiber, and moisture content) and kernel morphological traits (length, width, and thickness) were evaluated using univariate and multivariate statistical analyses. Significant effects of hybrid, growing season, row spacing, and their interactions were detected for most evaluated traits. Growing-season variability influenced seed composition and kernel morphology, while row spacing and plant density further contributed to trait expression. Costanza exhibited greater stability for most traits, particularly starch content and kernel morphology, whereas LG 3535 showed more variable responses across growing seasons and row spacing combinations. Correlation and multivariate analyses revealed strong associations among starch content, kernel width, and kernel thickness, whereas protein, ash, and crude fiber were less closely associated with kernel size traits. These findings demonstrate the importance of hybrid × growing-season interactions in shaping maize kernel characteristics and highlight the value of multi-environment evaluation for identifying hybrids with stable kernel quality traits under Mediterranean production conditions.