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Due to climatic changes around the world, maize is currently exposed to a variety of biotic and abiotic pressures in time and place that affect the performance of maize hybrids. Plant breeders need genotypes that respond consistently and preferentially to different environmental conditions. The present investigation was carried out with seven inbred lines, twenty-one F1 hybrids which were developed through a diallel matting scheme, and three hybrid checks at six environments which comprise three locations and two crop growing seasons. The pooled analysis of variance indicated highly significant mean squares due to environments, genotypes, and genotype by environment interactions (GEI) for all the traits like Days to 50 per cent anthesis, days to 50 per cent silk, anthesis-silking interval, days to 50 per cent physiological maturity, plant height, ear height, ear length, ear diameter, kernel rows per ear, kernels per row, grains per plant, 1000-kernel weight, shelling per cent and grain yield per plant. The mean squares of analysis of variance for all the studied traits in maize over the six environments revealed highly significant due to genotypes, Env. + (G x Env.), environment (linear), and pooled deviation. The significant to highly significant mean squares due to G × E (linear) were observed for all the traits under study except for days to 50% anthesis and silking, plant height, ear length, kernels per row, and grains per plant. The higher magnitude of mean squares due to environment (linear) than the corresponding G × E (linear) were recorded for all the studied traits indicating that the linear response of environment accounted for a major part of the total variance. The estimates of environmental indices revealed that environment, E4 (Rabi 2019-20, BAU, Sabour) had highly positive, therefore E4 is considered the most favorable environment amongst the six environments for the expression of all the studied characters. The estimates of stability parameters for grain yield per plant revealed nine hybrids, namely, P1 × P2, P1 × P4, P1 × P5, P2 × P4, P2 × P5, P3 × P4, P3 × P5, P4 × P7, and P5 × P6 had high mean grain yield, unit regression coefficient (bi=1) and non-significant deviation from regression (S2di=0) indicating these hybrids were stable for this trait over the test environments. [ABSTRACT FROM AUTHOR]

Estimation of variability and genetic relationships among breeding materials is one of the important strategies in crop improvement programs. Morphological (plant height, spike length, a number of florets/spike), physiological (chlorophyll content, chlorophyll fluorescence, and rapid light curve parameters) and Directed amplification of minisatellite DNA (DAMD) markers were used to investigate the relationships among 50 Gladiolus cultivars. Cluster analysis based on morphological data, physiological characteristics, molecular markers, and cumulative data discriminated all cultivars into seven, five, seven, and six clusters in the unweighted pair-group method using arithmetic mean (UPGMA) dendrogram, respectively. The results of the principal coordinate analysis (PCoA) also supported UPGMA clustering. Variations among the Gladiolus cultivars at phenotypic level could be due to the changes in physiology, environmental conditions, and genetic variability. DAMD analysis using 10 primers produced 120 polymorphic bands with 80% polymorphism showing polymorphic information content (PIC = 0.28), Marker index (MI = 3.37), Nei’s gene diversity (h = 0.267), and Shannon’s information index (I = 0.407). Plant height showed a positive significant correlation with Spike length and Number of florets/spike (r = 0.729, p < 0.001 and r = 0.448, p = 0.001 respectively). Whereas, Spike length showed positive significant correlation with Number of florets/spike (r = 0.688, p < 0.001) and Chlorophyll content showed positive significant correlation with Electron transport rate (r = 0.863, p < 0.001). Based on significant morphological variations, high physiological performance, high genetic variability, and genetic distances between cultivars, we have been able to identify diverse cultivars of Gladiolus that could be the potential source as breeding material for further genetic improvement in this ornamental crop. [ABSTRACT FROM AUTHOR]