The selection of genotypes based on various characteristics is a critical challenge in plant breeding. An experiment was carried out in a randomized complete block design (RCBD) in three replications over two crop years, 2018-2019, to compare the effects of genotype × trait (GT) and the genotype × yield-trait (GYT) methods as well as investigate the relationships between grain yield and different agronomic traits. Plant materials ten sunflowers (Helianthus annuus L.) genotypes. Based on the combined analysis of variance, there was a significant difference in parameters except leaf length. The effect of year × genotype was significant in all traits except plant height, stem diameter, and leaf length (P≤ 0.01). Gabur, Azargol and Favorite genotypes were ranked as genotypes in the years of the experiment. Based on the graphical analysis performed on the effect of genotype × trait (GT), Zaria genotype was selected as the best and stable genotype. The genotype × yield-trait (GYT) biplot ranked genotypes by yield and other desired trait levels and depicts their trait profiles, or strengths and weaknesses. The correlation biplot revealed positive correlations between most traits with grain yield. This method is pictorial, objective, effective, and simple compared to the genotype × trait (GT) method. The GYT biplot technique is based on the paradigm shift that genotypes should be assessed by their yield levels in combination with other variables rather than individually. The graphical analysis of the effect of genotype × yield-trait (GYT) revealed that Gabur and Armavirski genotypes were selected as the best for all traits investigated and could be recommended for cultivation in the Karaj location.

Garlic (Allium sativum), cultivated worldwide for its medicinal and nutritional value, faces challenges due to diseases caused by various pathogens. In this study, eleven garlic genotypes from Iran and one from China were selected and sown under natural infection rendered by the rust fungus (Puccinia alli) over two consecutive years. Subsequently, disease distribution and severity, percentage of infection and susceptibility of different garlic genotypes to rust disease were investigated. The results showed that genotype Solan was the most susceptible, with disease severity of 30.81%. In comparison, genotypes Aliabad and Bahar were resistant against rust disease with the lowest infection percentages of 13% and 16.37%, respectively. Further, genetic diversity was assessed using random-amplified polymorphic DNA (RAPD) markers. Out of 10 primers used, 95 scorable bands were generated, of which 66 (69.48%) were found to be polymorphic. A dendrogram was constructed based on RAPD polymorphism using the UPGMA method, and the genotypes were separated into six distinct clusters based on Jaccard's coefficient of similarity. Additionally, it was observed that there is no genetic differentiation among the genotypes based on their geographical origin. This study highlights the significant diversity in resistance and susceptibility among garlic genotypes, which can be harnessed in plant breeding programs.

Selection and breeding for high‐yielding in oilseed rape have always been one of the leading objectives for oilseed rape breeders. This process becomes more complicated when all quantitative traits are considered in selection in addition to grain yield. In the present study, 18 oilseed rape genotypes along with 2 check cultivars (RGS003 and Dalgan) were evaluated across 16 environments (a combination of 2 years and eight locations) in the tropical climate regions of Iran during 2018–2019 and 2019–2020 cropping seasons. The experiments were conducted in a format of randomized complete block design (RCBD) with three replications. The obtained multienvironmental trial data were utilized to conduct multivariate analysis, genotype by trait (GT) biplot, and genotype by yield*trait (GYT) biplot (Breeding, Genetics and Genomics, 1:2019). The GT and GYT biplot accounted for 55.5% and 93.6% of the total variation in the first two main components. Based on multivariate analysis and GT biplot, pod numbers in plant (PNP) and plant height (PH) were chosen as two key traits in spring oilseed rape genotypes for indirect selection due to high variation, strong positive correlation with grain yield (GY), and their high representatively and discriminability in genotype selection. The mean × stability GT biplot represented G10 (SRL‐96‐17) as the superior genotype. Based on the mean × stability GYT biplot, eight above‐average genotypes were identified that took high scores in stability, high‐yielding, and all evaluated quantitative traits at the same time. Based on the superiority index of GYT data, G10 (SRL‐96‐17) and G5 (SRL‐96‐11) indicated the best yield–trait combinations profile and ranked above check cultivars and then selected as superior genotypes. Similarly, cluster analysis using the WARD method also separated eight superior genotypes. Based on the result of the present study, GT ad GYT methodologies are recommended for trait profiling and genotype selection in oilseed rape breeding projects, respectively.

Rainfed regions have inconsistent spatial and temporal rainfall. So, these regions could face water deficiency during critical stages of crop growth. In this regard, multi-environment trials could play a key role in introducing stable genotypes with good performance across several rainfed regions. Grass pea, as a potential forage crop, is a resilient plant that could grow in unsuitable circumstances. In this study, agro-morphological attributes of 16 grass pea genotypes were examined in four semi-warm rain-fed regions during the years 2018–2021. The MLM analysis of variance showed a significant genotype-by-environment interaction (GEI) for dry yield, seed yield, days to maturity, days to flowering, and plant height of grass pea. The PLS (partial least squares) regression revealed that rainfall in the grass pea establishment stage (October and November) is meaningful. For grass pea cultivation, monthly rainfall during plant growth is important, especially in May, with an aim for seed yield. Regarding dry yield, G5, G10, G11, G12, G13, and G15 were selected as good performers and stable genotypes using DY × WAASB biplots, while SY × WAASB biplot manifested G2, G3, G12, and G13 as superior genotypes with stable seed yield. Considering equal weights for yield as well as the WAASB stability index (50/50), G13 was selected as the best one. Among test environments, E2 and E11 played a prominent role in distinguishing the above genotypes from other ones. In this study, MTSI (multi-trait stability index) analysis was applied to select a stable genotype, considering all measured agro-morphological traits simultaneously. Henceforth, the G5 and G15 grass pea genotypes were discerningly chosen due to their commendable performance in the WAASBY plot. In this context, G13 did not emerge as the winner based on MTSI; however, it exhibited an MTSI value in close proximity to the outer boundary of the circle. Consequently, upon comprehensive consideration of all traits, it is deduced that G5, G13, and G15 can be appraised as promising superior genotypes with stability across diverse environmental conditions.