Deciphering genotype-by-environment interaction of grass pea genotypes under rain-fed conditions and emphasizing the role of monthly rainfall.

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.

Molecular evidence depicts genetic divergence among Agropyron elongatum and A. cristatum accessions from gene pool of Iran.

The genus Agropyron has an important role in soil protection and forage production in rangelands. The investigation utilized 37 ISSR primers, resulting in the detection of 956 loci within the A. elongatum genome and 705 loci within the A. cristatum genome. The findings revealed a high level of polymorphism, with 97% of loci in A. elongatum and 84% of loci in A. cristatum exhibiting variability. Notably, the primer (AC)8GCT emerged as a promising candidate for evaluating genetic diversity due to its ability to amplify numerous loci in both species. Using both the UPGMA algorithm and Bayesian analysis, the examined Agropyron accessions were categorized into two subgroups based on their respective species. The Q values associated with these subgroups suggested that certain accessions, namely "G16," "G19," "G20," "G21," "G22," "G23," "G24," and "G25," displayed potential admixture genomes. An analysis of molecular variance (AMOVA) underscored the significance of within-species variability, which accounted for 69% of the overall diversity, compared to between-species variability at 31%. Various genetic diversity parameters, including Na, Ne, I, He, and the number of private loci, were found to be higher in A. elongatum when compared to A. cristatum. Furthermore, Jaccard similarity coefficients ranged from 0.33 to 0.66 in A. cristatum and from 0.25 to 0.7 in A. elongatum, indicating the extent of genetic relatedness among these species. Intriguingly, the study identified two and three heterotic groups in A. cristatum and A. elongatum, respectively, which could be harnessed in the development of synthetic varieties to exploit heterosis. The results also indicated that a small proportion of ISSR loci pairs (5.2% in A. elongatum and 0.5% in A. cristatum) exhibited significant levels of linkage disequilibrium (LD) (P≤0.05), suggesting the potential utility of LD-based association mapping in Agropyron species. In conclusion, this research sheds light on the genetic diversity of Agropyron species and provides valuable insights into their potential applications in soil protection and forage production, as well as the prospects for enhancing genetic variability and heterosis in these species.

Trait profiling and genotype selection in oilseed rape using genotype by trait and genotype by yield*trait approaches.

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.

Assessment of genetic diversity among sunflower genotypes using microsatellite markers.

Genetic diversity estimation of plant materials is one of the important pre-breeding activities in breeding field crops. Twenty-one microsatellite markers used to assess genetic diversity and relationship of 68 sunflower genotypes (Helianthus annuus L.). All of 21 pairs of SSR (Simple Sequence Repeats) markers produced a total number of 49 polymorphic bands. DNA fragments ranged from 92 to 850 bp. The highest and lowest polymorphic information content (PIC) values were determined as 0.58 and 0.10 for marker Ha806-ar and Ha494-ar. The number of alleles per locus was calculated as 2-6 with the average of 2.86. In this study, CMS (Cytoplasmic Male Sterility) lines showed the highest and Iranian hybrids showed the least polymorphism, respectively. Principal coordinates analysis revealed that Iranian hybrids were well-separated compare to the other groups. The analysis of molecular variance (AMOVA) indicated higher genetic variation within groups (90%) rather than among groups (10%). This study revealed that the SSR markers such as Ha806-ar could be a useful tool for distinguishing sunflowers genotypes. According to the study, there is a significant genetic distance among individuals. Parental lines (R26 and CMS502 lines with lowest similarity coefficient) may be useful for future sunflower crossing and hybrid breeding programs. Generally, high similarity coefficient estimation among investigated sunflower groups revealed that there was a narrow genetic base in investigated materials suggesting broadening its genetic base by introduction of new genes into existing breeding materials.