The study of genetic variations in Catharanthus roseus L. induced by gamma rays and sodium azide using RAPD markers transpired in 2021–2022 at the Department of Biology, University of Kufa, Iraq. The seeds of two cultivars of Catharanthus roseus L., i.e., victory pure white and local (pink variety), received two doses of gamma rays (50 and 75 Gray) and four sodium azide concentrations (0.2%, 0.4%, 0.6%, and 0.8%). Non-treated seeds of both cultivars also served as a control for comparison. Evaluating the effects obtained through the exposure of C. roseus seeds to gamma rays and sodium azide employed DNA markers, including 16 primers used in applying RAPDs. DNA extraction, accomplished from fresh apical leaves, underwent molecular markers application. RAPD markers could detect the generation of genetic variation induced by gamma rays and sodium azide treatments through the appearance of polymorphic bands. Using 16 RAPD primers, the largest molecular size was 2,543 bp produced by primer OPB-17, with the lowest 114 bp produced by primer OPC-08. The highest number of main and polymorphic bands was 18 and 10, respectively, in primer OPA-10. The highest number of monomorphic bands was eight in primer OPX-17, which affected its ability to give the lowest value for polymorphism. The highest number of amplified bands was 78 bands in primer OPC-09. Primer OPA-10 provided the highest number of polymorphic and unique bands, as well as, the highest values for discrimination and primer efficiency. Primer OPC-09, with seven treatments resulting in a unique fingerprint, is superior to all other primers.

Keywords: Catharanthus roseus L., RAPDs, gamma rays, sodium azide

Key findings: In the presented molecular study, RAPD markers assessed genetic variations generated by both gamma ray exposure and sodium azide treatments with diverse doses and concentrations.

The current study comprising molecular identification of the mutagenic effects of gamma rays and sodium azide on Catharanthus roseus using scot markers took place at the Department of Biology, University of Kufa, Iraq. The seeds of two cultivars, i.e., ‘victory carmine’ and a local variety (pink variety) of Catharanthus roseus L (carmine var.) received irradiation with two doses of gamma rays (50 Gray and 75 Gray). Afterward, these got soaked in sodium azide with four concentrations (0.2%, 0.4%, 0.6%, and 0.8%) to induce the genetic variation in the cultivar. The non-treated seeds served as control treatments for comparison with treated ones. Accomplishing irradiation was at an average of 18 Gy/h using Cobalt-60. The effects of gamma rays and sodium azide treatments’ evaluation were through 10 start codon targeted (SCoT) DNA markers. The higher number of distinctive fingerprints was three produced by primers SCoT-26, while primer SCoT-60 provided a distinct fingerprint for only one treatment. However, primer SCoT-40 failed to recognize any treatment with a distinctive fingerprint. The highest molecular size (2488 bp) came from primer SCoT-54, whereas the lower molecular size (143 bp) resulted in primer SCoT-12. Primer SCoT-33 provided the highest value for chief and unique bands, reaching 33 and 18, respectively. The highest number of amplified bands was 77 bands in primer SCoT-54. Primer SCoT-60 produced the highest value for monomorphic bands, primer SCoT-12 gave the highest value for polymorphic bands, polymorphism, and discriminatory (15, 68.18, and 20.83, respectively), and primer SCoT-9 produced the highest value for efficiency.

Keywords: Catharanthus roseus, SCoT primers, gamma rays, sodium azide, genetic variation

Key findings: In the presented molecular study, using ScoT markers were capable of assessing the genetic variations generated by gamma rays and sodium azide treatments with diverse doses and concentrations, respectively.

The increasing global population demands potential high-yielding wheat genotypes, even under changing climatic conditions. Wheat Research Institute (WRI), Faisalabad, designed a two-year study during 2018–2020, following augmented block design, to assess the association between yield and quality parameters in 245 bread wheat genotypes, including 10 checks. Separating all genotypes into four sets was according to their origin, i.e., local landraces, exotic material from CIMMYT (International Maize and Wheat Improvement Center), Pakistani accessions, and miscellaneous. A sufficient amount of genetic variation among all the genotypes for the measured traits was evident from the analysis of variance (ANOVA). Correlation studies demonstrated a similar trend of association among traits in Pakistani and CIMMYT lines, but distinct patterns of association among landraces and mixed genotypes occurred. The whole population of diversified germplasm showed a positive association of yield with all the traits except chapatti quality, pH of flour, and gluten during 2018–2019. Similarly, in 2019–2020, grain yield was positively associated with all the traits except test weight, chapatti quality, and pH of flour. The attributes responsible for the grain size, i.e., grain length, width, thickness, and a thousand kernel weight, expressed a strong association among each other and with the grain yield. A positive correlation between grain yield and grain quality characters (bread and chapatti quality, test weight, gluten, and protein) emerged in the pre-green revolution germplasm during both years, which can benefit wheat quality improvement. The study concluded that for future wheat breeding

Keywords: wheat, population, hunger, grain size, quality, trait association

Key findings: For the selection of wheat genotypes with high-yielding potential, the seed traits (grain size: length, width, thickness, a thousand kernel weight, and test weight) should require more importance. The study indicated that to improve the quality of modern wheat cultivars, more focus on using pre-green revolution era wheat materials should materialize in the wheat breeding programs.

Ranunculus is a well-known flower having a great economic value for its bright colors and vibrant patterns. Given the importance of the ranunculus cut flower, conducting this study elucidated the genetic behavior and variability of various morphological attributes in ranunculus genotypes. Assessment of six ranunculus genotypes measured germination percentage (%), days to emergence, days to maturity, stem length, stem thickness, flowers per plant, flower size, and flower duration on the plant. Analysis of variance depicted significant variation in all the studied traits except days to emergence, number of stems, and germination percentage. Clustering ranunculus genotype with the Euclidean distances-based hierarchical clustering resulted in two clusters of the genotype. One genotype (red) did not join any group, indicating an early separation of this genotype during the evolution of Ranunculus species. Correlation analysis showed that most studied traits negatively correlated, with only a few positively correlating traits. The number of flowers per plant and stem length showed a d positive correlation (0.7437 and 0.8064, respectively). Overall, the results showed that the red, yellow, and rose genotypes are the best performers for cultivation to produce better-quality flowers. Genetic analysis using line × tester analysis revealed higher values for the SCA component than GCA, suggesting non-additive gene action for most traits under study. Moreover, the hybrids developed in the current study developed new color combinations/shades. These hybrids could further benefit ranunculus stable variant improvement.

Keywords: Ranunculus, color variance, general combining ability, specific combining ability, flower quality, gene action

Key findings: The red, yellow, and rose genotypes are the best performers. Most studied traits are under non-additive gene action control. Based on better GCA, the genotypes T1 (yellow) and T3 (white) could benefit future breeding programs for quality improvement.

Line × tester analysis is an efficient method to evaluate many entries for GCA (general combining ability) and SCA (specific combining ability) effects. Fifteen lines and three testers of sesame (Sesamum indicum L.) gained evaluation for shattering, yield, and oil quality traits. Crossing selected tolerant and sensitive accessions in line × tester fashion ensued, with the resultant F₁, parent material, and commercially cultivated varieties sown in the field to ascertain the genetic mechanisms to assess heterosis manifestation and generation turnover. Combining ability analysis exhibited variable direction and magnitude of GCA effects among line and testers and SCA effects among crosses. The lines SG-41, G-43, and SG-50 and testers SG-60 and SG-1 were the best general combiners. Crosses SG-44 × SG-60, SG-50 × SG-60, SG-103 × SG-14, SG-103 × SG-60, SG-110 × SG-14, SG-50 × SG-1, and SG-113 × SG-60 had a positive significant SCA effect for maximum yieldrelated traits. SG-39 × SG-60, SG-44 × SG-60, and SG-50 × SG-60 had positive significant SCA effects for maximum oil-related qualities. Crosses SG-41 × SG-1, SG-41 × SG-60, SG-43 × SG-60, SG-50 × SG-14, and SG-50 × SG-60 had positive and significant heterosis over the mid-parent, a better parent, and commercial hybrids for most of the traits. Conditioning on secondary branches, flower initiation, capsule length, and 1000-seed weight were by non-additive genetic effect, with all the other parameters under the control of additive gene action. The variance ratio of GCA to SCA showed less than unity; in contrast, the additive genetic variance was more than the dominant variance for all traits except for secondary branches, flower initiation, capsule length, and 1000-seed weight. The association of traits based on correlation and path analyses suggested that plant height, oil content, and 1000-seed weight can serve as criteria for selecting sesame for a future breeding program.

Keywords: Sesame (Sesamum indicum L.), heterosis, line × tester analysis, GCA and SCA, gene action, correlation

Key findings: Crosses SG-44 × SG-60, SG-50 × SG-60, SG-103 × SG-14, SG-103 × SG-60, SG-110 × SG-14, SG-50 × SG-1, and SG-113 × SG-60 had the positive significant SCA effects for maximum yield-related traits; these crosses were best specific combiners for most of the traits.

The knowledge of genetic variability, combining capability, and gene activity are vital in enhancing wheat productivity. Six diverse wheat genotypes, Anmol91, Fatehjung16, Khattakwal, Auqab2000, PR128, Abaseen 2021, and KT06, crossed with three strip rust-resistant wheat lines, i.e., YR5, YR10, and YR15, employed line × tester hybridization. The analysis determined that the general combining ability (GCA) and specific combining ability (SCA) variances were significantly different for examined parameters (p < 0.05). Parental lines Auqab2000 and Fatehjung16 emerged as better general combiners for earliness and yield-related attributes; however, Auqab2000 × YR5, KT06 × YR5, Khattakwal × YR10, PR128 × YR5, Khattakwal × Auqab, and KT06 × YR10, proved the top particular cross combinations for contributing features of grain yield per plant. Results also showed that lines import sufficient variety to manifest the traits under investigation. For almost all tested qualities, the value of σ²_gca/ σ²_sca demonstrated a non-additive gene effect, except for days to maturity, which the additive gene action influenced. The selection of superior plants should take time until later segregation generation when non-additive gene activities dominate. The genotypes chosen for the current study are crucial genetic resources for wheat’s continued gene development.

Keywords: Combining ability, tester analysis, parental lines, heritability, YR-5, YR-10

Key findings: The wheat genotypes Anmol91, Fatehjung16, Khattakwal, Auqab2000, PR128 Abaseen2021, and KT06, crossed with three strip rust-resistant wheat lines, i.e., YR5, YR10, and YR15, showed their GCA and SCA variances significantly (p < 0.05) for examined traits. Parental lines Auqab2000 and Fatehjung16 resulted as better general combiners for earliness and yield-related attributes. Likewise, Auqab2000 × YR5, KT06 × YR5, Khattakwal × YR10, PR128 × YR5, Khattakwal × Auqab, and KT06 × YR10 demonstrated the best particular cross combinations for contributing features of grain yield per plant.

An investigation of the phenotypic characteristics of 19 rhizobial strains, isolated from root nodules of different plant legumes grown in the soil of agriculture farms in Ismailia governorate, transpired. Most isolates were creamy or white opaque, mucoid, with a convex elevation, translucent, and smooth margined. Microscopic investigation revealed that all bacterial isolates were rod-shaped and had no positive affinity for Gram-stain. Identifying rhizobial cultures from any bacterial contaminants employed confirmatory tests based on prepared special media, including YMA supplement with Congo red, glucose peptone agar, Kit-lactose agar, and Hoffer’s alkaline test. Based on an infectivity test, all isolates proved their ability to reinfect their host. These rhizobial isolates, classified into two categories, included fast and slow-growing rhizobia according to their growth in the YEM medium containing bromothymol blue (BTB). Meanwhile, the assessment of the genetic diversity among these isolates proceeded using ISSR and RAPD markers, which ISSR marker proved a more powerful tool in discriminating among the tested isolates than the RAPD marker. The cluster analysis, with the RAPD marker, classified the isolates into two main groups. The first group included the isolates (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 13), while the second group contained the isolates (12, 14, 15, 16, 17, 18, and 19). Moreover, using ISSR markers also showed a cluster of two main groups with diverse categories; the first cluster included isolates 1 to 11, and the second group contained isolates 12 to 19.

Keywords: Rhizobia, ISSR, RAPD, and phenotypic characterization

Key findings: ISSR markers proved a more powerful tool in discriminating among the tested rhizobial isolates than RAPD markers.

The study, conducted at the research area of Raja Wala farm, University of Agriculture, Faisalabad, Pakistan, assessed the sunflowers’ (Helianthus annuus L.) early maturity and yield improvement. Experimental material came from the United States Department of Agriculture and the National Agricultural Research Centre. Cytoplasmic male sterile lines and restorers, grown in the field, had their data gathered regarding early maturity. Then, the crossing of selected lines employed the line × tester design. The following season, the resulting crosses and their parents’ evaluation proceeded in a randomized complete block design (RCBD) using three replications. The crosses declared as best hybrids in terms of early maturity and yield were 7-A × 86-R, 11-A × 83-R, 23-A × 81-R, 25-A × 80- R, 25-A × 94-R, and 27-A × 80-R. These best hybrids further underwent oil content and quality analysis. The crosses 23-A × 81-R and 25-A × 80-R revealed good performance for oil contents (palmitic, stearic, linoleic, and oleic acids) and quality traits like early maturing with better yield. Using RAPD markers, the authenticity assessment of the best hybrids through the presence and absence of bands compared with parents ensued. These hybrids will be helpful in future breeding programs for the development of early maturing varieties with improved achene yield and quality, which is rare in Pakistan. This material will also help develop the required hybrids.

Keywords: sunflower, male sterility, line × tester, oil quality parameters, primers

Key findings: Genotypes 80-R, 81-R, 83-R, 86-R, 94-R, and 96-R proved early maturing. The hybrids 23-A × 81-R and 25-A × 80-R emerged as the best crosses for early maturity, yield, and oil qualityrelated traits.

Early maturity and genotype by environment interaction (GEI) have always been challenging concerns for breeders in selecting appropriate parents for breeding programs. The presented study aimed to investigate early maturity and the dimension of gene action, as well as, assess the performance of half-diallel populations using eight advanced sweet corn inbred lines and their 28 F₁ hybrids with two commercial checks for maturity and yield-related traits in the spring of 2018 at the Nowshera (plain) and Swat (hilly) areas, Khyber Pakhtunkhwa, Pakistan. Analysis revealed significant differences among the genotypes for the studied traits over both locations. General combining ability (GCA) effects were significant for all the traits at both the agro-climatic conditions, except 100-kernel weight, with the specific combining ability (SCA) effects relevant for grain yield at both locations. The GCA-SCA ratio for studied traits indicated dominance gene action, which also gained support by higher values of SCA than GCA variances. Based on the results, the identified inbred lines SWTS-1-8 and SODS-1 serve as good general combiners for traits like earliness and grain yield attributes, making them better parents to improve the stated characteristics in sweet corn. However, the F₁ hybrids, i.e., NARCCCRI-19 × CCRI-34 at Nowshera and CCRI-34 × SODS-1 at Swat, showed the best specific combiners for maturity. Likewise, F₁ hybrids, i.e., SWTS-1-4 × SWTS-1-8 and SWTS-1-8 × CCRIS-34, emerged as desirable for grain yield at Nowshera and Swat, respectively. The inbred lines for the mentioned hybrids can be a source of germplasm improvement, breaking through undesirable linkages in future sweet corn breeding programs.

Keywords: Sweet corn, combining ability, specific combining ability, general combining ability, Hayman’s half diallel approach, gene action

Key findings: Combining ability analysis revealed that variations in the genetic magnitude over the two test locations indicated a significant role of environment on gene expression and would likely concentrate favorable alleles for the target corn yield attributes. Most of the traits showed nonadditive gene linkage, which indicates that inter matting of selected progeny in the upcoming early segregating generation obtained by crossing these parents will release hidden genetic variability through the breakage of undesirable linkages. Over-dominance gene action revealed that delayed selection could be more effective in developing early maturing sweet corn hybrids with modified plant architectures.

The enhancement in cayenne pepper (Capsicum frutescens L.) productivity is intently needed due to the ever-increasing demand, considered a vital vegetable commodity with complete nutrition and high economic value in Indonesia. Conventional plant breeding is one of the strategies to produce superior cultivars with increased yield. Thus, the latest research aimed to identify genetic diversity and gene inheritance patterns for selecting high-yielding F₂ populations of cayenne pepper made through double and three-way crosses. The said research employed an augmented design combined with a randomized complete block design as an environmental design. The research factors consisted of non-repeating cayenne pepper (Capsicum frutescens L.) lines with a limited number of seeds originating from 10 parental populations. The resulting 100 and 52 F2₂ individual populations, obtained from double and three-way crosses, respectively, were evaluated in comparison with four control cultivars, i.e., Bara, Dewata, Ungara, and Katokkon. The non-repeated rows, divided into five blocks, included the control cultivars planted repeatedly in each block. The results indicated that almost all traits have high genetic diversity and heritability and have potential use as selection criteria. The traits plant habitus (0.135), stem diameter (0.202), number of productive branches (0.359), and fruit weight (0.171) have a direct utmost influence on yield compared with other traits; thus, these promising traits can serve as selection criteria along with yield.

Keywords: Cayenne pepper (Capsicum frutescens L.), double and three-way crosses, growth traits, heritability, path analysis

Key findings: Lines selection in F₂ populations is most important in developing cultivars in crop plants, including cayenne pepper (Capsicum frutescens L.). The results revealed that the genetic traits of plant habitus, stem diameter, number of productive branches, and fruit weight directly impact yield compared with other traits; thus, these distinct traits can be effective selection criteria, along with yield.