Appropriate parental selection is the breeder’s main concern to exploit the highest genetic diversity and generate superior genotypes for subsequent breeding programs. Hence, the presented investigation proceeded to evaluate 353 breeding lines of rice at three breeding zones (Rajshahi, Cumilla, and Gazipur) in Bangladesh in replicated yield trials during the Boro season of 2018–2019 to identify the best genotypes and utilize them as parental materials. Data recorded on 12 yield-related traits helped to determine the best breeding lines with higher predicted breeding values. The first five principal components (PC1, PC2, PC3, PC4, and PC5) represented more than 70% (75.1%) contribution to the variability of the data. Three hundred fifty-three rice genotypes incurred distribution into five clusters over three environments. Clusters I, II, III, IV, and V comprised 66, 51, 83, 79, and 74 genotypes, respectively. Based on estimated breeding values (EBVs), IR107971-B-B RGA-B RGA-202 showed the highest value (0.395), followed by IR 108000-B-B-B-B-13 (0.329), IR 103309-B-B RGA-B RGA-194 (0.321), IR 107982-B-41-1-2-1 (0.291), IRRI 174 (0.264), and IR 107976-B-B RGA-B RGA-254 (0.234). The lowest EBV (0.022) appeared in IR103309-B-B RGA-B RGA-204 among the top 20 genotypes. Both IR 103309-B-B RGA-B RGA-194 (0.321) and IR 107982-B-41-1-2-1 (0.291) could benefit as parents for further breeding programs having higher EBVs and higher genetic diversity.

Keywords: Rice, cluster analysis, estimated breeding values, parental materials

Key findings: EBVs and cluster analysis can assist breeders in selecting the best parents for the next breeding program. The top 20 genotypes based on EBVs with the highest genetic diversity may serve as parents to produce desired plant progenies crucial for the ever-growing populations. More specifically, IR 103309-B-B RGA-B RGA-194 and IR 107982-B-41-1-2-1 will be more effective as parents due to their higher EBVs and more genetic diversity.

The molecular identification of maize dwarf mosaic virus (MDMV) and its effects on the morphophysiological traits of maize (Zea mays L.) was the focus of the presented research, intending to study the activity dynamics of two main types of enzymes, peroxidases, weakly binding to the membrane, and soluble peroxidases. The molecular identification of the virus engaged the use of the RT-PCR method. Results revealed that in the climatic conditions of Uzbekistan, red necrotic spotting, yellow mosaic with a large border on the edge of the leaf, curling of the leaves, yellow striped mosaic, and short stature all appeared in the maize plants. According to previous symptoms, the visual diagnostic methods used determine the maize yellow mosaic virus indications. In the existing study, the gene responsible for the protein coat synthesis (SR) nucleotide sequence served to diagnose the MDMV, and as a result, PCR tests showed yellow streaks on the leaves of maize plants. The mosaic and motility symptoms have been characteristic proofs of MDMV. The MDMV infects the maize plants in the initial growth phase (3–5 leaves), then the symptoms appear after a few days. Through morphological indicators, viral disease identification is possible at subsequent stages (6–7 leaves). Using spectrophotometry, the peroxidase enzyme activity in maize plants receives the virus infection to determine an early level of infectivity. The results confirmed that, in infected maize plants, peroxidase associated with the cell membrane was much more active than in control plants. It proves that contaminated Zea mays plants were in a stressful situation due to the virus. The RT-PCR method, widely used in diagnostics, sought to identify the virus species affiliation. PCR proceeded based on the virus соat protein (CP) gene.

Keywords: Maize (Zea mays L.), maize dwarf mosaic virus (MDMV), distribution, peroxidase, ascorbate peroxidase (APX), guaiacol peroxidase (GPX), thylakoid

Key findings: Given the participation of the peroxidase enzyme in the protection mechanism of the maize plants from MDVM disease, its consideration for use succeeded on local maize cultivars with high peroxidase activity, such as, Sherzod, and acclimatized cultivars, i.e., Extra Early Dightau-209 and Hickax, for the selection of virus-resistant cultivars.

One of the major tasks faced by wheat breeders in Uzbekistan is to enhance wheat genotypes’ adaptability to soil and other environmental conditions and improve the grain quality, making the country self-sufficient in wheat grains and later becoming an exporter. Better results are achievable using the world wheat collection, including the CIMMYT germplasm. Determination of the positive correlation of physiological traits of new wheat cultivars, the importance of physiological indicators of water balance with productivity, and the vital role of these indicators in productivity level were the chief concerns. The timely study evaluated heat resilience, rust resistance, and grain yield in bread wheat genotypes. Bread wheat germplasm obtained from CIMMYT with a background of artificial infection of yellow rust incurred scrutiny for their rust resistance. A 15% incidence was detectable in seven genotypes; however, necrosis quickly formed around the symptoms of the disease in plant leaves, preventing its further development. Resistant wheat accessions, i.e., 1088, 1164 (R), 1006, and 1251 (MR), occurred as moderately resistant, showing high leaf area and grain yield. The average value of the genotypes was low, mainly due to the two rust-resistant samples, and the 1000-grain weight was 34.8 g and 34.6 g, respectively, and the grains per spike and grain yield were lower than the average. The chlorophyll a and b, total chlorophyll, carotenoid content, relative water content, flag leaf area, and production traits of the genotypes К-1088 and К-1164 gained assessment, revealed to be physiologically effective under the field conditions of Tashkent, Uzbekistan. Quantitative indicators of the productivity of these wheat genotypes indicated positive differentiation. Selection ensued for promising accessions to develop initial sources for producing the wheat genotypes with rust resistance and high grain yield under the environmental conditions of Uzbekistan.

Keywords: Bread wheat (T. aestivum L.), wheat yellow rust, rust resistance, heat tolerance, leaf area, chlorophyll a and b, carotenoid, water content, grain yield

Key findings: By comparing with the standard check, a lower average value of the wheat accessions
was mainly due to the two rust-resistant genotypes, K-1164 and K-1289, which also have 1000-grain weights of 36.1 g and 34.8 g, respectively. The grain yield of these genotypes was also much lower than the average yield. Desirable chlorophyll a and b, total chlorophyll and carotenoid content, relative water content, leaf area of flag leaves, and higher grain yield were substantial in the wheat landraces К-1088, К-1082, and К-1164 and proved to be physiologically effective under environmental conditions of Tashkent, Uzbekistan. Quantitative indicators of the productivity of these accessions provided positive differentiation, with these genotypes recording higher values than the rest of the entries.

The following research on citrus (Citrus aurantium L.) rootstocks transpired in 2020 at the Citrus Production Nursery of the Directorate of Horticulture and Forestry, Al-Hindiyya District, Iraq. The study aimed to explore the effect of foliar application of amino acids on citrus rootstocks and their various characteristics. The experiment was factorial in a randomized complete block design with two factors and three replications. The first factor included four citrus rootstocks (Citrus aurantium, Troyer citrange, Volkameriana, and Swingle citrumelo), while the second factor included four amino acid treatments, i.e., control, arginine (250 mg L^-1), tryptophan (150 mg L^-1), and arginine (250 mg L^-1) + tryptophan (150 mg L^-1), symbolized as A1, A2, A3, and A4, respectively. Results showed the citrus rootstock Swingle citrumelo emerged superior in seedling height, stem diameter, number of leaves, and contents of carbohydrate, nitrogen, phosphorus, and potassium, with average values of 123.75 cm, 1.13 cm, 96.88 leaves seedling^-1, 13.86%, 1.55%, 0.46%, and 1.51%, respectively. Amino acids’ foliar application had a significant effect, with the treatment A4 (arginine 250 mg L^-1 + tryptophan 150 mg L^-1) excelling in the seedling height and diameter, the number of leaves, and contents of chlorophyll, carbohydrates, nitrogen, phosphorus, and potassium. Corresponding average values were 110.55 cm, 1.23 cm, 104.23 leaves seedling^-1, 136.98 mg 100 g^-1, 14.41%, 1.60%, 0.52%, and 1.58%.

Keywords: Citrus aurantium L., rootstocks, amino acids, vegetative growth, biochemical traits, qualitative and yield traits

Key findings: The presented study revealed the citrus (Citrus aurantium L.) rootstock Swingle citrumelo had the best vegetative growth and biochemical properties, while the rootstock Volkameriana had the highest chlorophyll content. The combined foliar application of the amino acids (arginine 250 mg L^-1 + tryptophan 150 mg L^-1) showed the best performance in vegetative growth and biochemical properties.

The study on potato (Solanum tuberosum L.) took place during the cropping season of 2019–2020 at the Babil Governorate, Abu Gharq Region, Iraq. This study aimed to determine the response of five potato cultivars, Burren (control), Everest, Arizona, Argos, and Evora, to foliar application of Loenergy Plus Nano-nutrient solution with three concentrations (0, 1.5, and 2.5 m^l-1) and three replicates. The results showed the Loenergy Plus Nano-nutrient solution’s spraying significantly affected the potato cultivars’ vegetative and yield characteristics, especially when used at a concentration of 2.5 ml L^-1. It resulted in the highest average values compared with the lower concentration and the control (distilled water). The potato Argos cultivar expressed the maximum values in vegetative traits among the studied potatoes. The research showed the different potato cultivars behaved differently to the same factor in the Iraqi environmental conditions.

Keywords: Potato (S. tuberosum L.), solanaceae, nano-materials, foliar application, tuber

Key findings: Foliar spraying of Loenergy Plus Nano-nutrient solution (2.5 ml L^-1) resulted in increased potato (S. tuberosum L.) growth and yield regardless of the cultivar type. Some potato cultivars showed suitability to grow in Iraqi environmental conditions much better than the Burren cultivar as the most commonly cultivated variety in local farms.

The aim of this study sought to determine the effect of Azotobacter and nitrogen fertilizer on the growth, yield, and accumulation of capsaicin content in fruits of two chili pepper (Capsicum annuum L.) hybrids. Carried out in the crop season of 2022–2023 at the University of Kerbala, District Husseiniya, Iraq, the experiment was in a randomized complete block design (RCBD) with a split-plot arrangement and three replicates. The study included two factors: the first factor was two chili pepper hybrids, i.e., Barbarian and Hyffa, and the second factor was eight fertilizer combinations (control, Azotobacter, urea [150 mg L⁻¹], urea [300 mg L⁻¹], urea [450 mg L⁻¹], Azotobacter + urea [150 mg L⁻¹], Azotobacter + urea [300 mg L⁻¹], and Azotobacter + urea [450 mg L⁻¹]). Results showed the Barbarian hybrid gave the highest total yield (18.12 t ha^-1) and capsaicin content in fruits (742.41 mg kg^-1) compared with the Hyffa hybrid. The fertilizer combination Azotobacter + urea (450 mg L⁻¹) also excelled other treatments in plant height (71.47 cm), the number of branches (9.50 branches plant^-1), stem diameter (2.37 cm), total yield (29.06 t ha^-1), and capsaicin content in chili fruits (820.20 mg kg^-1).

Keywords: Chili pepper (C. annuum L.), cultivars, Azotobacter, nitrogen fertilizer, growth and yield traits, capsaicin content

Key findings: In chili peppers (C. annuum L.), the hybrid Barbarian gave the maximum values in total yield and capsaicin content in fruits compared with the hybrid Hyffa. The fertilizer combination Azotobacter + urea (450 mg L⁻¹) showed the highest values for plant height, the number of main branches, stem diameter, total yield, and capsaicin content in fruits.

The following research assessed the effect of the biostimulant isabion and zinc on the productivity and quality parameters of two cabbage (Brassica oleracea L.) hybrids. The experiment, carried out in the autumn of 2023–2024, transpired at the University of Kerbala, District Al-Husseiniyah, Kerbala Governorate, Iraq. The experiment, laid out in a randomized complete block design, had a split-plot arrangement with three replications. The main plots comprised two cabbage hybrids: Zeina F1 (red cabbage) and Wight Moon (green cabbage). Meanwhile, the subplots included eight fertilizer combinations with different ratios. Results showed hybrid green cabbage was superior in head weight, marketable yield, total yield, and protein percentage in leaves, with average values of 1,087.34 g head^-1, 31.32 t ha^-1, 38.72 t ha^-1, and 12.44%, respectively. As for fertilizer treatments, evidently, the fertilizer combination Isabion (9 L ha^-1) + zinc (1 g L^-1) excelled in head weight, marketable yield, total yield, total dissolved solids, ascorbic acid, and protein content in leaves. Their average values are 1,252.43 g head^-1, 36.07 t ha^-1, 42.93 t ha^-1, 4.48%, 69.04 mg 100 mg^-1, and 17.26%, respectively. The interaction between both factors was also significant for all the cabbage traits under study.

Keywords: Cabbage (B. oleracea L.), biostimulant Isabion, zinc, growth and yield traits, ascorbic acid, protein content

Key findings: Results revealed hybrid green cabbage (B. oleracea L.) was leading in head weight, marketable yield, total yield, protein content, and ascorbic acid in the leaves. As for fertilizer treatments, the fertilizer combination of Isabion (9 L ha^-1) + zinc (1 g L^-1) also excelled in all the cabbage traits.

The use of silicon is an option for reducing the adverse effects of water deficit conditions. The recent study took place at the Agricultural Research and Experiment Station of the Faculty of Agriculture, Cairo University, Giza, Egypt (30°02′ N and 31°13′ E, with an altitude of 30 m) in two seasons of 2019 and 2020. The study’s chief objective aimed to investigate the effect of water deficit at flowering on maize and its relation to silicon spraying. The study included two water treatments: non-stress (NS) and water stress (WS); three silicon treatments: (0, 3, and 6 mM L^-1); and five single-cross hybrids. A split-split plot under the concentration of 6 mM L^-1. The most interesting observation in the study showed the noteworthy increase in oil yield/ha for all studied hybrids, ranging from 13.33% (SC-3444) to 29.41% (SC-3433). It resulted from the application of the concentration of 6 mM L^-1. The hybrids SC-30N11, SC-3433, and SC-3444 proved the best hybrids, displaying tolerance to water.

Keywords: Maize (Zea mays L.), water stress, silicon, yield, carbohydrate, protein, oil, stress-tolerance index

Key findings: The water deficit condition at the flowering stage caused a significant reduction in yield and its components in maize. The silicon treatment 6 mM L^-1 concentration notably enhanced the grain and oil yields and carbohydrates.

This research aimed to determine the effects of different levels of marine seaweed extract on growth and yield traits of Roselle (Hibiscus sabdariffa L.) cultivars (eggplant, red, white, and striped) and their six half diallel hybrids. The experiment layout was in a randomized complete block design with a factorial arrangement and three replications. The first factor included four cultivars and their semi-reciprocal hybrids, while the second factor comprised the foliar application of marine seaweed extract with three concentrations (0, 10, and 20 ml L^-1). The results showed the roselle cultivar eggplant surpassed all other cultivars and provided the highest values for the traits, i.e., plant height, leaf area, dry weight of nuts, nuts per plant, and seeds of nut (160.03 cm, 635.50 cm², 402.77 g plant^-1, 172.44 nuts plant^-1, and 28.69 seeds nut^-1, respectively). The marine seaweed extract with the strongest concentration (20 ml L^-1) also displayed better performance for the above traits (176.02 cm, 615.58 cm², 361.22 g plant^-1, 176.74 nuts plant^-1, and 25.80 seeds nut^-1, respectively).

Keywords: Roselle (H. sabdariffa L.), cultivars, seaweed extract, growth and yield traits

Key findings: The Roselle (H. sabdariffa L.) cultivar eggplant excelled all other cultivars for growth and yield traits. The marine seaweed with the strongest concentration (20 ml L^-1) also provided better performance for growth and yield traits in Roselle.

This study presents the use of plant tissue culture technology in inducing callus from different plant parts and varying concentrations of growth regulators in common grape vine (Vitis vinifera L.). The research, carried out in 2022–2023 at the Tissue Culture Laboratory-College of Agriculture, University of Kerbala, Kerbala, Iraq, comprised two stages, including sterilizing the explants using various concentrations of sodium hypochlorite (0%, 0.5%, 1%, 1.5%, and 2%) for 5, 10, and 15 minutes. The second stage included establishing callus types by growing the explants on MS medium prepared with different concentrations of 2,4-D (0, 1, 2, 3, and 4 mg L^-1) and benzyl adenine (BA) (0, 0.1, 0.2, and 0.4 mg L^-1). The results showed the sterilizing agent (1.5%) with 10 minutes gave the lowest contamination without affecting the vitality of explants. The interaction of 2,4-D (3 mg L^-1) and BA (0.4 mg L^-1) emerged superior by showing the highest response rate (80%) to callus induction from shoots. The growing apex with 2,4-D (2 mg L^-1) achieved the maximum fresh and dry weights of callus (3.32 and 1.03 mg, respectively).

Keywords: Grape vine (V. vinifera L.), explants, growth regulators, 2,4-D, benzyl adenine, fresh and dry weights of callus

Key findings: In the common grape vine (V. vinifera L.), the sodium hypochlorite (1.5%) with a duration of 10 minutes showed the lowest percentage of contamination without affecting the vitality of explants. The interaction of 2,4-D (3 mg L^-1) and BA (0.4 mg L^-1) was superior in most of the studied traits.