Rhizobia are important bacteria, playing a vital role in atmospheric nitrogen fixation. In addition, it increases soil fertility, enhancing crop production and preserving the soil from pollution resulting from inorganic fertilizers’ use. From 81 bacteria samples, nine isolates segregated from nine types of leguminous crops are economically valuable for cultivation within nine different locations in Nineveh Governorate, Iraq. The isolates underwent initial diagnosis by phenotypical and cultural characteristics and host specialization tests. Molecular characterization also ran on the selected bacterial isolates. Performing the 16S rRNA region amplification applied forward primer 27F and a reverse primer 1541R using the polymerase chain reaction (PCR) technique. The results of restriction fragment length polymorphism (RFLP-PCR) employing three endonuclease enzymes showed that EcoRI had similar sequences among the isolates under study but significantly different for MspI and HaeIII. Based on the analysis of results using the statistical program MVSP version 3.22, the degree of similarity divided the isolates into three groups. Results revealed that there were genetic differences between the isolates and the suppressing enzymes, providing more accurate results in recognizing the similarity among the bacterial isolates as a result of the difference in the location and environmental conditions from which the bacteria were isolated, in addition to the different agricultural processes used for those regions.

Keywords: Leguminous crops, rhizobium, culture and biochemical tests, endonuclease enzymes, RFLP-PCR, 16S Rrna

Key findings: The use of 16S rRNA-RFLP technology enables the division of isolated bacteria by studying their genetic polymorphisms treated with restriction enzymes. Detecting three distinct groups from three different sections in Mosul City, Iraq, was possible. The differences were due to the influence of the environments and plants from which the bacteria were isolated and were evident using RFLP. It was possible to determine the phylogenetic tree that shows the degree of genetic affinity between the bacterial isolates.

Assembly, genetic analysis, and preservation of wheatgrass (Agropyron cristatum L. Gaertn.) diversity is an important task in improving the said crop under the environmental conditions of the Republic of Kazakhstan. The presented study evaluated and isolated various wheatgrass species and their populations for breeding and developing promising cultivars based on the genetic principles to improve the degraded pasture situation in South-East Kazakhstan from the perspective of global climate change. For the succeeding investigations, collection of the wheatgrass landraces from various regions of Kazakhstan ensued, as well as from accessions already conserved in the gene pool, and gained evaluation under the environmental conditions of South-East Kazakhstan. In performance-based screening, 20 wheatgrass cultivars identified underwent further genotyping by using inter-simple sequence repeat (ISSRs) polymerase chain reaction markers. The pertinent study significantly contributes to understanding the Agropyron species’ genetic structure and molecular characteristics. Using seven ISSR primers helped study the kinship and genetic polymorphism of the five Agropyron species collected from diverse locations. The ISSR primers were extremely informative for determining the Agropyron’s genetic diversity and interspecific similarity. Moreover, they come highly recommended for an in-depth study comparing the DNA sequencing of the Agropyron populations available in the National Center for Biotechnology’s database.

Keywords: Wheatgrass (Agropyron cristatum L. Gaertn.), genetic diversity, perennial grasses, drought resistance, DNA electrophoresis, phylogenetic tree

Key findings: The study contributed to understanding the Agropyron species’ genetic structure and molecular characteristics. The seven ISSR primers investigated the affinity and genetic polymorphism of five Agropyron species collected from various locations. The ISSR primers were also highly informative in determining the Agropyron’s genetic diversity and interspecific resemblance.

Brassica rapa is an important oilseed crop in Pakistan. It is a rich source of oil and contains 40%–46% oil. In addition, its meal has 38%–40% protein. Given their high levels of erucic acid and glucosinolate, mustard and rapeseed oil is unhealthy as regular cooking oil. A dire need to exploit the genetic variability of rapeseed germplasm is necessary to improve the performance of cultivars. The line × tester analysis helped estimate various types of gene actions that are important to quantitative traits. The key to successful research is selecting suitable lines and testers and designing good mating patterns. Choosing and developing genotypes with high yield and fatty acid profiles are the major concern of rapeseed breeders. The current research on hybridization and evaluation of Brassica rapa accessions sought better harvest and its related traits from the selected germplasm. The combining ability effects determination used line × tester analysis in rapeseed. The accessions’ variability analysis exhibited extremely significant differences in yield and related traits. Recorded data for different morphological and yield-related qualities provided days till 50% flowering, the number of major branches per plant, and the number of secondary branches per plant had positive and significant general combining ability estimates, and all yield-related variables had extremely notable specific combining ability estimates. All the yield-related characteristics displayed a favorable and substantial connection in the examined germplasm. Among the lines, 28244, 40980, and 40981 occurred to be the best general combiners showing the additive gene action. The cross combinations, 40977 × 26283, 40979 × 26283, and 40981 × 26283, indicated significant specific combining ability effects, which showed the non-additive genetic effects of total variance due to the dominance and/or epistasis. The results suggested that the research material used in the remarkable study can benefit by improving yield and fatty acids-related components and can further enhance upcoming breeding programs based on strong particular combining ability impacts.

Keywords: additive, non-additive, line × tester, glucosinolate, erucic acid, protein, rapeseed, analysis of variance

Key findings: Among 150 accessions screened concerning yield and their related traits, the accessions 40977 × 26283, 40979 × 26283, and 40981 × 26283 were the best cross combinations for yield and fatty acids-related components. These accessions will benefit future breeding programs for harvest enhancement along with its quality components.

The latest study aimed to analyze the path coefficient for synthetic cultivars of maize (Zea mays L.) to determine the selection criterion for improved grain yield. In achieving this goal, a field experiment commenced in 2022 at the Ibn-Al-Bitar Preparatory Vocational School, Kerbala Governorate, Iraq. The study set up in a randomized complete block design (RCBD) used a split-plot arrangement and three replications. The main plots comprised six combinations of mineral and organic fertilizers, while subplots were the six synthetic corn cultivars, Fajr1, Maha, 5018, Sumer, Sarah, and Baghdad-3. The genotypic path coefficient analysis showed that grains per ear in the first and second fertilizer levels could benefit as a selection index, achieving the highest total effect (genotypic correlation) of 0.9459 and 0.9957, respectively, obtained through an indirect influence of the biological yield. The third level of fertilizer combination gave a harvest index that can also be a selection index because it showed the highest total result of 0.9825, obtained from a direct consequence of the grain yield (0.8745). In the fourth fertilizer combination, the biological yield can become a selection index because it gained the highest total outcome of 0.9898 from the direct effect of the grain yield (6.7848). In the fifth and sixth fertilizer combinations, the total uptake of nitrogen may be the basis for the selection index reaching the maximum total effects of 0.9806 and 0.9834, respectively, acquired through indirect effects of the biological yield in the fifth and total uptake of phosphorus in the sixth fertilizer combination.

Keywords: Maize (Zea mays L.), mineral fertilizers, organic manures, path coefficient, selection criteria, nitrogen uptake, growth and yield traits

Key findings: The grains per ear at the first and second fertilizer levels, the harvest index at the third level, the biological yield at the fourth level, and the total nitrogen uptake at the fifth and sixth fertilizer levels can be effective selection indicators for improving the maize grain yield.

The presented maize experiment commenced in autumn 2022 at the Al-Hussainiya, Kerbala, Iraq. The experiment comprised two factors: the first included nitrogen (0, 150, and 300 kg N ha^-1) and phosphorus (0, 50, and 100 kg P ha^-1), and the second was the seaweed extract (2 and 4 ml L^-1) used as a foliar application. The seaweed extracts (Algazone Mx30) were treatments applied in the main plots, while the subplots received mineral fertilizer combinations. A randomized complete block design (RCBD) consisted of a factorial arrangement and three replications to evaluate the maize cultivar ‘Maha’s’ response in clay loam soil. In most growth and yield parameters, applying nitrogen-phosphorous fertilizer combinations and the foliar application of seaweed extract (4 ml L^-1) had a substantial effect. The interaction between the seaweed extract and nitrogen and phosphate fertilizers significantly improved leaf area, stem diameter, chlorophyll index in leaves, 500-grain weight, and biological and grain yields. The treatments with seaweed extract (4 ml L^-1) and the combination of 150 N + 50 P performed better for leaf area (55.48 cm² plant^-1), stem diameter (23.10 mm), chlorophyll index (48.54 SPAD), 500-grain weight (141.17 g), biological yield (357.56 g plant^-1), and grain yield (201.46 g plant^-1).

Keywords: Maize (Zea mays L.), seaweed extract, nitrogen and phosphorus fertilizers, growth and yield traits, chlorophyll index

Key findings: A significant improvement in growth and yield traits of maize resulted from the foliar application of seaweed extract (4 ml L^-1) in combination with nitrogen and phosphorus fertilizers.

Pulses are notably good nutritive complements of carbohydrate-rich staple diets, such as, wheat, maize, and rice. Mung bean is an essential pulse crop with different proteins and antioxidants proven beneficial for health. The yield of mung bean in Pakistan is comparable to the world average, but overall production is low because of several biotic and abiotic factors. Cercospora leaf spot (CLS) is one of mung bean’s most damaging diseases, limiting its productivity, causing significant losses in yield and an overall gap in production. The presented investigation progressed to comprehending the genetics of resistance to CLS in mung bean. A minicore set of 293 mung bean genotypes developed and maintained by the World Vegetable Center, Taiwan, served as samples in the study. Observed CLS attacks occur during flowering and reduce the yield by decreasing the number of pods per plant. The genetics to resistance against CLS has a single recessive gene controlling it; hence, homozygous recessive plants will be CLS-resistant. Therefore, single gene transfer methods, such as, backcross breeding, are recommendable for incorporating CLS resistance in high-yielding mung bean genotypes.

Keywords: Cercospora, CLS, generation mean analysis, mung bean, minicore

Key findings: Cercospora leaf spot (CLS) negatively correlates with number of pods per plant (PPP), and PPP positively correlates with seed yield per plant (SYPP). Thus, ultimately, CLS reduces plant yield by reducing PPP. Genotype VI000105 BG was the most susceptible, and genotype VI004954 BG was the most tolerant to CLS. Both genotypes can be valuable in different breeding programs to focus on CLS resistance as an objective. None of the checks were resistant to CLS. Resistance to CLS has the control by a single recessive gene.

The latest study aimed to identify the effects of organic manure (sheep manure) with four concentrations (0, 5, 10, and 15 g seedling^-1) and nano-zinc four levels (0, 1, 2, and 3 g L^-1) on the growth of peach cultivar Hollywood seedlings. The experiment began in 2022 at private nurseries in Babylon province, Iraq. The nano-zinc application with three foliar sprays transpired at 30-day intervals. The experiment continued in a randomized complete block design (RCBD) with three replications. The addition of organic manure treatment (15 g seedling^-1) excelled in traits of seedling length, stem diameter, number of leaves, chlorophyll content, shoot dry weight, leaves area, and zinc in the leaves, with highest averages of 62.03 cm, 8.08 mm, 51.20 leaf seedling^-1, 43.8 SPAD, 57.35 g seedling^-1, 1322.3 cm², and 56.40 mg kg^-1, respectively, compared with the control treatment. The addition of nano-zinc (3 g L^-1) was significantly superior in performance and excelled other treatments by revealing the highest values for the above growth traits, i.e., 60.45 cm, 7.83 mm, 50.90 leaves seedling^-1, 42.35 SPAD, 54.85 g seedling^-1, 1251.90 cm², and 53.63 mg kg^-1, respectively.

Keywords: Peach (Prunus persica L.), organic matter, nano-zinc, foliar nutrition, growth traits, physiological parameters

Key findings: Organic manure (15 g seedling^-1) produced the highest averages of 62.03 cm, 8.08 mm, 51.20 leaf seedling^-1, 43.8 SPAD, 57.35 g seedling^-1, 1322.3 cm², and 56.40 mg kg^-1 for the seedling’s length, stem diameter, number of leaves, chlorophyll content, dry matter of the seedling shoot, leaf area, and zinc content in the leaves, compared with the control treatment.

This study aimed to determine the effect of electrocution with magnetized water on the seed germination and seedling growth characteristics of Acacia cyanophylla. The seeds exposed to electrocution with magnetized water at low magnetic flux levels had different exposure durations using a device designed for this purpose. The parameters were zero × zero, four amps × zero, four amps × 500 gauss, four amps × 850 gauss, and four amps × 1100 gauss, while the exposure durations were four, six, and eight minutes. The experiment occurred in a randomized complete block design (RCBD) with three blocks. The results showed that treating A. cyanophylla seeds with an intensity of 4 amperes × 850 watts in all exposure periods displayed a significant increase in the seed germination ratio (60.00%) compared with the control treatment, recorded with the lowest germination ratio (37.77%). For growth characteristics, the treated seedlings with four amps × 850 gauss for four min emerged with the highest seedling height, dry weight, and shoot diameter, compared with the control treatment providing the lowest rates for studied growth traits.

Keywords: Acacia cyanophylla, magnetic flux, germination ratio, germination stimuli, seed treatments, dormancy-breaking phase

Key findings: Treating Acacia cyanophylla seeds with an intensity of four amps × 850 watts with four min exposure time showed a significant increase in germination percentage. It was excellent over all other interactions in most traits.

This study pursued tests on 17 local and exotic soybean (Glycine max L. Merr.) cultivars with two different water regimes. In the optimal irrigated condition (control), the soybean plants gained five times irrigation in the scheme of 1:3:1 during the vegetation period, with the total volume of water used for that irrigation being 5000–5500 m³/ha. For the water deficit condition, irrigation was only three times on the scheme 1:1:1, using a total volume of water at 3000–3500 m³/ha. In the optimal irrigated condition, water provision was only once during the formation of soybean leaves, three times during the budding period, and once again at the beginning of the blooming period. In that condition, the provision of an artificially created water deficit condition and drought with one irrigation ensued at the beginning of the blossoming period. According to the results, chlorophyll “b” pigment was more sensitive to water deficit conditions than chlorophyll “a.” The increase in chlorophyll “b” under drought conditions increased chlorophyll’s protection function, the primary photosynthetic pigment, with its reception of photons from sunlight. Stress enzyme activity increased to different extents compared with optimal water supply conditions in the soybean cultivars under water deficit conditions. The number of chloroplast pigments in plant leaves and the activity of peroxidase, catalase, and superoxide dismutase enzymes in leaves strongly influenced local and exotic soybean genotypes during the blooming-harvest period under drought conditions. With water deficit conditions, the number of pods per plant and 1000-grain weight reduced from 8.6% to 63.7% and 1.7% to 12.8% in the local and 3.8% to 28.3% and 5.6% to 58.8% in exotic soybean cultivars compared with water optimal conditions.

Keywords: Soybean (Glycine max L. Merr.), genotypes, diverse water regimes, water deficit condition, peroxidase, catalase, chlorophyll, carotenoids

Key findings: Under water stress conditions, the peroxidase enzyme activity was notably higher in local soybean cultivars Genetic-1 and Tomaris and the exotic cultivar Selecta-301 compared with other genotypes.

Drought tolerance is a quantitative trait that is exceedingly challenging to breed, especially for allotetraploids like cotton. The scenario of limited water resources necessitates developing drought-tolerant cultivars that conserve significant irrigation water throughout the summer. Therefore, the presented study used a design to statistically analyze the morphological, physiological, and fiber quality parameters linked with drought tolerance, which is a comprehensive method for choosing better genotypes from the available cotton germplasm. Measuring these parameters ensued for plants grown under field conditions. The germplasm comprised 150 cotton genotypes studied at two water regimes, i.e., regular and water-stressed conditions for two consecutive seasons of 2015–2016 and 2016–2017. Data recording ran for different morpho-physiological and fiber quality parameters. Significant differences occurred for all the treatments, genotypes, and Genotype × Environment interaction for all the morphological, physiological, and fiber quality parameters under study. Additive Main effects and Multiplicative Interaction (AMMI) analysis and AMMI biplot analysis helped analyze the results, which revealed that the cotton genotypes FH-900, FH-901, FH-312, AS-1, AS-2, AS-3, RH-510, RH-627, AR-2, AR-9, BH-118, BH-175, SLH-74, CIM-1100, CIM-598, and MM-58 were drought tolerant and ranked highest concerning stress condition. Moreover, correlation studies distinguished the relationship between relevant traits concerning drought tolerance.

Keywords: AMMI analysis, cotton, drought tolerance, morpho-physiological traits, field evaluation

Key findings: The drought-tolerant cotton genotypes, FH-900, FH-901, FH-312, AS-1, AS-2, AS-3, RH-510, RH-627, AR-2, AR-9, BH-118, BH-175, SLH-74, CIM-1100, CIM-598, and MM-58, stood out in this study to benefit a cotton breeding program for drought tolerance.