Mohammad Nur Alam

Soil salinity is a rapidly intensifying abiotic stress that significantly limits wheat productivity, particularly in coastal and irrigated agroecosystems. Although sodium (Na ⁺ ) ion exclusion has been recognized as a key tolerance mechanism, the integration of physiological performance with Nax1 -mediated molecular regulation among regionally adapted wheat genotypes remains insufficiently characterized. The present study aimed to dissect salinity tolerance by combining hydroponic phenotyping, multivariate trait analysis, molecular marker profiling, and quantitative expression analysis of the Na ⁺ ion transporter gene Nax1 . Seventeen spring wheat genotypes were evaluated under four salinity levels (0.0, 10, 12, and 14 dS m⁻¹). Germination and survival rate, shoot and root growth, and biomass accumulation were measured. Principal component analysis (PCA) and hierarchical clustering were performed to classify genotypes, while SSR (simple sequence repeat) and Nax -linked markers assessed genetic diversity. Relative Nax1 expression was quantified using qRT-PCR (quantitative real-time polymerase chain reaction). Salinity significantly reduced germination, survival, elongation, and biomass, with strong genotype-dependent variation. Multivariate analyses clearly separated tolerant and sensitive genotypes, with biomass retention and survival contributing most to total variation. Marker analysis revealed moderate genetic polymorphism. Notably, tolerant genotypes exhibited 3-6-fold induction of Nax1 under severe salinity, positively correlating with biomass maintenance. These findings demonstrate that salinity tolerance in wheat is associated with coordinated physiological resilience and enhanced Nax1 -mediated Na⁺ ion exclusion, thereby advancing mechanistic understanding and supporting molecular-assisted breeding for salt-affected environments.

Monascus pigments (MPs) are valuable natural colorants, but their industrial production is often hampered by scarce high-yield strains and inefficient processes. In this study, a novel MPs-producing strain was isolated from red yeast rice and named as Monascus purpureus HC-5. This strain exhibited notable hydrolase activities, indicating a high efficiency in substrate utilization. In addition, using rice as the optimal substrate, the key parameters of solid-state fermentation were optimized. Response surface analysis revealed that soaking time and temperature were the most critical influencing factors. The optimal combination conditions were an inoculum size of 8.91%, a soaking time of 13.59 h, and a temperature of 32 °C. Under these optimized conditions, the MPs yield reached 2185 ± 255.7 U/g, which displayed an approximately four-fold increase compared to the initial unoptimized process. Briefly, this study identified a strain of Monascus purpureus and optimized its solid-state fermentation conditions, which significantly increased the yield of MPs. This provides an important theoretical basis and scientific evidence for the large-scale industrial production of MPs.

Wheat, a crop highly sensitive to temperature, faces increased risks due to global warming. This study aimed to analyze DNA to identify wheat genotypes that respond well to heat and to uncover genetic similarities and differences among them. Fifteen wheat genotypes were planted on two dates, November 21 (Irrigated Timely Sowing, ITS) and December 21 (Irrigated Late Sowing, ILS), and analyzed with 13 SSR markers. A dendrogram divided the genotypes into two primary groups, each containing four sub-clusters. The greatest genetic distances were observed between BAW 1290 and BARI Gom 28 (0.929), while the smallest genetic distance (0.000) was found between Nadi 2 and BAW 1147. These results suggest that genotypes in both Cluster I and Cluster II (Group A) display moderate tolerance to heat, as indicated by their Heat Susceptibility Index (HSI) for 1000-grain weight (TGW) and grain yield, with HSI values between 0.50 and 1.00, allowing them to perform under heat stress. In contrast, genotypes in Group B, especially those in Cluster III, showed higher HSI values (1.04-1.23) and significant declines in TGW and yield under heat, indicating susceptibility. Similarly, Cluster IV genotypes exhibited heat sensitivity (HSI>1.00). Seven genotypes, specifically BARI Gom 33, BARI Gom 32, BARI Gom 31, BARI Gom 30, BARI Gom 29, BARI Gom 26, and BARI Gom 25 were identified as suitable for cultivation under heat stress. These findings and other studies on heat-tolerant genotypes are valuable for advancing heat-resilient breeding programs based on SSR marker selection. Bangladesh J. Agri. 2025, 50(1): 20-35

Bangladesh faces a significant deficit in wheat grain production relative to its national demand, largely due to the prolonged duration-typically 10 to 12 years-required to release a new variety through conventional breeding approaches. Traditional methods involve multiple years of crossing between male and female parents or their progenies, followed by recurrent selection to develop homozygous lines (from the F1 to F6 generations) possessing desired traits. In contrast, the doubled haploid (DH) method offers a faster, simpler, and more reliable alternative, enabling the development of homozygous lines within just 2–3 years. In this study, DH lines were produced by crossing two F1 wheat hybrids with maize. A 0.1 % colchicine solution was applied to induce chromosome doubling in the F₂ progeny. Of the 421 florets pollinated, 340 (80.8 %) developed into green parthenocarpic caryopses (GPC). From these, 70 embryos (20.6 %) were successfully rescued, and 35 (50 %) of the rescued embryos germinated. Ten green haploid plants (28.6 % of the germinated embryos) were regenerated and subsequently transplanted. After colchicine treatment of nine haploid (H₁) plants, eight (88.9 %) survived. Among them, one plant (12.5 %) successfully produced homozygous doubled haploid (DH₁) seed. These seeds were then multiplied to obtain DH₂ seeds, which were evaluated in a preliminary yield trial next year. The results confirm the effectiveness of this method in generating homozygous lines within a significantly shorter time frame (2–3 years) by utilizing maize pollination and colchicine-induced chromosome doubling.

Wheat has to face the effects of global warming standing on the thread worldwide, and competing with many crops in the Rabi season (15 Oct to 15 Mar). Wheat is Bangladesh’s second staple, meeting 13.6% of the country's cereal demand. However, despite an annual demand of 7.5 million metric tons (MMT), domestic wheat production in the 2023-24 season was only 1.19 MMT, covering just 15.9% of its demand and necessitating imports costing $2.21 billion. Demand continues to rise by 7-13% each year. Wheat production has declined from 1.99 in the 1998-99 season to 1.19 MMT in the 2023-24 season due to high crop competition with Boro rice, maize, mustard, and other crops during the Rabi season. Wheat production is reduced by other factors, such as low prices and insufficient mechanization, lack of time decision, etc. to purchase wheat grains by the government and businessmen which discourage framers from its cultivation. Expanding wheat cultivation with high-yielding stress-tolerant varieties in fallow lands and non-traditional areas would reduce greenhouse gas (GHG) emissions, malnutrition, groundwater harvesting, etc. Our study aims to offer new insights to policymakers and national and international benevolent agencies regarding the reasons behind the decline in wheat production and potential strategies to increase it. Additionally, this content will provide guidelines for policymakers and other stakeholders on how to reduce severe malnutrition and minimize greenhouse gas emissions and groundwater harvesting, thereby supporting the implementation of the United Nations' Sustainable Development Goals (SDGs).

Cereals are essential for global food consumption, providing half of the world’s calorie intake and ranking as the top traded agricultural commodity. By 2032, 41% of cereals are expected to be consumed directly by humans, with 37% used as animal feed. As key sources of carbohydrates, protein, minerals, vitamins, and fiber, cereals deliver balanced nutrients for humans and livestock. Rice and wheat are the most widely consumed, yet over 3 billion people still suffer from micronutrient deficiencies, particularly iron, zinc, and vitamin A, leading to widespread malnutrition affecting over 2 billion globally. Nutrient deficiencies contribute significantly to childhood mortality, with undernutrition causing 45% of deaths in children under five. Cereals naturally contain essential micronutrients, including iron, zinc, and B vitamins, along with fiber that supports cardiovascular health and reduces cancer risks. While the growth rate of cereal consumption is slowing, it remains steady, especially in developing countries, where cereals provide 56% of daily caloric intake. To address malnutrition, biofortifying cereals to enhance iron, zinc, and vitamin A content could be transformative. This review highlights the nutritional importance of cereals, the need for balanced diets, and how biofortification and genetic editing can combat global malnutrition.

Wheat is threatened by global warming. This study aimed to characterize based on DNA profile and identify heat-tolerant wheat genotypes. Fifteen wheat genotypes were sown in Nov 21 and Dec 21 and evaluated within 13 SSR markers. A dendrogram classified the genotypes into two main groups. The highest genetic distances (0.93) were drawn between BAW 1290 and BARI Gom 28, and the lowest one between Nadi 2 and BAW 1147. Heat susceptibility index (HSI) values for 1000-grain weight (TGW) and grain yield indicated moderate heat tolerance in Cluster I genotypes (HSI 0.50-1.00), closely matching Group A's Cluster II members. In Group B, Cluster III genotypes had higher HSI (1.04-1.23) and significant reductions in TGW and grain yield under heat stress, indicating heat susceptibility. The varieties BARI Gom 25, 26, 27, 28, 29, and 30 were identified as heat-stress tolerant. This research provides insights for future heat stress-molecular breeding programs.

Worldwide the severity of abiotic stress like heat, drought, salinity, cold, waterlogging, etc. are being increased because of global warming. Wheat crops must adapt to harsh environments through physiological, molecular, and genetic manipulation. Because of abiotic stress, reactive oxygen species (ROS) and reactive nitrogen species (RNS) produced in wheat plants break down DNA and RNA bases, protein, lipid, and other macro- and micromolecules, resulting in stunted growth and yield decline. Abiotic stress also induces the crop's molecular functions, physiological, biological, and cellular processes, and their compositions. Different stressors like high light intensity, heat, drought, and salinity also impair photosynthesis damaging various pigments. Antioxidant enzymes, such as catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), and ascorbate peroxidase (APX), etc. synthesized in harsh environments can ameliorate ROS/RNS produced in oxidative stress. Under abiotic stress, heat shock proteins (HSPs) heat shock transcription factors (HSFs) in heat stress, and dehydration-responsive element binding proteins (DREBs) in drought stress are activated to synthesize proteins to mitigate the deleterious effects of those stressors. Na⁺ exclusive genes (NAX1, NAX2) and Na⁺/H⁺ (K⁺) antiporter genes (NHX1, NHX2) hinder those ions from uptake into leaf sheaths and blades of wheat resulting in the declination of salinity in plants. Exogenous hormones like gibberellic acid, salicylic acid, and melatonin, etc., and osmoprotectants like proline, and gene manipulation in plants through genetic engineering are being employed to mitigate the toxic effects of abiotic stress on plants, as portrayed in many literatures. The review depicts how abiotic stress affects phenotypic, physiological, and molecular structures and functions of wheat crops, and their mitigation strategies to lessen their noxious effects on wheat.

Over 3.0 billion people of the 7.75 billion globally suffer from malnutrition due to deficiencies in micronutrients, particularly iron, zinc, and vitamins (such as vitamin A, B complex, E, and folate, etc.). In response, there is growing consumer interest in foods that provide traditional nutrients and contain additional compounds beneficial to health and well-being. Wheat is the most important cereal crop in terms of both production and consumption, contributing about 30% of total cereal consumption worldwide. It provides a significant source of carbohydrates and gluten protein (around 12-14% protein), which supply substantial energy. Wheat grain is also rich in various nutrients, such as macro-elements like phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg); microelements like iron (Fe), zinc (Zn), manganese (Mn), and vitamins B complex: thiamin (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxine (B6), biotin (B7), folate (B9), additionally soluble fiber and other trace minerals which are higher than in other major cereals. The inner bran coats, phosphates, and other mineral salts in wheat contribute to its beneficial effects on bowel movements. Despite its nutritional benefits, the quality of wheat's nutrients is a topic of ongoing discussion. Exploring ways to enhance the nutritional quality of wheat could provide valuable insights for scientists working to improve global nutrition status.