Salinity critically limits rice metabolism, growth, and productivity worldwide. Improvement of the salt resistance of locally grown high-yielding cultivars is a slow process. The objective of this study was to develop a new salt-tolerant rice germplasm using speed-breeding. Here, we precisely introgressed the hst1 gene, transferring salinity tolerance from “Kaijin” into high-yielding “Yukinko-mai” (WT) rice through single nucleotide polymorphism (SNP) marker-assisted selection. Using a biotron speed-breeding technique, we developed a BC₃F₃ population, named “YNU31-2-4”, in six generations and 17 months. High-resolution genotyping by whole-genome sequencing revealed that the BC₃F₂ genome had 93.5% similarity to the WT and fixed only 2.7% of donor parent alleles. Functional annotation of BC₃F₂ variants along with field assessment data indicated that “YNU31-2-4” plants carrying the hst1 gene had similar agronomic traits to the WT under normal growth condition. “YNU31-2-4” seedlings subjected to salt stress (125 mM NaCl) had a significantly higher survival rate and increased shoot and root biomasses than the WT. At the tissue level, quantitative and electron probe microanalyzer studies indicated that “YNU31-2-4” seedlings avoided Na⁺ accumulation in shoots under salt stress. The “YNU31-2-4” plants showed an improved phenotype with significantly higher net CO₂ assimilation and lower yield decline than WT under salt stress at the reproductive stage. “YNU31-2-4” is a potential candidate for a new rice cultivar that is highly tolerant to salt stress at the seedling and reproductive stages, and which might maintain yields under a changing global climate.

Worldwide crop productivity hampers severely due to the adverse effects of salinity. Global warming causes a rapid escalation of the salt-affected area, and new agricultural land is affected through saltwater intrusion. The ever-growing human population impulses to utilize the saline area for crop cultivation to ensure food security. Salinity resistance crops could be a promising substitute but with minor success because inappropriate tactics on saline soil management resulted in unsatisfactory yield. Salt-tolerant plant growth-promoting rhizobacteria (ST-PGPR) is considered an alternate way towards enhancing crop growth in saline ecosystems. It is reported that PGPR is enabled to produce exopolysaccharides which lead to biofilm formation and generate osmoprotectants and antioxidant enzymes that can significantly contribute to stimulating plant growth in the saline ecosystem. In addition, several plant growth-promoting characteristics of PGPR such as the acquisition of essential nutrients and upsurge hormone production could enhance plant growth simultaneously. In this review, we will explore the survival mechanisms of ST-PGPR and their influence on plant growth promotion in saline ecosystems.

Next-generation sequencing (NGS) is a revolutionary advancement allowing large-scale discovery of functional molecular markers that has many applications, including plant breeding. High-quality genomic DNA (gDNA) is a prerequisite for successful NGS library preparation and sequencing; however, few reliable protocols to obtain such plant gDNA exist. A previously reported nuclear pellet (NP) method enables extraction of high-yielding gDNA from fresh leaf tissue of maize (Zea mays L.), but the quality does not meet the stringent requirements of NGS. In this study, we optimized the NP method for whole-genome sequencing of rice (Oryza sativa L.) through the integration of simple purification steps. The optimized NP method relied on initial nucleus enrichment, cell lysis, extraction, and subsequent gDNA purification buffers. The purification steps used proteinase K, RNase A, phenol/chloroform/isoamyl alcohol (25:24:1), and chloroform/isoamyl alcohol (24:1) treatments for protein digestion and RNA, protein, and phenol removal, respectively. Our data suggest that this optimized NP method allowed extraction of consistently high-yielding and high-quality undegraded gDNA without contamination by protein and RNA. Moreover, the extracted gDNA fulfilled the quality metrics of NGS library preparation for the Illumina HiSeq X Ten platform by the TruSeq DNA PCR-Free Library Prep Kit (Illumina). We provide a reliable step-by-step guide to the extraction of high-quality gDNA from fresh leaf tissues of rice for molecular biologists with limited resources.

The dissipation pattern and mobility of applied pesticides in the soil represent a crucial process for pesticide safety and subsequent groundwater contamination. In this study, two distinct experiments were conducted to explore the environmental fate, dissipation, and mobility of two pesticides, phorate and boscalid, in greenhouse conditions and laboratory soil column studies, respectively. The role of organic matter and growing conditions was evaluated during dissipation and mobility studies. In the first study, commercial formulations of phorate (10 G) and boscalid (20% SC) were sprayed in the designated greenhouse for Korean cabbage following the recommended dosage. A sequential collection of plant samples (e.g., 0, 7, 14, 21 days) was performed. On the other hand, three sets of packing columns were prepared (control, biochar-amended, and H₂O₂ treated). The effect of organic matter addition or removal during the leaching of pesticides was explored. A 14-day interval after the last spray was suggested for safe spraying. After 30 days of leachate collection, no pesticide residue was detected in the leaching water, indicating the immobility of the studied pesticides. However, the metabolic transformation of phorate was evident during this column study, with slight mobility within soil columns. In particular, phorate sulfoxide and sulfone were mostly detected in the top soil layer (vadose zone) of the soil column. In summary, phorate and boscalid were considered immobile pesticides with moderate persistence in the soils. The safe pre-harvest interval should be maintained to reduce the health risk of pesticides.

Background: Selection of a suitable planting time is one of the key factors for obtaining a desirable rice grain yield. This study focuses on the effect of planting date on the key agronomic traits and provides useful information on optimal planting window to maximize grain yield of Bangabandhu dhan100 in the cold-prone Rangpur region, Bangladesh. Methods: The study was conducted at the Rangpur regional station farm of the Bangladesh Rice Research Institute from October 2021 to June 2022. The selected cultivar was seeded on eight different dates at a 15-day interval, starting on October 16. Time series data on agronomic parameters including seedling biomass, leaf number of seedlings and tiller number per plant were collected at a 15-day interval. Result: A good relationship was found between accumulated GDD (growing degree days) and the associated leaf number per plant and the highest leaf number was observed with early seeding. Similarly, seedling biomass yield depended on accumulated GDD and it was found to be higher at early seeding than late seeding. The tillering pattern of Bangabandhu dhan100 was influenced by planting dates and reached its peak at 60 days after planting for all seeding dates. The highest tiller number (368/plants) was found when the cultivar was seeded on December 1. Total biomass showed an increasing trend after planting and reached its maximum of 13.9 t/ha with December 1 seeding. Planting time significantly influenced the grain yields and the highest yields were observed during seeding between 1 and 16 December; yields gradually decreased with the advancement of seeding dates. This finding provided a good idea for the selection of an optimal planting time for Bangabandhu dhan100 to maximize grain in the Rangpur region, Bangladesh.

Confronting the challenges of climate change, population expansion, and food security in Bangladesh demands the development of high-yielding, resilient rice varieties adapted to various agro-ecological zones. This study aimed to identify superior rice genotypes with consistent performance during the dry season (November-May) under irrigated condition using multi-environment trials (METs) at ten locations. Seven genotypes, along with a control variety, were evaluated for grain yield and agronomic parameters, including plant height, growth duration, panicle number, filled spikelets per panicle, and thousand-grain weight (TGW). The genotype-by-environment interaction (GEI) was analyzed, and stability was assessed using Weighted Average of Absolute Scores with Yield (WAASBY) and Multi-Trait Stability Index (MTSI) metrics. Results revealed significant GEI effects, with genotype BR(Bio)9777-116-12-2-5 demonstrating the highest yield and stability across environments. Grain yield showed strong positive correlations with most traits except TGW. WAASBY analysis identified BR(Bio)9777-116-12-2-5 as top-performing and stable genotypes, whereas others, such as BR(Bio)9777-84-4-1-1 and BR(Bio)9777-123-4-6-1 were less productive and unstable. MTSI further confirmed the exceptional performance of BR(Bio)9777-116-12-2-5, highlighting its suitability for varied agro-ecological zones. These outcomes underscore the significance of combining yield and stability metrics in breeding programs providing a valuable framework for developing climate-resilient rice varieties to enhance productivity and ensure food security in Bangladesh. This research offers valuable guidance for addressing emerging agricultural challenges and promoting sustainable food systems in the face of global environmental and population pressures.