Thousand-grain Weight Research Articles

Effect of Mixed Spraying of SA and ABA on the Growth and Development of Winter Oilseed Rape (Brassica napus L.) During the Post-Waterlogging Podding Period

Winter oilseed rape is particularly vulnerable to waterlogging stress during its growth and development stages, especially at the podding stage, leading to impaired photosynthesis, reduced antioxidant enzyme activity, and significant declines in yield and oil content. Previous studies have demonstrated that exogenous plant growth regulators, such as salicylic acid (SA) and abscisic acid (ABA), enhance crop resistance to abiotic stresses. Nevertheless, their combined application for winter oilseed rape recovery under waterlogging stress remains underexplored. In this study, a pot experiment was conducted to investigate the effects of SA, ABA, and their combination on the growth, photosynthesis, antioxidant enzyme activity, and yield of winter oilseed rape at the podding stage following waterlogging stress. The results showed that mixed spraying of SA and ABA significantly improved plant height, effective branching number, yield per plant, and thousand-grain weight of winter oilseed rape, surpassing the effects of individual treatments. Structural equation modeling revealed that mixed spraying enhanced yield components through direct improvements in photosynthesis and indirect regulation of antioxidant enzyme activities. This study is the first to systematically evaluate the role of mixed spraying of SA and ABA in mitigating waterlogging stress and restoring yield and quality in winter oilseed rape. This approach effectively alleviates the adverse effects of waterlogging and provides a valuable reference for post-waterlogging management of other crops. These results hold significant implications for addressing the impacts of climate change and ensuring global food security.

Dissecting the genetic basis of fruiting efficiency for genetic enhancement of harvest index, grain number, and yield in wheat

BackgroundGrain number (GN) is one of the key yield contributing factors in modern wheat (Triticum aestivum) varieties. Fruiting efficiency (FE) is a key trait for increasing GN by making more spike assimilates available to reproductive structures. Thousand grain weight (TGW) is also an important component of grain yield. To understand the genetic architecture of FE and TGW, we performed a genome-wide association study (GWAS) in a panel of 236 US soft facultative wheats that were phenotyped in three experiments at two locations in Florida and genotyped with 20,706 single nucleotide polymorphisms (SNPs) generated from genotyping-by-sequencing (GBS).ResultsFE showed significant positive associations with GN, grain yield (GY), and harvest index (HI). Likewise, TGW mostly had a positive correlation with GY and HI, but a negative correlation with GN. Eighteen marker-trait associations (MTAs) for FE and TGW were identified on 11 chromosomes, with nine MTAs within genes. Several MTAs associated with other traits were found within genes with different biological and metabolic functions including nuclear pore complex protein, F-box protein, oligopeptide transporter, and glycoside vacuolar protein. Two KASP markers showed significant mean differences for FE and TGW traits in a validation population.ConclusionsKASP marker development and validation demonstrated the utility of these markers for improving FE and TGW in breeding programs. The results suggest that optimizing intra-spike partitioning and utilizing marker-assisted selection (MAS) can enhance GY and HI.

Regulation of Rice Grain Quality by Exogenous Kinetin During Grain-Filling Period

Cytokinins (CKs) play important functions in plant growth and development and in response to adversity stress. However, little is known about the role CK plays in rice grain quality. We hypothesized that exogenous cytokinins could improve rice grain quality by regulating physiological traits and genes related to starch synthesis. Therefore, we exogenously applied different concentrations of kinetin (KT), an exogenous CK, during the grain-filling period. Our results show that all the different concentrations of exogenous KT treatments resulted in a significant increase in thousand-grain weight. In particular, chalkiness and chalky grain rate were significantly reduced, and gel consistency (GC) content and alkali spreading value (ASV) were significantly increased in 10−8 M KT treatment. Meanwhile, the exogenous application of 10−8 M KT positively affected the transcription of some starch synthesis-related genes, which was in contrast to the 10−5 M KT treatment. In conclusion, the exogenous application of appropriate concentrations of KT during the grain-filling period can ultimately affect rice grain quality by regulating the changes in the relevant indicators, such as appearance quality (AQ) and eating and cooking qualities (ECQ).

Phenotypic Plasticity of Grain Size-Related Traits in Main-Crop and Ratoon Rice.

Grain size and weight of main-crop are larger than those of ratoon rice, indicating that increasing grain size and weight of ratoon rice is an effective way to increase rice yield. Thus, grain length (GL), grain width (GW), and thousand-grain weight (TGW) of main-crop and ratoon rice in 159 indica rice accessions were used to associate with 2 017 495 SNP markers to detect quantitative trait nucleotides (QTNs) and their interactions with meteorological factors (QMIs), such as temperature and sunlight hours. Around 59 QMIs identified for temperature and 80 QMIs identified for sunlight hours, first,candidate gene LOC_Os02g40840 for GW and LOC_Os04g45480 for TGW were found to interact with temperature, while LOC_Os01g19970 for GL, LOC_Os02g39360 and LOC_Os07g05720 for GW, and LOC_Os07g49460 for TGW were found to interact with sunlight hours. Based on the results of previous studies, LOC_Os04g45480 exhibits high expression levels in the main-crop under higher temperature, thereby enhancing the accumulation of the auxin receptor TIR1. TIR1, in turn, promotes starch accumulation in the endosperm, explaining why TGW is heavier in main-crop than in ratoon rice. Finally, the analysis of best linear unbiased prediction values revealed 1 (LOC_Os08g10350) and 3 (LOC_Os02g50860, LOC_Os08g28680, and LOC_Os08g29160) candidate genes responsible for GW and TGW, respectively. In addition, we discussed the four available and six unavailable candidate genes in ratoon rice breeding. This study provides new method and genes for studying differences in grain size-related traits between main-crop and ratoon rice.

Melatonin Promotes Yield Increase in Wheat by Regulating Its Antioxidant System and Growth Under Drought Stress.

Drought stress constitutes a major challenge to wheat production. Melatonin plays a vital role in plants' resistance to drought stress. Nevertheless, the influence of melatonin seed coating on the drought resistance ability of wheat remains unclear. Hence, in this study, wheat (Yunmai 112) was chosen as the experimental material. The research results indicated that 100 µM exogenous melatonin treatment enhanced the germination rate of wheat seeds by 11% compared to the CK group. Melatonin seed coating (100 or 200 µM) significantly inhibited the accumulation of ROS in wheat seedlings under drought stress conditions and facilitated the growth of wheat seedlings. Then, 100 µM melatonin seed coating elevated the activity of antioxidant enzymes (CAT, Cu/Zn-SOD, POD, and T-GSH) in wheat seedlings and strengthened the resistance of wheat to drought stress. In contrast to the control, 100 or 200 µM melatonin seed coating significantly raised the contents of soluble protein and chlorophyll in wheat seedlings. Further studies demonstrated that 100 µM melatonin seed coating promoted the increase in the thousand-grain weight and yield of wheat under drought stress. Taking together, melatonin seed coating is an effective approach for enhancing the stress resistance and the yield of wheat under drought stress.

Identification of significant SNPs for yield-related salt tolerant traits in rice through genome-wide association analysis.

Rice salt tolerance is highly anticipated to meet global demand in response to decreasing farmland and soil salinization. Therefore, dissecting the genetic loci controlling salt tolerance in rice for improving productivity is of utmost importance. Here, we evaluated six salt-tolerance-related traits of a biparental mapping population comprising 280 F2 rice individuals (Oryza sativa L.) at the seedling and reproductive stages. We performed a genome-wide association study (GWAS) to identify marker-trait associations under artificially induced salt stress using the 1K RICA chip (Agriplex Genomics, Cedar Avenue, Suite 250, Cleveland, 011444106, USA). We have identified 8 single nucleotide polymorphisms (SNPs) representing eight genomic regions on chromosomes 5, 8, 9, and 10. These were significantly associated with the six salt-tolerance-related traits, no. of tillers per plant (TPP), effective tillers per plant (ETP), spikelet fertility percentage (SFP), field grain number (FGN), grain length breadth ratio (LBR) and thousand-grain weight (TGW). FGN has two significant SNPs (SNP0758 and SNP0759) on Chromosome 9, whereas SFP on chromosomes 8 and 12 (SNP1127 and SNP0966, respectively). Similarly, for TPP (SNP0796), a significant SNP was detected on chromosome 10, and for ETP (SNP0414) on chromosome 5. Two significant SNPs were found in chromosome 12 for LBR (SNP0920) and TGW (SNP0976). Based on all loci, we screened 3 possible candidate genes in chromosomes 8, 9, and 12 between the genomic region of SNP0920 and SNP1127 under salt stress. Interestingly, these genes were involved in protein coding, none of which was previously reported as being involved in plant salt tolerance. Further, the genetic relationship between the mapping population and population structure was classified by STRUCTURE v 2.3. Genotypes with ≥ 80% of shared ancestry were explained into two major clusters (I and II), and < 80% of shared ancestry were categorized as admixtures. An unrooted alpha was developed by TASSEL 5.0, dividing the genotypes into three major groups where 97 individuals were in Cluster 1, cluster 2 consisted of 93 individuals, and the remaining Cluster 3 included 90 individuals. A kinship matrix developed from 860 SNPs indicated group formation and more substantial relatedness among the genotypes with a red zone. Our findings provide valuable information for enhancing the understanding of complicated salt tolerance mechanisms in rice seedlings and the identified candidates potentially used for breeding salt-tolerant genotypes.

Comparative study of the grain yield and morpho-physiological behavior of three varieties of hard-wheat (Triticum durum Desf.) under saline stress

This study examined the impact of salinity on the physiology and productivity of three durum wheat varieties (M.B.B., Waha, and Boussellam) under different salt concentrations (0 mmol, 4 mmol, and 8 mmol). A factorial design was applied in a pot experiment with soil capacity of approximately 7 kg. Key physiological and productivity parameters, such as leaf area, plant height, number of plants, and grain yield, were assessed. The results showed that the highest salinity level (8 mmol) had a significant negative effect on leaf area, plant height, number of plants, number of ears, and grains per ear. At a salinity of 4 mmol, canopy temperature, number of tillers, biomass, thousand grain weight (TGW), and overall yield were affected. Among the varieties tested, M.B.B. and Boussellam demonstrated greater tolerance to salinity compared to Waha. These findings highlight the differential response of durum wheat varieties to salinity stress, suggesting that M.B.B. and Boussellam may be more resilient options for saline environments.

Genetic dissection of flag leaf morphology traits and fine mapping of a novel QTL (Qflw.sxau-6BL) in bread wheat (Triticum aestivum L.).

Total 60-QRC for FLM traits were detected by meta-genomics analysis, nine major and stable QTL identified by DH population and validated, and a novel QTL Qflw.sxau-6BL was fine mapped. The flag leaf is an "ideotypic" morphological trait providing photosynthetic assimilates in wheat. Although flag leaf morphology (FLM) traits had been extensively investigated through genetic mapping, there is a desire for FLM-related loci to be validated in multi-environments and fine mapping. In order to identify the stable genomic regions for FLM traits, we conducted a meta-genomic analysis based on reports from 2008 to 2024. Experimentally, a doubled haploid (DH) population was used to assess the genetic regions associated with FLM traits in nine environments. The meta-genomic analysis extracted 60 QTL-rich clusters (QRC), 45 of which were verified in marker-trait association (MTA) study. Nine major and stable QTL were found being associated with FLM traits across three-to-seven environments including BLUP, with phenotypic variance explained (PVE) ranging from 5.05 to 34.95%. The KASP markers of the nine QTL were validated (P < 0.005) in more than three environments using a panel of diverse wheat collections from Shanxi Province in China. Two co-located major and stable QTL viz. Qflw.sxau-6B.5 and Qfla.sxau-6B.4 were found novel and contributed to increaseFLW by 12.09-19.21% and FLA by 5.45-13.28%. They also demonstrated high recombination rates in LD analysis based on the resequencing of 145 wheat landmark cultivars. The fine mapping of Qflw.sxau-6BL narrowed it down to a 1.27Mb region as a result of the combined genotypic and phenotypic analysis for secondary mapping population. Comparing to NIL-ND3338, the NIL-LF5064 showed higher FLW by 20.45-27.37%, thousand-grain weight by 1.88-2.57% and grain length by 0.47-2.30% across all environments. The expression analysis of 11 tissues revealed seven highly expressed genes within the fine map region. This study provides a genetic basis for the FLM traits for further map-based cloning of FLW genes in wheat.

Study of various types of rice field management systems on the functional properties of rice

The purpose of this study was to investigate how various rice field management strategies affected the Mentik Wangi and IR64 white rice (Oryza sativa L.) varieties’ physical, chemical, physicochemical, functional, and sensory qualities. With just one factor—the conventional, semi-organic, and organic rice field management systems—the methodology applied a fully randomized design. The One Way ANOVA test and the DMRT test were employed for data analysis, with a 5% significance level. The analysis’s findings demonstrated that the rise in white degree value and thousand-grain weight was substantially impacted by the semi-organic rice field management system. Additionally, it improved both kinds’ solubility and swelling power. Meanwhile, because it is preferable as far as of color, appearance, and overall quality, the organic rice field management system greatly enhances the sensory experience. Conversely, the conventional rice field management approach on Mentik Wangi and IR64 rice raised the protein content (%db) and amylose content of all kinds.

Effect of Different Urea Doses on the Performance of Wheat Under the Agro-Climatic Conditions of Mansehra, Khyber Pakhtunkhwa, Pakistan

The research conducted aimed to evaluate the impact of varying urea doses on the performance of wheat (Triticum aestivum), with a focus on growth, yield, and nitrogen use efficiency. Urea, a common nitrogen fertilizer, is crucial in enhancing crop productivity. The experiment was conducted in 2022-2023 at the Agriculture Research Station Baffa Mansehra in Khyber Pakhtunkhwa, Pakistan. The research material consisted of a Wheat variety. The Seeds were sown in RCBD design on 15th October 2022 at an Agriculture Research Station Baffa Mansehra. The experiment used a randomized complete block design with three replications. In the agro-climatic conditions of Mansehra, comprehensive data were gathered on various morphological and yield-related attributes. These included morphological parameters such as days to heading, leaf area index (cm), days to maturity, number of tillers/ plant-1, plant height (cm), spike length (cm), spikelet /spike, thousand-grain weight (g), grain yield kg/ha-1, and biological yield kg/ha-1. The study concludes that from experiments that wheat on different urea applications gives significant results from germination to till harvesting under the agro-climatic condition of Mansehra. It means that the wheat on different Urea applications shows improvement in Plant height, Spike length, Spikelet /spike, 1000-grain weight, grain yield and biological yield. Based on these results, it is recommended to apply urea at optimal rates to enhance wheat growth and yield, with the most effective rate being 65 grams per 6 m².

Morphological and Variability Assessment of (F7) Wheat Lines Under Normal and Rainfed Conditions

A field trial was performed to identify the potential genotypes in 100 wheat lines (96 F7 fixed lines and 4 controls) for yield and yield-associated traits in an augmented design under irrigated and rainfed conditions. These lines/genotypes were analyzed for days to heading, days to maturity, plant height, grain per spike, thousand-grain weight and grain yield. The wheat genotypes showed a significant G×E for all the traits across irrigated and rainfed conditions. The evaluation of variances revealed significant differences among the wheat genotypes for the evaluated morphological traits. According to the findings of the present experiment genotype, the CCRIG7-82 showed the best performance in grain yield under normal conditions. However, wheat lines CCRIG7-1 surpassed all other genotypes in grain yield under rainfed conditions. Furthermore, wheat genotypes CCRIG7-1 showed stability of the traits i.e. days to maturity in both environments i.e. (irrigated and rainfed conditions). Different drought tolerance indices were evaluated for grain yield under rainfed (Ys) and irrigated (Yp) conditions. The stress tolerance (TOL) index identified CCR1G7-82 (8100 Kg ha-1), as the most tolerant, whereas, based on mean productivity, CCR1G7-59 and CCR1G7-60 (5900 Kg ha-1), were tolerant. Similarly, the geometric mean productivity (GMP) identified genotypes CCR1G7-60 (5246 Kg ha-1), as the best tolerant. In the same way, CCR1G7-85 (4716 Kg ha-1) were identified as tolerant genotypes based on harmonic mean (HM). Stress susceptibility index (SSI), grouped genotypes CCR1G7-64 (0.07), were stress tolerant. Stress tolerance index (STI) clustered genotypes CCR1G7-60 (5.87), as the most tolerant, while yield index (YI) ranked genotypes CCR1G7-76, CCR1G7-85 (1.71), as the most tolerant. The yield stability index (YSI) desirable genotypes were CCR1G7-64 (0.90) and were noted as drought tolerance genotypes in stressed conditions

Coinheritance Studies of Yield and Yield Related Traits in Wheat (Triticum Aestivum L.) Preliminary Lines

A field trial was performed to explore the genetic diversity and coheritability among the 64 bread wheat genotypes. These lines/genotypes were analyzed for days to heading, days to maturity, plant height, flag leaf area, spikelet Spike-1, grain per spike, thousand-grain weight, and grain yield. Based on the mean performance, the best genotype for early maturity was CCRIA1-10, CCRIA1-1, and CCRIA1-11. Likewise, for the flag leaf area, desirable genotypes were CCRIA1-16 and CCRIA1-27, and for grain spike-1, CCRIA1-28 and CCRIA1-22. In addition, the best genotypes for 1000-grain weight were CCRIA1-64 and CCRIA1-37. The highest genotypic and phenotypic coefficients of variation (PCV = 1054.40%, GCV = 446.68%) were recorded for grain yield, followed by grain spike-1 (PCV = 125.29 and GCV = 123.39). The highest heritability (0.97) was indicated by spike weight and grains spike-1(0.97), while plant height (0.58), 1000 grain weight (0.44), and flag leaf area (0.31) showed moderate heritability. The lowest heritability estimates were recorded for the length of the peduncle (0.01), length of spikes (0.13), grain yield (0.18), days to heading, and spikelet spike-1 (0.25). High coheritability was observed among day to maturity and spike weight (0.99), on the contrary, minimum coheritability was observed for the flag leaf area with heading (0.12). The most desired inheriting pairs were spikelet spike-1 with grains spike-1 (0.97), weight of spike with spikelet spike-1(0.92), and flag leaf area with spike weight (0.86), spike length with grains spike-1, spike weight with grains spike-1 and flag leaf area with grains spike-1.

Principal component and cluster analysis in grain appearance, milling and cooking quality traits in rice (Oryza sativa L.)

Rice grain quality characteristics such as grain appearance, milling, cooking, and eating parameters are quite complex phenotypic attributes. The rice grain quality is governed principally by the genetic makeup of the rice variety, the biochemical composition of rice grain, and the bio-physical environment where it is produced or grown. In addition to this grain quality is also affected by the moisture conditions of rice gains at the time of processing, the equipment by which rice is processed to a finished product, and to some extent how the product is stored. It is necessary to improve grain quality traits in rice to meet the consumers' demand for premium quality rice, reduce loss at the time of milling, increase production efficiency by increasing total head rice yield, and give more profit to producers and traders of the rice supply chain. This investigation aimed to evaluate the extent of diversity present in the population comprising one hundred-five genotypes for fifteen-grain quality attributes through principal component analysis and cluster analysis. The principal component analysis identified five principal components, (PCs) accounting for 73.10% of the sum total of variations perceived between the rice genotypes of the population. From the biplot analysis of PC1 and PC2, as the two axes of a 2-dimensional coordinate plain, it was found that the grain quality traits, kernel L/B ratio, water uptake, gel consistency, head rice recovery, kernel length after cooking, thousand-grain weight, milling percentage, and kernel length have a greater contribution to the total diversity of the rice population. By using UPGMA cluster analysis, all 105 genotypes of the population were classified into five discrete groups or clusters. The observed inter-cluster distance was largest between the clusters of cluster I and cluster III (149.22), the next largest inter-cluster distance was between cluster II and cluster IV (128.35), and that of cluster III and cluster IV was (109.61) which indicated significant genetic divergence among the genotypes. A larger inter-cluster distance between the clusters suggests the possibility of harnessing heterosis for the quality traits under study as they possess higher mean values for quality attributes with corresponding greater diversity.

Characterization of a Natural Accession of Elymus sibiricus with In Situ Hybridization and Agronomic Evaluation.

Elymus sibiricus, valued for its perennial nature, broad adaptability, strong cold tolerance, and high economic value in forage production, plays a crucial role in combating grassland degradation, desertification, and salinization. Using morphological and cytogenetic methods, this study evaluated the cold tolerance, post-harvest regeneration capacity, and perennial characteristics of the E. sibiricus accession 20HSC-Z9 in the Harbin region of China from 2020 to 2023. This accession exhibited a germination rate of over 90% and a 100% green-up rate, with purple coleoptiles indicating its strong cold tolerance. Over the three growing seasons, 20HSC-Z9 maintained stable green-up and regeneration rates, confirming its perennial nature. Morphologically, 20HSC-Z9 had an average tiller count ranging from 56 to 74, similar to that of the control accession 20HSC-ES, and its plant height was significantly lower than that of 20HSC-IWG. Furthermore, 20HSC-Z9 produced over 100 grains per spike, with a seed setting rate exceeding 90%, and a thousand-grain weight comparable to that of 20HSC-IWG. The grain protein content of 20HSC-Z9 reached a maximum of 21.19%, greater than that of the control accessions (15.6% and 18.5%). Chromosome composition analysis, using sequential multicolor genomic in situ hybridization and multicolor fluorescence in situ hybridization, confirmed the StStHH genomic constitution of 20HSC-Z9 and revealed translocations between the St and H subgenome chromosomes. These results suggest that 20HSC-Z9 has significant potential as a new perennial forage grass germplasm for cold regions, suitable for further domestication and breeding efforts.

Impact of wheat-Agropyron germplasm on the improvement of grain weight and size: a comprehensive QTL analysis

Abstract Grain weight and size significantly influence wheat yield and quality. This study aimed to dissect the genetic basis of quantitative trait loci (QTL) associated with grain weight and size in hexaploid wheat (Triticum aestivum L.) using the novel wheat-Agropyron germplasm Pubing3228. A population of 210 F8 recombinant inbred lines derived from Pubing3228 and Jing4839 was evaluated across multiple environments for grain length, width, thickness and thousand-grain weight (TGW). Genotyping was conducted using the Illumina Infinium iSelect 55 K SNP chip, followed by QTL mapping with QTL IciMapping software. A total of 114 QTLs were identified across 20 wheat chromosomes, highlighting major QTLs for grain length, width/thickness and TGW. Candidate gene analysis revealed 22 genes expressed in grains, including those specifically associated with TGW, grain width/thickness and grain length. These findings enhance our understanding of the genetic mechanisms underlying wheat grain traits, providing insights for marker-assisted selection in wheat breeding programmes.

Mapping and Validation of Quantitative Trait Loci on Yield-Related Traits Using Bi-Parental Recombinant Inbred Lines and Reciprocal Single-Segment Substitution Lines in Rice (Oryza sativa L.)

Yield-related traits have higher heritability and lower genotype-by-environment interaction, making them more suitable for genetic studies in comparison with the yield per se. Different populations have been developed and employed in QTL mapping; however, the use of reciprocal SSSLs is limited. In this study, three kinds of bi-parental populations were used to investigate the stable and novel QTLs on six yield-related traits, i.e., plant height (PH), heading date (HD), thousand-grain weight (TGW), effective tiller number (ETN), number of spikelets per panicle (NSP), and seed set percentage (SS). Two parental lines, i.e., japonica Asominori and indica IR24, their recombinant inbred lines (RILs), and reciprocal single-segment substitution lines (SSSLs), i.e., AIS and IAS, were genotyped by SSR markers and phenotyped in four environments with two replications. Broad-sense heritability of the six traits ranged from 0.67 to 0.94, indicating their suitability for QTL mapping. In the RIL population, 18 stable QTLs were identified for the six traits, 4 for PH, 6 for HD, 5 for TGW, and 1 each for ETN, NSP, and SS. Eight of them were validated by the AIS and IAS populations. The results indicated that the allele from IR24 increased PH, and the alternative allele from Asominori reduced PH at qPH3-1. AIS18, AIS19, and AIS20 were identified to be the donor parents which can be used to increase PH in japonica rice; on the other hand, IAS14 and IAS15 can be used to reduce PH in indica rice. The allele from IR24 delayed HD, and the alternative allele reduced HD at qHD3-1. AIS14 and AIS15 were identified to be the donor parents which can be used to delay HD in japonica rice; IAS13 and IAS14 can be used to reduce HD in indica rice. Reciprocal SSSLs not only are the ideal genetic materials for QTL validation, but also provide the opportunity for fine mapping and gene cloning of the validated QTLs.

Effects of Salt Stress During the Growth Period on the Yield and Grain Quality of Hybrid Rice

Hybrid rice typically surpasses conventional rice in terms of biomass, yield, and stress resistance, whereas developing and utilizing saline–alkali-tolerant hybrid rice is crucial to obtain crop harvests from salt-affected soils. In the present study, conventional rice varieties (paternal parents), i.e., Hua-Zhan and 9311, and four hybrid varieties, i.e., Xiang-Liang-You-Hua-Zhan, Jing-Liang-You-Hua-Zhan, Guang-8-You-Hua-Zhan, and Y-Liang-You-1-Hao, denoted as V1, V2, V3, V4, V5, and V6, respectively, received an application of two salt levels, i.e., 0% and 0.3% saltwater irrigation, during 2022–2023. The results reveal that the V1 (parental parent) had the highest salt tolerance index, which was significantly greater than that of its hybrid rice varieties, i.e., V3, V4, and V5. Moreover, the salt tolerance index of V2 (paternal parent) was also greater than that of its hybrid rice (V6). The lower salt tolerance index of the hybrid varieties might be owing to the lower relative loss number of effective panicles, total number of grains per panicle, seed setting rate, and thousand-grain weight. Moreover, our study revealed that the appearance of different rice varieties was enhanced at a salt concentration of 0.3%. Among all the rice cultivars, the largest reductions in chalkiness and chalky grain rate were observed in hybrid rice V3, i.e., 81.13% and 63.49%, as well as V6, i.e., 84.03% and 87.53%, respectively. The protein and sodium contents and sodium-potassium ratio of all the rice cultivars increased significantly under salt stress; however, no significant effect on cooking or sensory quality were noticed in all rice varieties under saline conditions. Overall, salt stress negatively affected the grain yield and quality, but hybrid rice is more salt-tolerant than conventional rice, harnessing heterosis to improve the yield of saline-tolerant rice.

Exogenous Application of Lanthanum Chloride to Rice at Booting Stage Can Increase Chlorophyll Content, Modulate Chlorophyll Fluorescence and Promote Grain Yield Under Deficit Irrigation

To sustain agricultural productivity and safeguard global food security, and confront the escalating challenges posed by climate change and water scarcity, it is essential to enhance the growth and productivity of rice under water stress. This study investigated the effects of lanthanum chloride on the chlorophyll fluorescence characteristics and grain yield of rice under different irrigation modes. The rice cultivar H You 518 was selected and sprayed 20, 100, or 200 mg·L−1 lanthanum chloride at the booting and heading stages under deficit irrigation (where no rewatering was applied after the initiation of stress, allowing the water layer to evaporate naturally under high temperatures) or conventional irrigation (with daily rewatering to maintain a consistent water level). The results showed that the application of low concentrations lanthanum chloride promoted the chlorophyll content, whereas high concentrations decreased the chlorophyll content, under deficit irrigation, the effect of lanthanum chloride on the green fluorescence parameters of rice leaves at the booting stage was greater than that at the heading stage, and the booting stage was more sensitive to water deficit. The application of 100 mg·L−1 lanthanum chloride reduced the initial fluorescence (F0) and the non-photochemical quenching coefficient (qN); promoted the activity of leaf photosynthetic system II (PSII); and maximized the photochemical quantum yield (Fv/Fm), photochemical quenching coefficient (qP), and PSII relative electron transfer efficiency (ETR). Under deficit irrigation, this treatment significantly enhanced grain yield by increasing the thousand-grain weight, spikelet filling rate, and number of grains per panicle. These results suggest that spraying 100 mg·L−1 lanthanum chloride at the booting stage under deficit irrigation can effectively increase the chlorophyll content, thereby increasing the light energy conversion efficiency of the PS II reaction center, ultimately resulting in increased spikelet filling rate and grain yields.

Evaluation of hybrid rice varieties for growth and yield traits under irrigated transplanted conditions in Lumbini Province, Nepal

This study aimed to evaluate the performance of early- to medium-maturing hybrid rice varieties for growth and yield traits under irrigated transplanted conditions in Lumbini Province, Nepal, and identify varieties with high yield potential and favorable agronomic traits. A field experiment was conducted using a Randomized Complete Block Design (RCBD) with three replications during the summer seasons of 2022 and 2023. Twenty-five hybrid rice varieties were tested, with Arize 6444 as the standard check. Key agronomic traits, including grain yield, tillers per plant, plant height, and thousand-grain weight, were measured and analyzed statistically. The hybrid variety LG94.2 recorded the highest average grain yield (6603 kg ha-¹), followed by SH 4613 (6338 kg ha-¹) and F1 9446 (6062.7 kg ha-¹). Thousand-grain weight (r = 0.72) and tillers per plant (r = 0.65) were positively correlated with grain yield. The findings suggest that LG94.2, SH 4613, and F1 9446 are the top-performing varieties. LG94.2 showed the best performance, with high grain yield and favorable traits, making it a strong candidate for improving rice productivity in Nepal. The study confirms that hybrid rice varieties such as LG94.2 and SH 4613 have the potential to significantly increase rice yields in Nepal's subtropical regions, offering a sustainable solution to meet the country’s rising food demand.

Phosphogypsum as Fertilizer: Impacts on Soil Fertility, Barley Yield Components, and Heavy Metals Contents.

According to the FAO, 828 million people were facing acute food insecurity in 2021. Fertilization is a critical input factor in crop production and food security achievement. Therefore, fertilization is a critical input factor in crop production and food security achievement. However, there is room for improvement in the application of fertilizers in certain regions. Thus, new fertilizers with a relatively low cost could enhance farmers' access to these essential inputs. Phosphogypsum (PG) is used as fertilizer because it contains many nutrients essential for plant growth, including calcium, sulfur, and phosphorus. A two-year field experiment was conducted using two Moroccan PG products (PG1 and PG2, obtained from two different industrial sites), applied at four rates (0, 1.5, 3, and 4.5 t/ha). The aim was to assess the impact of PG source and rate on barley crops, including yield component, nutrients uptake, and heavy metals content. The study's findings revealed that as the rate of PG application increased, there were significant enhancements in the number of spikes, tillers, grains, total biomass, grain yield, and thousand-grain weight. In fact, when compared to the control, the application of 1.5, 3, and 4.5 t/ha of PG led to a remarkable increase in grain yield by 21%, 34%, and 39%, respectively. Furthermore, the uptake of nutrients (N, P, K, Ca, Mg, and S) by the shoots and grains was significantly influenced by the PG application rates, with higher rates resulting in greater nutrient uptake. Notably, the application of PG had no discernible impact on the heavy metal content in shoots, grains, or soil.