Search

Introduction Wheat (Triticum aestivum L.) is one of the oldest and most widely used crops in the world and is the most important source of human food that grows in a wide range of climatic conditions in the world. In arid and semi-arid regions, water is the main limitation. Iran is a dry and semi-arid country with limited precipitations. Therefore, the mean annual rainfall in Iran is even less than one third of the global average. There are many solutions for sustainability in agriculture, one of which is the use of biological fertilizers. Among these biofertilizers are mycorrhizal fungi. The symbiotic relationship between the arbuscular mycorrhizal fungus and the roots of the host plant significantly increases the growth and absorption of plant nutrients. In this research, the aim is to investigate the effect of arbuscular mycorrhizal fungus on improving the yield, yield components, and chlorophyll index of wheat by applying water deficit stress through increasing the interval of irrigation cycles. Materials and Methods This factorial experiment was conducted based on a randomized complete block design in four replications in the research farm of the Azad Islamic University of Miandoab, northwestern Iran in 2021. The experimental factors included the application of arbuscular mycorrhiza fungus species in three levels, control (without inoculation), inoculation with Glomus mosseae and inoculation with Glomus intraradices and three levels of irrigation regimes (i.e. irrigation after every 6, 13 and 20 days). Seeds of Elvand wheat cultivar were inoculated with mycorrhizal fungus, then the inoculated seeds were immediately planted into a depth of 3. Before planting, 15 tons/ha of manure and 25 kig of nitrogen fertilizer in the form of urea were uniformly applied to the soil. During the growing season, 50 kg of nitrogen fertilizer in the form of urea was used during the two stages of stem growth and spike formation. To measure wheat grain yield components, 10 plants were harvested and to determine grain yield and plant above- ground dry mass, 0.25 m-2 was taken from each plot. In this way, after removing two rows from each side and half a meter from the beginning and end of all rows as a margin, sampling of experimental units was done. The evaluated traits included the spikes/plant, grains/spike, the thousand-grain weight, plant aboveground dry mass, grain yield, harvest index, and greenness index Results and Discussion Results indicated that the effect of irrigation intervals and mycorrhiza fungus were significant for grains/spike, thousand-grain weight, grain yield, above-ground dry mass, harvest index, chlorophyll index, photosynthetic pigments and proline concentrations. G. mosseae species increased the grains/spike, thousand-grain weight, above-ground dry mass, harvest index, and chlorophyll concentration compared to G. intraradices species by 5.21, 9.73, 8.86, 6.96 and 4.08% and increased the above-mentioned attributes compared to the control by 29.94, 30.28, 39.68, 27.90 and 21.43%, respectively. The highest spikes/plant, grain yield, chlorophyll index and concentration of chlorophyll a belonged to irrigation interval of 6 days and inoculation with G. mosseae species with 6.34, 612.45 g m-2, 62.89 SPAD unit, and 0.306 mg g-1 FW, respectively. Prolongation of irrigation interval by creating water deficit stress caused the sterility of the spikes and significantly reduced the grains/spikes. The irrigation regime had a significant effect on the grain yield and by reducing the irrigation intervals, the grain yield was increased. The drought-induced decrease in grain yield stemmed from the decrease in green index, chlorophyll concentration, spikes/plant and grains/spike, leading to decrease in the harvest index. With increase in the irrigation interval, the concentration of chlorophyll a and b decreased, but the mycorrhizal inoculation led to significant increase in the concentration of chlorophyll a and b under water deficit stress. The plants inoculated with mycorrhizal fungus suffered less from water deficit stress than the non-colonized plants, and as a result, the concentration of proline increased less compared to the plants deprived from mycorrhizal fungus. According to these results, irrigation of wheat plants every 13 days and application of G. mosseae can produce the desirable grain yield, while decreasing water consumption for wheat production. Conclusions Mycorrhizal fungus increased the plant's resistance to drought stress by improving the absorption of water and nutrients under water stress deficit. G. mosseae was more effective in increasing the resistance of wheat against water deficit stress and as a result, it increased the grain yield, yield components, chlorophyll index and chlorophyll concentration of wheat to a greater extent compared to G. intraradices. In order to make the best use of water resources and soil nutrients, irrigation of wheat should be done every 13 days and must be accompanied by inoculation with G. mosseae to achieve an acceptable grain yield. [ABSTRACT FROM AUTHOR]

Durum wheat (DW) is one of the major crops grown in the Mediterranean area, a climate-vulnerable region where the increase in day/night (d/n) temperature is severely threatening DW yield stability. In order to improve DW heat tolerance, the introgression of chromosomal segments derived from the wild gene pool is a promising strategy. Here, four DW-Thinopyrum spp. near-isogenic recombinant lines (NIRLs) were assessed for their physiological response and productive performance after intense heat stress (IH, 37/27 °C d/n) had been applied for 3 days at anthesis. The NIRLs included two primary types (R5, R112), carriers (+) of a differently sized Th. ponticum 7el1L segment on the DW 7AL arm, and two corresponding secondary types (R69-9/R5, R69-9/R112), possessing a Th. elongatum 7EL segment distally inserted into the 7el1L ones. Their response to the IH stress was compared to that of corresponding non-carrier sib lines (−) and the heat-tolerant cv. Margherita. Overall, the R112+, R69-9/R5+ and R69-9/R112+ NIRLs exhibited a tolerant behaviour towards the applied stress, standing out for the maintenance of leaf relative water content but also for the accumulation of proline and soluble sugars in the flag leaf and the preservation of photosynthetic efficiency. As a result, all the above three NIRLs (R112+ > R69-9/R5+ > R69-9/R112+) displayed good yield stability under the IH, also in comparison with cv. Margherita. R112+ particularly relied on the strength of spike fertility/grain number traits, while R69-9/R5+ benefited from efficient compensation by the grain weight increase. This work largely confirmed and further substantiated the value of exploiting the wild germplasm of Thinopyrum species as a useful source for the improvement of DW tolerance to even extreme abiotic stress conditions, such as the severe heat treatment throughout day- and night-time applied here. [ABSTRACT FROM AUTHOR]

IDEAL PLANT ARCHITECTURE1 (IPA1) is a pivotal gene controlling plant architecture and grain yield. However, little is known about the effects of Triticum aestivum SQUAMOSA PROMOTER‐BINDING‐LIKE 14 (TaSPL14), an IPA1 ortholog in wheat, on balancing yield traits and its regulatory mechanism in wheat (T. aestivum L.). Here, we determined that the T. aestivum GRAIN WIDTH2 (TaGW2)‐TaSPL14 module influences the balance between tiller number and grain weight in wheat. Overexpression of TaSPL14 resulted in a reduced tiller number and increased grain weight, whereas its knockout had the opposite effect, indicating that TaSPL14 negatively regulates tillering while positively regulating grain weight. We further identified TaGW2 as a novel interacting protein of TaSPL14 and confirmed its ability to mediate the ubiquitination and degradation of TaSPL14. Based on our genetic evidence, TaGW2 acts as a positive regulator of tiller number, in addition to its known role as a negative regulator of grain weight, which is opposite to TaSPL14. Moreover, combinations of TaSPL14‐7A and TaGW2‐6A haplotypes exhibit significantly additive effects on tiller number and grain weight in wheat breeding. Our findings provide insight into how the TaGW2‐TaSPL14 module regulates the trade‐off between tiller number and grain weight and its potential application in improving wheat yield. [ABSTRACT FROM AUTHOR]

Grain weight and grain shape are important traits that determine rice grain yield and quality. Mining more quantitative trait loci (QTLs) that control grain weight and shape will help to further improve the molecular regulatory network of rice grain development and provide gene resources for high-yield and high-quality rice varieties. In the present study, a QTL for grain length (GL) and grain width (GW), qGL5.2, was firstly fine-mapped into a 21.4 kb region using two sets of near-isogenic lines (NILs) derived from the indica rice cross Teqing (TQ) and IRBB52. In the NIL populations, the GL and ratio of grain length to grain width (RLW) of the IRBB52 homozygous lines increased by 0.16–0.20% and 0.27–0.39% compared with the TQ homozygous lines, but GW decreased by 0.19–0.75%. Then, by analyzing the grain weight and grain shape of the knock-out mutant, it was determined that the annotation gene Os05g0551000 encoded a RING-type E3 ubiquitin ligase, which was the cause gene of qGL5.2. The results show that GL and RLW increased by 2.44–5.48% and 4.19–10.70%, but GW decreased by 1.69–4.70% compared with the recipient. Based on the parental sequence analysis and haplotype analysis, one InDel variation located at −1489 in the promoter region was likely to be the functional site of qGL5.2. In addition, we also found that the Hap 5 (IRBB52-type) increased significantly in grain length and grain weight compared with other haplotypes, indicating that the Hap 5 can potentially be used in rice breeding to improve grain yield and quality. [ABSTRACT FROM AUTHOR]

The sink strength of developing ovaries in wheat determines the grain weight potential. The period from booting to the grain setting stage is critical for ovary growth and development and potential sink capacity determination. However, the underlying regulatory mechanism during this period by which the wheat plant balances and coordinates the floret number and ovary/grain weight under water stress has not been clarified. Therefore, we designed two irrigation treatments of W0 (no seasonal irrigation) and W1 (additional 75 mm of irrigation at the jointing stage) and analyzed the responses of the ovary/grain weight to water stress at the phenotypic, metabolomic, and transcriptomic levels. The results showed that the W0 irrigation treatment reduced the soil water content, plant height, and green area of the flag leaf, thus reducing grain number, especially for the inferior grains. However, it improved the grain weight of the superior and inferior grains as well as average grain weight at maturity, while the average ovary/grain weight and volume during –3 to 10 days after anthesis (DAA) also increased. Transcriptomic analysis indicated that the genes involved in both sucrose metabolism and phytohormone signal transduction were prominently accelerated by the W0 treatment, accompanied by greater enzymatic activities of soluble acid invertase (SAI) and sucrose synthase (Sus) and elevated abscisic acid (ABA) and indole-3-acetic acid (IAA) levels. Thus, the sucrose content decreased, while the glucose and fructose contents increased. In addition, several TaTPP genes (especially TaTPP-6) were down-regulated and the IAA biosynthesis genes TaTAR1 and TaTAR2 were up-regulated under the W0 treatment before anthesis, which further increased the IAA level. Collectively, water stress reduced the growth of vegetative organs and eliminated most of the inferior grains, but increased the ABA and IAA levels of the surviving ovaries/grains, promoting the enzymatic activity of Sus and degrading sucrose into glucose and fructose. As a result, the strong sucrose utilization ability, the enhanced enzymatic activity of SAI and the ABA- and IAA-mediated signaling jointly increased the weight and volume of the surviving ovaries/grains, and ultimately achieved the trade-off between ovary/grain weight and number in wheat under water stress.

The main sown areas in the Republic of Crimea are occupied by winter grain crops. The study conducted by Crimean scientists over many years and confirmed in production has shown that productivity of winter grain crops is unstable and varies significantly in years with different weather conditions. The difference in productivity is also found to depend on a variety. The purpose of the current study was to estimate the main elements of productivity and yield of new winter common wheat varieties developed by the FSBSI “ARC “Donskoy” in the contrasting weather conditions of the steppe Crimea. The current paper has summed up the results of the long-term study of winter common wheat cultivation and identified the varieties most adapted to dry conditions. The trials were carried out on the fields of the FSBSI “Research Institute of Agriculture in Crimea” after black fallow in the years of different weather conditions (2018–2023). The objects of research were 12 winter common wheat varieties from the Agricultural Research Center “Donskoy”, the standard variety being ‘Ermak’. The registration area of the experimental plots was 25 m2 . The placement of plots was systematic and repeated four times. The wheat sowing rate was 5 million pcs. of germin. grains per hectare. The trials and statistical processing were performed according to the methods of B. A. Dospekhov and the State Variety Testing. The study of winter wheat varieties bred by the ARC “Donskoy” has shown their different responses to the contrasting weather conditions of Crimea from the early periods of plant growth and development up to the formation of basic productivity indicators. Under unfavorable conditions of 2020, the mean productivity of varieties was 3.90 t/ha; in 2019, 2022 and 2023 it exceeded 5.0 t/ha. The study has made it possible to identify varieties with maximum productivity, such as ‘Donskaya Step’ (5.38 t/ha) and ‘Razdolie’ (5.33 t/ha). The main component of the productivity of the variety ‘Donskaya Step’ was grain weight per ear, and that of variety ‘Razdolie’ was a productive stem.

Grain size is a key factor influencing grain weight in rice. In this study, a chromosome segment substitution line (CSSL9-17) was identified, that exhibits a significant reduction in both grain size and weight compared to its donor parent 93-11. Further investigation identified two quantitative trait loci (QTL) on chromosome 11, designated qGW11a and qGW11b, which contribute to 1000-grain weight with an additive effect. LOC_Os11g05690, encoding the amino acid permease OsCAT8, is the target gene of qGW11a. Overexpression of OsCAT8 resulted in decreased grain weight, while OsCAT8 knockout mutants exhibited increased grain weight. The 287-bp located within the OsCAT8 promoter region of 93-11 negatively regulates its activity, which is subsequently correlated with an increase in grain size and weight. These results suggest that OsCAT8 functions as a negative regulator of grain size and grain weight in rice. [ABSTRACT FROM AUTHOR]

Grain size is a primary determinant of grain weight, which is one of the three essential components of rice grain yield. Mining the genes that control grain size plays an important role in analyzing the regulation mechanism of grain size and improving grain appearance quality. In this study, two closely linked quantitative trait loci (QTL) controlling grain size, were dissected and fine-mapped in a 515.6-kb region on the long arm of chromosome 10 by using six near isogenic line populations. One of them, qGS10.2, which controlled 1000 grain weight (TGW) and grain width (GW), was delimited into a 68.1-kb region containing 14 annotated genes. The Teqing allele increased TGW and GW by 0.17 g and 0.011 mm with the R2 of 12.7% and 11.8%, respectively. The other one, qGL10.2, which controlled grain length (GL), was delimited into a 137.3-kb region containing 22 annotated genes. The IRBB52 allele increased GL by 0.018 mm with the R2 of 6.8%. Identification of these two QTL provides candidate regions for cloning of grain size genes. [ABSTRACT FROM AUTHOR]

Introduction: To address issues related to shallow soil tillage, low soil nutrient content, and single tillage method in maize production in the Western Inner Mongolia Region, this study implemented various tillage and straw return techniques, including strip cultivation, subsoiling, deep tillage, no-tillage, straw incorporation with strip cultivation, straw incorporation with subsoiling, straw incorporation with deep tillage, and straw incorporation with no tillage, while using conventional shallow spinning by farmers as the control. Methods: We employed Xianyu 696 (XY696) and Ximeng 6 (XM6) as experimental materials to assess maize 100-grains weight, grain filling rate parameters, and grain nutrient quality. This investigation aimed to elucidate how tillage and straw return influence the accumulation of grain material in different maize varieties. Results and discussion: The results indicated that proper implementation of tillage and straw return had a significant impact on the 100-grains weight of both varieties. In comparison to CK (farmer's rotary rotation), the most notable rise in 100-grains weight was observed under the DPR treatment (straw incorporation with deep tillage), with a maximum increase of 4.84% for XY696 and 6.28% for XM6. The proper implementation of tillage and straw return in the field resulted in discernible differences in the stages of improving the grain filling rates of different maize varieties. Specifically, XY696 showed a predominant increase in the filling rate during the early stage (V1), while XM6 exhibited an increase in the filling rates during the middle and late stages (V2 and V3). In comparison to CK, V1 increased by 1.54% to 27.56% in XY696, and V2 and V3 increased by 0.41% to 10.42% in XM6 under various tillage and straw return practices. The proper implementation of tillage and straw return had a significant impact on the nutritional quality of the grains in each variety. In comparison to CK, the DPR treatment resulted in the most pronounced decrease in the soluble sugar content of grains by 25.43% and the greatest increase in the crude fat content of grains by 9.67%. Conclusion: Ultimately, the proper implementation of soil tillage and straw return facilitated an increase in grain crude fat content and significantly boosted grain weight by improving the grouting rate parameters at all stages for various maize varieties. Additionally, the utilization of DPR treatment proved to be more effective. Overall, DPR is the most promising strategy to improve maize yield and the nutritional quality of grain in the long term in the Western Inner Mongolia Region. [ABSTRACT FROM AUTHOR]

Grain yield is determined mainly by grain number and grain weight. In this study, we identified and characterized MORE GRAINS1 (MOG1), a gene associated with grain number and grain weight in rice (Oryza sativa L.), through map‐based cloning. Overexpression of MOG1 increased grain yield by 18.6%–22.3% under field conditions. We determined that MOG1, a bHLH transcription factor, interacts with OsbHLH107 and directly activates the expression of LONELY GUY (LOG), which encodes a cytokinin‐activating enzyme and the cell expansion gene EXPANSIN‐LIKE1 (EXPLA1), positively regulating grain number per panicle and grain weight. Natural variations in the promoter and coding regions of MOG1 between Hap‐LNW and Hap‐HNW alleles resulted in changes in MOG1 expression level and transcriptional activation, leading to functional differences. Haplotype analysis revealed that Hap‐HNW, which results in a greater number and heavier grains, has undergone strong selection but has been poorly utilized in modern lowland rice breeding. In summary, the MOG1–OsbHLH107 complex activates LOG and EXPLA1 expression to promote cell expansion and division of young panicles through the cytokinin pathway, thereby increasing grain number and grain weight. These findings suggest that Hap‐HNW could be used in strategies to breed high‐yielding temperate japonica lowland rice. [ABSTRACT FROM AUTHOR]

Introduction: Autotetraploid rice holds high resistance to abiotic stress and substantial promise for yield increase, but it could not be commercially used because of low fertility. Thus, our team developed neo-tetraploid rice with high fertility and hybrid vigor when crossed with indica autotetraploid rice. Despite these advances, the molecular mechanisms underlying this heterosis remain poorly understood. Methods: An elite indica autotetraploid rice line (HD11) was used to cross with neo-tetraploid rice, and 34 hybrids were obtained to evaluate agronomic traits related to yield. WE-CLSM, RNA-seq, and CRISPR/Cas9 were employed to observe endosperm structure and identify candidate genes from two represent hybrids. Results and discussion: These hybrids showed high seed setting and an approximately 55% increase in 1000-grain weight, some of which achieved grain yields comparable to those of the diploid rice variety. The endosperm observations indicated that the starch grains in the hybrids were more compact than those in paternal lines. A total of 119 seed heterosis related genes (SHRGs) with different expressions were identified, which might contribute to high 1000-grain weight heterosis in neo-tetraploid hybrids. Among them, 12 genes had been found to regulate grain weight formation, including OsFl3, ONAC023, OsNAC024, ONAC025, ONAC026, RAG2, FLO4, FLO11, OsISA1, OsNF-YB1, NF-YC12, and OsYUC9. Haplotype analyses of these 12 genes revealed the various effects on grain weight among different haplotypes. The hybrids could polymerize more dominant haplotypes of above grain weight regulators than any homozygous cultivar. Moreover, two SHRGs (OsFl3 and SHRG2) mutants displayed a significant reduction in 1000-grain weight and an increase in grain chalkiness, indicating that OsFl3 and SHRG2 positively regulate grain weight. Our research has identified a valuable indica autotetraploid germplasm for generating strong yield heterosis in combination with neo-tetraploid lines and gaining molecular insights into the regulatory processes of heterosis in tetraploid rice. [ABSTRACT FROM AUTHOR]

Enlarging the lateral space of drip tubes saves irrigation equipment costs (drip tubes and bypass), but it will lead to an increased risk of grain yield heterogeneity between wheat rows. Adjusting wheat row spacing is an effective cultivation measure to regulate a row's yield heterogeneity. During a 2-year field experiment, we investigated the variations in yield traits and photosynthetic physiology by utilizing two different water- and fertilizer-demanding spring wheat cultivars (NS22 and NS44) under four kinds of drip irrigation patterns with different drip tube lateral spacing and wheat row spacing [① TR4, drip tube spacing (DTS) was 60 cm, wheat row horizontal spacing (WRHS) was 15 cm; ② TR6, DTS was 90 cm, WRHS was 15 cm; ③ TR6L, DTS was 90 cm, WRHS was 10 cm, inter-block spacing (IBS) was 35 cm; and ④ TR6S, DTS was 80 cm, WRHS was 10 cm, IBS was 25 cm]. The results showed that under 15-cm equal row spacing condition, after the number of wheat rows served by a single tube increased from four (TR4, control) to six (TR6), NS22 and NS44 exhibited a marked decline in yield. The decline of NS22 (9.93%) was higher than that of NS44 (9.04%), and both cultivars also showed a greater decrease in grain weight and average grain-filling rate (AGFR) of inferior grains (NS22: 23.19%, 13.97%; NS44: 7.78%, 5.86%) than the superior grains (NS22: 10.60%, 8.33%; NS44: 4.89%, 4.62%). After the TR6 was processed to narrow WRHS (from 15 to 10 cm) and add IBS (TR6L: 35 cm; TR6S: 25 cm), the grain weight per panicle (GWP) and AGFR of superior and inferior grains in the third wheat row (RW3) of NS22 and NS44 under TR6L increased significantly by 26.05%, 8.22%, 14.05%, 10.50%, 5.09%, and 5.01%, respectively, and under TR6S, they significantly increased by 20.78%, 9.91%, 16.19%, 9.28%, 5.01%, and 4.14%, respectively. The increase in GWP and AGFR was related to the increase in flag leaf area, net photosynthetic rate, chlorophyll content, relative water content, actual photochemical efficiency of PSII, and photochemical quenching coefficient. Among TR4, TR6, TR6L, and TR6S, for both NS22 and NS44, the yield of TR6S was significantly higher than that of TR6 and TR6L. Furthermore, TR6S showed the highest economic benefit. [ABSTRACT FROM AUTHOR]

The application rate of potassium fertilizer is closely related to the yield of crops. Thin-shelled Tartary buckwheat is a new variety of Tartary buckwheat with the advantages of thin shell and easy shelling. However, little is known about application rate of potassium fertilizer on the yield formation of thin-shelled Tartary buckwheat. This study aimed to clarify the effect of potassium fertilizer on the growth and yield of thin-shelled Tartary buckwheat. A field experiment to investigate the characteristics was conducted across two years using thinshelled Tartary buckwheat (Miku 18) with four potassium fertilizer applications including 0 (no potassium fertilizer, CK), 15 (low-concentration potassium fertilizer, LK), 30 (medium-concentration potassium fertilizer, MK), and 45 kg·ha-1 (high-concentration potassium fertilizer, HK). The maximum and average grain filling rates; starch synthase activity; superoxide dismutase and peroxidase activities in leaves; root morphological indices and activities; available nitrogen, phosphorus, and organic matter content in rhizosphere soil; urease and alkaline phosphatase activities in rhizosphere soil; plant height, main stem node number, main stem branch number, leaf number; grain number per plant, grain weight per plant, and 100-grain weight increased first and then decreased with the increase in potassium fertilizer application rate and reached the maximum at MK treatment. The content of malondialdehyde was significantly lower in MK treatment than in other three treatments. The yields of thin-shelled Tartary buckwheat treated with LK, MK, and HK were 1.22, 1.37, and 1.07 times that of CK, respectively. In summary, an appropriate potassium fertilizer treatment (30kg·ha-1) can delay the senescence, promote the grain filling, and increase the grain weight and final yield of thin-shelled Tartary buckwheat. This treatment is recommended to be used in production to achieve high-yield cultivation of thin-shelled Tartary buckwheat. [ABSTRACT FROM AUTHOR]

Grain yield in rice is a complex trait and it is controlled by a number of quantitative trait loci (QTL). To dissect the genetic basis of rice yield, QTL analysis for nine yield traits was performed using an F2 population containing 190 plants, which was developed from a cross between Youyidao (YYD) and Sanfenhe (SFH), and each plant in the population evaluated with respect to nine yield traits. In this study, the correlations among the nine yield traits were analyzed. The grain yield per plant positively correlated with six yield traits, except for grain length and grain width, and showed the highest correlation coefficient of 0.98 with the number of filled grains per plant. A genetic map containing 133 DNA markers was constructed and it spanned 1831.7 cM throughout 12 chromosomes. A total of 36 QTLs for the yield traits were detected on nine chromosomes, except for the remaining chromosomes 5, 8, and 9. The phenotypic variation was explained by a single QTL that ranged from 6.19% to 36.01%. Furthermore, a major QTL for grain width and weight, qGW2-1, was confirmed to be newly identified and was narrowed down to a relatively smaller interval of about ~2.94-Mb. Collectively, we detected a total of 36 QTLs for yield traits and a major QTL, qGW2-1, was confirmed to control grain weight and width, which laid the foundation for further map-based cloning and molecular design breeding in rice. [ABSTRACT FROM AUTHOR]

Common bean is an important crop due to its high nutritional value. However, its production in Ecuador has decreased due to biotic and abiotic factors. Understanding the mechanisms that determine the yield components of this crop is essential to establish strategies that allow increasing the yield. In this study, the plant density was modified to evaluate its impact on yield and its two main components, the grain number and grain weight under field conditions in an Andean region of Ecuador. Two experiments planted on different dates were performed, where two planting densities 4 and 11 plants m􀀀2 were evaluated. The effect of the treatments was studied on the length of the period, from emergence to anthesis, the number of full and empty pods, grain number, 100 grain weight and grain yield. The results indicate that the plant density has a significant effect (p<0.05) on the yield, reaching an average of 257.15 g m􀀀2 in high density, and 151.45 g m􀀀2 in low density. The yield main components showed a different response to plant density modification; the grain number exhibited a strong variability and was positively associated with final grain yield (p<0.05) while the grain weight was not affected. [ABSTRACT FROM AUTHOR]

Grain size and grain weight contribute greatly to the final grain yield in rice. In order to identify QTLs conferring grain size and grain weight, an F2 population derived from a cross between two indica rice accessions, Guangzhan 63-4S (GZ63-4S) and Dodda, and its derived F2:3 population were developed, and were exploited for QTL analysis of the five related traits, namely grain length (GL), grain width (GW), length-to-width ratio (LWR), grain thickness (GT) and thousand-grain weight (TGW). A total of 36 QTLs were detected, and the number of beneficial alleles was contributed roughly equally by the two parents. Among those, 7 QTL regions were repeatedly detected in the two populations. In order to further validate effects of QTLs detected, a BC1F2 population derived from a backcross of a mixture of F2 plants with GZ63-4S was developed and was exploited for QTL selection. Heterozygous regions of 3 QTLs, qGS3, qTGW6.2 and qGT7 were identified respectively, and corresponding near-isogenic lines (NILs) of each QTL were constructed with three rounds of self-crosses. In the background of NILs, qGS3 was responsible for GL, LWR, GT and TGW, qTGW6.2 was for GL and TGW, and qGT7 was for GT and TGW. These results have laid the foundation of further fine mapping work, and could be of great use in breeding and improvement of rice lines with desirable size and yield. [ABSTRACT FROM AUTHOR]

This article, published in the Plant Biotechnology Journal, discusses the discovery of a gene in wheat called GRAIN WIDTH2 (TaGW2) that has a dual effect on enhancing leaf rust resistance and increasing grain weight. Leaf rust, caused by the fungal pathogen Puccinia triticina Eriksson, is a major threat to global wheat production. The limited number of cloned resistance genes often have undesirable agronomic traits, so finding new resistance genes while balancing yield is important for breeding strategies. The researchers used CRISPR/Cas9 technology to edit TaGW2 and found that knockout plants had increased resistance to leaf rust and increased grain weight, offering a novel approach to enhancing wheat's resistance without sacrificing yield. [Extracted from the article]

Grain weight and grain shape are important traits that determine rice grain yield and quality. Mining more quantitative trait loci (QTLs) that control grain weight and shape will help to further improve the molecular regulatory network of rice grain development and provide gene resources for high-yield and high-quality rice varieties. In the present study, a QTL for grain length (GL) and grain width (GW), qGL5.2, was firstly fine-mapped into a 21.4 kb region using two sets of near-isogenic lines (NILs) derived from the indica rice cross Teqing (TQ) and IRBB52. In the NIL populations, the GL and ratio of grain length to grain width (RLW) of the IRBB52 homozygous lines increased by 0.16–0.20% and 0.27–0.39% compared with the TQ homozygous lines, but GW decreased by 0.19–0.75%. Then, by analyzing the grain weight and grain shape of the knock-out mutant, it was determined that the annotation gene Os05g0551000 encoded a RING-type E3 ubiquitin ligase, which was the cause gene of qGL5.2. The results show that GL and RLW increased by 2.44–5.48% and 4.19–10.70%, but GW decreased by 1.69–4.70% compared with the recipient. Based on the parental sequence analysis and haplotype analysis, one InDel variation located at −1489 in the promoter region was likely to be the functional site of qGL5.2. In addition, we also found that the Hap 5 (IRBB52-type) increased significantly in grain length and grain weight compared with other haplotypes, indicating that the Hap 5 can potentially be used in rice breeding to improve grain yield and quality.

Plant transcription factors (TFs), such as basic helix-loop-helix (bHLH) and AT-rich zinc-binding proteins (PLATZ), play critical roles in regulating the expression of developmental genes in cereals. We identified the bHLH protein TaPGS1 (T. aestivum Positive Regulator of Grain Size 1) specifically expressed in the seeds at 5-20 days post-anthesis in wheat. TaPGS1 was ectopically overexpressed (OE) in wheat and rice, leading to increased grain weight (up to 13.81% in wheat and 18.55% in rice lines) and grain size. Carbohydrate and total protein levels also increased. Scanning electron microscopy results indicated that the starch granules in the endosperm of TaPGS1 OE wheat and rice lines were smaller and tightly embedded in a proteinaceous matrix. Furthermore, TaPGS1 was bound directly to the E-box motif at the promoter of the PLATZ TF genes TaFl3 and OsFl3 and positively regulated their expression in wheat and rice. In rice, the OsFl3 CRISPR/Cas9 knockout lines showed reduced average thousand-grain weight, grain width, and grain length in rice. Our results reveal that TaPGS1 functions as a valuable trait-associated gene for improving cereal grain yield.

Changes in yield components and spike traits are associated with wheat grain yield genetic progress. The aim of this study was to determine variation in yield components, spike and individual grain traits, and their role in winter wheat grain yield genetic improvement under conditions of the Pannonian Plain. Therefore, two-year field trials were conducted in a southern Pannonian location (Novi Sad, Serbia) with ten winter wheat cultivars released between 1931 and 2015. The grain yield had a significant positive linear relationship with the year of cultivar release, showing the improvement rate of 46.4 kg ha−1 yr−1. Grain yield increase has been positively related to the improvement of spike grain weight. Spike grain weight improvement with a rate of 0.25 g yr−1 was followed by simultaneous rise of the individual grain number and grain weight at different positions within a spikelet. Compared to other grains at different positions within a spikelet, G3 grains showed the highest rate of grain weight and the grain number improvement with the year of cultivar release. On the other hand, there was a significant decrease trend of grain protein content in individual grains at different positions. Therefore, wheat breeders should be more focused on grain number and weight improvement of distal grains in order to regain higher grain yield genetic gain under conditions of the Pannonian Plain. [ABSTRACT FROM AUTHOR]

Grain size is a key component of grain yield in cereals. It is a complex quantitative trait controlled by multiple genes. Grain size is determined via several factors in different plant development stages, beginning with early tillering, spikelet formation, and assimilates accumulation during the pre-anthesis phase, up to grain filling and maturation. Understanding the genetic and molecular mechanisms that control grain size is a prerequisite for improving grain yield potential. The last decade has brought significant progress in genomic studies of grain size control. Several genes underlying grain size and weight were identified and characterized in rice, which is a model plant for cereal crops. A molecular function analysis revealed most genes are involved in different cell signaling pathways, including phytohormone signaling, transcriptional regulation, ubiquitin–proteasome pathway, and other physiological processes. Compared to rice, the genetic background of grain size in other important cereal crops, such as wheat and barley, remains largely unexplored. However, the high level of conservation of genomic structure and sequences between closely related cereal crops should facilitate the identification of functional orthologs in other species. This review provides a comprehensive overview of the genetic and molecular bases of grain size and weight in wheat, barley, and rice, focusing on the latest discoveries in the field. We also present possibly the most updated list of experimentally validated genes that have a strong effect on grain size and discuss their molecular function. [ABSTRACT FROM AUTHOR]

In order to reduce the loss of stored grain, it is important to detect insects in it at the early stages of infection, for which it is important to know their preferred habitats. The purpose of the current study was to gain knowledge about the distribution of insects in the top layer of grain, from which samples are taken at enterprises to estimate pest infestation. In the samples taken in five repetitions from a barley bulk-grain stored in a granary, there were identified and counted pest species and their number. The temperature was determined at the sampling sites. The air temperature above the bulk-grain was from minus 2 °С to 0 °С. In layers with a depth of 0–28 cm, 28–56 cm, and 56–84 cm at a mean temperature of 9, 14 and 18°C, respectively, the confidence limits at p = 0.05 were within 5–13, 8–20 and 12–24 °C, respectively. The confidence limits of all three means have overlapped, proving that the difference in mean temperatures is not statistically significant. There have been found three species of insects in grain samples. Beetles Sitophilus oryzae clustered in greater numbers in grain layers where the temperature was higher. Rhizopertha dominica was found only in the warmest bottom layer of the grain. Liposcelis bostrychophila was concentrated in the greatest amount in the second deepest grain layer. There has been found an increase in the crowding of adults of all three species in grain layers with a higher temperature.

Grain size is a primary determinant of grain weight, which is one of the three essential components of rice grain yield. Mining the genes that control grain size plays an important role in analyzing the regulation mechanism of grain size and improving grain appearance quality. In this study, two closely linked quantitative trait loci (QTL) controlling grain size, were dissected and fine-mapped in a 515.6-kb region on the long arm of chromosome 10 by using six near isogenic line populations. One of them, qGS10.2, which controlled 1000 grain weight (TGW) and grain width (GW), was delimited into a 68.1-kb region containing 14 annotated genes. The Teqing allele increased TGW and GW by 0.17 g and 0.011 mm with the R2 of 12.7% and 11.8%, respectively. The other one, qGL10.2, which controlled grain length (GL), was delimited into a 137.3-kb region containing 22 annotated genes. The IRBB52 allele increased GL by 0.018 mm with the R2 of 6.8%. Identification of these two QTL provides candidate regions for cloning of grain size genes.

Delays in sowing have significant effects on the grain yield, yield components, and grain protein concentrations of winter wheat. However, little is known about how delayed sowing affects these characteristics at different positions in the wheat spikes. In this study, the effects of sowing date were investigated in a winter wheat cultivar, Shannong 30, which was sown in 2019 and 2020 on October 8 (normal sowing) and October 22 (late sowing) under field conditions. Delayed sowing increased the partitioning of 13C-assimilates to spikes, particularly to florets at the apical section of a spike and those occupying distal positions on the same spikelet. Consequently, the increase in grain number was the greatest for the apical sections, followed by the basal and central sections. No significant differences were observed between sowing dates in the superior grain number in the basal and central sections, while the number in apical sections was significantly different. The number of inferior grains in each section also increased substantially in response to delayed sowing. The average grain weights in all sections remained unchanged under delayed sowing because there were parallel increases in grain number and 13C-assimilate partitioning to grains at specific positions in the spikes. Increases in grain number m–2 resulted in reduced grain protein concentrations as the limited nitrogen supply was diluted into more grains. Delayed sowing caused the greatest reduction in grain protein concentration in the basal sections, followed by the central and apical sections. No significant differences in the reduction of the grain protein concentration were observed between the inferior and superior grains under delayed sowing. In conclusion, a 2-week delay in sowing improved grain yield through increased grain number per spike, which originated principally from an increased grain number in the apical sections of spikes and in distal positions on the same spikelet. However, grain protein concentrations declined in each section because of the increased grain number and reduced N uptake.

CRISPR/Cas9 system has emerged as an efficient tool for sustainable crop improvement. Roots are the “principal hidden organ” that has a crucial function in vascular plants. Receptor-like protein kinase 1 (RPK1) has been reported to regulate root architecture system (RAS), abiotic stress, and yield both in Arabidopsis and rice. We employed a CRISPR/Cas9-based system, namely LR-1 and LR-2 constructs having double guided RNAs transformed via agrobacterium for targeted mutagenesis of TaRPK1 genes to alter the root architecture and hence yield in Triticum aestivum. Sequencing confirmed seven CRISPR/Cas9-based mutated T0 lines of LR-1 constructs and six T0 lines of LR-2 constructs, with an overall mutation efficiency of 41.93%. The T0 plants displayed higher monoallelic mutation compared to the diallelic mutation. 37.5% monoallelic mutation at target site 1 within the D genome by gRNA1 was observed by the LR-1 construct. The LR-2 constructs showed a higher monoallelic mutation frequency of 26.67% at target sites 1 and 2 within A, B, and D genomes. The deletions were mainly short, however longer deletions such as 12d, 17d, 19d, and 20d were detected by gRNA2 of LR-1 construct. Transgenic lines revealed significant alteration in morphology and RSA with a significant increase in number of effective tillers, grain weight, root length, root depth, root volume, and root surface area while reduced root diameter, root angle, and spike length, compared to the wild plants. Tillers and total grain weight increased significantly, suggesting edited lines increased grain production by decreasing spike length. The study validates that CRISPR/Cas9 mediated targeted editing of TaRPK1 is a practical approach for modifying RAS and hence yield enhancement in wheat.

It is crucial to synergistically improve the yield and quality of sweet maize by implementing precise and strategic planting methods. However, a comprehensive understanding of how increasing plant density affects the sweet maize fresh ear yield, grain-filling rate, and grain carbohydrate concentration is not fully understood. Thus, a field experiment was performed using a split-plot design in Southeast China in 2021 and 2022, involving four sweet maize varieties (MT6855 and WT2015 were compact-type varieties, XMT10 and YZ7 were flat-type varieties) and three plant densities (D1: 4.5 plants m−2; D2: 6.0 plants m−2; and D3: 7.5 plants m−2). The results showed that an increasing plant density markedly increased the fresh ear yield of sweet maize varieties (MT6855 and WT2015) over the two years. However, it did not influence the fresh ear yield of XMT10 and YZ7. Across all four varieties in 2021 and 2022, the increasing plant density decreased the sweet maize filled ear length, while it did not affect the grain soluble solid concentration and grain residue ratio. The sweet maize grain weight, the maximum grain-filling rate, and the mean grain-filling rate decreased significantly with the increase in planting density across all four varieties. However, plant density did not significantly affect the grain soluble sugar, sucrose, fructose, and starch concentrations across different varieties at most stages during the grain filling. The current study also found that the sweet maize fresh ear yield was dramatically positively correlated with ears ha−1, grains per ear, grain-filling rate, and grain starch concentration but negatively correlated with the bare plant rate. Notably, a parabolic relationship existed between the fresh ear yield and 100-grain weight. These findings suggest that optimizing the plant density, particularly with compact-type varieties, can improve the sweet maize fresh ear yield without decreasing its quality. [ABSTRACT FROM AUTHOR]

Increasing grain weight under dense planting conditions can further improve maize yield. 6-BA is known to be involved in regulating grain development and influencing grain weight. Maize grain development is closely linked to starch accumulation and hormone levels. In this work, the effects of applying 6-BA at the flowering stage under high density on the grain filling characteristics, starch content, starch synthesis critical enzyme activity, and endogenous hormones levels of maize grains (including inferior grains (IGs) and superior grains (SGs)) of two high-yielding summer maize varieties widely cultivated in China were investigated. The findings indicated that applying 6-BA significantly improved maize yield compared to the control, mainly as a result of increased grain weight due to a faster grain filling rate. Additionally, the activities of enzymes associated with starch synthesis, including sucrose synthase (SuSy), ADP-glucose pyrophosphorylase (AGPase), granule-bound starch synthase (GBSS), soluble starch synthase (SSS), and starch branching enzyme (SBE), were all increased following 6-BA application, thus facilitating starch accumulation in the grains. Applying 6-BA also increased the zeatin riboside (ZR), indole-3-acetic acid (IAA), and abscisic acid (ABA) levels, and reduced the gibberellin (GA3) level in the grains, which further improved grain filling. It is worth noting that IG had a poorer filling process than SG, possibly due to the low activities of critical enzymes for starch synthesis and imbalanced endogenous hormones levels. However, IG responded more strongly to exogenous 6-BA than SG. It appears that applying 6-BA is beneficial in improving filling characteristics, promoting starch accumulation by enhancing the activities of critical enzymes for starch synthesis, and altering endogenous hormones levels in the grains, thus improving grain filling and increasing the final grain weight and yield of maize grown under crowded conditions. These results provide theoretical and technical support for the further utilization of exogenous hormones in high-density maize production. [ABSTRACT FROM AUTHOR]

IntroductionAbsorption of nutrients from the soil depends on soil moisture, fertilizer application, soil nutrients and other factors. Foliar application of nutrients under water stress is one of the ways to reduce the effect of stress on the quantity and quality of agricultural products. Today, in many countries, a variety of organic acids such as humus fertilizers are used to improve the quantity and quality of crops and orchards. These fertilizers can be used with irrigation, foliar application, hydroponic cultivation, soil application and seed inoculation. One of the objectives of this project was to identify new wheat cultivars tolerant to water stress condition and use micro elements to introduce suitable cultivars and the effect of these elements in increasing grain yield.Materials and methodsIn order to study the effect of foliar application of nutrients on grain yield and grain quality of bread wheat cultivars in conditions of water stress, the field studies were carried out during 2017-2018 and 2018-2019 at the Agricultural Research Station of Miandoab, in West Azerbaijan province, Iran (46º 3´ E, 36º 58´ N, altitude 1142 m). The experiment was performed as a factorial split plot in a randomized complete block design with three replications. Irrigation treatments in the main plots were included stopping irrigation at flowering stage until maturity and full irrigation until seed maturity. Sub-plots were foliar application treatments with zinc, potassium, phosphorus, magnesium and humic acid with four cultivars of wheat included Orum, Zare, Mihan and Heidari Each plot was planted in six rows with a length of four meters and a width of 1.2 meters at row intervals of 20 cm. Foliar application of micro elements was at the time of spike emergence and before flowering. Grain yield in the final harvest stage and removal of half a meter from the beginning and end of each plot was performed by a combine of grain experiments. After final sampling, 30 g of seeds per plot after digestion was used to measure micro elements in the grain using an atomic absorption. Combined analysis of variance of data from two years of study and drawing graphs was performed using MSTATC, SPSS and Excel software.Results and discussionIn this study, foliar application of zinc, increased 1000-grain weight, grain yield, harvest index, iron, manganese, zinc, and copper content in grin under normal irrigation by 9.30, 15.99, 18.30, 35.35, 102.10, 18.34, and 20.45 percent respectively under normal conditions and by 9.73, 4.36, 9.00, 41.81, 65.51, 43.24 and 29.78 percent respectively under drought conditions, Under normal irrigation conditions, foliar application of zinc in Mihan cultivar had the highest 1000-grain weight, grain yield, harvest index, manganese, zinc, and copper content in grain. Under drought stress conditions, the highest 1000-grain weight, grain yield, harvest index, manganese, and zinc content were allocated to foliar application of zinc in the Mihan cultivar. In this study, foliar application with zinc, potassium, phosphorus, and humic acid treatments in Mihan cultivar had equal grin yield and more than the control foliar application under normal irrigation conditions and was able to replace some of the water requirement of plant, Therefore, foliar application of these treatments along with selecting the appropriate cultivar can be a solution to improve the quantitative and qualitative yield of wheat in areas where the plant experiences periods of water deficit stress with different intensities.ConclusionsConsidering the favorable effect of foliar application of nutrients, especially zinc and humic acid on the quality and quantity of wheat grains, it is suggested that extension projects be carried out to transfer these results to farmers. Also, due to higher grain yield and high grain quality of Mihan cultivar, it is suggested that this cultivar gradually replace the previous cultivars.

Grain yield in rice is a complex trait and it is controlled by a number of quantitative trait loci (QTL). To dissect the genetic basis of rice yield, QTL analysis for nine yield traits was performed using an F2 population containing 190 plants, which was developed from a cross between Youyidao (YYD) and Sanfenhe (SFH), and each plant in the population evaluated with respect to nine yield traits. In this study, the correlations among the nine yield traits were analyzed. The grain yield per plant positively correlated with six yield traits, except for grain length and grain width, and showed the highest correlation coefficient of 0.98 with the number of filled grains per plant. A genetic map containing 133 DNA markers was constructed and it spanned 1831.7 cM throughout 12 chromosomes. A total of 36 QTLs for the yield traits were detected on nine chromosomes, except for the remaining chromosomes 5, 8, and 9. The phenotypic variation was explained by a single QTL that ranged from 6.19% to 36.01%. Furthermore, a major QTL for grain width and weight, qGW2-1, was confirmed to be newly identified and was narrowed down to a relatively smaller interval of about ~2.94-Mb. Collectively, we detected a total of 36 QTLs for yield traits and a major QTL, qGW2-1, was confirmed to control grain weight and width, which laid the foundation for further map-based cloning and molecular design breeding in rice.

Ear photosynthesis plays a key role in wheat photosynthesis during the grain filling stage, particularly under drought stress. Thus, dissecting the responsibilities of the glume and awn in photosynthetic carbon fixation and assimilates transportation during the grain filling stage in spikes is imperative. In this study, the detachment of the glume (DG) and awn (DA) of a wheat variety (Pubing143) was used to estimate their influences on ear photosynthesis and dry matter distribution. Radioactive carbon-14 (14C) isotope was detected by a multifunctional liquid scintillation counting system. The accumulation of 14C assimilates and their contributions to grain weight were then calculated. Under well-watered conditions, ear photosynthesis was reduced by 16.8 % and 46.2 % 25 d after anthesis (DAA) in the de-glumed control (DGC) and de-awned control (DAC) treatments, respectively, compared with the intact ear control (IEC). Under drought stress, ear photosynthesis was reduced by 46 % and 74.2 % at 25 DAA after removing the glume and awn, respectively. Under normal conditions, the number of 14C assimilates of DGC, and DAC was reduced by 14.6 % and 20.9 % in grains at 25 DAA, respectively, compared with the IEC. Compared with IED, the 14C assimilates of DGD, and DAD declined by 17.2 % and 27 %, respectively, in grains at 25 DAA under drought conditions. Under well-watered conditions, the grain weight per pot was reduced by 11.2 % and 25.4 % in the de-glumed control (DGC) and de-awned control (DAC) treatments, respectively, compared with the intact ear control (IEC). The grain weight per pot was further reduced after removing the glume and awn (16 % and 32.2 %, respectively) under drought stress. Furthermore, the awn contribution to grain weight was twice that of the glume. Our results suggest that the glume and awn of ears play prominent roles during grain filling in wheat, especially under drought stress, and that the awn is more crucial than the glume.

SUMMARY: Grain size is a key factor in determining rice (Oryza sativa) yield, and exploring new pathways to regulate grain size has immense potential to improve yield. In this study, we report that OsCBL5 encodes a calcineurin B subunit protein that significantly promotes grain size and weight. oscbl5 plants produced obviously smaller and lighter seeds. We further revealed that OsCBL5 promotes grain size by affecting cell expansion in the spikelet hull. Biochemical analyses demonstrated that CBL5 interacts with CIPK1 and PP23. Furthermore, double and triple mutations were induced using CRISPR/Cas9 (cr) to analyze the genetic relationship. It was found that the cr‐cbl5/cipk1 phenotype was similar to that of cr‐cipk1 and that the cr‐cbl5/pp23, cr‐cipk1/pp23, and cr‐cbl5/cipk1/pp23 phenotype was similar to that of cr‐pp23, indicating that OsCBL5, CIPK1, and PP23 act as a molecular module influencing seed size. In addition, the results show that both CBL5 and CIPK1 are involved in the gibberellic acid (GA) pathway and significantly affect the accumulation of endogenous active GA4. PP23 participates in GA signal transduction. In brief, this study identified a new module that affects rice grain size, OsCBL5–CIPK1–PP23, which could potentially be targeted to improve rice yield. Significance Statement: The discovery of the OsCBL5–CIPK1–PP23 module and its role in rice (Oryza sativa) yield represents a significant breakthrough not only in reproductive biology but also in the agricultural field for rice breeding. [ABSTRACT FROM AUTHOR]

The varieties and lines that have reached a constant state at the Research Institute of Cereals and Leguminous Crops have been tested in the 3-year competitive variety test nursery in the experimental hybrid lines AC2012-D3, AC-2010-D23, AC-2014-D7, AC-2013-D30, AC-2010-D21, AC2012-D41-8, the IDK indicator of the lines was 70-80%, it was determined that they belonged to the I-group, and the productivity of the studied lines was a positive indicator for 3 years AC-2010-D33, AC-2010-D45, in lines AC-2010-D21, AC-2012-D31, AC-2012-D14, AC-2013-D30, AC-2013-D33 was 70.0 to 81.7 ts/ha. Most of the lines achieved higher yields than the model varieties. [ABSTRACT FROM AUTHOR]

Wheat is one of the major food crops in the world. Functional validation of the genes in increasing the grain yield of wheat by genetic engineering is essential for feeding the ever-growing global population. This study investigated the role of ABP7, a bHLH transcription factor from maize involved in kernel development, in regulating grain yield-related traits in transgenic wheat. Molecular characterization showed that transgenic lines HB123 and HB287 contained multicopy integration of ABP7 in the genome with higher transgene expression. At the same time, QB205 was a transgenic event of single copy insertion with no significant difference in ABP7 expression compared to wild-type (WT) plants. Phenotyping under field conditions showed that ABP7 over-expressing transgenic lines HB123 and HB287 exhibited improved grain yield-related traits (e.g., grain number per spike, grain weight per spike, thousand-grain weight, grain length, and grain width) and increased grain yield per plot, compared to WT plants, whereas line QB205 did not. In addition, total chlorophyll, chlorophyll a, chlorophyll b, and total soluble sugars were largely increased in the flag leaves of both HB123 and HB287 transgenic lines compared to the WT. These results strongly suggest that ABP7 positively regulates yield-related traits and plot grain yield in transgenic wheat. Consequently, ABP7 can be utilized in wheat breeding for grain yield improvement.

ADP-glucose pyrophosphorylase (AGPase) influences cereal productivity. There are few reports on the function of cytosolic AGPase small subunit in bread wheat (TaAGPS). In the present study, TaAGPS was preferentially expressed in developing endosperm during grain-filling stages in bread wheat. TaAGPS allelic variations were characterized in 143 wheat accessions by PacBio RS II sequencing. Two haplotypes (TaAGPS-7A-TG and TaAGPS-7A-CT) of TaAGPS-7A were identified and corresponding functional markers were developed, whereas no variants of TaAGPS-7B and TaAGPS-7D were detected. TaAGPS-7A was associated with thousand-kernel weight (TKW) by haplotype–trait association analysis in two populations. Near-isogenic lines (NILs) with TaAGPS-7A-TG showed higher TKW and total kernel starch content than those with TaAGPS-7A-CT, owing to the higher AGPase activity of TaAGPS-7A-TG than TaAGPS-7A-CT both in vitro and in vivo. Overexpression of TaAGPS-7A-TG in bread wheat doubled the transcription levels of TaAGPS and increased AGPase activity by 55.7%, resulting in a 3.0-g higher TKW than in the wild type (WT). Knockdown of TaAGPS led to reduced expression of TaAGPS, AGPase activity, and TKW than in the WT. Thus, owing to the 218th amino acid change of Ser to Ala in TaAGPS-7A, the favorable haplotype TaAGPS-7A-TG showed higher AGPase activity, resulting in higher kernel starch content and grain weight. This finding could be applied to increasing starch content and grain weight in bread wheat.

Abstract Grain weight and size, mostly determined by grain length, width and thickness, are crucial traits affecting grain quality and yield in rice. A quantitative trait locus controlling grain length and width in rice, qGS1-35.2, was previously fine-mapped in a 57.7-kb region on the long arm of chromosome 1. In this study, OsPUB3, a gene encoding a U-box E3 ubiquitin ligase, was validated as the causal gene for qGS1-35.2. The effects were confirmed firstly by using CRISPR/Cas9-based mutagenesis and then through transgenic complementation of a Cas9-free knock-out (KO) mutant. Two homozygous KO lines were produced, each having a 1-bp insertion in OsPUB3 which caused frameshift mutation and premature termination. Compared with the recipient and a transgenic-negative control, both mutants showed significant decreases in grain weight and size. In transgenic complementation populations derived from four independent T0 plants, grain weight of transgenic-positive plants was significantly higher than transgenic-negative plants, coming with increased grain length and a less significant decrease in grain width. Based on data documented in RiceVarMap V2.0, eight haplotypes were classified according to six single-nucleotide polymorphisms (SNPs) found in the OsPUB3 coding region of 4695 rice accessions. Significant differences on grain size traits were detected between the three major haplotypes, Hap1, Hap2 and Hap3 that jointly occupy 98.6% of the accessions. Hap3 having the largest grain weight and grain length but intermediate grain width exhibits a potential for simultaneously improving grain yield and quality. In another set of 257 indica rice cultivars tested in our study, Hap1 and Hap2 remained to be the two largest groups. Their differences on grain weight and size were significant in the background of non-functional gse5, but non-significant in the background of functional GSE5, indicating a genetic interaction between OsPUB3 and GSE5. Cloning of OsPUB3 provides a new gene resource for investigating the regulation of grain weight and size.

Biochar is considered as a soil amendment for enhancing crop productivity. However, limited information is available on the residual effect of biochar application on rice grain yield and yield attributes. In this study, a fixed field experiment was conducted in a double rice-cropping system from 2017 to 2019. The dynamics of rice grain yield and yield attributes were monitored in the six growing seasons with 0, 20, and 40 t/ha biochar application. The results showed that the averaged grain yields in the first four seasons were increased by 2.56-16.84% and 6.15-10.77% with 20 and 40 t/ha biochar application. The trend of increased grain yield in rice with biochar application during the first seasons was mainly attributable to an increase in total biomass, panicles per m2 and spikelets per panicle. Nonetheless, the grain yields in the sixth season were not influenced by biochar addition due to decreases in panicles per m2 and spikelets per panicle. Thus, it can be seen that the positive effects of biochar application on rice yield and yield attributes depend on the duration of biochar application.

The source–sink ratio during grain filling is a critical factor that affects crop yield in wheat, and the main objective of this study was to determine the source–sink relations at both the canopy scale and the individual culm level under two nitrogen (N) levels at the post-jointing stage. Nine widely-used cultivars were chosen for analyzing source–sink relations in southwestern China; and three typical cultivars of different plant types were subjected to artificial manipulation of the grain-filling source–sink ratio to supplement crop growth measurements. A field experiment was conducted over two consecutive seasons under two N rates (N+, 150 kg ha−1; N–, 60 kg ha−1), and three manipulations were imposed after anthesis: control (Ct), removal of flag and penultimate leaves (Lr) and removal of spikelets on one side of each spike (Sr). The results showed that the single grain weights in the three cultivars were significantly decreased by Lr and increased by Sr, which demonstrated that wheat grain yield potential seems more source-limited than sink-limited during grain filling, but the source–sink balance was obviously changed by climatic variations and N deficient environments. Grain yield was highly associated with sink capacity (SICA), grain number, biomass, SPAD values, and leaf area index during grain filling, indicating a higher degree of source limitation with an increase in sink capacity. Therefore, source limitation should be taken into account by breeders when SICA is increased, especially under non-limiting conditions. Chuanmai 104, a half-compact type with a mid-sized spike and a long narrow upper leaf, showed relatively better performance in source–sink relations. Since this cultivar showed the characteristics of a lower reduction in grain weight after Lr, a larger increase after Sr, and a lower reduction in post-anthesis dry matter accumulation, then the greater current photosynthesis during grain filling contributed to the grain after source and sink manipulation.

Meteorological factors are one of the important factors that determine maize kernel weight and grain nutritional quality. Analyzing the influence of meteorological factors before and after anthesis on maize kernel weight and nutritional quality components is of great significance for improving corn yield and quality. Therefore, five different maize hybrids and conducted continuous experiments from 2018 to 2021 were selected in this study, to explore the response of maize kernel weight and grain nutritional quality to meteorological factors in different growth periods, and to quantify the linear relationship between grain nutritional quality parameters, grain weight, and meteorological factors. The main results were as follows: the 100-grain weight reached the maximum value of 39.53 g in 2018; the contents of crude protein, total starch, and crude fat in grains reached the maximum in 2018, 2020, and 2018, respectively, which were 9.61%, 69.2%, and 5.1%. Meteorological factors significantly affected the maize grain weight (p < 0.05). Before anthesis, total sunshine duration, average temperature, relative humidity, and the accumulated temperature had strong effects on grain weight. After anthesis, average daily temperature, total rainfall, temperature difference, accumulated temperature, average daily highest temperature, and total sunshine hours had strong effects on grain weight. There was also a significant correlation between grain weight and grain nutritional quality components (p < 0.05). The multivariate polynomial equation analysis revealed that further potential for maize grain weight could be exploited by adjusting the content of each quality component of the kernels under the current test conditions. Meteorological elements can indirectly affect the 100-grain weight through their relationship with the nutritional quality of the grains, with accumulated temperature before anthesis, average temperature after anthesis, and accumulated temperature after anthesis having the greatest indirect effect on the 100-grain weight. Therefore, the effects of pre-anthesis accumulation temperature, post-anthesis average temperature, and post-anthesis accumulation temperature on the nutritional quality of the grains can be harmonized by the application of hybrids of different lengths of vegetation and by adjusting the sowing time in agricultural production. Ultimately, maize grain weight can be increased on the basis of optimizing the content of various quality components in the grains. [ABSTRACT FROM AUTHOR]

Grain size and flag leaf angle are two important traits that determining grain yield in rice. However, the mechanisms regulating these two traits remain largely unknown. In this study, a rice long grain 5 (lg5) mutant with a large flag leaf angle was identified, and map-based cloning revealed that a single base substitution followed by a 2 bp insertion in the LOC_Os05g40384 gene resulted in larger grains, a larger flag leaf angle, and higher plant height than the wild type. Sequence analysis revealed that lg5 is a novel allele of elongated uppermost internode-1 (EUI1), which encodes a cytochrome P450 protein. Functional complementation and overexpression tests showed that LG5 can rescue the bigger grain size and larger flag leaf angle in the Xiushui11 (XS) background. Knockdown of the LG5 transcription level by RNA interference resulted in elevated grain size and flag leaf angle in the Nipponbare (NIP) background. Morphological and cellular analyses suggested that LG5 regulated grain size and flag leaf angle by promoting cell expansion and cell proliferation. Our results provided new insight into the functions of EUI1 in rice, especially in regulating grain size and flag leaf angle, indicating a potential target for the improvement of rice breeding. [ABSTRACT FROM AUTHOR]

Identifying traits for improving sink strength is a bottleneck to increasing wheat yield. The interacting processes determining sink strength and yield potential are reviewed and visualized in a set of 'wiring diagrams', covering critical phases of development (and summarizing known underlying genetics). Using this framework, we reviewed and assembled the main traits determining sink strength and identified research gaps and potential hypotheses to be tested for achieving gains in sink strength. In pre-anthesis, grain number could be increased through: (i) enhanced spike growth associated with optimized floret development and/or a reduction in specific stem–internode lengths and (ii) improved fruiting efficiency through an accelerated rate of floret development, improved partitioning between spikes, or optimized spike cytokinin levels. In post-anthesis, grain, sink strength could be augmented through manipulation of grain size potential via ovary size and/or endosperm cell division and expansion. Prospects for improving spike vascular architecture to support all rapidly growing florets, enabling the improved flow of assimilate, are also discussed. Finally, we considered the prospects for enhancing grain weight realization in relation to genetic variation in stay-green traits as well as stem carbohydrate remobilization. The wiring diagrams provide a potential workspace for breeders and crop scientists to achieve yield gains in wheat and other field crops. [ABSTRACT FROM AUTHOR]

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Grain number, size and weight primarily determine the yield of barley. Although the genes regulating grain number are well studied in barley, the genetic loci and the causal gene for sink capacity are poorly understood. Therefore, the primary objective of our work was to dissect the genetic architecture of grain size and weight in barley. We used a multi-parent population developed from a genetic cross between 23 diverse barley inbreds in a double round-robin design. Seed size-related parameters such as grain length, grain width, grain area and thousand-grain weight were evaluated in the HvDRR population comprising 45 recombinant inbred line sub-populations. We found significant genotypic variation for all seed size characteristics, and observed 84% or higher heritability across four environments. The quantitative trait locus (QTL) detection results indicate that the genetic architecture of grain size is more complex than previously reported. In addition, both cultivars and landraces contributed positive alleles at grain size QTLs. Candidate genes identified using genome-wide variant calling data for all parental inbred lines indicated overlapping and potential novel regulators of grain size in cereals. Furthermore, our results indicated that sink capacity was the primary determinant of grain weight in barley. [ABSTRACT FROM AUTHOR]

Around the world, salinity a critical limiting factor in agricultural productivity. Plant growth is affected by salt stress at all stages of development. The contemporary investigation focused on Chaetomorpha antennina aqueous extracts (SWEs) to decrease the effects of salt strain on rice germination, growth, yield, and the production of key biological and biochemical characters of the rice, Oryza sativa L. (Poaceae). SWE improved the germination capacities of rice seedlings by promoting their emergence 36.27 h prior to those that had been exposed to saline stress. The creation of 79.647% longer radicles by SWE treatment on salt-stressed seeds which boosted the establishment effectiveness of seeds produced under salt stress longer radicles resulted in plants that were 64.8% taller. SWE treatment was effective in revoking the levels of protein (26.9%), phenol (35.54%), and SOD (41.3%) enzyme levels that were previously constrained by salinity stress. Additionally, SWE were also efficient in retaining 82.6% of leaf water content and enhancing the production of photosynthetic pigments affected by salt exposure earlier. The improvement in plant functionality was evident from the display of increase in tiller numbers/hill (62.36%), grain yield (58.278%), and weight (56.502%). The outcome of our research shows that SWEs protected the plants from the debarring effects of salinity by enhancing the plant functionality and yield by mechanistically enriching their physiological (germination and vegetative growth) and biochemical attributes (leaf RWC, photosynthetic pigments, protein, phenol, and SOD). Despite the increase in TSS and starch levels in rice grain exposed to salinity stress, SWE improved the grain protein content thus cumulatively enhancing rice nutrition and marketability. The current investigation reveals that the extracts of C. antennina can help alleviate rice plants from salt stress in an efficient, eco-friendly, as well as economical way. [ABSTRACT FROM AUTHOR]

Grain yield is a polygenic trait that can be influenced by environmental factors and genetic compositions at all plant growth stages. Currently, the molecular mechanisms behind the coordination of the interaction between grain yield-related traits remain unknown. In this study, we characterized the function of four STRESS_tolerance and GRAIN_LENGTH (OsSGL) Poaceae ortholog genes that are transcribed into DUF1645 domain-containing proteins in relation to the grain length, grain weight, and drought stress-tolerance of rice. The transgenic plants with overexpressing or heterologous high levels of Poaceae OsSGL ortholog genes exhibited longer grain size than the wild type plants. Larger cells were seen in panicles of the four transgenic lines with paraffin sectioning and scanning electron microscopy analyses. In addition, four Poaceae OsSGL ortholog genes positively affected the drought tolerance of rice. Four transgenic plants displayed higher resistance to drought stress at the seedling and vegetative stages. RNA-sequencing and qRT-PCR results indicated that over- or heterologous-expression of four Poaceae OsSGL ortholog genes also affected the transcriptome of rice plants. These genes may play a role in auxin and cytokinin biosynthesis and their transduction pathways. Taken together, these results suggested that the four OsSGL orthologs have a conserved function in the regulation of stress-tolerance and cell growth by modulating hormonal biosynthesis and signaling.

Grain size is a key component of grain yield in cereals. It is a complex quantitative trait controlled by multiple genes. Grain size is determined via several factors in different plant development stages, beginning with early tillering, spikelet formation, and assimilates accumulation during the pre-anthesis phase, up to grain filling and maturation. Understanding the genetic and molecular mechanisms that control grain size is a prerequisite for improving grain yield potential. The last decade has brought significant progress in genomic studies of grain size control. Several genes underlying grain size and weight were identified and characterized in rice, which is a model plant for cereal crops. A molecular function analysis revealed most genes are involved in different cell signaling pathways, including phytohormone signaling, transcriptional regulation, ubiquitin–proteasome pathway, and other physiological processes. Compared to rice, the genetic background of grain size in other important cereal crops, such as wheat and barley, remains largely unexplored. However, the high level of conservation of genomic structure and sequences between closely related cereal crops should facilitate the identification of functional orthologs in other species. This review provides a comprehensive overview of the genetic and molecular bases of grain size and weight in wheat, barley, and rice, focusing on the latest discoveries in the field. We also present possibly the most updated list of experimentally validated genes that have a strong effect on grain size and discuss their molecular function.

It is crucial to synergistically improve the yield and quality of sweet maize by implementing precise and strategic planting methods. However, a comprehensive understanding of how increasing plant density affects the sweet maize fresh ear yield, grain-filling rate, and grain carbohydrate concentration is not fully understood. Thus, a field experiment was performed using a split-plot design in Southeast China in 2021 and 2022, involving four sweet maize varieties (MT6855 and WT2015 were compact-type varieties, XMT10 and YZ7 were flat-type varieties) and three plant densities (D1: 4.5 plants m−2; D2: 6.0 plants m−2; and D3: 7.5 plants m−2). The results showed that an increasing plant density markedly increased the fresh ear yield of sweet maize varieties (MT6855 and WT2015) over the two years. However, it did not influence the fresh ear yield of XMT10 and YZ7. Across all four varieties in 2021 and 2022, the increasing plant density decreased the sweet maize filled ear length, while it did not affect the grain soluble solid concentration and grain residue ratio. The sweet maize grain weight, the maximum grain-filling rate, and the mean grain-filling rate decreased significantly with the increase in planting density across all four varieties. However, plant density did not significantly affect the grain soluble sugar, sucrose, fructose, and starch concentrations across different varieties at most stages during the grain filling. The current study also found that the sweet maize fresh ear yield was dramatically positively correlated with ears ha−1, grains per ear, grain-filling rate, and grain starch concentration but negatively correlated with the bare plant rate. Notably, a parabolic relationship existed between the fresh ear yield and 100-grain weight. These findings suggest that optimizing the plant density, particularly with compact-type varieties, can improve the sweet maize fresh ear yield without decreasing its quality.

Increasing grain weight under dense planting conditions can further improve maize yield. 6-BA is known to be involved in regulating grain development and influencing grain weight. Maize grain development is closely linked to starch accumulation and hormone levels. In this work, the effects of applying 6-BA at the flowering stage under high density on the grain filling characteristics, starch content, starch synthesis critical enzyme activity, and endogenous hormones levels of maize grains (including inferior grains (IGs) and superior grains (SGs)) of two high-yielding summer maize varieties widely cultivated in China were investigated. The findings indicated that applying 6-BA significantly improved maize yield compared to the control, mainly as a result of increased grain weight due to a faster grain filling rate. Additionally, the activities of enzymes associated with starch synthesis, including sucrose synthase (SuSy), ADP-glucose pyrophosphorylase (AGPase), granule-bound starch synthase (GBSS), soluble starch synthase (SSS), and starch branching enzyme (SBE), were all increased following 6-BA application, thus facilitating starch accumulation in the grains. Applying 6-BA also increased the zeatin riboside (ZR), indole-3-acetic acid (IAA), and abscisic acid (ABA) levels, and reduced the gibberellin (GA3) level in the grains, which further improved grain filling. It is worth noting that IG had a poorer filling process than SG, possibly due to the low activities of critical enzymes for starch synthesis and imbalanced endogenous hormones levels. However, IG responded more strongly to exogenous 6-BA than SG. It appears that applying 6-BA is beneficial in improving filling characteristics, promoting starch accumulation by enhancing the activities of critical enzymes for starch synthesis, and altering endogenous hormones levels in the grains, thus improving grain filling and increasing the final grain weight and yield of maize grown under crowded conditions. These results provide theoretical and technical support for the further utilization of exogenous hormones in high-density maize production.

To study the difference among cytoplasm at the different nitrogen conditions, a research experiment was conducted using five different cytoplasmic male sterile (CMS) hybrid rice with nitrogen levels at N0, N1, N2, and N3; the nitrogen application rates were 0, 90, 180, and 270 kg/ha, from 2018 to 2019. Results showed that among tested cultivars of CMS hybrid rice, JW (J803A × Chenghui727) showed the highest yield in both years for the low nitrogen and high nitrogen treatments. The dry matter accumulation and translation of JW type in nutritive organs were higher than that of others during the low nitrogen level (N1). We concluded that the nutrient translocation within plants organs and dry biomass accumulation were highly dependent on CMS type and nitrogen application. This research indicates that selecting a rice cultivar with greater efficiency of nitrogen is favourable for raising the number of grains per panicle, grain yield, and nitrogen use efficiency. JW cytoplasm displayed great efficiency in low nitrogen, which is a potential cytoplasmic resource.

The assessment of biological and actual grain yields, as well as the results of studying the percentage of realization of biological yields of varieties of wintering oats of various uses cultivated in soil and climatic conditions of the south foothill zone of the Northwest Caucasus, showed the advantage of grain-type varieties. For comparison, the grain yields of 2018 and 2020 were taken. with differences in the amount of precipitation during the most important period of culture development – the grain filling phase. In the conditions of the first year of research, the grain yield of wintering oats was 100–147 g/m2 and it ranged from 288 g/m2 (Guzeripl) to 438 g/m2 (Oshten) in 2019–2020. Biological yield in 2018 was formed at the level of 150–245 g/m2. In more favorable weather conditions in 2020, the level of biological yield varied from 436 g/m2 (Oshten) to 902 g/m2 (Verny). For two years of research, the average value of biological yield was 293–540 g/m2. The number of plants was: 2018 – 100–124 pcs./m2, 2020 – 132–224 pcs./m2. Grain weight varied from 1,3 to 1,8 g (2018), in 2020 it was 2,3–4,9 g. On average, over two years, the number of plants varied from 124 pcs./m2 (Guzeripl) to 174 pcs./m2 (AGU 75), the grain weight was 1,9–3,2 g. Studies have found that the most highly productive varieties are Oshten, AGU 75, Mezmai. The Verny variety is distinguished by a high biological yield of grain, Oshten is characterized by the highest percentage of biological yield realization.