Grain Yield Of Cereal Crops Research Articles

Boosting Triticeae crop grain yield by manipulating molecular modules to regulate inflorescence architecture: insights and knowledge from other cereal crops.

One of the challenges for global food security is to reliably and sustainably improve the grain yield of cereal crops. One solution is to modify the architecture of the grain-bearing inflorescence to optimize for grain number and size. Cereal inflorescences are complex structures, with determinacy, branching patterns, and spikelet/floret growth patterns that vary by species. Recent decades have witnessed rapid advancements in our understanding of the genetic regulation of inflorescence architecture in rice, maize, wheat, and barley. Here, we summarize current knowledge on key genetic factors underlying the different inflorescence morphologies of these crops and model plants (Arabidopsis and tomato), focusing particularly on the regulation of inflorescence meristem determinacy and spikelet meristem identity and determinacy. We also discuss strategies to identify and utilize these superior alleles to optimize inflorescence architecture and, ultimately, improve crop grain yield.

A Meta-Analysis Approach to Estimate the Effect of Cover Crops on the Grain Yield of Succeeding Cereal Crops within European Cropping Systems

Farming practices such as cover cropping, crop rotation systems, and soil tillage practices, along with climate conditions and soil type play important roles in determining final crop production. Numerous empirical studies have documented the heterogeneous effects of cover crops on the yield of successive crops, exhibiting variations across diverse regions, climate regimes, soil characteristics, cover crop types, and agricultural management practices. A meta-analysis was conducted to comprehensively summarize and evaluate the impact of cover crops (CCs) in the agroecosystem. The main goal of the study is to promote a transition towards more sustainable cereal crop production by exploring the potential of currently unexploited CCs in Europe. The study demonstrated that the incorporation of legume CCs resulted in the most pronounced and statistically significant increase in grain yield among cereal crops. CCs from the Brassicaceae family also demonstrated a positive impact on grain yield under southern European climates. Cover cropping had a positive effect on the subsequent cash crop under conventional tillage practice. A positive, but not significant impact, was detected under both conservation tillage practices, which include reduced tillage (RT) and no-till (NT). The result of the study suggests that NT practices are more suitable for Northern Europe, while RT practices are preferable for Southern Europe zones. This study indicates that the adoption of cover cropping represents a viable and effective agronomic strategy for enhancing grain yield in cereal crops cultivated across European agricultural systems.

Identification of QTL underlying the main stem related traits in a doubled haploid barley population.

Lodging reduces grain yield in cereal crops. The height, diameter and strength of stem are crucial for lodging resistance, grain yield, and photosynthate transport in barley. Understanding the genetic basis of stem benefits barley breeding. Here, we evaluated 13 stem related traits after 28 days of heading in a barley DH population in two consecutive years. Significant phenotypic correlations between lodging index (LI) and other stem traits were observed. Three mapping methods using the experimental data and the BLUP data, detected 27 stable and major QTLs, and 22 QTL clustered regions. Many QTLs were consistent with previously reported traits for grain filling rate, internodes, panicle and lodging resistance. Further, candidate genes were predicted for stable and major QTLs and were associated with plant development and adverse stress in the transition from vegetative stage to reproductive stage. This study provided potential genetic basis and new information for exploring barley stem morphology, and laid a foundation for map-based cloning and further fine mapping of these QTLs.

Role of neonicotinoid preparations for spike grain crop seedlings protection against click beetle and Frit fly larvae in Belarus

Recently, in winter and spring grain crops for pre-sowing seed treatment among the assortment of insecticides the preparations of insecticidal and insectofungicidal action based on neonicotinoids: acetamiprid, imidacloprid, clothianidin and thiamethoxam have been widely used. At the current stage of chemical method development of plant protection against harmful arthropods, neonicotinoids are rapidly developing and promising group of neurotoxic insecticides and having a fundamentally different mechanism of action on insects – they inhibit nicotine-acetylcholine receptors. Pre-sowing seed material treatment with insecticides protects the sown seeds, hypocotyls and aboveground plant organs against soil and intrastem pests. It is revealed that during the growing seasons of 2019–2021 in the experimental field, economically significant phytophages are lined click beetle (Agriotes lineatus L.) and Frit flies of autumn and spring generations (Oscinella spp.), indicating the study of their larvae number and harmfulness and measures allowing to control the vital activity of insects in agrocenoses conditions. Plants damaged by them lag behind in growth and die. Improving the range of effective preparations with different active substances used by the method of pre-sowing treatment of grain crop seeds to protect plants during germination against phytophages is an obligatory link in the technology of crops cultivation and one of the factors of their number effective control, what has determined the relevance of the choice of our research topic. Pre-sowing winter and spring cereals seed treatment with neonicotinoid preparations based on imidacloprid (Coyote, SC, Sidoprid, FSC, Tabu, WSC), acetamiprid (Leatrin, SC, Bagrets Plus, SC, Vershina Plus, SC) and thiamethoxam (Questor Forte, SC) have provided plant seedlings high protection against click beetle and Frit fly larvae damage. The results of studies conducted in 2019–2021 have shown that the effectiveness of preparations have varied by years depending on weather conditions and pests number before sowing and at seedlings stage. The indicators of winter grain crops plant damage reduction by wireworms have made 78,8–91,1 %, Frit flies 60,0–85,0 %, spring cereals – 80,0–91,6 % and 80,7–91,1 %, respectively. Through years of research the insecticides for seed treatment have helped to increase the stored grain yield of cereal crops, on the average, from 0,7 to 6,2 cwt/ha, or 1,0–13,5 %. The data obtained will serve as a basis for justifying protective measures to reduce the number and harmfulness of soil-dwelling and terrestrial pests in order to improve the phytosanitary situation in the agrocenoses of cereals.

Root system architecture in cereals: progress, challenges and perspective.

Roots are essential multifunctional plant organs involved in water and nutrient uptake, metabolite storage, anchorage, mechanical support, and interaction with the soil environment. Understanding of this 'hidden half' provides potential for manipulation of root system architecture (RSA) traits to optimize resource use efficiency and grain yield in cereal crops. Unfortunately, root traits are highly neglected in breeding due to the challenges of phenotyping, but could have large rewards if the variability in RSA traits can be fully exploited. Until now, a plethora of genes have been characterized in detail for their potential role in improving RSA. The use of forward genetics approaches to find sequence variations in genes underpinning desirable RSA would be highly beneficial. Advances in computer vision applications have allowed image-based approaches for high-throughput phenotyping of RSA traits that can be used by any laboratory worldwide to make progress in understanding root function and dissection of the genetics. At the same time, the frontiers of root measurement include non-invasive methods like X-ray computer tomography and magnetic resonance imaging that facilitate new types of temporal studies. Root physiology and ecology are further supported by spatiotemporal root simulation modeling. The discovery of component traits providing improved resilience and yield advantage in target environments is a key necessity for mainstreaming root-based cereal breeding. The integrated use of pan-genome resources, now available in most cereals, coupled with new in-field phenotyping platforms has the potential for precise selection of superior genotypes with improved RSA.

INTERMEDIUM-C mediates the shade-induced bud growth arrest in barley.

Tiller formation is a key agronomic determinant for grain yield in cereal crops. The modulation of this trait is controlled by transcriptional regulators and plant hormones, tightly regulated by external environmental conditions. While endogenous (genetic) and exogenous (environmental factors) triggers for tiller formation have mostly been investigated separately, it has remained elusive how they are integrated into the developmental program of this trait. The transcription factor gene INTERMEDIUM-C (INT-C), which is the barley ortholog of the maize domestication gene TEOSINTE BRANCHED1 (TB1), has a prominent role in regulating tiller bud outgrowth. Here we show that INT-C is expressed in tiller buds, required for bud growth arrest in response to shade. In contrast to wild-type plants, int-c mutant plants are impaired in their shade response and do not stop tiller production after shading. Gene expression levels of INT-C are up-regulated under light-limiting growth conditions, and down-regulated after decapitation. Transcriptome analysis of wild-type and int-c buds under control and shading conditions identified target genes of INT-C that belong to auxin and gibberellin biosynthesis and signaling pathways. Our study identifies INT-C as an integrator of the shade response into tiller formation, which is prerequisite for implementing shading responses in the breeding of cereal crops.

Limiting factors for panicle photosynthesis at the anthesis and grain filling stages in rice (Oryza sativa L.).

Panicle photosynthesis is crucial for grain yield in cereal crops; however, the limiting factors for panicle photosynthesis are poorly understood, greatly impeding improvement in this trait. In the present study, pot experiments were conducted to investigate the limiting factors for panicle photosynthesis at the anthesis stage in seven rice genotypes and to examine the temporal variations in photosynthesis during the grain filling stage in the Liangyou 287 genotype. At the anthesis stage, leaf and panicle photosynthesis was positively correlated with stomatal conductance and maximum carboxylation rate, which were in turn associated with hydraulic conductance and nitrogen content, respectively. Panicle hydraulic conductance was positively correlated with the area of bundle sheaths in the panicle neck. During grain filling, leaf and panicle photosynthesis remained constant at the early stage but dramatically decreased from 8 to 9 days after anthesis. The trends of variations in panicle photosynthesis were consistent with those in stomatal conductance but not with those in maximum carboxylation rate. At first, the maximum carboxylation rate and respiration rate in the panicle increased, through elevated panicle nitrogen content, but then drastically decreased, as a result of dehydration. The present study systematically investigated the limiting factors for panicle photosynthesis, which are vital for improving photosynthesis and crop yield.

Genetic analyses of lodging resistance and yield provide insights into post-Green-Revolution breeding in rice.

SummaryLodging reduces grain yield in cereal crops. Understanding the genetic basis of lodging resistance (LR) benefits LR breeding. In the study, 524 accessions from a rice germplasm collection and 193 recombinant inbred lines were phenotyped for 17 LR‐related traits. Height and culm strength (the magnitude of applied force necessary to break the culm) were two major factors affecting LR. We conducted genome‐wide association study (GWAS) and identified 127 LR‐associated loci. Significant phenotypic correlations between culm‐strength traits and yield‐related traits were observed. To reveal the genetic relationship between them, we conducted GWAS of culm‐strength traits with adding yield‐related trait as a covariate and detected 63 loci linking culm strength and yield. As a proof, a near‐isogenic line for an association locus on chromosome 7 showed enhanced LR and yield. Strikingly, 58 additional loci were identified in the covariate‐added GWAS. Several LR‐associated loci had undergone divergent selection. Linkage analysis supported the GWAS results. We propose that introgression of alleles beneficial for both culm strength and panicle weight without negative effects on panicle number or pyramiding high‐yielding alleles and lodging‐resistant alleles without effects on yield can be employed for the post‐Green‐Revolution breeding.

A light-regulated gene, TaLWD1L-A, affects flowering time in transgenic wheat (Triticum aestivum L.)

Flowering time is an important agronomic trait that greatly influences plant architecture and grain yield in cereal crops. The present study identified a light-regulated gene, TaLWD1L-A, from hexaploid wheat that encodes a WD40 domain-containing protein. TaLWD1L-A was localized in the nucleus. Phenotypic analysis demonstrated that TaLWD1L-A overexpression in transgenic wheat led to an obvious early flowering phenotype. Upregulation of the floral activator gene TaFT1 caused the early flowering phenotype in transgenic wheat plants. TaLWD1L-A also affected the expression of circadian clock genes, including TaTOC1, TaLHY, TaPRR59, TaPRR73 and TaPRR95, and indirectly regulated the expression of the TaFT1 in transgenic plants by affecting the expression of vernalization-related genes TaVRN1 and TaVRN2 and photoperiod-related genes TaPpd-1 and TaGI. The early flowering phenotype in TaLWD1L-A-overexpressing transgenic lines led to a relatively shorter phenotype and yield reduction. Our results revealed that TaLWD1L-A affected the expression of circadian clock-related genes and played an important role in wheat flowering regulation by influencing the expression of genes related to vernalization and photoperiod pathways.

Senescence‐related translocation of nonstructural carbohydrate in rice leaf sheaths under different nitrogen supply

AbstractThe translocation of nonstructural carbohydrates (NSC) from leaf sheaths to filling grains after anthesis contributed greatly to the grain yield of cereal crops. In this study, the effect of nitrogen (N) supply levels on the accumulation and translocation of NSC in leaf sheath tissues and its relationship with the initiation and progression of leaf senescence during grain filling was investigated using two rice (Oryza sativa L.) genotypes, namely, premature flag leaf senescence mutant (psf) and its wild‐type. Three N treatment levels were used to examine N‐supply induced alteration in the activities of several key enzymes involved in NSC translocation and N assimilation in different leaf sheaths. The results show that the NSC translocation rate in leaf sheaths under low nitrogen (LN) treatment was significantly higher than those under normal nitrogen (NN) and high nitrogen (HN) treatments. However, the positive effect of LN on the NSC translocation in leaf sheath was closely associated with its negative effect on grain yield, due to accelerated leaf senescence and shortened leaf longevity. Comparatively, the upper‐positional sheath had a lower NSC amount and higher NSC translocation rate than the lower‐leaf sheaths after heading. High N suppressed sucrose‐phosphate synthase (SPS) activity in leaf sheaths, but enhanced the activity of key enzymes involving in N assimilation in leaf sheaths. The upper sheath had higher activity of sucrose‐metabolizing enzymes and lower activity of N‐assimilating enzymes. Hence, the upper‐leaf sheath had a relatively weak N assimilation and stronger NSC translocation than the lower‐leaf sheaths.

Molecular Basis of Pollen Germination in Cereals.

Understanding the molecular basis of pollen germination in cereals holds great potential to improve yield. Pollen, a highly specialized haploid male gametophyte, transports sperm cells through a pollen tube to the female ovule for fertilization, directly determining grain yield in cereal crops. Although insights into the regulation of pollen germination and gamete interaction have advanced rapidly in the model Arabidopsis thaliana (arabidopsis), the molecular mechanisms in monocot cereals remain largely unknown. Recently, pollen-specific genome-wide and mutant analyses in rice and maize have extended our understanding of monocot regulatory components. We highlight conserved and diverse mechanisms underlying pollen hydration, germination, and tube growth in cereals that provide ideas for translating this research from arabidopsis. Recent developments in gene-editing systems may facilitate further functional genetic research.

Assessment of the individual and combined effects of Rht8 and Ppd-D1a on plant height, time to heading and yield traits in common wheat

Grain yield in cereal crops is a complex trait controlled by multiple genes and influenced by developmental processes and environment. Here we report the effects of alleles Rht8 and Ppd-D1a on plant height, time to heading, and grain yield and its component traits. Association analysis and quantitative trait locus mapping using phenotypic data from 15 environments led to the following conclusions. First, both Rht8 and Ppd-D1a reduce plant height. However, Ppd-D1a but not Rht8 causes earlier heading. Second, both Rht8 and Ppd-D1a promote grain yield and affect component traits. Their combined effects are substantially larger than those conferred by either allele alone. Third, promotion of grain yield by Rht8 and Ppd-D1a is through increasing fertile spikelet number. We speculate that Rht8 and Ppd-D1a act independently and additively in control of plant height, grain yield and yield component. Combination of the two alleles is desirable for adjusting plant height and enhancing grain yield and abiotic stress tolerance.

Improving soil organic carbon pools through inclusion of summer mungbean in cereal-cereal cropping systems in Indo-Gangetic plain

ABSTRACTLong-term effect of mungbean inclusion in lowland rice-wheat and upland maize-wheat systems on soil carbon (C) pools, particulate organic C (POC), and C-stabilization was envisaged in organic, inorganic and without nutrient management practices. In both lowland and upland systems, mungbean inclusion increased very-labile C (Cfrac1) and labile C (Cfrac2) in surface soil (0–0.2 m). Mungbean inclusion in cereal-cereal cropping systems improved POC, being higher in lowland (107.4%). Lowland rice-based system had higher passive C-pool (11.1 Mg C ha−1) over upland maize-based system (6.6 Mg C ha−1) indicating that rice ecology facilitates the stabilization of passive C-pool, which has longer persistence in soil. Organic nutrient management (farmyard manure + full crop residue + biofertilizers) increased Cfrac1 and carbon management index (CMI) over inorganic treatment. In surface soil, higher CMI values were evident in mungbean included cropping systems in both lowland and upland conditions. Mungbean inclusion increased grain yield of cereal crops, and yield improvement followed the order of maize (23.7–31.3%) > rice (16.9–27.0%) > wheat (lowland 7.0–10.7%; upland 5.4–16.6%). Thus, the inclusion of summer mungbean in cereal-cereal cropping systems could be a long-term strategy to enrich soil organic C and to ensure sustainability of cereal-cereal cropping systems.

Microorganisms reveal what plants do not: wheat growth and rhizosphere microbial communities after Azospirillum brasilense inoculation and nitrogen fertilization under field conditions

Azospirillum brasilense is one of plant growth promoting bacteria used to improve plant growth and grain yield of cereal crops. The level of inoculation response is defined by complex plant-microorganism interactions, many of them still unknown. Thus, we evaluated both agronomic response and microbial ecology of wheat crop under A. brasilense inoculation and nitrogen fertilization at field conditions in order to improve inoculation efficiency. Treatments were: control, nitrogen fertilization and inoculation with 40M and 42M strains. Functional and structural diversity of rhizosphere bacterial communities were evaluated by community-level physiological and terminal restriction fragment length polymorphism profiles. Besides, aerial biomass, grain yield and counts of microaerophilic diazotrophic rhizobacteria were determined. Plant ontogeny modified the number of culturable microaerophilic diazotrophic rhizobacteria. Although agronomic response did not show differences, plant ontogeny and the agricultural practices modified both physiology and genetic structure of rhizosphere microbial communities. Interestingly, these differences due to the treatments were observed at jointing stage but not at grain-filling stage of wheat. Our results demonstrate how different management decisions can change plant- microorganism relationships. While wheat could not show differences between some agricultural treatments, under the soil surface microbial communities could show them.

GW5 acts in the brassinosteroid signalling pathway to regulate grain width and weight in rice.

Grain size is a major determinant of grain yield in cereal crops. qSW5/GW5, which exerts the greatest effect on rice grain width and weight, was fine-mapped to a 2,263-bp/21-kb genomic region containing a 1,212-bp deletion, respectively. Here, we show that a gene encoding a calmodulin binding protein, located ∼5 kb downstream of the 1,212-bp deletion, corresponds to qSW5/GW5. GW5 is expressed in various rice organs, with highest expression level detected in young panicles. We provide evidence that the 1,212-bp deletion affects grain width most likely through influencing the expression levels of GW5. GW5 protein is localized to the plasma membrane and can physically interact with and repress the kinase activity of rice GSK2 (glycogen synthase kinase 2), a homologue of Arabidopsis BIN2 (BRASSINOSTEROID INSENSITIVE2) kinase, resulting in accumulation of unphosphorylated OsBZR1 (Oryza sativa BRASSINAZOLE RESISTANT1) and DLT (DWARF AND LOW-TILLERING) proteins in the nucleus to mediate brassinosteroid (BR)-responsive gene expression and growth responses (including grain width and weight). Our results suggest that GW5 is a novel positive regulator of BR signalling and a viable target for genetic manipulation to improve grain yield in rice and perhaps in other cereal crops as well.

Study on leaf area index and leaf area duration of growth analytical parameters in Wheat, Barley, and Oat

An experiment were conducted in rabi season during 2012–2013 and 2013–2014 to find out the effect of cereal crops (Wheat, Oat, Barley) and cutting schedule on forage and grain yield. The study revealed the maximum chlorophyll accumulation in Barley and wheat during the initial stage at 95 DAS and wheat and barley during the reproductive stage at 30 DAS. Cutting at 50 DAS is proved beneficial on chlorophyll accumulation. Photosynthetic rate was maximum in wheat at 90 DAS. However cutting did not affect photosynthesis rate stomatal conductance and transpiration rate. Barley gave maximum fodder yield (fresh/day). Cutting at 50 DAS was beneficial in producing maximum forage yield without sacrificing grain yield of cereal crops.

Study of cutting management on proximate analysis in wheat, oat and barley crops

An experiment were conducted in rabi season during 2012–2013 to find out the effect of cereal crops (Wheat, Oat, Barley) and cutting schedule on forage and grain yield. The study revealed the maximum chlorophyll accumulation in Barley and wheat during the initial stage at 95 DAS and wheat and barley during reproductive stage at 30 DAS. Cutting at 50 DAS is proved beneficial on chlorophyll accumulation. Photosynthetic rate were maximum in wheat at 90 DAS. However cutting did not affect photosynthesis rate stomatal conductance and transpiration rate. Barley gave maximum fodder yield (fresh/day). Cutting at 50 DAS was beneficial in producing maximum fodder yield without sacrificing grain yield of cereal crops.

Regulation of OsmiR156h through Alternative Polyadenylation Improves Grain Yield in Rice.

Substantial increases in grain yield of cereal crops are required to feed a growing human population. Here we show that a natural variant of SEMIDWARF AND HIGH-TILLERING (SDT) increases harvest index and grain productivity in rice. Gain-of-function sdt mutation has a shortened polyadenylation tail on the OsmiR156h microRNA precursor, which cause the up-regulation of OsmiR156h. The plants carrying the semidominant sdt allele exhibit reduced plant height, enhanced lodging resistance, increased tiller numbers per plant, and resulting in an increased grain yield. We also show that combining the sdt allele with the OsSPL14WFP allele can be effective in simultaneously improving tillering capacity and panicle branching, thereby leading to higher harvest index and grain yield. Most importantly, pyramiding of the sdt allele and the green revolution gene sd1 enhances grain yield by about 20% in hybrid rice breeding. Our results suggest that the manipulation of the polyadenylation status of OsmiR156 represents a novel strategy for improving the yield potential of rice over what is currently achievable.

Growth and yield responses in wheat and barley to potassium supply under drought or moderately saline conditions in the south-west of Western Australia

This study assessed whether more potassium (K) was required for optimal growth and grain yield of cereal crops under drought and salinity than under non-stressed conditions. In 2011, three experiments on wheat (Triticum aestivum L.) with four K rates (0, 20, 40, 80 kg K/ha), four application times (0, 5, 10, 15 weeks after sowing, WAS) and two sources (KCl, K2SO4) were conducted in the central and southern grainbelts of Western Australia. The lack of plant response to K supply at the sites of Bolgart (36 mg K/kg at 0–30 cm) and Borden (25 mg K/kg at 0–30 cm), compared with significant gain in K uptake, dry matter and grain yield at Dowerin (29 mg K/kg at 0–30 cm), was not explained by differences in soil K levels. However, rain fell regularly through the growing season at Bolgart and Borden, whereas a dry spell occurred from stem elongation to grain development at Dowerin. The effectiveness of K application time followed the trend of 0, 5 > 10 > 15 WAS. In 2012, barley (Hordeum vulgare L.) was grown on a moderately saline (saturation extract electrical conductivity ~4 dS/m) and low K (20 mg K/kg) farm in the central grainbelt and treated with 0, 20, 40 and 120 kg K/ha. Applying K increased K uptake but decreased Na uptake, especially at 120 kg K/ha. Plant growth and grain yield increased with K supply, but the difference between the K rates was relatively small, indicating possible partial K substitution by Na. Higher than normal fertiliser K supply on low K soils would enhance the adaptation by cereals to water-limited environments, but K-fertiliser management on moderately saline soils may need to account for both K and Na uptake and use by the crops.

Strigolactones regulate rice tiller angle by attenuating shoot gravitropism through inhibiting auxin biosynthesis.

Tiller angle, a key agronomic trait for achieving ideal plant architecture and increasing grain yield, is regulated mainly by shoot gravitropism. Strigolactones (SLs) are a group of newly identified plant hormones that are essential for shoot branching/rice tillering and have further biological functions as yet undetermined. Through screening for suppressors of lazy1 (sols), a classic rice mutant exhibiting large tiller angle and defective shoot gravitropism, we identified multiple SOLS that are involved in the SL biosynthetic or signaling pathway. We show that SL biosynthetic or signaling mutants can rescue the spreading phenotype of lazy1 (la1) and that SLs can inhibit auxin biosynthesis and attenuate rice shoot gravitropism, mainly by decreasing the local indoleacetic acid content. Although both SLs and LA1 are negative regulators of polar auxin transport, SLs do not alter the lateral auxin transport of shoot base, unlike LA1, which is a positive regulator of lateral auxin transport in rice. Genetic evidence demonstrates that SLs and LA1 participate in regulating shoot gravitropism and tiller angle in distinct genetic pathways. In addition, the SL-mediated shoot gravitropism is conserved in Arabidopsis. Our results disclose a new role of SLs and shed light on a previously unidentified mechanism underlying shoot gravitropism. Our study indicates that SLs could be considered as an important tool to achieve ideal plant architecture in the future.