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Crop biomass is the reservoir of carbon (C), a valuable input to the soil, thus supporting the soil fauna and enhancing soil health. There are limited studies that compared the major cereal crops for C storage for regenerative agriculture and to optimize C sequestration strategies. The objective of this study was to quantify the extent of variation in biomass allocation and C storage between maize (Zea mays L.), sorghum (Sorghum bicolor [L.] Moench), and wheat (Triticum aestivum L.) for crop production, and C sequestration potential. The study used metadata from 40 global studies that reported on the allocation of plant biomass and C between roots and shoots of the major cereal crops. Key statistics were computed to determine the variability between genotypes for total plant biomass (Pb), shoot biomass (Sb), root biomass (Rb), root‐to‐shoot biomass ratio (Rb/Sb), total plant carbon content, shoot carbon content, root carbon content, total plant carbon stock (PCs), shoot carbon stock, root carbon stock, and root‐to‐shoot carbon stock ratio (RCs/SCs). Maize exhibited the highest variability for Pb (with a coefficient of variation [CV] of 31.2% and a mean of 4.2 ± 1.3 Mg ha−1 year−1), followed by wheat (CV of 24.2% and a mean of 1.5 ± 0.4 Mg ha−1 year−1) and sorghum (CV of 16.8% and a mean of 2.0 ± 0.8 Mg ha−1 year−1), respectively. A similar trend was observed for PCs, with maize (CV of 40.1% and mean of 1.6 ± 0.7 Mg ha−1 year−1) showing the highest total plant C stock variability, followed by wheat (24.4% and 0.2 ± 0.1 Mg ha−1 year−1) and sorghum (16.3% and 0.9 ± 0.3 Mg ha−1 year−1), respectively. Maize (with a CV of 24.4% and mean of 0.1 ± 0.03 Mg ha−1 year−1) exhibited the highest variability for Rb/Sb, while wheat (30.92% and 0.2 ± 0.05 Mg ha−1 year−1) exhibited the highest variability for RCs/SCs. Correlation analysis revealed the following significant associations: Pb and mean annual temperature (MAT) (r = −0.47), and Sb and MAT (r = −0.43), and Pb and mean annual precipitation (MAP) (r = −0.34), and Sb and MAP (r = −0.30). Rb had a strong, significant positive correlation with MAT (r = 0.72) and MAP (r = 0.85). The meta‐analysis revealed that maize and sorghum have the highest variability for Pb and plant carbon stocks, while wheat exhibited the highest variability for the below‐ground biomass and carbon stocks. The data aided in crop selection and suggested that the best cultivars could be developed and identified for production and C sequestration potential for cultivation by farmers, land rehabilitation, and climate change mitigation. Core Ideas: There is sufficient genetic variation in maize, sorghum, and wheat cultivars for manipulation of biomass and carbon allocation.Root carbon is a major contributor to soil organic carbon.Above‐ground biomass is important for atmospheric carbon sequestration. [ABSTRACT FROM AUTHOR]

Trichothecenes are sesquiterpenoid toxins produced by diverse ascomycetes, including Fusarium. The trichothecene analog deoxynivalenol (DON) produced by the Fusarium head blight (FHB) pathogen Fusarium graminearum is a virulence factor on wheat and a major food and feed safety concern. In Fusarium, the trichothecene biosynthetic gene (TRI) cluster consists of 7–14 genes. Most TRI cluster genes are conserved and their specific roles in trichothecene biosynthesis have been determined. An exception is TRI14, which is not required for DON synthesis in vitro but is required for spread of F. graminearum in wheat heads. In the current study, gene expression analyses revealed that TRI14 was highly induced in infected wheat heads. We demonstrated that TRI14 was not only required for F. graminearum spread but also important for initial infection in wheat. Although a prior study did not detect DON in infected seeds, our analyses showed significantly less DON and fungal biomass in TRI14-mutant (designated ∆tri14)-inoculated heads than wild-type-inoculated heads. Gene expression comparison showed that the level of expression of TRI genes was similar in the wheat tissues infected with ∆tri14 or the wild type, indicating the reduced toxin levels caused by ∆tri14 may be due to less fungal growth. ∆tri14 also caused less lesion and grew less in wheat coleoptiles than the wild type. The growth of ∆tri14 in carboxymethylcellulose medium was more sensitive to hydrogen peroxide than the wild type. The data suggest that TRI14 plays a critical role in F. graminearum growth, and potentially protects the fungus from plant defense compounds. [ABSTRACT FROM AUTHOR]

In this study, we investigated the genetic mapping of root biomass and root/shoot ratio. We utilized a large (n = 345) bi‐parental recombinant inbred line (RIL) population from the 'Penny' × 'Yecora‐Rojo' cross to investigate the partitioning of biomass above‐ and belowground and to identify the quantitative trait loci (QTL) that influence root biomass and root/shoot ratio. Genotyping of 345 RILs by using genotyping by sequencing produced 2918 single‐nucleotide polymorphism markers by which a genome‐wide map of 3507 cM was constructed. Phenotyping was conducted in an augmented design with large pots in controlled environment. We identified two significant QTL regions, QRt.peye‐5A and QRt.peye‐5B, which control root biomass and the root/shoot ratio. QRt.peye‐5A, marking a 3.15 Mbp region on chromosome 5A, explained 11% of variations in root biomass and 9.5% of variations in root/shoot ratio, with the narrow region harbouring 28 genes. QRt.peye‐5B, marking a 12.2 Mbp region on chromosome 5B, explained 7% of variations in root/shoot ratio and harbours 104 genes. The root/shoot ratio enhancing alleles at QRt.peye‐5A and QRt.peye‐5B come from 'Penny' and 'Yecora‐Rojo' respectively. These QTL regions contains genes such as the two MADS box transcription factors on the 5A QTL that are candidate genes for Vrn1 locus, and other genes previously postulated for root traits such as a COBRA‐like COBL2 and landmark hormonal responses genes such as IAA16, IAA4 and BRI1, DREB2A‐INTERACTING PROTEIN2 (DRIP2) and bHLH92 which has a role in amelioration of stress conditions. [ABSTRACT FROM AUTHOR]

Summary: How plants distribute biomass among organs influences resource acquisition, reproduction and plant–plant interactions, and is essential in understanding plant ecology, evolution, and yield production in agriculture. However, the genetic mechanisms regulating allocation responses to the environment are largely unknown.We studied recombinant lines of wheat (Triticum spp.) grown as single plants under sunlight and simulated canopy shade to investigate genotype‐by‐environment interactions in biomass allocation to the leaves, stems, spikes, and grains. Size‐corrected mass fractions and allometric slopes were employed to dissect allocation responses to light limitation and plant size.Size adjustments revealed light‐responsive alleles associated with adaptation to the crop environment. Combined with an allometric approach, we demonstrated that polymorphism in the DELLA protein is associated with the response to shade and size. While a gibberellin‐sensitive allelic effect on stem allocation was amplified when plants were shaded, size‐dependent effects of this allele drive allocation to reproduction, suggesting that the ontogenetic trajectory of the plant affects the consequences of shade responses for allocation.Our approach provides a basis for exploring the genetic determinants underlying investment strategies in the face of different resource constraints and will be useful in predicting social behaviours of individuals in a crop community. [ABSTRACT FROM AUTHOR]

The intermittent ozone (O3) exposure of crops to alternating high and low concentrations is common in fields, but its impact on crop production has not been thoroughly investigated. In this study, two widely planted and O3-sensitive crops, winter wheat and soybean, were intermittently exposed to elevated O3 concentrations in open-top chambers. The results showed that the winter wheat and soybean yields significantly decreased with O3 exposure (AOT40, cumulative hourly O3 concentration above 40 ppb) (p < 0.001). The relative yield losses were 0.99% per AOT40 for winter wheat and 1.2% per AOT40 for soybean, respectively. The responses of the crop biomasses to elevated O3 concentrations were lower than that of crop yield. Although the O3-induced crop yield and biomass losses under continuous O3 exposure were greater than those under intermittent O3 exposure, the differences were not statistically significant. Therefore, we can conclude that the effects of elevated O3 concentrations on crops are closely related to the exposure dose but not significantly related to the temporal distribution of elevated O3 concentrations. This study improves our understanding of how crop production responds to intermittent O3 exposure. [ABSTRACT FROM AUTHOR]

Perennial wheat yields for several years after sowing, and develops a deep and dense root system, thereby improving soil structure and preserving soil fertility. It is also drought resistant, which increases its future potential under the ongoing climate change. Moreover, perennial wheat offers and effective strategy for carbon sequestration through increasing soil carbon stocks. However, the effect of perennial wheat on soil properties remains uncertain in the conditions of south-eastern Kazakhstan due to the lack of data. To fill this gap, we conducted a study in which five varieties of perennial wheat were grown in the Almaty region in soils of different fertility for two years. As a result, in the plot where topsoil was removed to a depth of 25 cm, total carbon increased by nearly three times, from 0.54% to 1.42%, and the number of microorganisms increased from 715.1x103±0.2x103 to 48.0x103±0.6x103 colony forming units per ml of soil. The photosynthetic performance of perennial wheat varieties in the experimental plot was not negatively affected by the removal of top soil suggesting that perennial wheat can successfully restore soil fertility and replenish soil with chemical elements involved in photosynthesis. Our results confirm that in the conditions of the south-eastern Kazakhstan perennial wheat makes a significant contribution to the soil carbon stock accumulation and development of soil biota; in our study, these effects were particularly strong in the case of degraded soil. [ABSTRACT FROM AUTHOR]

Wheat yield and nitrogen use efficiency (NUE) have improved simultaneously with the genetic development of wheat varieties. However, wheat selection is carried out routinely in N‐rich field conditions, with breeding progress limited under low soil available nitrogen. Thus, we performed a 2‐year field investigation using eight milestone winter wheat varieties released between 1947 and 2017 in the Huang‐Huai‐Hai region of China with two N applications—normal (CK; 220 kg N ha−1) and reduced (RN; 110 kg N ha−1)—in Shaanxi, China, to examine changes in wheat yield, NUE, water use efficiency (WUE) and root biomass. Our findings revealed average annual yield increases of 49.615 kg ha−1 and 36.905 kg ha−1 under CK and RN, respectively. Notably, the NUE trend mirrored yield, increasing with the release year of wheat varieties, with average annual increases in NUE of 0.192 and 0.336 kg kg−1 under CK and RN, respectively. In the RN treatment, N uptake efficiency (UPE) increased with year of release, while N utilization efficiency (UTE) had no significant relationship. In the CK treatment, UTE increased with year of release, while UPE had no significant relationship. Across the 2‐year experiment, surface root biomass (0–20 cm layer) increased with year of release under CK but had no relationship under RN, while deep root biomass (20–200 cm layer) decreased with year of release under CK and increased under RN. The roots of modern wheat varieties responded better to soil nitrogen levels and produced higher yields, NUE and WUE than earlier varieties by adjusting root biomass distribution in soil. [ABSTRACT FROM AUTHOR]

Roots are the main sensing organ, initiating multiple signaling pathways in response to abiotic factors, including nutrients, drought, and salt stress. A focus on improving the root system architecture is a key strategy to mitigate these stresses in wheat crop. In the present study, a diversity panel comprising indigenous landraces and historical cultivars from Pakistan was characterized for the root system architecture (RSA) and important loci were identified using a genome‐wide association study (GWAS). RSA of the diversity panel was characterized 30 days after sowing in brunch tubes, and root images were taken. A high‐throughput root imaging analysis using Rhizovision software was performed by setting the scale to extract the eight RSA traits and four plant biomass‐related traits. GWAS identified 323 association signals for 12 root and biomass traits present on all wheat chromosomes, while the most important and reliable genetic loci (based on pleotropic loci and candidate genes) were identified on chromosomes 2A, 2B, 5A, 5D, 6A, 7B, and 7D for RSA. SNP annotation and transcriptome profiling identified nine candidate genes regulating the RSA and plant biomass traits, including ROOTLESS WITH UNDETECTABLE MERISTEM1, MYB TRANSCRIPTION FACTOR4, BRASSINOSTEROID INSENSITIVE1, SLENDER RICE1, AUXIN‐RESPONSIVE FACTOR25, SCARECROW, NARROW LEAF2, PIN‐FORMED1 AND PHOSPHATE TRANSCRIPTION FACTOR1. This study provided pre‐breeding information for deep‐rooting genotypes and associated markers that will accelerate the incorporation of such traits in breeding. [ABSTRACT FROM AUTHOR]

Climate change‐induced drought stress (DS) poses a significant threat to crop production, emphasizing the need for innovative strategies to mitigate its adverse effects. Prior studies have demonstrated the distinct capacities of salicylic acid (SA) and sodium hydrosulfide (NaHS) to augment plant resilience against drought‐related stressors. However, little is known about how they work together or the specific processes by which they increase DS tolerance. The purpose of this research was to determine how SA and NaHS affected the performance of wheat plants during the growing seasons of 2021–2022 and 2022–2023, when there was a drought. The research employed a block‐randomized experimental layout with split plots, where the primary factors included two irrigation levels: full irrigation (IW1, 100% of water requirement) and deficit irrigation (IW2, 50% of water requirement). Secondary factors included the application of mock control, 0.5 mM SA, and 0.3 mM NaHS, an H2S donor, either individually or in combination, administered before the onset of DS. The application of SA, NaHS, or their combination significantly enhanced wheat plant resistance to DS. Significant increases in a number of physiological markers, including proline content, relative water content (RWC), Fv/Fm, chlorophyll content, and antioxidant enzyme activity, demonstrated this improvement. Furthermore, in drought‐stressed wheat plants, SA and NaHS treatments decreased the amounts of hydrogen peroxide (H2O2), malondialdehyde (MDA) content, and electrolyte leakage (EL). In conclusion, our study highlights the possibility of SA and NaHS, whether applied individually or in combination, to improve drought resistance in wheat plants, presenting a viable approach to lessen the effects of climate change on agricultural yield. [ABSTRACT FROM AUTHOR]

The source and sink relationships determine the amount and distribution of biomass in plants. Field and laboratory experiments were conducted to study the effect of nitrogen rate and spikelet removal on seed yield and germination traits of wheat. The field experiment was conducted employing sink manipulation (no spikelet removal and ½ spikelet removal) and source manipulation (nitrogen rate of 0, 75, and 150 kg ha-1 ). This study was performed as a factorial experiment in a randomized complete block design with three replications. Seeds obtained from the field experiment were subjected to determine the effect of the sink and source manipulation on seed germination traits in the laboratory experiment. Results showed that most traits under study were not affected by source and sink manipulation. Seed yield and seed weight were not affected by spikelet removal and varying nitrogen applications. Although some of the wheat spikelets have been removed, those plants have been able to maintain the number of seeds per spike and the weight of a single seed. The use of nitrogen at the spike emergence stage did not affect the seed yield of the Pishtaz cultivar. Nitrogen needed for the seeds could be compensated by the remobilization of nitrogen from various plant organs such as the stem. Nitrogen application of 150 kg ha-1 with the removal of ½ spikelets improved seed germination (%) and vigor comparing control (no spikelet removal with no nitrogen application). Considering that seed yield and seed weight did not change under the influence of source and sink manipulation, it can be concluded that Pishtaz wheat is more sink-limited than source-limited. [ABSTRACT FROM AUTHOR]

Studying the long‐term effect of elevated atmospheric CO2 concentration (e[CO2]) on wheat (Triticum aestivum L.) over multiple generations has received increasing attention. Here, five wheat cultivars were grown under ambient CO2 concentration (a[CO2], 400 ppm) and e[CO2] (800 ppm), respectively, for three consecutive generations (G1 to G3) under two nitrogen (N) levels (1N and 2N). Compared to plants grown under a[CO2], e[CO2] increased shoot biomass and grain yield (GY) over three generations and the enhancement was greater in G3 than in G1. However, plant N concentration was lowered by e[CO2] and the reduction was not mitigated by higher N supply. The carbon (C) concentration significantly increased in leaf and stem but decreased in grain, indicating an inhibited C translocation to grain under e[CO2]. Most importantly, these negative impacts were exacerbated in G3. Concentrations of mineral nutrients in grain were significantly lowered by e[CO2] with larger reduction in G3 than in G1 in some micronutrients such as Zn, Cu and Fe. These findings suggest that long‐term exposure to e[CO2] sustained the positive effects on plant growth and production but aggravated the reduction of grain quality over multiple generations. Among the five cultivars, 325Jimai showed the greatest increase in shoot biomass and GY, and a greater sink capacity compared with the other cultivars, indicating its potential for future breeding strategies. [ABSTRACT FROM AUTHOR]

Soil sodicity is a major constraint to seedling emergence and crop production, potentially reducing plant growth due to physical and chemical constraints. Studying responses to ion imbalances may help identify genotypes tolerant to chemical constraints in sodic soils, thereby improving productivity. We evaluated the performance of four wheat (Triticum aestivum L.) genotypes in solutions with five sodium adsorption ratios (SARs) ranging from 0 to 60. For all four genotypes, seedling emergence and shoot dry matter (DM) decreased significantly with increasing SARs. A significant positive correlation was observed between Ca concentration in roots as well as both root and shoot DM for all genotypes. At SAR values > 20, the more tolerant genotype (EGA Gregory) displayed higher Ca concentrations in root tissues, whereas the more sensitive genotype (Baxter) exhibited Na-induced Ca deficiency. Thus, the selection of genotypes that are able to accumulate Ca in roots in sodic conditions may be a useful trait for selecting genotypes tolerant of soils with high ESP values. However, for soils that restrict plant growth at ESP (SAR) values of 6–10%, it is likely that growth is restricted by physical constraints rather than by a Na-induced Ca deficiency. [ABSTRACT FROM AUTHOR]

The genetic heritage of wheat (Triticum spp.) crops has been shaped by millions of years of predomestication natural selection, often driven by competition among individuals. However, genetic improvements in yield potential are thought to involve selection towards reduced competitiveness, thus enhancing adaptation to the crop environment. We investigated potential trade‐offs between individual plant fitness and community performance using a population of introgression lines carrying chromosome segments of wild emmer (nondomesticated) in the background of an elite durum cultivar. We focused on light as a primary factor affecting plant–plant interactions and assessed morphological and biomass phenotypes of single plants grown in mixtures under sunlight and a simulated canopy shade, and the relevance of these phenotypes for the monoculture community in the field. We found that responses to canopy shade resemble responses to high density and contribute to both the individual and the community. Stepwise regressions suggested that grain number per spike and its persistence under shade are essential attributes of productive communities, advocating their use as a breeding target during early‐generation selection. Overall, multiple phenotypes attained under shade could better explain community performance. Our novel, applicable, high‐throughput set‐up provides new prospects for studying and selecting single‐plant phenotypes in a canopy‐like environment. Summary statement: Individual fitness and the performance of the monoculture community are associated with distinct and conflicting plant behaviours, some related to response to shade. Simulation of canopy shade on single plants can improve our predictions of the genotype performance as a community. [ABSTRACT FROM AUTHOR]

Several biogeochemical models have been applied to understand the potential effects of management practices on soil organic carbon (SOC) sequestration, crop growth, and yield. In this study, the denitrification and decomposition (DNDC) model was used to simulate soil SOC dynamics and harvested C-biomass in rice–wheat rotation under organic/inorganic fertilization with conventional tillage (CT) and reduced tillage (RT). Before calibration, DNDC underpredicted harvestable grain C-biomass of rice where percent difference (PD) varied from 29.22% to 42.14%, and over-simulated grain C-biomass of wheat where PD was −55.01% with 50% nitrogen–phosphorus–potassium (NPK) and 50% animal manure applied under the CT treatment. However, after calibration by adjusting default values of soil and crop parameters, DNDC simulated harvestable grain C-biomass of both crops very close to observed values (e.g., average PD ranged from −2.81% to −6.17%). DNDC also predicted the effects of nutrient management practices on grain C-biomass of rice/wheat under CT/RT using d-index (0.76 to 0.96) and the calculated root mean squared error (RMSE of 165.36 to 494.18 kg C ha−1). DNDC simulated SOC trends for rice–wheat using measured values of several statistical indices. Regression analysis between modeled and observed SOC dynamics was significant with R2 ranging from 0.35 to 0.46 (p < 0.01), and intercept ranging from 0.30 to 1.34 (p < 0.65). DNDC demonstrated that combined inorganic and organic fertilization may result in higher C-biomass and more SOC sequestration in rice–wheat systems. [ABSTRACT FROM AUTHOR]

Background and aims: Soil carbon sequestration can play an important role in mitigating climate change. Higher organic C inputs to agricultural soils are needed in order to increase soil organic carbon (SOC) stocks. Genotype selection and breeding towards increased root biomass may enhance root C inputs to the soil and could therefore be a promising, easy-to-implement management option for potentially increasing C sequestration. However, an increase in root C inputs may compromise yield, which is not desirable in terms of food security. Methods: Data from 13 global studies with field experiments were compiled in order to estimate the potential of optimised genotype selection for enhancing root biomass without compromising the yield of winter wheat, spring wheat, silage maize, winter rapeseed and sunflower. A lack of data on the effect of variety on rhizodeposition was identified which thus had to be excluded. Results: Systematic genotype selection increased mean yields by 52% and mean root biomass by 22% across all crops and sites. A median root C increase of 6.7% for spring wheat, 6.8% for winter rapeseed, 12.2% for silage maize, 21.6% for winter wheat and 26.4% for sunflower would be possible without a yield reduction. Conclusion: Overall, this review demonstrates that optimised genotype selection can be a win-win option for increasing root biomass C input to soil while maintaining or even enhancing yield. [ABSTRACT FROM AUTHOR]

Given the worldwide effort to improve crop drought resistance, it is crucial to understand the mechanisms of root system adaptation of ploidy wheat to water‐deficient environments. A meta‐analysis was performed to examine the changes in root system mechanisms under drought conditions. Data used in the analysis were drawn from 192 papers, taking into account wheat ploidy levels as well as pot and field studies. The results illustrated that water stress reduced grain yield and aboveground biomass to a greater extent in diploid and tetraploid compared with hexaploid genotypes. In contrast, drought reduced root biomass, root surface area and root volume more in hexaploid than in diploid and tetraploid wheat. Under water‐limited conditions, diploid and tetraploid genotypes exhibited greater root biomass and root length densities in the topsoil. Hexaploid genotypes greatly reduced root biomass and root length density in the topsoil and maintained higher root biomass and root length density in subsoil. These genotypes also showed smaller root diameter and xylem centre vessel diameter under drought conditions. The analysis revealed that grain yield was negatively correlated with topsoil root biomass and root length density, root volume, root diameter and xylem centre vessel, but positively correlated with subsoil root mass, root length density and root vigour. The study demonstrated that domestication and selection pressures of ploidy wheat have altered wheat root system traits while improving grain yield. Greater root mass and root length densities in the subsoil facilitate access to soil moisture from deep layers, contributing to high yields in drought environments. [ABSTRACT FROM AUTHOR]

Selecting cultivars with greater biomass results in higher yields and greater carbon sequestration. Storage of atmospheric carbon in the plant/soil pool contributes not only to food security but also to mitigating climate change and other agroecological benefits. The objective of this study was to determine: (1) grain, residue, and root biomass yields; (2) harvest indexes; (3) residue-to-product ratio; (4) root-to-shoot ratio; (5) biomass carbon and nitrogen contents; and (6) C:N ratios for two new and two old winter wheat cultivars. The greatest yield difference was found between old Srpanjka (the lowest) and new Kraljica (the highest) cultivar where grain, residue, root, and total biomass yield was higher by 38%, 91%, 71%, and 64%, respectively. Total biomass was composed of 40–47% grain, 10–11% roots, 32–36% stems + leaves, 9–11% chaff, and 1–2% spindle. The range of HI was 0.45–0.53, RPR 0.91–1.25, and R:S ratio 0.12–0.13. For all cultivars, positive carbon and negative nitrogen balance within the plant pool was determined. Still, root biomass and rhizodeposition carbon remain open questions for a better understanding of agroecosystems' C dynamics. [ABSTRACT FROM AUTHOR]

Increasing biomass allocation to the root system may increase soil-organic carbon stocks and confer drought adaptation in water-limited environments. Understanding the genetic bases and inheritance of biomass allocation is fundamental for drought tolerance breeding and soil health. The objective of this study was to determine the general and specific combining ability, maternal effects and the mode of gene action controlling the major yield and biomass allocation related traits in wheat to identify good combiners for breeding and enhanced carbon sequestration. Ten selected wheat genotypes were crossed in a full diallel mating design, and 90 F2 families were generated and evaluated in the field and greenhouse under drought-stressed and non-stressed conditions. Significant differences were recorded among the tested families revealing substantial variation for plant height (PH), kernels per spike (KPS), root biomass (RB), shoot biomass (SB), total plant biomass (PB) and grain yield (GY). Additive gene effects conditioned PH, SB, PB and GY under drought, suggesting the polygenic inheritance for drought tolerance. Strong maternal and reciprocal genetic effects were recorded for RB across the testing sites under drought-stressed conditions. Line BW162 had high yield and biomass production and can be used to transfer favourable genes to its progeny. The parental line LM75 maintained the general combining ability (GCA) effects in a positive and desirable direction for SB, PB and GY. Early generation selection using PH, SB, PB and GY will improve drought tolerance by exploiting additive gene action under drought conditions. Higher RB production may be maintained by a positive selection of male and female parents to capture the significant maternal and reciprocal effects found in this study. [ABSTRACT FROM AUTHOR]

Radiation interception, radiation use efficiency (RUE) and harvest index (HI) are the key determinants of grain yield in cereal species. However, little is known about how these traits affect grain yield among spring wheat genotypes grown under low and optimum nitrogen (N) fertiliser supply. We used two experiments, in a field (Experiment 1; 2017–2018) and glasshouse (Experiment 2; 2018–2019) to investigate the effects of these traits on grain yield. Grain yield increased by 35% with increasing N fertiliser supply to 8.80 t/ha in Experiment 1 and 151% to 8.33 t/ha in Experiment 2. Grain yield was lowest for 'Reliance' and highest for 'Discovery' in both experiments. Differences in grain yield were not associated with HI. As the RUE did not differ among genotypes, the yield differences were attributed to the different amounts of radiation intercepted; a result of the faster leaf area expansion rate (LAER) and subsequent higher maximum green leaf area index (GLAI), and a longer leaf area duration (LAD). The differences in LAER and maximum GLAI among the genotypes were associated with a differences in specific leaf area (cm2/g). Our results suggest that improved grain yields in spring wheat can be achieved by focusing breeding efforts on canopy characteristics to increase radiation interception. [ABSTRACT FROM AUTHOR]

Phosphorus (P) management in wheat grown under saline soil conditions requires a better understanding of how P placement and salt stress affect spatial root distribution, plant agronomic performance, and nutrient utilization. A column culture experiment was conducted with two wheat genotypes, Alice and LX99, five P placements ('Top Dressed High P', TopHP; 'Top Dressed Reduced P', TopRP; 'Deep Banded High P', DeepHP; 'Deep Banded Reduced P', DeepRP; and 'No P added', −P), and two salt stress levels ('salt stress', +S; 'non-salt stress', −S) to investigate differences in biomass accumulation, nutrient utilization, and root distribution (0–20 cm, 20–40 cm, and 40–100 cm) among treatments. Deep P placement under non-salt stress increased root distribution at 20–40 cm soil depth for both genotypes compared to top P placement. P application under salt stress increased root weight at all three soil depths in both genotypes and P accumulation in aboveground plant parts (except for LX99 under TopRP). The highest P utilization efficiency occurred in Alice with TopRP and in LX99 with DeepRP under non-salt and salt stresses. Overall, a coordinated adaptation in allocating biomass between belowground and aboveground plant parts, along with altered nutrient utilization, was necessary to reach a growth compromise in response to P supply changes and salinity. Therefore, genotype, P placement depth, and soil salinity should be considered to improve wheat P utilization efficiency under saline conditions. [ABSTRACT FROM AUTHOR]

The effect of methyl jasmonate (MJ) (1 µM) on wheat (Triticum aestivum L. cv. Moskovskaya 39), seedlings and the fatty acid (FA) content of leaves under optimal and cadmium (Cd) (100 µM) stress conditions wasinvestigated. Height and biomass accumulation was studied traditionally; the netphotosynthesis rate (Pn) was studied using a photosynthesis system, FAs'profile—GS-MS. No effect on the height and Pn rate of the MJ pre-treatment wheat at optimum growth conditions was found. MJ pre-treatment led to a decrease in the total amount of saturated (about 11%) and unsaturated (about 17%) identified FAs, except α-linoleic FA (ALA), which is probably associated with its involvement in energy-dependent processes. Under Cd impact, the MJ-treated plants had a higher biomass accumulation and Pn rate compared to untreated seedlings. Both MJ and Cd caused stress-induced elevation of palmitic acid (PA) versus an absence of myristic acid (MA), which is used for elongation. It is suggested that PA participates in alternative adaptation mechanisms (not only as a constituent of the lipid bilayer of biomembrane) of plants under stress. Overall, the dynamics of FAs showed an increase in the saturated FA that is important in the packing of the biomembrane. It is supposed that the positive effect of MJ is associated with lower Cd content in plants and a higher ALA content in leaves. [ABSTRACT FROM AUTHOR]

AquaCrop is one of the dynamic and user-friendly models for simulating different conditions governing plant growth in the field. But this model requires many input parameters such as plant information, soil, climate, groundwater, and management factors. In this research, to solve this problem and develop a model with fewer input data, artificial neural network (ANN), support vector regression (SVR), and combined support vector regression with firefly algorithm (SVR-FFA) were used. For this purpose, 440 scenarios were created in 2 farms located in Iran, and the values of yield and biomass obtained by the AquaCrop model were compared with intelligent models. Also, consumable seed and irrigation were considered as inputs of intelligent models. The 99WestW2 farm in Miandoab had a seed yield of 6.588 t/ha, and the WestW10 farm in Mahabad had a seed yield of 5.05 t/ha. The results of this research showed that for both 99WestW2 and WestW10 farms, the SVR-FFA3 model was able to have the lowest amount of error so that for the amount of grain yield, the error values ​​for the farms were 0.033 and 0.069 t/ha, respectively. The error value of biomass was obtained for farms as 0.057 and 0.066 t/ha respectively. After SVR-FFA model, SVR and ANN models also showed good performance due to proper accuracy and saving time. Finally, SVR-FFA, SVR, and ANN models were able to predict yield and biomass values in the shortest time and with the highest accuracy with only two inputs. [ABSTRACT FROM AUTHOR]

In India, 700 million tons of agricultural waste generated annually is burned by farmers in the fields, which decreases biological activity in soil. The issue of handling the enormous amounts of crop residues that emerge from increased crop output might be resolved by composting. However, different crop residues improve soil physico-chemical and biological properties in different ways. Crop residue incorporation and fertilization (NPK) impact crop productivity due to changes in soil microbial biomass carbon, nitrogen, phosphorous, and the soil enzymatic activity. A field experiment was conducted for two years (2020–2021 and 2021–2022), which comprises five partially composted crop residues treatments viz., control, clusterbean straw, groundnut shell, pearlmillet husk, and sesame stover (added at rate of 5 t ha−1), and four fertilization (NPK) treatments viz., control, 75% RDF, 100% RDF, and 125% RDF. The microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), microbial biomass phosphorus (MBP), enzymatic activities in soil and wheat yield were studied under a semi-arid environment (India). Data showed that the continuous application of crop residues and fertilizer significantly affected MBC, MBN, MBP, and soil enzymatic activity after two years of experimentation in a semi-arid region environment. The highest levels of microbial biomass (viz, MBC, MBN, MBP) and enzyme activities were noticed in the sesame stover and 125% recommended dose of fertilizer (RDF) treatments. Therefore, this study highlights the need for restoring crop residue for effective soil management. The crop residue and NPK fertilization are more efficient in improving the soil's microbial properties and the yield of wheat. [ABSTRACT FROM AUTHOR]

Two types of microplastics (MPs) (micro polyethylene (mPE) and micro polypropylene (mPP)) were studied alongside and cadmium (Cd) to determine how they affected soil-wheat systems, both individually and in mixed combinations. This was accomplished by carrying out a pot experiment to reveal their respective interaction effects. Results showed that in different Cd pollution levels soils (0, 1, and 5 mg kg−1), chlorophyll concentrations in wheat leaves decreased markedly with rising levels of mPE/mPP. In the single mPE treatment, as the mPE content in the soil increased, the aboveground and root biomass improved. By contrast, in the single mPP treatment, when the mPP content was low, the aboveground biomass of wheat increased and with the mPP content increased, the aboveground biomass of wheat decreased. This result was also shown in the combined contamination of mPE/mPP and Cd (1 mg kg−1) in the root biomass. With an increase in Cd concentration (that is, at 5 mg kg−1) in the combined contamination, this phenomenon continued in the aboveground biomass while in the roots, there was a promotion effect. At Cd contaminated soil (1 mg kg−1), MPs inhibited Cd enrichment in aboveground wheat, but at 5 mg kg−1, Cd enrichment was promoted instead, in both aboveground and roots. Adding mPE/mPP diminished pH and the Cd effective state concentration in soil. The combined contamination of mPE/mPP and Cd affected the Cd biological enrichment in the wheat to some extent, which was influenced by the types of MP and pollution levels of Cd in the soil. [Display omitted] • Wheat leaves Chlorophyll concentrations decreased markedly with rising levels of MPs. • The wheat aboveground and root biomass improved with rising contents of mPE in soil. • In lower Cd contaminated soil, MPs inhibited Cd enrichment in aboveground wheat. • MPs and Cd combined contamination affected the Cd biological enrichment in the wheat. [ABSTRACT FROM AUTHOR]

Winter wheat production is threatened by drought stress under rainfed conditions; thus, screening high- and stable-yielding wheat varieties to ensure the sustainable development of wheat production and food security in the Huang-Huai-Hai Plain (HHHP) is vital. In this research, four-year field experiments with twelve winter wheat varieties were conducted during the winter wheat-growing seasons between 2016 and 2020 in order to: (1) screen high- and stable-yielding winter wheat varieties under rainfed conditions, (2) investigate the mechanism of high-yielding wheat yield formation and the relationships among grain-yield formation traits, and (3) investigate the nitrogen utilization efficiency (NUtE) of high-yielding wheat. The results showed that high-yield level wheat varieties (HL; Yannong999, Taimai1918 and Yannong173) obtained a higher average grain yield than medium-yield level wheat varieties (ML) and low-yield level wheat varieties (LL) by 10.1% and 29.0%, respectively. Compared with ML and LL, HL had a higher biomass at anthesis, higher spike dry matter at anthesis, higher spike partitioning index and fruiting efficiency (grain set per unit of spike dry weight at anthesis), and the highest grain number per square meter (24.2 × 103 m−2). Simultaneously, HL maintained a higher leaf area index (LAI) at anthesis and a higher net photosynthesis rate (Pn) of flag leaves after anthesis, which contributed to a higher post-anthesis biomass; HL also had higher maturity biomass, harvest index (HI), and biomass remobilization in comparison to ML and LL. The above results demonstrated that HL improved grain yield by increasing grain number per square meter, post-anthesis biomass, biomass remobilization, maturity biomass, and HI. Additionally, HL also obtained higher NUtE by improving grain yield. Therefore, screening winter wheat varieties with traits such as HL can help achieve high and stable yields and high NUtE under rainfed conditions. [ABSTRACT FROM AUTHOR]

Source traits are currently of great interest for the enhancement of yield potential; for example, much effort is being expended to find ways of modifying photosynthesis. However, photosynthesis is but one component of crop regulation, so sink activities and the coordination of diverse processes throughout the crop must be considered in an integrated, systems approach. A set of 'wiring diagrams' has been devised as a visual tool to integrate the interactions of component processes at different stages of wheat development. They enable the roles of chloroplast, leaf, and whole-canopy processes to be seen in the context of sink development and crop growth as a whole. In this review, we dissect source traits both anatomically (foliar and non-foliar) and temporally (pre- and post-anthesis), and consider the evidence for their regulation at local and whole-plant/crop levels. We consider how the formation of a canopy creates challenges (self-occlusion) and opportunities (dynamic photosynthesis) for components of photosynthesis. Lastly, we discuss the regulation of source activity by feedback regulation. The review is written in the framework of the wiring diagrams which, as integrated descriptors of traits underpinning grain yield, are designed to provide a potential workspace for breeders and other crop scientists that, along with high-throughput and precision phenotyping data, genetics, and bioinformatics, will help build future dynamic models of trait and gene interactions to achieve yield gains in wheat and other field crops. [ABSTRACT FROM AUTHOR]

In common root and crown rot (CRR), Bipolaris sorokiniana (Sace.) is one of the important in wheat, causing considerable yield losses globally. Sources of resistance can provide a feasible and effective method of control for plant disease management. However, knowledge on mechanisms of resistance is scarce.We screened 33 wheat genotypes against B. sorokiniana under greenhouse and field conditions. In addition, real‐time quantitative PCR (qPCR) analysis using ten novel candidate gene markers, Cre3, EDS1, LTP5, PGIP, PR‐1, PIEP1, TLP, UGT, Stb6 and PFT, was conducted on leaves and roots, along with changes in activity of antioxidant enzymes, peroxidase, catalase, β‐1,3‐glucanase, and phenolic content for their involvement in disease impact mechanisms.Lowest disease severity was in 'Alvand', followed by 'Baharan' and 'Bam' as resistant genotypes. Quantitative gene expression showed that, although the candidate defence genes were upregulated 1.24‐ to 3.5‐fold in wheat roots and leaves inoculated with B. sorokiniana, they were highly regulated in resistant varieties 'Alvand', 'Mehregan' and 'Bam'. Cre3, a resistance gene to cereal cyst nematode Heterodera filipjevi, was regulated in cultivars resistant to B. sorokiniana. Similar results were obtained for Stb6, a gene resistant to Septoria tritici blotch, EDS1 resistant to powdery mildew, Blumeria graminis, and the genes PR‐1 and UGT resistant to leaf rust, Puccinia triticina. Antioxidant enzyme activity also showed the highest increases in resistant genotypes.In conclusion, the T. aestivum–B. sorokiniana interaction in resistant wheat cultivars uses defence‐related genes and enzymes that protect wheat towards sustainable development. Further such studies will shed light on simultaneous resistance to other diseases in wheat cultivars. [ABSTRACT FROM AUTHOR]

Development of low-nitrogen (N) tolerant and N-responsive durum wheat genotypes is required since nitrogen efficiency has emerged as a highly desirable trait from economic and environmental perspectives. Two hundred durum wheat genotypes were evaluated at three locations under optimum (ON) and low (LN) nitrogen conditions to screen genotypes for low-nitrogen tolerance and responsiveness to an optimum N supply. The results showed significant variations among the durum wheat genotypes for low-N tolerance and responsiveness. The average reduction in grain yield under the LN condition was 48.03% across genotypes. Only 17% of the genotypes tested performed well (grain yield reduction <40%) under LN conditions. Based on the absolute grain yield, biomass yield, and normalized difference vegetative index value, on average, 32, 14, 17, and 37% of the tested genotypes were classified as efficient and responsive, efficient and nonresponsive, inefficient and responsive, and inefficient and nonresponsive, respectively. Considering the absolute and relative grain yield, biomass yield, normalized difference vegetative index values, and stress tolerance indices as selection criteria, 17 genotypes were chosen for subsequent breeding. Among the screening indices, geometric mean productivity, stress tolerance index, yield index, and stress susceptibility index exhibited positive and significant correlations with grain yield under both N conditions; hence, either of these traits can be used to select low-N-tolerant genotypes. The common genotypes identified as LN-tolerant and responsive to N application in this study could be used as parental donors for developing N-efficient and responsive durum wheat varieties. [ABSTRACT FROM AUTHOR]

This study combines proximal sensing technology based on a mobile visible imaging device and a dynamic ecophysiological model to estimate the growth status of two winter wheat crops (Apache and Rubisko cultivars) in the presence of uncontrolled broadleaf weeds. Working at early growth stages and on four different dates, each plot was photographed and then destructive biomass samples were collected. After calibration, crop aboveground biomass is inferred from an image indicator, the fractional vegetation cover (FVC). A supervised image classification algorithm was used to calculate FVC for crop (FVCc) and for weeds (FVCw). Analysis of FVC measurements focused on stand heterogeneity by comparing their variability and the impact of weeds on crop growth. Over time, the discrepancy between plant biomass derived from the image and data simulated from a simple ecophysiological model increased for most areas of the plot, indicating the presence of crop stress. At the same time, the weed pressure (WP) study concluded that weeds did not have a major influence on crop growth, although locally some areas showed a negative impact on crop growth. Therefore, weeds were not the major stress observed on the later dates of the study. These low-cost technologies aim to determine stress in wheat crop and support farmers in their transition to agroecology for highly accurate plot monitoring. [ABSTRACT FROM AUTHOR]

High biomass and nutrient acquisition are desirable for oat (Avena sativa L.) as a cover crop. However, our understanding of oat genotypes suitable for cover crops and associated traits is limited. The objectives of this experiment on growing oat as a cover crop, after winter wheat (Triticum aestivum L.) harvest, were to determine biomass production, nutrient uptake of a set of oat genotypes, and to identify phenotypic traits that can be used as indicators to select cultivars suitable for cover crops. The results showed that the top biomass-producing genotypes took up larger amounts of soil nutrients, up to 142 kg N ha−1 and 17 kg P ha−1 in 2016, and 43.5 kg N ha−1 and 8.3 kg P ha−1 in 2017. The biomass production was significantly related to plant height and leaf area index (LAI) in both years, and to the normalized difference vegetation index (NDVI) in 2017. Both NDVI and LAI were closely related to the total amounts of N and P uptake. The poor association between biomass and NDVI in 2016 was due to vigorous growth of volunteer wheat and weeds as well as severe rust (Puccinia coronata f. sp. avenae Eriks.) infestation. Our results suggest that it is important to choose oat varieties as cover crops. Leaf area index can be used as a nondestructive indicator for final biomass and nutrient acquisition, while both NDVI and LAI are important traits for choosing oats as soil conservation cover crops. [ABSTRACT FROM AUTHOR]

Successfully evaluating and improving the salt tolerance of genotypes requires an appropriate analysis tool to allow simultaneous analysis of multiple traits and to facilitate the ranking of genotypes across different growth stages and salinity levels. In this study, we evaluate the salt tolerance of 56 recombinant inbred lines (RILs) in the presence of salt-tolerant and salt-sensitive control genotypes using multivariate analysis of plant dry weight, measured at 75 (PDW-75) and 90 (PDW-90) days from sowing, biological yield (BY), grain yield (GY), and their salt tolerance indices (STIs). All RILs and genotypes were evaluated under the control and 15 dS m−1 for two consecutive years (2019/2020 and 2020/2021). Results showed significant main effects of salinity and genotype as well as their interactions on four plant traits. Significant genotypic differences were also found for all calculated STIs. STIs exhibited moderate to strong relationships with the four plant traits when measured under either the control or salinity conditions and between each other. The principal component analysis (PCA) showed that the most variation among all analyzed variables was explained by the first two PCs, with the PC1 and PC2 explained at 61.8–71.8% and at 28.0–38.2% of the total variation, respectively. The PC1 had positive and strong correlations with the four plant traits measured under salinity conditions and STI, YI, REI, SWPI, MRPI, MPI, GMPI, and HMPI. The PC2 had strong correlations with BY and GY measured under the control conditions and SSI, TOL, RSE, and YSI. The PC1 was able to identify the salt-tolerant genotypes, while the PC2 was able to isolate the salt-sensitive ones. Cluster analysis based on multiple traits organized 64 genotypes into four groups varied from salt-tolerant to salt-sensitive genotypes, with the salt-tolerant group attaining higher value for plant traits under salinity conditions and the STIs related to the PC1. In conclusion, the use of multivariate analysis together with the STIs that evaluated the performance of genotypes under contrasting environmental conditions will help breeders to distinguish salt-tolerant genotypes from salt-sensitive ones, even at the early growth stages of plant development. [ABSTRACT FROM AUTHOR]

Elevated atmospheric CO2 concentrations (e[CO2]) have a significant impact on plant physiology, grain yield and quality and the specific response of plants to e[CO2] is closely linked to cultivars. Here, five Chinese wheat (Triticum aestivum L.) cultivars were grown under ambient CO2 (a[CO2], 400 ppm) and e[CO2] (800 ppm). CO2 enrichment significantly increased net photosynthetic rate and water use efficiency but depressed stomatal conductance. e[CO2] increased the carbon (C) concentration but decreased the nitrogen (N) concentration in all five cultivars, whereas the effect of e[CO2] on grain yield was highly dependent on cultivar. Moreover, e[CO2] caused a significant reduction in grain minerals and protein, although the magnitude of reduction was different among these cultivars. The starch concentrations in the grains and flour viscosity were not significantly affected at e[CO2]. These findings improve our understanding of the interactive effect of CO2 conditions and cultivars on plant performances and provide a research basis to select suitable wheat cultivars to deal with food crisis in future climate. [ABSTRACT FROM AUTHOR]

Straw is a by-product from cereal cultivation. Using straw surplus as a biofuel is a popular means of its management. However, before being used for fuel purposes, straw can be successfully used as a sorbent. The present study investigated the sorption properties of wheat straw (Triticum aestivum L.) modified with ammonia water and epichlorohydrin against the reactive dye Reactive Black 5 (RB5). The tested sorbents were characterized based on FTIR, elemental analysis (C/N content), and pHPZC. The scope of the research included, among others, research on the effect of pH (pH 2–11) on the RB5 sorption efficiency, research on sorption kinetics, and determination of the maximum sorption capacity of the tested sorbents. The sorption efficiency of RB5 on the tested sorbents was the highest at pH 2–3. The experimental data from the research on the sorption kinetics of RB5 were best described by a pseudo-second-order model. The introduction of primary amine groups to the structure of sorbents significantly increased their sorption capacity towards RB5. The obtained sorption capacity of the aminated straw and the aminated straw pre-activated with epichlorohydrin was 24.12 mg RB5/g and 91.04 mg RB5/g, respectively, and it was higher by 44.3% and 444.5% compared to the unmodified straw. [ABSTRACT FROM AUTHOR]

• This study proposes a model capable of identifying the phenological stages of wheat. • The camera combined with unmanned aerial vehicle are employed for biomass estimation. • The wheat biomass estimating accuracy is improved by identifying phenological stages. • The model demonstrates good adaptability under various treatments. Conventional models for estimating crop biomass are influenced by the wheat fertility process and often result in large errors, limiting the accurate crop biomass monitoring throughout the reproductive period. In this study, we developed a ResNet-Wheat model to extract phenological information from wheat and used this information to establish an aboveground biomass (AGB) estimation model. Using the spectral information obtained from unmanned aerial vehicles (UAVs), we inverted the coefficients (k, b) of the biomass estimation model to construct a new wheat biomass estimation model (FIWheat-AGB). The ResNet-Wheat model achieved overall recognition accuracy of 94.4 % at various phenological stages, proving it to be a dependable, accurate source of fertility period index (FI) for the FIWheat-AGB model. By combining the Lasso model with six vegetation indexes (VIs) with strong correlations with AGB, we could invert the biomass coefficients (k, b) with an R2 above 0.86 in all five phenological periods. The RMSE and MAE also remained stable. The FIWheat-AGB model utilized phenological information and VIs, leading to a high degree of precision in predicting AGB with an R2 range of 0.84–0.91, maintaining RMSE at 1.69–2.11 t/ha, and consistently maintaining an MAE of less than 1 t/ha over several periods. Thus, compared with the multi-period segmentation model (with an R2 range of 0.57–0.75) that is directly monitored by spectra, the suggested model is better suited for monitoring the entire wheat phenological period, and it provides a higher accuracy in estimating whole fertility biomass compared with the common spectral biomass estimation model and the crop simulation model. The proposed techniques can aid in estimating agronomic parameters in other crops throughout the fertility period. [ABSTRACT FROM AUTHOR]

Selenium (Se) biofortification by seed treatments has been poorly explored in wheat due to the difficulties in establishing seed treatments without compromising plant productive traits. We investigated the effects of Se seed soaking as a pre-sowing treatment in bread wheat. Five soaking periods and six Se concentrations were assessed on germination and seedling traits and compared to unsoaked seeds. Twelve hours of soaking was found beneficial for most tested Se concentrations. Then, we evaluated the effects of untreated, 0, 2.5 and 25 mM Se in 12 h seed soaking treatments along the wheat crop cycle under water-deficit (WD) and well-watered (WW) conditions in a pot experiment. Our results evidenced that 12 h of 2.5 mM Se soaking did not affect the germination percentage, and speed-up seedling emergence resulted in a considerable Se seed uptake. These plants also displayed enhanced antioxidant capacity and vegetative biomass accumulation, especially under WD. The treatment with 25 mM of Se negatively affected aerial biomass, suggesting potential toxicity. Physiological responses of Se-treated plants remained unchanged, as well as grain traits. Altogether, we propose that 12 h soaking with 2.5 mM Se is a promissory pre-sowing approach to enrich bread wheat grain and straw, particularly under water-limited environments. [ABSTRACT FROM AUTHOR]

The rapid and nondestructive determination of wheat aboveground biomass (AGB) is important for accurate and efficient agricultural management. In this study, we established a novel hybrid model, known as extreme gradient boosting (XGBoost) optimization using the grasshopper optimization algorithm (GOA-XGB), which could accurately determine an ideal combination of vegetation indices (VIs) for simulating wheat AGB. Five multispectral bands of the unmanned aerial vehicle platform and 56 types of VIs obtained based on the five bands were used to drive the new model. The GOA-XGB model was compared with many state-of-the-art models, for example, multiple linear regression (MLR), multilayer perceptron (MLP), gradient boosting decision tree (GBDT), Gaussian process regression (GPR), random forest (RF), support vector machine (SVM), XGBoost, SVM optimization by particle swarm optimization (PSO), SVM optimization by the whale optimization algorithm (WOA), SVM optimization by the GOA (GOA-SVM), XGBoost optimization by PSO, XGBoost optimization by the WOA. The results demonstrated that MLR and GOA-MLR models had poor prediction accuracy for AGB, and the accuracy did not significantly improve when input factors were more than three. Among single-factor-driven machine learning (ML) models, the GPR model had the highest accuracy, followed by the XGBoost model. When the input combinations of multispectral bands and VIs were used, the GOA-XGB model (having 37 input factors) had the highest accuracy, with RMSE = 0.232 kg m−2, R2 = 0.847, MAE = 0.178 kg m−2, and NRMSE = 0.127. When the XGBoost feature selection was used to reduce the input factors to 16, the model accuracy improved further to RMSE = 0.226 kg m−2, R2 = 0.855, MAE = 0.172 kg m−2, and NRMSE = 0.123. Based on the developed model, the average AGB of the plot was 1.49 ± 0.34 kg. [ABSTRACT FROM AUTHOR]

Context. Although waterlogging is known to decrease grain yield in wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.), its effect on plant N traits is still unknow. Aims. This study evaluated biomass N dynamics and partitioning to grains, in wheat and barley plants subjected to waterlogging. Methods. Under contrasting environmental conditions, two pot experiments exposing wheat and barley plants to waterlogging events for 15–20 days at five different developmental stages, from emergence to maturity were performed. Grain N concentration, grain N content, biomass N concentration, N utilisation efficiency (NUE) and N remobilisation were recorded. Key results. Both species responded similarly to waterlogging for most N traits. Reductions in grain N content differed according to the moment waterlogging occurred. The greatest reductions (46–77% compared to the control) being for waterlogging from the beginning of stem elongation to anthesis, which also showed the highest reductions in N remobilisation, N uptake at maturity, and N partitioning to the grains, but only a slight decrease in NUE. Grain N concentration raised drastically (up to 45 mg N g DW−1 ) with minimal grain yields. N concentration of aboveground biomass decreased during waterlogging, recovering control values at maturity. N content at maturity was related to the total biomass. Conclusions. Waterlogging differentially reduced N uptake and remobilisation to grains of wheat and barley depending on the developmental stage when water excess occurred. Implications. The impact of waterlogging on N economy of wheat and barley appears indirect and predominantly related to carrying effects of the stress on carbon economy due to growth reductions. [ABSTRACT FROM AUTHOR]

Genetic diversity is invaluable in developing climate-smart and drought-adapted wheat varieties. The aim of this study was to determine the extent of genetic variation present in wheat germplasm collections for biomass allocation and drought tolerance based on complementary phenotypic and root attributes and high-density single nucleotide polymorphism (SNP) markers to select breeding parents. A total of 97 bread wheat (Triticum aestivum L.) genotypes were evaluated in field and greenhouse trials under drought-stressed and non-stressed conditions. The molecular variance analysis showed that the intrapopulation variance was very high at 99%, with a small minimal inter-population variance (1%). The genetic distance, polymorphic information content and expected heterozygosity were 0.20–0.88, 0.24–1.00 and 0.29–0.58, respectively. The cluster analysis based on SNP data showed that 44% and 28% of the assessed genotypes maintained their genetic groups when compared to hierarchical clusters under drought-stressed and non-stressed phenotypic data, respectively. The joint analysis using genotypic and phenotypic data resolved three heterotic groups and allowed the selection of genotypes BW140, BW152, BW157, BW162, LM30, LM47, LM48, LM52, LM54 and LM70. The selected genotypes were the most genetically divergent with high root biomass and grain yield and are recommended for production or breeding. [ABSTRACT FROM AUTHOR]

There are a substantial number of studies on the biofertilization effects of cyanobacteria in rice paddy fields, mainly attributed to biological fixation of N2, but not much attention has been given to their fertilizing capacity in aerobic soils. Few studies have used solid media (i.e. a soil) when testing the plant-growth-promoting effects of microalgae on plants, and particularly on wheat. The purpose of this study was to test the biofertilizing effect of a filamentous cyanobacterium, previously isolated from an agricultural soil, in order to evaluate the potential substitution of chemical fertilizers and to test its phyto-stimulating capacity. Seedlings of Triticum aestivum were grown in pots with a peat-vermiculite mixture (1:1 weight basis) in an experiment designed as a complete randomized block, consisting of four treatments and with four replicates each: a pure culture of Anabaena cylindrica concentrated by centrifugation to 2 g dry matter L−1 (treatment B); spent cyanobacteria growth medium filtered at 0.22 µm (treatment F); harvested cyanobacterial mat re-suspended in distilled water (treatment WB); and distilled water as a control (treatment W). Aboveground wheat plant mass was improved by 40% in both treatments with cyanobacterial biomass (B and WB), as compared to the control (W) and filtrate (F), demonstrating that the co-cultivation with living cyanobacterial biomass was key to plant improvement. Chlorophyll contents were also increased by nearly 50% and nitrogen by over 10% in the treatment WB, clearly indicating that nutrients in the filtrate were irrelevant to the beneficial effects on plant growth. [ABSTRACT FROM AUTHOR]

Spring wheat is currently dominating wheat production in Norway. The introduction of combine harvesting in the 1950s spurred breeding efforts to improve lodging and preharvest sprouting resistance, and to integrate good breadmaking quality in the locally adapted germplasm. Release of landmark cultivars Runar and Reno in the 1970s revitalized the country's production and marked the onset of modern wheat cultivation in Norway. Since that time, new cultivars have been developed but little is known about the genetic basis of the achieved yield gains. We collected 21 representative cultivars released since 1972 in Norway and tested them in a multiyear field trial including two fertilization rates: 75 and 150 kg ha–1 N. We assessed grain yield, plant height, heading, maturity, length of grain filling period, grain protein content, protein yield, aboveground biomass, harvest index, grain weight, test weight, grains per spike, grains per square meter, and spikes per square meter and their response to fertilization. We document an annual increase in grain yield of 17.8 kg ha–1 (0.34%), at both rates of N fertilization. None of the traits exhibited significant genotype × management interaction. Wheat breeding has led to the development of higher‐yielding cultivars with higher protein yield that mature later, have a prolonged grain‐filling period, and produce more grains per spike and grains per unit area. Core Ideas: Grain yield in the 1972–2019 period increased by 17.8 kg ha−1 (0.34%) per year due to improved cultivars.Grain yield gains do not rely on intensive N fertilization.Cultivars do not exhibit significant genotype × management interactions for any of the measured traits.Breeding in Norway since 1972 caused the cultivars to have a 2‐d longer grain‐filling period and reach physiological maturity 3 d later.New cultivars in Norway produce more grains per spike and grains per unit area. [ABSTRACT FROM AUTHOR]

Simple Summary: Nitrogen is one of the most important elements for plant growth and development. However, irrational fertilization causes many environmental problems: high rates of nitrogen fertilizers change the soil pH, encourage nitrate and nitrite accumulation in plants and the soil, leached nitrogen compounds cause water eutrophication and drinking water contamination, and gaseous losses of nitrogen contribute to global warming. The biological nitrogen fixation (BNF) process, in which atmospheric nitrogen is converted to ammonia by microorganisms, has a significant role in the global nitrogen cycle and agriculture. Nitrogen-fixing-bacteria inoculants could help to reduce the losses of consistently rising prices of mineral fertilizers and help to implement green revolution strategies. In this research, we found the bacteria strain Paenibacillus sp. MVY-024 that has a positive impact on nitrogen accumulation in spring wheat and was easily applied on an industrial scale. In this study, thirteen isolates, which were possibly expected to fix nitrogen, were isolated from soil and pea root nodules and identified by the gene analysis of 16S rDNA sequences. Two of these isolates that were able to form endospores and grow on nitrogen-free media were selected for spring wheat development research. The isolate Paenibacillus sp. S7 identified as Paenibacillus polymyxa was found to significantly increase the amount of ammonium and mineral N amounts in the soil. Furthermore, increased nitrogen accumulation in grains and a chlorophyll index were obtained after wheat treatment. Paenibacillus sp. S7 isolate was selected for further studies and the accession number MT900581 and strain name MVY-024 in NCBI nucleotide bank for this isolate were assigned. During the cultivation of Paenibacillus sp. MVY-024, sugarcane molasses and a yeast extract were determined as the most suitable carbon and nitrogen sources, whose optimal concentrations were 100 g L−1 and 10 g L−1, respectively. The optimal pH range for the cell culture was between 6.5 and 7.0, and the optimal air flow rate was 0.4 vvm. It was found that the air flow has an effect on biomass production and endospore formation. After Paenibacillus sp. MVY-024 biomass cultivation optimization, the cultured cell number was, on average, 2.2 × 109 cfu m L−1. [ABSTRACT FROM AUTHOR]

Six cycles of recurrent selection for early shoot vigour in wheat resulted in significant increases in leaf width and shoot biomass. Here, in replicated controlled-environment studies, the effect of early shoot vigour on root biomass, rhizosheath size, root hair length, and cell size in the roots and leaves was examined across different cycles of selection. Increased shoot vigour was associated with greater root biomass, larger rhizosheath size, and longer root hairs. Our findings demonstrate that rhizosheath size was a reliable surrogate for root hair length in this germplasm. Examination of the root epidermis revealed that the 'cell body' of the trichoblasts (hair-forming cells) and the atrichoblasts (non-hair-forming cells) decreased in size as shoot vigour increased. Therefore, in higher vigour germplasm, longer root hairs emerged from smaller trichoblasts so that total trichoblast volume (root hair plus cell body) was generally similar regardless of shoot vigour. Similarly, the sizes of the four main cell types on the leaf epidermis became progressively smaller as shoot vigour increased, which also increased stomatal density. The relationship between shoot vigour and root traits is considered, and the potential contribution of below-ground root traits to performance and competitiveness of high vigour germplasm is discussed. [ABSTRACT FROM AUTHOR]

The growth of leaves is subject to strict time regulation. Several genes influencing leaf growth have been identified, but little is known about how genes regulate the orderly initiation and growth of leaves. Here, we demonstrate that TaKLU/TaCYP78A5 contributes to a time regulation mechanism in leaves from initiation to expansion. TaKLU encodes the cytochrome P450 CYP78A5, and its homolog AtKLU has been described whose deletion is detrimental to organ growth. Our results show that TaKLU overexpression increases leaf size and biomass by altering the time of leaf initiation and expansion. TaKLU-overexpressing plants have larger leaves with more cells. Further dynamic observations indicate that enlarged wheat leaves have experienced a longer expansion time. Different from AtKLU inactivation increases leaf number and initiation rates, TaKLU overexpression only smooths the fluctuations of leaf initiation rates by adjusting the initiation time of local leaves, without affecting the overall leaf number and initiation rates. In addition, complementary analyses suggest TaKLU is functionally conserved with AtKLU in controlling the leaf initiation and size and may involve auxin accumulation. Our results provide a new insight into the time regulation mechanisms of leaf growth in wheat. [ABSTRACT FROM AUTHOR]

The large-scale industrial use of polysaccharides to obtain energy is one of the most discussed subjects in science. However, modern concepts of biorefinery have promoted the diversification of the use of these polymers in several bioproducts incorporating concepts of sustainability and the circular economy. This work summarizes the major sources of agro-industrial residues, physico-chemical properties, and recent application trends of cellulose, chitin, hyaluronic acid, inulin, and pectin. These macromolecules were selected due to their industrial importance and valuable functional and biological applications that have aroused market interests, such as for the production of medicines, cosmetics, and sustainable packaging. Estimations of global industrial residue production based on major crop data from the United States Department of Agriculture were performed for cellulose content from maize, rice, and wheat, showing that these residues may contain up to 18%, 44%, and 35% of cellulose and 45%, 22%, and 22% of hemicellulose, respectively. The United States (~32%), China (~20%), and the European Union (~18%) are the main countries producing cellulose and hemicellulose-rich residues from maize, rice, and wheat crops, respectively. Pectin and inulin are commonly obtained from fruit (~30%) and vegetable (~28%) residues, while chitin and hyaluronic acid are primarily found in animal waste, e.g., seafood (~3%) and poultry (~4%). [ABSTRACT FROM AUTHOR]

Increasing temperature is a key component of global climate change, affecting crop growth and productivity worldwide. Wheat is a major cereal crop grown in various parts of the globe, which is affected severely by heat stress. The morphological parameters affected include germination, seedling establishment, source-sink activity, leaf area, shoot and root growth. The physiological parameters such as photosynthesis, respiration, leaf senescence, water and nutrient relation are also affected by heat. At the cellular level, heat stress leads to the generation of reactive oxygen species that disrupt the membrane system of thylakoid, chloroplast and plasma membrane. The deactivation of the photosystem, reduction in photosynthesis and inactivation of rubisco affect the production of photoassimilates and their allocation. This ultimately affects anthesis, grain filling, size, number and maturity of wheat grains, which hamper crop productivity. The interplay of various systems comprising antioxidants and hormones plays a crucial role in imparting heat stress tolerance in wheat. Thus, implementation of various omics technologies could foster in-depth insights on heat stress effects, eventually devising heat stress mitigation strategies by conventional and modern breeding to develop heat-tolerant wheat varieties. This review provides an integrative view of heat stress responses in wheat and also discusses approaches to develop heat-tolerant wheat varieties. [ABSTRACT FROM AUTHOR]

In order to realize the rapid and non-destructive monitoring of wheat biomass, field wheat trials were conducted based on different densities, nitrogen fertilizers and varieties, and unmanned aerial vehicle (UAV) was used to obtain RGB images in the pre-wintering stage, jointing stage, booting stage and flowering stage of wheat. The color and texture feature indices of wheat were obtained using image processing, and wheat biomass was obtained by manual field sampling in the same period. Then the relationship between different color and texture feature indices and wheat biomass was analyzed to select the suitable feature index for wheat biomass estimation. The results showed that there was a high correlation between image color index and wheat biomass in different stages, the values of r were between 0.463 and 0.911 (P<0.05). However, the correlation between image texture feature index and wheat biomass was poor, only 5 index values reached significant or extremely significant correlation level. Based on the above results, the color indices with the highest correlation to wheat biomass or the combining indices of color and texture features in different growth stages were used to construct estimation model of wheat biomass. The models were validated using independently measured biomass data, and the correlation between simulated and measured values reached the extremely significant level (P<0.01), and root mean square error (RMSE) was smaller. The R2 of color index model in the four stages were 0.538, 0.631, 0.708 and 0.464, and RMSE were 27.88, 516.99, 868.26 and 1539.81 kg/ha, respectively. The R2 of the model combined with color and texture index were 0.571, 0.658, 0.753 and 0.515, and RMSE were 25.49, 443.20, 816.25 and 1396.97 kg/ha, respectively. This indicated that the estimated results using the models were reliable and accurate. It also showed that the estimation models of wheat biomass combined with color and texture feature indices of UAV images were better than the single color index models. [ABSTRACT FROM AUTHOR]

Agricultural technologies aimed at increasing yields require the development of highly productive and stress-tolerant cultivars. Phenotyping can significantly accelerate breeding; however, no reliable markers have been identified to select the most promising cultivars at an early stage. In this work, we determined the light-induced dynamic of chlorophyll fluorescence (ChlF) parameters in young seedlings of 10 wheat (Triticum aestivum L.) cultivars and evaluated potency of these parameters as predictors of biomass accumulation and stress tolerance. Dry matter accumulation positively correlated with the effective quantum efficiency of photosystem II (Φ PSIIef) and negatively correlated with the half-time of Φ PSIIef reaching (t 1/2(Φ PSIIef)). There was a highly significant correlation between t 1/2(Φ PSIIef) and dry matter accumulation with increasing prediction period. Short-term heating and drought caused an inhibition of biomass accumulation and photosynthetic activity depending on the stressor intensity. The positive correlation between the Φ PSII dark level (Φ PSIId) in young seedlings and tolerance to a rapidly increasing short-term stressor (heating) was shown. In the case of a long-term stressor (drought), we revealed a strong negative relationship between tolerance and the level of non-photochemical fluorescence quenching (NPQ). In general, the results show the potency of the ChlF parameters of young seedlings as predictors of biomass accumulation and stress tolerance. Phenotyping can significantly accelerate breeding of new plant cultivars. However, no reliable markers have been identified to date for the selection of the most promising cultivars at an early stage. The results of the present study show the possibility of using the chlorophyll fluorescence parameters of young seedlings as predictors of plant biomass accumulation and tolerance to drought and short-term heat stress. We believe that the time needed for new cultivar creation can be significantly shortened using these parameters. [ABSTRACT FROM AUTHOR]

Warming nights are correlated with declining wheat growth and yield. As a key determinant of plant biomass, respiration consumes O2 as it produces ATP and releases CO2 and is typically reduced under warming to maintain metabolic efficiency. We compared the response of respiratory O2 and CO2 flux to multiple night and day warming treatments in wheat leaves and roots, using one commercial (Mace) and one breeding cultivar grown in controlled environments. We also examined the effect of night warming and a day heatwave on the capacity of the ATP-uncoupled alternative oxidase (AOX) pathway. Under warm nights, plant biomass fell, respiratory CO2 release measured at a common temperature was unchanged (indicating higher rates of CO2 release at prevailing growth temperature), respiratory O2 consumption at a common temperature declined, and AOX pathway capacity increased. The uncoupling of CO2 and O2 exchange and enhanced AOX pathway capacity suggest a reduction in plant energy demand under warm nights (lower O2 consumption), alongside higher rates of CO2 release under prevailing growth temperature (due to a lack of down-regulation of respiratory CO2 release). Less efficient ATP synthesis, teamed with sustained CO2 flux, could thus be driving observed biomass declines under warm nights. [ABSTRACT FROM AUTHOR]

Combining ability effects for yield related traits can serve as selection criteria to pursue breeding for optimal biomass allocation in wheat (Triticum aestivum). The objective of this paper is to provide information based on a retrospective quantitative genetic analysis on combining ability studies of wheat for yield and yield‐related traits to predict potential genetic gains achievable in improving biomass allocation for drought tolerance and soil carbon storage. The study compares data on the general combining ability and specific combining ability effects of wheat for yield and related traits under optimum and drought stressed conditions from 40 studies around the world. Days to heading (DTH), plant height (PH), number of tillers per plant (TN), kernels per spike (KPS), 1,000‐kernel weight (TKW), shoot biomass (SB), and grain yield (GY) exhibited wide variation for general combining ability (GCA) and specific combining ability effects. Progeny performance increased by 14.30 and 4.04% for SB and GY, respectively, compared with parental values under optimum water conditions. Number of tillers and SB exhibited positive associations with GY (.45 ≤ r ≤.85, p <.05) under both water conditions. Meta effect sizes for drought stress were negative. The highest meta‐effect sizes were calculated for DTH (−4.5) followed by SB (−2.0), whereas KPS (−1.25) had the lowest. The genetic gains for PH, SB, and other yield components showed that divergent crosses involving complementary parents could enhance biomass allocation patterns in wheat. This could be used as a basis for improving biomass allocation to roots. Core Ideas: There is sufficient genetic variation in wheat genotypes for manipulating biomass allocation.The number of kernels per spike is stable under varying moisture conditions.Shoot biomass and grain yield expression are severely confounded by drought.Aboveground traits are important for indirect selection of root traits. [ABSTRACT FROM AUTHOR]