Early Grain Research Articles

Genome-wide association study identified QTLs and genes underlying early seedling vigour in aus rice (Oryza sativa L.).

Early seedling vigour (ESV) is a key trait that enhances early establishment, stress tolerance, and grain yield in rice, especially in direct-seeded rice (DSR) systems. The aus varietal groups is known for its high seedling vigour. The screening of aus diversity panel for ESV traits and subsequent genome-wide association study (GWAS) can lead to the identification of genetic components of ESV. Here, we report the genetic variation in seven ESV traits along with days to 50% flowering and grain yield in a panel of 181 aus accessions evaluated under field conditions. We observed significant variations in the studied traits. The vegetative vigour, scored visually, was significantly correlated with most of the traits, suggesting its impact on overall plant performance. Comparative analysis of aus genetic groups revealed significant variations, and the subpopulation that includes early maturing drought tolerant genotypes was the most vigorous, and thus ideal for donor selection. GWAS using 918, 863 single nucleotide polymorphism (SNP) markers identified 14 significant QTLs, including seven novel ones, linked to vegetative vigour, average growth rate and seedling biomass. Candidate genes like OsPDR1, NCKAP1, and OsSAUR10, involved in jasmonic acid biosynthesis, ABA signaling, and brassinosteroid pathways, were identified to be associated with ESV regulation. This study provides insights into the genetic basis of ESV in aus rice, identifying promising germplasm and genes that could improve seedling vigour and yield in DSR systems. Future research should validate these findings and integrate them into breeding programs for enhanced rice performance in various environments.

The Comprehensive Effects of Biochar Amendments on Soil Organic Carbon Accumulation, Soil Acidification Amelioration and Heavy Metal Availability in the Soil–Rice System

In recent years, biochar (BC) and biochar-based soil amendments (CSAs) have been widely used in agriculture and the environment. In the present study, a two-rice-season field study was conducted to explore the comprehensive effects of applying BC (1%) and CSA (0.5% and 1%) on soil organic carbon accumulation, soil acidification amelioration and heavy metal availability in a soil–rice system. The results show that soil pH was increased by 0.5–1.7 units and 0.3–1.0 units, respectively, in the early rice season and late rice season treated by the amendments compared with CK. Soil organic contents were increased by 18–30% in the early rice season and by 15–25% in the late rice season in the amended treatments. In addition, soil available phosphorus contents were largely increased as a result of BC and CSA addition. Soil CaCl2 extractable heavy metals (Cd, Ni, Cu and Zn) were simultaneously decreased by BC or CSA amendments. In addition, Cd contents in early rice grain and late rice grain were significantly reduced by 25–48% and 52–83% in amended treatments, while Zn contents were generally not affected. The uptake of Cu and Ni was also decreased by BC and CSA. This study demonstrates that biochar application alone or combinates with inorganic amendments (limestone, sepiolite and potassium dihydrogen phosphate) can significantly improve soil properties and nutrient content and decrease the heavy metal (especially for Cd and Ni) uptake and accumulation from soil to rice grain, where the combination application is more effective.

Early estimation of glutelin to gliadin ratio in wheat grain using high-dimensional and hyperspectral reflectance

Precise and timely estimation of the glutelin-to-gliadin ratio (Glu/Gli) in wheat grain is pivotal for crop monitoring, as it is a crucial quality indicator ensuring the production of high-quality wheat flour. Despite the recognized potential of hyperspectral technology in crop phenotype estimation, its application to estimate Glu/Gli in wheat grains faces challenges due to complex spectral-chemical relationships and the influence of growing seasons. This study addresses this gap by cultivating 11 wheat varieties and collecting high-dimensional hyperspectral data from field experiments during various growth stages of wheat (2018–2019 and 2019–2020). Utilizing vegetation indices (VIs) in conjunction with linear mixed-effects model (LMM) and random forest regression model (RFR), it constructs a robust Glu/Gli estimation model (with a Glu/Gli range of 1.063 to 2.218). Results reveal that a singular VI application suffers from data limitations, while the integration of multiple VIs significantly enhances estimation accuracy. The mid-grain filling period emerges as a critical stage for accurate Glu/Gli estimation, with TCARI (transformed chlorophyll absorption reflectance index) demonstrating notable significance and high correlation. In model performance, RFR (R2 = 0.691, rRMSE = 0.096, RPD = 1.872, RER = 6.028) outperforms LMM (R2 = 0.477, rRMSE = 0.131, RPD = 1.383, RER = 4.453), exhibiting superior accuracy in estimating grain Glu/Gli for diverse wheat varieties. This study introduces a rapid and accurate approach for early wheat grain Glu/Gli estimation, offering valuable insights for wheat value chain and precision farming.

Micro-facies characterization of the Cane Creek Shale, Paradox Basin, Utah: implications of diagenetic controls on reservoir quality

The fine-grained Pennsylvanian Cane Creek Shale of the Paradox Formation, Paradox Basin, Utah exhibits relatively thin cyclic interbeds of contrasting lithologies including fine sandstone to siltstone, organic-rich carbonate and dolomitic mudstone, and evaporites. As such, it provides a unique opportunity to evaluate micro-facies and the fluid storage capacity potential of mixed fine-grained systems. Micro-facies descriptions were performed using core and petrographic analyses, including scanning electron microscopy with energy dispersive spectroscopy. The study leverages core-based porosity and permeability data, as well as previous core description. These data are used together to explore mineralogical depositional and diagenetic controls on porosity and permeability. Twelve micro-facies were described based on sedimentological textures, grain size, lithology, and mineralogy categorized into three groups: 1) sandstone to siltstone, 2) mudstone, and 3) evaporitic micro-facies. Sandstone to siltstone micro-facies exhibit variable porosity and permeability. Porosity connectivity is dependent on the degree of authigenic cementation and compaction that negatively impacts porosity. Mudstone micro-facies show less variability in porosity and permeability; and are characterized by carbonate content, organic-matter, and clay nanopores. The development of early carbonate grains maintains porosity in mudstone and dolomitic siltstone micro-facies. Evaporitic micro-facies represented by evaporitic sabkha-like conditions are characterized by pore-reducing anhydrite and halite cement. A diagenetic paragenetic sequence was developed to assess the timing and impact of mineralogy on reservoir quality. Early (eogenetic), Middle (mesogenetic), and Late (telogenetic) stages correspond with diagenetic stages and known tectonic basin events. Syndepositional dolomite and diagenetic illite/smectite authigenic cements are the main controls on reservoir quality and have opposing effects related to porosity and permeability by preserving early pore space or reducing porosity and permeability.

Evaporative characteristics of winter wheat in the guanzhong loess plateau region of shaanxi, china

This study explain the evaporative characteristics of winter wheat in the Guanzhong Loess Plateau region of Shaanxi through stem flow meters and weighing lysimeters. It examines the diurnal variations in evapotranspiration rates, leaf area index, and soil moisture's impact on winter wheat evaporation. Additionally, it explores the ratio of transpiration to evaporation and compares the evaporation measured by the water balance method with that of the lysimeters. The findings reveal distinct diurnal variations in transpiration rates under different weather conditions, with sunny days exhibiting an unimodal curve while cloudy and rainy days showcase irregular multi-peaked curves. The evaporation curve generally follows an unimodal pattern, with both leaf area index and soil moisture significantly influencing the evaporation process. From heading to early grain filling, the ratio of transpiration to evaporation ranges from 80.3 to 83.4%. Evaporation obtained through the water balance method (0-220 cm) is 6% less than that measured by the lysimeters. Bangladesh J. Bot. 53(3): 689-695, 2024 (September) Special

Nitrogen Supply Mitigates Heat Stress on Photosynthesis of Maize (Zea mays L.) During Early Grain Filling by Improving Nitrogen Assimilation

ABSTRACTHigh temperature during early grain‐filling stage is one of the serious abiotic stresses limiting maize yield in the North China Plain. Nitrogen (N) fertiliser has an important role in promoting crop growth, especially under abiotic stresses. However, its contribution to alleviating heat stress (HS) inhibition on maize photosynthesis during early grain‐filling stage is still unclear. Experiments with three N rates (LN, low nitrogen; MN, medium nitrogen; HN, high nitrogen) and two temperature (HS, heat stress; CK, ambient temperature as control) regimes were conducted to examine the effects of increasing N supply on photosynthesis, N assimilation, antioxidant system, and hormones homeostasis of maize during early grain‐filling stage using two maize hybrids Xianyu335 (XY335, heat‐sensitive) and Zhengdan (ZD958, heat‐tolerant). HS negatively affected photosynthesis of both two hybrids, exhibited lower net photosynthetic rate, chlorophyll content and activities of Rubisco and phosphoenolpyruvate carboxylase (PEPC) compared with CK, and then decreased dry matter accumulation of maize, with a lesser extent for ZD958 than XY335. However, increasing N supply alleviated the adverse effects of HS on maize photosynthesis due to improved N assimilation capacity. Under HS condition, greater N content and higher activities of glutamine synthetase and glutamate synthase in maize ear leaf were found in treatment of HN compared with LN and MN. HN with higher N assimilation capacity directly increased the net photosynthetic rate due to improved chlorophyll content, activities of Rubisco and PEPC and antioxidant capacity. HS‐induced abscisic acid (ABA) accumulation was also repressed by HN, and then enhanced the stomatal conductance and transpiration rate to maintain higher photosynthetic capacity compared with LN and MN. Moreover, the positive effects of increasing N supply on maize photosynthesis under HS condition exhibited a larger extent for XY335 than ZD958. As a result of improved photosynthesis and N assimilation capacity by adequate N supply, maize accumulated more biomass under HS, especially for heat‐sensitive hybrid.

Maize Responses to High Night Temperature During Postflowering and Early Grain Filling: Effects on Yield Components, Kernel Growth and Dry Matter Allocation

ABSTRACTWarm night frequency has increased steadily in the last years across maize production regions, but high night temperature (HNT) effects on growth, grain yield and maize dry matter allocation (DMA) to different plant organs remain poorly understood. In this study, we aimed to (i) analyse the DMA among reproductive and vegetative organs, (ii) evaluate the individual kernel weight through its determinants, rate and duration of grain filling and (iii) quantify changes in grain yield per plant and its components due to HNT during the postflowering and early grain‐filling period. Field‐grown maize was subjected to HNT induced by shelters during a 15‐ or 30‐day period after silking, encompassing the postflowering period (HNT15) and extending the heating into early grain filling (HNT30), respectively. The HNT was applied from 1900 to 0700 h while control plots remained at ambient night temperature (ANT). Kernel number per plant was decreased under both temperature regimes (i.e., HNT15 and HNT30); however, significant reductions in grain yield were only observed under HNT30. The DMA during the heating period was differentially affected by the duration of heating. While DMA to the stem was likewise reduced by both heating treatments, the partition to the uppermost ear was only reduced under HNT30. Related to the lack of response to HNT treatments of the rate and duration of grain filling, the individual kernel weight was not reduced. The source‐sink ratio was not affected by HNT, meanwhile, the apparent reserve use was significantly reduced under HNT30. Our results demonstrate that the magnitude of HNT effects is subjected to the duration of the heating period, but also depends on the intensity of heating explored across seasons, especially for kernel number and grain yield.

Response of rice yield, grain quality to chilling at grain filling stages.

This study aims to quantify the impacts of chilling at the grain filling stage on rice yield and grain quality. A factorial experiment with four levels of temperature and duration of chilling treatments at the early and late grain filling stages was conducted in 2017, 2018 and 2019. Per 10 °C·day increase in the accumulated cooling degree day at the early and late grain filling stages, the rice emergence-maturity duration was delayed by 0.8% (0.6%) and rice yield decreased by 2.2% (1.7%). Chilling at the early grain filling stage decreased the rice heading rate, while chilling at the late grain filling stage increased rice amylose but decreased protein content. For chilling treatment at the early grain filling stage, rice yield and grain quality were mainly correlated with seed-setting rate, whereas for chilling treatment at the late grain filling stage the rice yield and grain quality were mainly correlated with 1000-grain weight. This study improved the understanding of how chilling at the grain filling stages affects rice phenology, yield and grain quality, providing a theoretical basis for maintaining rice yield while ensuring grain quality. The results could be used to guide the rice-growing community in combating chilling at grain filling stages. © 2024 Society of Chemical Industry.

A Comprehensive Analysis of Drought Stress Responses in Rice (Oryza sativa L.): Insights into Developmental Stage Variations from Germination to Grain Filling

Rice (Oryza sativa L.) is a critical staple food crop vulnerable to drought stress at key growth stages, namely the early seedling stage, vegetative phase, anthesis (reproductive stage), and grain ripening stage. The impact of drought stress on rice extends beyond mere water deficit, influencing a spectrum of morphological, physiological, biochemical, and molecular responses crucial for plant survival and productivity. This review synthesizes current understanding of rice responses to drought stress across its developmental stages, encompassing seed germination, seedling establishment, vegetative growth, reproductive development, and grain filling. Drought stress triggers multifaceted adaptations in rice, involving mechanisms such as escape, avoidance, tolerance, and recovery strategies to mitigate water scarcity effects. These responses are finely tuned across developmental stages, influencing traits like root architecture, stomatal conductance, photosynthetic efficiency, osmotic adjustment, and hormonal regulation. Understanding these responses is pivotal for enhancing rice resilience to drought, thereby safeguarding global food security and supporting the livelihoods of rice-dependent communities worldwide, particularly in regions like India where rice cultivation plays a crucial socioeconomic role. Challenges persist in deciphering the complex genetic and physiological networks underpinning drought responses in rice. Integrating omics approaches and advanced phenotyping techniques holds promise in unraveling these complexities and identifying genetic markers for drought tolerance. Furthermore, strategies such as breeding resilient cultivars and implementing agronomic practices tailored to specific growth stages are imperative for sustainable rice production under increasingly erratic climatic conditions. This review consolidates existing knowledge while highlighting gaps in current understanding, aiming to guide future research endeavors toward innovative solutions for enhancing rice drought resilience. By elucidating the intricate mechanisms governing rice responses to drought stress, this study contributes to the broader discourse on agricultural sustainability and climate change resilience in staple food crops.

Tissue- and time-dependent metabolite profiles during early grain development under normal and high night-time temperature conditions

BackgroundWheat grain development in the first few days after pollination determines the number of endosperm cells that influence grain yield potential and is susceptible to various environmental conditions, including high night temperatures (HNTs). Flag leaves and seed-associated bracts (glumes, awn, palea, and lemma) provide nutrients to the developing seed. However, the specific metabolic roles of these tissues are uncertain, especially their dynamics at different developmental stages and the time in a day. Tissue- and time-dependent metabolite profiling may hint at the metabolic roles of tissues and the mechanisms of how HNTs affect daytime metabolic status in early grain development.ResultsThe metabolite profiles of flag leaf, bract, seed (embryo and endosperm), and entire spike were analyzed at 12:00 (day) and 23:00 (night) on 2, 4, and 6 days after fertilization under control and HNT conditions. The metabolite levels in flag leaves and bracts showed day/night oscillations, while their behaviors were distinct between the tissues. Some metabolites, such as sucrose, cellobiose, and succinic acid, showed contrasting oscillations in the two photosynthetic tissues. In contrast, seed metabolite levels differed due to the days after fertilization rather than the time in a day. The seed metabolite profile altered earlier in the HNT than in the control condition, likely associated with accelerated grain development caused by HNT. HNT also disrupted the day/night oscillation of sugar accumulation in flag leaves and bracts.ConclusionsThese results highlight distinct metabolic roles of flag leaves and bracts during wheat early seed development. The seed metabolite levels are related to the developmental stages. The early metabolic events in the seeds and the disruption of the day/night metabolic cycle in photosynthetic tissues may partly explain the adverse effects of HNT on grain yield.

Effects of Foliar Spraying of Dicarboxylicdimethylammonium Chloride on Cadmium and Arsenic Accumulation in Rice Grains.

A field experiment with double cropping rice was carried out to study the foliar application effects of dicarboxylicdimethylammonium chloride (DDAC) on cadmium (Cd) and arsenic (As) accumulation in rice grains. The results showed that the spraying of DDAC could significantly reduce the accumulation of Cd and As in rice grains. The highest reductions in Cd and As content were observed when 1.5 mmol L-1 DDAC was sprayed, with 49.1% and 27.4% reductions in Cd and As content in early rice grains and 56.5% and 28.1% reductions in Cd and As content in late rice grains, respectively. In addition, the content of calcium (Ca) in rice grains increased significantly after DDAC foliar application, which was also conducive to the synthesis of amino acids such as glutamate (Glu), glycine (Gly) and cysteine (Cys) in rice grains. The results indicated that the foliar spraying of DDAC can inhibit the absorption, transport, accumulation and toxicity of Cd and As in rice grains by increasing amino acid synthesis and regulating the absorption and transport of essential elements.

Thermal imaging can reveal variation in stay-green functionality of wheat canopies under temperate conditions.

Canopy temperature (CT) is often interpreted as representing leaf activity traits such as photosynthetic rates, gas exchange rates, or stomatal conductance. This interpretation is based on the observation that leaf activity traits correlate with transpiration which affects leaf temperature. Accordingly, CT measurements may provide a basis for high throughput assessments of the productivity of wheat canopies during early grain filling, which would allow distinguishing functional from dysfunctional stay-green. However, whereas the usefulness of CT as a fast surrogate measure of sustained vigor under soil drying is well established, its potential to quantify leaf activity traits under high-yielding conditions is less clear. To better understand sensitivity limits of CT measurements under high yielding conditions, we generated within-genotype variability in stay-green functionality by means of differential short-term pre-anthesis canopy shading that modified the sink:source balance. We quantified the effects of these modifications on stay-green properties through a combination of gold standard physiological measurements of leaf activity and newly developed methods for organ-level senescence monitoring based on timeseries of high-resolution imagery and deep-learning-based semantic image segmentation. In parallel, we monitored CT by means of a pole-mounted thermal camera that delivered continuous, ultra-high temporal resolution CT data. Our results show that differences in stay-green functionality translate into measurable differences in CT in the absence of major confounding factors. Differences amounted to approximately 0.8°C and 1.5°C for a very high-yielding source-limited genotype, and a medium-yielding sink-limited genotype, respectively. The gradual nature of the effects of shading on CT during the stay-green phase underscore the importance of a high measurement frequency and a time-integrated analysis of CT, whilst modest effect sizes confirm the importance of restricting screenings to a limited range of morphological and phenological diversity.

The effect of texture on the very high cycle fatigue performance and deformation mechanism of rolled AZ31B magnesium alloys

AbstractRolling can result in anisotropy in the microstructure and mechanical properties of the sheet material. This study focuses on the very high cycle fatigue (VHCF) performance of magnesium alloys in the rolling direction (RD), normal direction (ND), and the bisecting angle between the ND and RD (ND–RD). The findings reveal that RD specimens demonstrate superior fatigue performance, while the ND specimens exhibit the lowest fatigue resistance. During the crack initiation stage, the primary influential factor is the maximum shear stress. Due to c‐axis alignment with ND direction in grains, the deformation mode for ND and RD specimens primarily involves first‐order pyramidal slip, while ND–RD specimens primarily undergo basal slip and prismatic slip. In early stable crack propagation, grain size and texture cause variations in the morphology of the rough area among the three directional specimens. Notably, the RD specimens show faster crack propagation during crack initiation than early stable propagation stage.

Efficient regulation of cadmium accumulation by carboxymethylammonium chloride in rice: Correlation analysis and expression of transporter gene OsGLR3

The mechanism of carboxymethylammonium chloride (CC) regulating cadmium (Cd) accumulation in rice was studied in field and hydroponic experiments. Field experiments showed that 0.2–1.2 mmol L−1 CC spraying effectively reduced Cd accumulation by 44 %–77 % in early rice grains and 39 %–78 % in late rice grains, significantly increased calcium (Ca) content and amino acids content in grains, as well as alleviated Cd-induced oxidative damage in leaves. Hydroponic experiments further verified the inhibition effect of CC on Cd accumulation. 1.2 mmol L−1 CC made the highest decrease of Cd content in shoots and roots of hydroponic seedlings by 45 % and 53 %, respectively. Exogenous CC significantly increased glutamate (Glu), glycine (Gly) and glutathione (GSH) content, and improved the activities of catalase (CAT) and superoxide dismutase (SOD) by 41–131 % and 11–121 % in shoots of hydroponic seedlings, respectively. Exogenous CC also increased the relative expression of OsGLR3.1–3.5 in the shoots and roots of hydroponic seedlings. The quantum computational chemistry was used to clarify that the Gly radical provided by CC could form various complexes with Cd through carboxyl oxygen atoms. These results showed that exogenous application of CC improved the tolerance to Cd by enhancing the antioxidant capacity; inhibited the absorption, transport and accumulation of Cd in rice by (1) promoting chelation, (2) increasing the GLRs activity through upregulating the content of Glu, Gly, as well as the expression of OsGLR3.1–3.5.

Characterization of sequences, expression profiling, and natural allelic variation analysis of the MYC gene family in sorghum (Sorghum bicolor)

Sorghum aphid (Melanaphis sacchari) and head smut fungi (Sporisorium reilianum) infesting sorghum cause delayed growth and development, and reduce yield and quality. This study use bioinformatics and molecular biological approaches to profile the gene expression pattern during sorghum development and under pest infestation, and analyzed the natural allelic DNA variation of sorghum MYC gene family. The findings provide insights for potential application in breeding the stress resistant and high productivity sorghum varieties. The results indicated that there are 28 MYC genes identified in sorghum genome, distributed on 10 chromosomes. The bHLH_MYC_N and HLH domains are the conserved domains of the MYC gene in sorghum. Gene expression analysis showed that SbbHLH35.7g exhibited high expression levels in leaves, SbAbaIn showed strong expression in early grains, and SbMYC2.1g showed high expression levels in mature pollen. In anti-aphid strains at the 5-leaf stage, SbAbaIn, SbLHW.4g and SbLHW.2g were significantly induced in leaves, while SbbHLH35.7g displayed the highest expression level in panicle tissue, which was significantly induced by the infection of head smut. Promoter cis-element analysis identified methyl jasmonate (MJ), abscisic acid (ABA), salicylic acid (SA) and MYB-binding sites related to drought-stress inducibility. Furthermore, genomic resequencing data analysis revealed natural allelic DNA variations such as single nucleotide polymorphism (SNP) and insertion-deletion (INDEL) for the key SbMYCs. Protein interaction network analysis using STRING indicated that SbAbaIn interacts with TIFYdomain protein, and SbbHLH35.7g interacts with MDR and imporin. SbMYCs exhibited temporal and spatial expression patterns and played vital roles during the sorghum development. Infestation by sugarcane aphids and head smut fungi induced the expression of SbAbaIn and SbbHLH35.7g, respectively. SbAbaIn modulated the jasmonic acid (JA) pathway to regulate the expression of defensive genes, conferring resistance to insects. On the other hand, SbbHLH35.7g participated in detoxification reactions to defend against pathogens.

The deterioration of starch physiochemical and minerals in high-quality indica rice under low-temperature stress during grain filling.

Low temperatures during the grain-filling phase have a detrimental effect on both the yield and quality of rice grains. However, the specific repercussions of low temperatures during this critical growth stage on grain quality and mineral nutrient composition in high-quality hybrid indica rice varieties have remained largely unexplored. The present study address this knowledge gap by subjecting eight high-quality indica rice varieties to two distinct temperature regimes: low temperature (19°C/15°C, day/night) and control temperature (28°C/22°C) during their grain-filling phase, and a comprehensive analysis of various quality traits, with a particular focus on mineral nutrients and their interrelationships were explored. Exposure of rice plants to low temperatures during early grain filling significantly impacts the physicochemical and nutritional properties. Specifically, low temperature increases the chalkiness rate and chalkiness degree, while decreases starch and amylopectin content, with varying effects on amylose, protein, and gelatinization temperature among rice varieties. Furthermore, crucial parameters like gelatinization enthalpy (ΔH), gelatinization temperature range (R), and peak height index (PHI) all significantly declined in response to low temperature. These detrimental effects extend to rice flour pasting properties, resulting in reduced breakdown, peak, trough, and final viscosities, along with increased setback. Notably, low temperature also had a significant impact on the mineral nutrient contents of brown rice, although the extent of this impact varied among different elements and rice varieties. A positive correlation is observed between brown rice mineral nutrient content and factors such as chalkiness, gelatinization temperature, peak viscosity, and breakdown, while a negative correlation is established with amylose content and setback. Moreover, positive correlations emerge among the mineral nutrient contents themselves, and these relationships are further accentuated in the context of low-temperature conditions. Therefore, enhancing mineral nutrient content and increasing rice plant resistance to chilling stress should be the focus of breeding efforts to improve rice quality.

The role of zinc fertilization and its interaction with nitrogen and phosphorus starter fertilization on early maize development and grain yield

The early planting of maize in temperate growing areas leads to yield and quality benefits, although a low soil temperature can affect the early nutrient uptake and delay plant development. Not only can the nitrogen (N) and phosphorus (P) uptake be limited, but that of zinc (Zn) can also be affected. Moreover, the application of N and P at early growth stages can result in an enhancement of maize growth. Two field experiment were carried out in North Italy during the 2012–14 period to: i) evaluate the most effective Zn application strategy by comparing seed, soil and foliar applications with an untreated control; ii) investigate the role of a Zn seed treatment on the early development and yield of maize grown in three different types of soils. The effect of Zn application was compared, in both experiments, to starter NP fertilization in bands at planting, according to a full factorial design. Zn fertilization significantly enhanced the early vigor and yield of the maize, although the effects were less pronounced than those of the NP fertilizer. Among the Zn fertilization strategies, maize growth was quicker for the seed and soil applications than for the foliar application or the untreated control. The former application significantly increased the plant height at stem elongation (+32%), shortened the planting-flowering period by 1 day, and increased the grain yield by 4%. Overall, the application of NP starter fertilizer shortened the planting-flowering period by 4.5 days and increased the yield by 10%, compared to the unfertilized control. In the second experiment, higher plant vigor indices were detected in all the soils for the NP starter fertilization (+22–27%) and for the Zn seed treatment (+3–9%) than in the controls. The NP starter fertilization reduced the grain moisture at harvest by 2.3% and increased grain yield by 14%, while the Zn treatment significantly increased the kernel weight but did not affect the grain yield or the moisture content. The interaction between the NP fertilization and the Zn treatment was never significant. Thus, the positive effect of Zn on the early vigor was an additional benefit to that produced by the starter NP fertilization. The study demonstrated that a Zn application at planting, with both a seed dressing and a soil treatment, significantly enhanced the early growth of different maize hybrids, in different growing seasons and soils, although the use of a NP starter fertilization led to more consistent agronomic benefits. Furthermore, the combination of NP and Zn starter fertilization resulted in a further advantage for all the considered production situations.

ТЕХНОЛОГИЯ ПЕРЕРАБОТКИ НЕОБМОЛОЧЕННЫХ КОЛОСЬЕВ ПШЕНИЦЫ РАННИХ ФАЗ СПЕЛОСТИ В КОРМ ДЛЯ РЫБ: ПРОБЛЕМЫ И РЕШЕНИЯ

The grain crops’ nonthreshed ears of the early stages of ripeness as raw materials for feed preparation can be used. The purpose of this study was: nonthreshed ears of early ripeness phases into food for omnivorous fish processing technology developing and substantiating. This study object - was the technological process of granulated feed from nonthreshed ears of early ripeness phases preparing. A preliminary technological scheme for granular feed preparation from ears had been developed. An experimental test had revealed shortcomings in technological process of feed from nonthreshed ears producing implementation, reducing its energy and economic efficiency and the processing line’s productivity and feed quality’s negative affecting. Possible solutions had been developed. For granular feed production from early ripening phases ears technology effective implementation, it is necessary the raw materials’ drying and grinding as technological operations, as well as its grinding and mixing to combine, for which new technological solutions were proposed. An improved technological scheme for granular fish feed from nonthreshed ears of early ripening producing has been developed, including combined technological operations. New technical means to be developed and already developed into the new scheme are integrated. The results of the study had shown that the technology of granulated feed from nonthreshed ears producing - is an effective means of livestock production’s profitability increasing, since feed produced by this technology using contains more protein than traditional one based on threshed forage grains, as a result fewer expensive protein additives in its composition can be included. The introduction of a new technology for the granular fish feed from nonthreshed ears preparation will make it possible early grain crops harvesting by the ochesmethod using for the feed nutritional value increasing.

Ограничения применения колесных тракторов в технологиях растениеводства по уплотняющему воздействию (в условиях Приамурья)

The natural conditions of the Amur region are characterized by seasonal soil freezing and thawing. In winter, it freezes to a depth of 2.5 m. In July, it completely thaws. Field work on soil preparation and sowing of early grain crops begins at a time when the soil thaws by only 0.08–0.10 m. In early spring field work, a tractor with high values of normal soil pressures can be used (without limiting the operating weight). The frozen under layer saves the soil from degradation. As the soil thaws, it is necessary to adhere to the established norms of mechanical action on soil, taking into account its physical and mechanical characteristics. The purpose of research is to reduce soil compaction from mechanical effects of tractor wheel thrusters. The objective of research is to substantiate the limits of wheeled tractor use in field work according to the permissible level of sealing effect. Theoretical and empirical methods are applied using statistical processing of experimental data. The change in soil density and compaction effect index are studied depending on the normal load transmitted by wheeled tractor movers. The values of distribution of operating weight along axes, maximum loads and value of compaction effect index of running systems of domestic and imported wheeled tractors used in crop production technologies of the Amur region are given. The limits of change in soil density depending on normal load under the wheel drive are given. The dependence of compaction effect index on the operating weight of tractor, axle load, wheel formula and number of unit passes along the track is established. Recommendations on the use of wheeled tractors in field work, depending on the time of their execution are given.

Phenotypic and transcriptomic responses of diverse rice accessions to transient heat stress during early grain development.

Heat stress (HS) occurring during the grain-filling period has a detrimental effect on grain yield and quality in rice (Oryza sativa). The development of heat-resilient cultivars could partly solve this issue if tolerant alleles can be identified and incorporated into the germplasm. In this study, we posit that some of the phenotypic variations for heat resilience during grain development could be due to variations in gene expression among accessions. To test this, we characterized the HS response of 10 diverse rice accessions from three major sub-populations using physiological and transcriptome analyses. At a single-grain level, grain width and grain thickness emerged as the most heat-sensitive traits. During a transient HS, IND-3 was categorized as highly sensitive, while five accessions exhibited moderate heat sensitivity, and four accessions were tolerant. Only a core set of 29.4% of the differentially expressed genes was common to the three rice sub-populations. Heat-tolerant accession TEJ-5 uniquely triggered an unfolded protein response (UPR) under HS, as evident from the induction of OsbZIP50 and downstream UPR genes. OsbZIP58, a gene that positively regulates grain filling, was more highly induced by HS in IND-2 despite its moderate heat sensitivity. Collectively, our analysis suggests that both unique gene expression responses and variation in the level of responses for a given pathway distinguish diverse accessions. Only some of these responses are associated with single-grain phenotypes in a manner consistent with the known roles of these genes and pathways.