Grain Yield and Nitrogen Use Efficiency Vary with Cereal Crop Type and Nitrogen Fertilizer Rate in Ethiopia: A Meta-Analysis

The crop production in Ethiopia is markedly constrained by soil nutrient depletion and limited fertilizer input. Nitrogen is among the most yield-limiting factors of cereal crops, especially in sub-Saharan Africa (SSA). A meta-analysis of 82 studies was carried out to evaluate the response of major cereal crops, viz. wheat, maize, barley, teff, and sorghum, to nitrogen fertilization in Ethiopia. The results showed that N-application significantly increased yields of all the five crops examined herein. The average yields of the treatment effects over controls for the five crops were 3775.8 kg∙ha−1 and 2593.3 kg∙ha−1, respectively. The overall yield response to nitrogen treatments for all the crops was 64.8% (wheat, 96.5%;maize, 40.65%;barley 84.36%;teff, 50.48%;and sorghum;23%). Overall, nitrogen agronomic efficiency (AEN) and partial factor productivity (PFPN) were 18.2 and 71.81 kg∙kg−1, respectively. A downtrend of nitrogen use efficiency with an increase in N rate was realized. The yield response was higher for the nitrogen treatment effects of >100 kg∙N∙ha−1 (123.9%), clay soils (75.46%), low initial soil organic carbon (SOC) and available phosphorous (AP) (92.4% and 101.6%), respectively, Therefore, we recommend the application of nitrogen fertilizer (>100 kg∙N∙ha−1), especially on infertile soils for improved grain yield and NUE in aforementioned cereal crops in Ethiopia and similar regions in sub-Saharan Africa (SSA).

Monitoring the Expression Profiles of Cereal Crops Seedlings by Using Rice cDNA Microarray

Through exploiting the high homology of cereal crop genes, membranous cDNA microarrays containing 3 311 unique rice transcripts (including 1 639 endosperm-derived transcripts and 1 672 mature stem-derived transcripts) were used for monitoring the expression profiles of 1-leaf stage seedlings of 4 cereal crop species: rice, maize, sorghum and barley. After hybridizing with [α-33P| labeled probes, 73.6 % of the arrayed genes generated reliable signals in all of the four cercal crops. Further analysis revealed that among the arrayed genes, a higher percentage of the endosperm-derived transcripts (86.6 %) expressed than that of the mature stem-derived genes (60.9 %), indicating that most of the endosperm expressed genes functioned in young seedlings while considerable amount of mature stem tissue expressed genes did not express. These results also inferred that some genes might function only at certain developmental stages. By comparing the obtained profiles, 84 genes were identified constantly expressed in all me four cereal crops. Many housekeeping genes, such as polyubiquitin, ubiquitin conjugating enzyme and ribosomal proteins were included in this catalogue. The experiment also identified 14 rice seedling specifically expressed genes, including 3 biotic and abiotic stress induced genes and 1 apoptosis suppressor encoding gene Bax inhibitor-1. This investigation provided invaluable information for comparative genomics of gramineae members.

Share-Shift Analysis of Geo-Economic Pattern on Global Cereal Crops in Recent 50 Years

In recent 50 years, with the rapid development of international food trade, the geoeconomic pattern of cereal crops has changed tremendously which produced a significant impact on global food security. This paper attempted to analysis the production pattern and trade pattern of global cereals, especially three main crops of wheat, maize and rice by using the method of share-shift. Given the fact of almost every economic phenomenon is driven by their economic return behind them, this paper attempted to a further step into their economic pattern by examining their net trade flow. The results showed that from the view of production and trade, the geographic pattern of global cereals has changed greatly which can be described as developing countries has replaced developed countries and become the world's biggest cereals production and trading area. But when moving to the net trade flow, it turns out to be another story that can depicted as the regional fixation features of economic returns which can be convinced from the labor division of global cereals trade, among which developed countries acts as net trade profit area while developing countries as net trade output area, and their gap between net export and net import has been widening from the view of evolution trend. So what we learn from the evolution of geoeconomic pattern on this topic is that our place in global cereals trade system, and therefore alert us to concern not only on the pattern transition but also the economic meaning behind it, only by doing so can we learn to plan our food future more wisely and effectively.

Response and resistance of cereal crops to pathogens

The special topic of the two papers is the systemic acquired resistance （SAR） and pathogenesis-related protein genes （PR）. SAR is an enhanced resistance against further potential parasite beyond the initial infection site, which can be induced by either pathogen infection or exogenous inducer, including synthetic chemicals and natural prod- ucts. As a ＂whole-plant＂ resistance defense, SAR confers broad-spectrum immunity to widely diverse pathogenic microorganisms, such as viruses, bacteria and fungi for a relatively long lasting period. Convincingly, it is a promising way to prevent crop diseases by activating the plants＇ own natural defenses via application of chemical inducers or creating resistant wheat cultivars.

Uptake of U-and Th-series radionuclides by cereal crops in Upper Egypt

The main aim of this study is to determine the activity concentrations of uranium series and thorium series radionuclide in crops cultivated in Upper Egypt.Fifteen types of cereal crops were collected from local markets and analyzed by γ-ray spectrometry.The mean activity concentrations of the natural radionuclides 238U,226Ra and 232Th were 0.67,1.27 and 0.56 Bq·kg-1,respectively.The annual effective doses from these radionuclides were estimated for different age groups.

Vitamin, Protein and Essential Mineral Enhancement of Cereal Crops for Food Security

Recent estimates indicate that more than half of the world's population suffers from diseases caused by dietary defi ciencies and inadequate supplies of essential micronutrients. This situation is exacerbated by the

Determining Nutritive Value of Cereal Crop Residues and Lentil (<i>Lens esculanta</i>) Straw for Ruminants

The chemical composition and in situ dry matter (DM) and organic matter (OM) degradability of seven different cereal crop residues were evaluated in this study. They included the Sorghum stovers (SS) and its threshed head residues (STH), millet stovers (MS) and its threshed head residues (MTH), corn stover (CS), wheat (WS) and barley (BS) straws. A legume crop residue (lentil, Lens esculanta, straw;LS) was included for comparison with the cereal crop residues. The CS was high (P crude protein (CP) and acid detergent lignin (ADL) and the lowest (P < 0.05) in Neutral Detergent Fibre (NDF) and acid detergent fibre (ADF) when compared to the amounts in SS and MS. It was found out that LS had higher (P < 0.05) CP, ADL, ME and low (P < 0.05) NDF and ADF than the cereal crop residues. There were differences in digestible DM (DMD) at various incubation times both between and within the feed samples. The DM and OM a, c fraction were highest (P < 0.05) for LS when compared to all the cop residues evaluated. The BS and MS had the lowest effective degradability (ED) DM at 0.02 and 0.05 (P < 0.05) rates of passage, while the LS had the highest. The chemical composition and degradability of different crop residues found in Eritrea indicate the potential the residues have in supplementing grazing animals.

Orchestrating seed storage protein and starch accumulation toward overcoming yield–quality trade-off in cereal crops

Achieving high yield and good quality in crops is essential for human food security and health.However,there is usually disharmony between yield and quality.Seed storage protein(SSP)and starch,the predominant components in cereal grains,determine yield and quality,and their coupled synthesis causes a yield–quality trade-off.Therefore,dissection of the underlying regulatory mechanism facilitates simultaneous improvement of yield and quality.Here,we summarize current findings about the synergistic molecular machinery underpinning SSP and starch synthesis in the leading staple cereal crops,including maize,rice and wheat.We further evaluate the functional conservation and differentiation of key regulators and specify feasible research approaches to identify additional regulators and expand insights.We also present major strategies to leverage resultant information for simultaneous improvement of yield and quality by molecular breeding.Finally,future perspectives on major challenges are proposed.

Water stress resilient cereal crops:Lessons from wild relatives

Cereal crops are significant contributors to global diets.As climate change disrupts weather patterns and wreaks havoc on crops,the need for generating stress-resilient,high-yielding varieties is more urgent than ever.One extremely promising avenue in this regard is to exploit the tremendous genetic diversity expressed by the wild ancestors of current day crop species.These crop wild relatives thrive in a range of environments and accordingly often harbor an array of traits that allow them to do so.The identification and introgression of these traits into our staple cereal crops can lessen yield losses in stressful environments.In the last decades,a surge in extreme drought and flooding events have severely impacted cereal crop production.Climate models predict a persistence of this trend,thus reinforcing the need for research on water stress resilience.Here we review:(i)how water stress(drought and flooding)impacts crop performance;and(ii)how identification of tolerance traits and mechanisms from wild relatives of the main cereal crops,that is,rice,maize,wheat,and barley,can lead to improved survival and sustained yields in these crops under water stress conditions.

Research Progress on the Biological Basis of Cereal Pollen Culture

This paper summarizes the physiological and metabolic mechanism of a series of processes in the cereal microspore culture from the angle of plant physiological metabolism, explores the physiological or cytology mechanism of several key processes, including microspore dedifferentiation and callus formation, differentiation and transformation, and sums up the current problems in this field and forecasts the direction of future development.

主要谷类粮食作物富硒研究概述

硒元素对人和动植物都十分重要,其摄入过量或缺少都会有一定的危害。人和动物可以从植物中摄取硒元素。着重选取近年来水稻、玉米、小麦具有代表性的富硒研究成果进行总结分析,结果表明:对作物适度施硒,不仅可以间接保证人体对硒元素的需求,还可以增加作物产量、提高作物品质和籽粒饱满度、减少作物对重金属元素的吸收,硒与某些中微量元素搭配施用可相互促进吸收。通过综合分析,为人们关注和合理补充硒元素,也为贫硒缺硒、重金属含量较高地区的作物种植提供参考。

Wheat streak mosaic virus： incidence in field crops, potential reservoir within grass species and uptake in winter wheat cultivars

Wheat streak mosaic virus（WSMV）has become a re-emerging pathogen in cereal crops in the Czech Republic.WSMV was first reported in the former Czechoslovakia in the early 1980s,and then no record of the virus was documented until 2009.The incidence of the virus was recorded in recent years in several winter wheat fields and many grass species.Here,we surveyed the incidence of WSMV in cereal crops.The results demonstrated the existence of the virus in winter wheat and volunteer wheat during each year of the monitoring period,which spanned from 2013–2016.Although the range of infected samples was low（6.4%of the total tested samples）,a high incidence of well-distributed virus was recorded.In at least six fields,the virus reached severe and potentially epidemic levels.In accordance with our previous report detailing WSMV infection of native grasses,we tested several grass species commonly grown in the Czech Republic.We found that some grass species acted as experimental hosts and possible reservoirs of the virus;these included Anthoxanthum odoratum（sweet vernal grass）,Arrhenatherum elatius（false oat-grass）,Lolium multiflorum（Italian rye-grass）,Bromus japonicus（Japanese chess）,Echinochloa crus-galli（barnyard grass）,Holcus lanatus（meadow soft grass）and Holcus mollis（creeping soft grass）.Some of these grass species are also important weeds of cereals,which may be the potential source of WSMV infection in cereal crops.Several widely used winter wheat cultivars were tested in the field after artificial inoculation with WSMV to evaluate virus titre by RT-qPCR.Overall,the tested cultivars had a low virus titre,which is associated with mild disease symptoms and may provide a good level of crop resistance to WSMV.

中国禾谷类作物种子质量指标的模拟分析与应用

种业竞争的核心是种子质量竞争,模拟种子质量指标变化动态,旨在适时适量优化质量标准,促进种业高质量发展。以2016—2020年禾谷类作物种子质量抽检数据为依据,构建水稻、玉米和小麦种子质量指标的Logistic模型,模拟各指标变化动态。结果表明,17个种子质量指标模型的决定系数都达到极显著水平,模型拟合精度均达到好或非常好水平。基于模拟分析结果,建议种子质量标准中的水稻杂交种纯度由96%提升到97%;水稻净度由98%提升到99%;玉米净度由99%提升到99.4%;玉米发芽率由85%大幅提升到90%左右;北方粳稻和玉米水分标准分别调整为15.0%和13.2%;其余指标不调整或微调。本研究的结论可为禾谷类作物种子质量标准修订提供参考依据。

摩天大厦型作物工厂——保障城市食物快速增长需求的作物高效生产系统

Vertical farming systems,such as sky farms,are a potential type of agricultural system for stable and effective food production.Here,we highlight the potential of the sky farm,denoted as the“skyscraper crop factory”(SCF),for cereal crop production and discuss some nascent technologies that would be applied in this production system.SCFs are ideal crop-production systems for increasing the effective arable area for crops and ensuring food security in times of crises that cause a shock in global trade.They can also provide food in urban areas to meet producers’and consumers’demands for the increased nutrition,taste,and safe production of cereal crops.Moreover,as their use can reduce greenhouse gas emissions,SCFs could be a sustainable addition to conventional agricultural crop production.

Physiological and Morphological Responses of Susceptible and Resistant Barleys to Bird Cherry-Oat Aphid Feeding

The bird cherry-oat aphid (Rhopalosiphum padi [Linnaeus, 1758]) is considered a key pest of cereal crops worldwide, causing direct damage through sap feeding and by acting as a vector for viral diseases. Managing aphids is challenging because of their biology and potential resistance to insecticides. Developing resistant barley genotypes is a sustainable strategy for managing BCOA. In this study, we assessed responses of susceptible “Morex” and resistant “BCO R001” barley, Hordeum vulgare L. genotypes to different initial BCOA densities (0, 50, 100 or 200 aphids.plant-1). Physiological and morphological parameters were measured weekly for four weeks after infestation. Chlorophyll content, photosynthetic rate, plant aerial fresh and dry weight were greater for the resistant cultivar at lower aphid abundances and up to three weeks after infestation. Carbon assimilation curves (A/Ci) of infested “BCO R001” were similar to controls 15 days post infestation, differing from Morex. However, BCOA infestation of 50 aphid.plant-1 for two weeks negatively impacted the fitness of both genotypes. Initial resistance by BCO R001 to BCOA infestation can allow growers and natural enemies more time contributing to more effective and sustainable management of BCOA infestations.

麦类作物对蚜虫抗性机制及抗性遗传研究进展

小麦蚜虫是小麦上的重大害虫,严重威胁小麦产量和粮食安全。种植抗虫品种为最经济有效的麦蚜防控措施之一,充分了解小麦品种对蚜虫的抗性及其机制是培育与利用抗性品种的基础。本文对近10年来小麦抗蚜品种的鉴定筛选、抗蚜机理、抗蚜基因与抗性遗传,以及转基因抗蚜小麦创制等研究进展进行了系统综述,并对今后研究进行展望,以期为深入研究小麦对蚜虫抗性机制,促进抗虫小麦改良,并为抗虫品种在麦蚜绿色防控中应用提供参考。

我国主要粮食作物施用锌肥增产效果的整合分析

锌是作物必需的营养元素,但我国主要粮食作物施锌的增产效果及其影响因素并不清楚。通过收集87篇文献,基于Meta分析研究了小麦、玉米和水稻等锌肥施用的增产效果及其关键影响因素。结果表明:小麦、玉米和水稻施用锌肥平均增产9.9%,其中水稻和玉米的增产率相似且均显著高于小麦。三类粮食作物锌肥土施增产率为8.2%,增产效果好于喷施,但相同施锌量条件下喷施的增产效果较好。水稻、玉米和小麦锌肥的合适用量范围分别为21~30、21~30和11~20 kg/hm^(2),锌肥的增产效果为华中地区水稻和小麦好于玉米,东北地区玉米好于水稻和小麦。此外,水稻、玉米和小麦锌肥增产幅度随着年代发生变化,2011年之后呈逐渐增高的趋势。综上所述,施用锌肥能有效提高粮食作物的产量,但是其增产效果受作物种类、施用方式、施用量、施用时期等因素的影响。因此,锌肥的施用要考虑多种因素条件,应选择合理的施用方式和施用量来提高锌肥的增产效果。

谷类作物β-葡聚糖合成酶基因家族的研究进展

Beta-葡聚糖是由β-(1,3)和β-(1,4)糖苷键连接的非纤维素多糖,主要分布在谷类作物籽粒胚乳及糊粉层中,在高尔基体合成,经由囊泡运输到质膜,最终在细胞壁上沉积。通过增加胆汁酸排泄,延迟葡萄糖吸收,β-葡聚糖可有效降低胆固醇及血糖水平。Beta-葡聚糖合成酶基因家族成员最早在水稻(Oryza sativa)中得到鉴定,后在其他作物中陆续被发现。该基因家族包括3个主要成员:CslF、CslH和CslJ亚基因家族,起源于不同分支,经过趋同演化,执行合成β-葡聚糖的功能。Beta-葡聚糖基因家族成员均受到负选择压力,演化过程中序列高度保守。CslF亚家族基因成员相对较多,常在染色体上形成基因簇,CslF6是介导β-葡聚糖合成的主效基因。CslF亚家族在叶基部等幼嫩组织中表达水平相对较高,且明显受到光照强度的影响;CslH和CslJ亚家族成员较少,其中CslH亚家族在叶尖等成熟组织中的表达水平高,而CslJ亚家族在籽粒中有较高的表达水平。该文综述了β-葡聚糖合成酶基因家族成员的系统发育关系、表达模式,β-葡聚糖合成酶的亚细胞定位,以及作物中的定向育种研究进展,提出β-葡聚糖合成酶基因家族在染色体上的精准定位是未来的研究趋势,以期推动染色体工程在作物β-葡聚糖定向育种中的应用。

全球谷物用农药市场及其产品研发

粮食作物中,谷物用农药市场最大,且除草剂和杀菌剂占据了85%以上份额。概述了全球谷物用农药市场及产品研发进展,并对市场规模较大或增长潜力较好的部分产品作了介绍。

黄土高原四种作物生产的温室气体排放比较

为探究粮食作物和饲草作物生产在温室气体排放方面的差异,识别潜在的减排热点,本研究基于2018—2021年在甘肃和宁夏获得的738份有效农户问卷调查数据,以小麦、玉米、苜蓿和饲用玉米四种作物为研究对象,使用生命周期评价的方法评估温室气体(CO_(2)当量)排放量。结果表明,研究区域每公顷的小麦、玉米、苜蓿、饲用玉米干物质产出分别为:6.45,16.81,6.28,17.05 t;蛋白质产出分别为:0.52,1.08,0.79,1.22 t。四种作物的温室气体排放量分别为:3.89,5.14,1.12,4.34 t·hm^(-2);但在每吨干物质和蛋白质产出基准下,苜蓿与饲用玉米均显示较低的排放强度,其中苜蓿的优势更为显著。敏感度分析表明,化肥和农机使用对排放结果的敏感度平均达到75.29%和11.51%。因此,建议研究区域使用优质饲草作物替代粮食作物支撑草食畜牧业,同时加强作物的田间施肥管理和提高机械使用效率,能有效地减少草食畜牧业在饲料生产端的温室气体排放量。