ABSTRACT: The hollowness phenomenon of radish (Raphanus sativus L.) root is very easy to occur during the storage, which seriously affects its quality. “Weixian radish” was used as the test material, and metabolomics technology and multivariate statistical analysis were employed to explore the underlying mechanism. The results revealed 384 differential metabolites in VL0 vs VL1 (174 up-regulated, 210 down-regulated), 440 differential metabolites in VL0 vs VL4 (279 up-regulated, 161 down-regulated), and 298 differential metabolites in VL1 vs VL4 (226 up-regulated, 72 down-regulated). The KEGG enrichment analysis indicated that a total of four metabolic pathways were significantly enriched in the process of radish hollowness. Notably, only cysteine and methionine metabolism was significantly enriched in the comparisons of VL0 vs VL1 and VL0 vs VL4 positive ions. Therefore, the cysteine and methionine metabolism could be the most critical metabolic pathway involved in the response of radish taproots to the hollowness phenomenon. The study suggested that a decrease in homocysteine content may lead to reducing glutathione levels, impacting the antioxidant capacity of radish taproots. In conclusion, hollowness may indirectly influence the anabolism of glucosinolates in radish taproots by affecting the metabolism of cysteine and methionine, as well as the biosynthetic pathways of phenylalanine, tyrosine, and tryptophan, thereby impacting the antioxidant capacity of radish taproots.

In wheat ( Triticum aestivum L.), yield component traits (YCTs) are the most important yield traits. Only several genes for YCTs have been originally cloned. The efficient cloning of genes for YCTs directly from wheat remains a challenge. Here, we proposed a strategy for cloning genes from quantitative trait loci (QTLs) by sequencing of recombinant inbred lines (RILs) (QTL-Seq-RIL). Using the ‘TN18 × LM6’ RIL population as an example, we identified 138 candidate unigenes (CUGs) for YCTs from 77 stable QTLs. The average of CUGs per QTL was 1.8, which enabled us to confirm the CUGs directly. We have confirmed seven CUGs, TaIFABPL, TaDdRp, TaRLK, TaTD, TaTFC3, TaKMT and TaSPL17 , via the CRISPR/Cas9 system. Of these, six genes were found firstly to regulate YCTs in crops except for TaSPL17 . Five CUGs (include TaSPL17 ) for which orthologous genes have been cloned previously with the same or similar agronomic functions. It is to say, 11 CUGs were preliminarily validated using a single RIL population. QTL-Seq-RIL provides an efficient method for rapid gene cloning using existing RIL populations.### Competing Interest StatementThe authors have declared no competing interest.

During chemical looping combustion (CLC) and chemical looping gasification (CLG) of coal, the release, migration, and speciation of mercury in coal are significantly influenced by oxygen-carrier materials; however, the underlying mechanism remains inadequately addressed. In this work, the effect of a typical iron-based oxygen carrier on the release behavior of mercury from a bituminous coal and a lignite was investigated based on the Ontario-Hydro method. It is found that the effect of the iron-based oxygen carrier is attributed to three aspects: the enhanced release rate of mercury from coal, the adsorption of the released mercury, and the oxidization of gaseous Hg0 into Hg2+. With the increasing temperature, the adsorbance of mercury by the iron-based oxygen carrier decreases, while the oxidation of mercury enhances. Even at 900 °C, the adsorbance of mercury by the oxygen carrier remained at 0.1687 g/g, with a relative content of Hg2+ at 22.55%. Additionally, it was observed that iron-based oxygen carriers can physically absorb both Hg0 and Hg2+, while chemisorption refers to complex-compound formation between the iron-based oxygen carrier and mercury.

Nitrogen (N), phosphorus (P), and potassium (K) are the three most important mineral nutrients for crop growth and development. We previously constructed a genetic map of unigenes (UG-Map) based on their physical positions using a RIL population derived from the cross of "TN18 × LM6" (TL-RILs). In this study, a total of 18 traits related to mineral use efficiency (MUE) of N/P/K were investigated under three growing seasons using TL-RILs. A total of 54 stable QTLs were detected, distributed across 19 chromosomes except for 3A and 5B. There were 50 QTLs associated with only one trait, and the other four QTLs were associated with two traits. A total of 73 candidate genes for stable QTLs were identified. Of these, 50 candidate genes were annotated in Chinese Spring (CS) RefSeq v1.1. The average number of candidate genes per QTL was 1.35, with 45 QTLs containing only one candidate gene and nine QTLs containing two or more candidate genes. The candidate gene TraesCS6D02G132100 (TaPTR gene) for QGnc-6D-3306 belongs to the NPF (NRT1/PTR) gene family. We speculate that the TaPTR gene should regulate the GNC trait.

为了研究不同水肥条件对辣椒产量和品质的影响,优化温室辣椒生产的水肥模式,对2种灌溉模式与3种不同追肥施用量共6个水肥组合条件下的辣椒产量和品质等7个指标进行主成分因子分析,同时对不同水肥组合进行灰色关联度综合评价.结果表明:不同水肥组合处理的辣椒产量和品质指标间均表现为显著差异.主成分因子分析结果显示,前2个主成分的特征值大于1,其方差累积贡献率达到86.53％,第一主成分代表了品质相关因子,第二主成分代表了产量相关因子.灰色关联度分析结果表明,滴灌—高肥组合和滴灌—中肥组合的灰色综合评判值分别为0.8720和0.8008,评为第1等级;漫灌—高肥组合的灰色综合评判值为0.7796,评为第2等级;滴灌—低肥组合和漫灌—中肥组合为第3等级;漫灌—低肥组合的灰色综合评判值最低,评为第4等级.滴灌与肥料调控相结合的水肥耦合技术对辣椒的产量和品质具有一定的促进作用.

Background Green-fleshed radish ( Raphanus sativus L.) is an economically important root vegetable of the Brassicaceae family, and chlorophyll accumulates in its root tissues. It was reported that the basic helix-loop-helix ( bHLH ) transcription factors play vital roles in the process of chlorophyll metabolism. Nevertheless, a comprehensive study on the bHLH gene family has not been performed in Raphanus sativus L. Results In this study, a total of 213 Raphanus sativus L. bHLH ( RsbHLH ) genes were screened in the radish genome, which were grouped into 22 subfamilies. 204 RsbHLH genes were unevenly distributed on nine chromosomes, and nine RsbHLH genes were located on the scaffolds. Gene structure analysis showed that 25 RsbHLH genes were intron-less. Collineation analysis revealed the syntenic orthologous bHLH gene pairs between radish and Arabidopsis thaliana / Brassica rapa / Brassica oleracea . 162 RsbHLH genes were duplicated and retained from the whole genome duplication event, indicating that the whole genome duplication contributed to the expansion of the RsbHLH gene family. RNA-seq results revealed that RsbHLH genes had a variety of expression patterns at five development stages of green-fleshed radish and white-fleshed radish. In addition, the weighted gene co-expression network analysis confirmed four RsbHLH genes closely related to chlorophyll content. Conclusions A total of 213 RsbHLH genes were identified, and we systematically analyzed their gene structure, evolutionary and collineation relationships, conserved motifs, gene duplication, cis-regulatory elements and expression patterns. Finally, four bHLH genes closely involved in chlorophyll content were identified, which may be associated with the photosynthesis of the green-fleshed radish. The current study would provide valuable information for further functional exploration of RsbHLH genes, and facilitate clarifying the molecular mechanism underlying photosynthesis process in green-fleshed radish.

[目的]挖掘与萝卜肉质根糖含量相关性状密切关联的SSR位点,为萝卜 品质改良提供参考.[方法]以134份萝卜品种构成的自然群体为材料,在成熟期对萝卜肉质根中的果糖、葡萄糖、蔗糖、可溶性总糖含量和甜度值进行连续3年(2015-2017年)的表型鉴定,利用SPSS 20.0软件对上述5个糖含量性状进行相关性分析,选用156对SSR引物进行群体扫描,利用PowerMarker V3.25软件分析134份萝卜品种的遗传多样性,应用Structure 2.3.4软件分析包含134份萝卜品种自然群体的遗传结构,利用Tassel 3.0软件对SSR标记与糖含量相关性状进行关联分析.[结果]134份萝卜品种的糖含量相关性状在群体中变异较广,甜度值的广义遗传力最高(60.10％),其次是葡萄糖(53.79％)、可溶性总糖(48.51％)和果糖(40.73％),蔗糖的广义遗传力最低(30.67％).用156对SSR引物从134份萝卜品种中共检测到349个多态性位点,多态性信息量(PIC)为0.106～0.864,多样性指数为0.112～0.877.群体结构分析表明,134份萝卜品种可分为2个亚群,其中亚群1包含46个萝卜品种,对应表1中1～46号品种;亚群2包含88个萝卜品种,对应表1中47～134号品种;且亚群分类与地理来源无明显对应关系.在P≤0.01阈值条件下,检测到与5个糖含量相关性状关联的位点61个,其中与葡萄糖含量关联的位点16个,与甜度值关联的位点13个,与蔗糖含量关联的位点13个,与可溶性总糖含量关联的位点10个,与果糖含量关联的位点9个,单个位点的表型变异解释率为5.19％～16.29％.[结论]获得61个与萝卜肉质根糖含量相关性状显著关联的SSR位点,其中有14个标记位点具有"一因多效"现象,能同时被2个或2个以上性状检测到.

Growth-regulating factors (GRFs) as plant-specific transcription factors exert an important role in plant growth and development; however, the function of GRFs has not been reported in apple (Malus domestica). In the present study, we identified 12 MdGRF genes, which located on six chromosomes with different densities. These MdGRFs were phylogenetically classified into four clusters based on the protein sequence similarity, and the intron-exon structure and functional domain of MdGRF genes were similar within each cluster. Interestingly, these MdGRFs were tissue-specific expressed, and several specific MdGRFs were strongly responsive to various hormonal treatments, either positively or negatively. The transgenic apple calli overexpressing MdGRF02 displayed higher fresh weight and the transgenic apple roots exhibited increased root elongation, indicating that MdGRF02 may be related with root growth regulation in apples. This study reports the identification and expression analysis of the MdGRFs and provides some useful information to reveal the potential roles of MdGRFs in apple growth regulation, especially the root growth.

The flesh of the taproot of Raphanus sativus L. is rich in chlorophyll (Chl) throughout the developmental process, which is why the flesh is green. However, little is known about which genes are associated with Chl accumulation in this non-foliar, internal green tissue and whether the green flesh can perform photosynthesis. To determine these aspects, we measured the Chl content, examined Chl fluorescence, and carried out comparative transcriptome analyses of taproot flesh between green-fleshed "Cuishuai" and white-fleshed "Zhedachang" across five developmental stages. Numerous genes involved in the Chl metabolic pathway were identified. It was found that Chl accumulation in radish green flesh may be due to the low expression of Chl degradation genes and high expression of Chl biosynthesis genes, especially those associated with Part Ⅳ (from Protoporphyrin Ⅸ to Chl a). Bioinformatics analysis revealed that differentially expressed genes between "Cuishuai" and "Zhedachang" were significantly enriched in photosynthesis-related pathways, such as photosynthesis, antenna proteins, porphyrin and Chl metabolism, carbon fixation, and photorespiration. Twenty-five genes involved in the Calvin cycle were highly expressed in "Cuishuai". These findings suggested that photosynthesis occurred in the radish green flesh, which was also supported by the results of Chl fluorescence. Our study provides transcriptome data on radish taproots and provides new information on the formation and function of radish green flesh.

分子标记辅助育种是现代小麦育种的研究热点之一.本研究利用134个小麦品种(系)的8650个SNP标记,进行全基因组关联分析(GWAS),检测全基因组范围内与株高、穗粒数、每平方米穗数和千粒重显著关联的位点,继而建立模型进行亲本评价和杂交组合设计.结果表明,134个品种(系)的评价得分值分布范围是-0.179～0.152,生产中表现好的品种大多评分较高.根据亲本评价结果筛选到500个得分较高的亲本组合,涉及35个亲本,评价得分较高的组合多集中于实际生产中大面积种植的优良品种,如济麦22、泰农18、良星99、山农29、烟农19、山农25等,以这些品种作为亲本设计组合,可能具有潜在的育种价值.利用根据育种经验确定的重点亲本泰农18和山农17,共设计出54个组合,其中的5个组合(5/54=9.3％)已育成10个国家和省级审定品种.

Radish is an important root vegetable crop worldwide.Assessment of sugar composition in taproots of radishes will provide helpful information for quality breeding of radishes.In this study,195 cultivars including 129 white-fleshed,48 green-fleshed and 18 red-fleshed radishes were collected and the variation of sugar composition in taproots was evaluated using high performance liquid chromatography analysis in three successive years.Three sugars including glucose,fructose and sucrose were identified in radish taproots.The most abundant sugar was glucose,followed by fructose and sucrose,and more than 20％ (46/195) of cultivars were sucrose free.These radish cultivars presented a wide range of variation from a minimum 5.39 mg/g to a maximum of 47.08 mg/g in total sugar mass fraction,from 3.2 mg/g to 27.61 mg/g in glucose mass fraction,from 0.6 mg/g to 19.42 mg/g in fructose mass fraction,from 0 to 9.02 mg/g in sucrose mass fraction,and from 1.01 to 6.67 in glucose/fructose ratio.By cluster analysis,all the tested cultivars were clustered into four groups.Cluster 4 had the highest mean for total sugar mass fraction of 41.81 mg/g,and Cluster 1 had the lowest mean for total sugar mass fractions of 13.68 mg/g.Furthermore,correlation analysis indicated that the sugar mass fraction was significantly correlated with the flesh color.Green-fleshed radishes had the highest amount of sugars,followed by red-fleshed and white-fleshed ones.Overall,glucose and fructose are the main sugars in these radish cultivars.The sugar mass fraction is not related to the skin color,but is strongly correlated with the flesh color of radishes.

采用Ontario-Hydro方法,在管式炉中考察了煤化学链燃烧/气化过程中Fe4Al6载氧体对煤中汞释放率、气态汞形态分布及汞在两反应器内释放行为的影响.结果表明,载氧体对煤中汞释放率具有显著的影响,在500～700℃,与无载氧体相比,化学链燃烧过程煤中汞释放率减少,化学链气化过程煤中汞释放率增大,而在900℃时,无论化学链燃烧过程还是化学链气化过程,煤中汞释放率均减小.Fe4Al6载氧体能够显著增加燃料反应器出口气态Hg2+的相对含量,其含量随温度的升高而逐渐升高.燃料反应器的温度也是影响煤中汞在两反应器中的分布以及空气反应器中不同价态汞百分含量的重要因素.此外,相同条件下不同煤种的汞释放率不同,主要与煤的组成不同有关.该研究对揭示载氧体对煤中汞迁移的影响机理以及煤化学链转化过程汞的控制提供了实验依据.

Plasma membrane permeability is an important character of dry seeds It indicates the degree of membrane integrity and hence seed quality. The molecular mechanisms that affect membrane permeability and repair during imbibition are not well understood. Seeds of wheat varieties 'Yuan 53646' and 'Luo Han 8', identified as differing in membrane permeability, were used for transcriptome sequencing of the embryos before (dry seeds) and after six hours imbibition. Comparative transcriptome analysis was performed. 1,354 significant differentially expressed genes (DEGs) in dry seeds and 728 significant DEGs in 6-hour imbibed seeds were identified. KEGG enrichment analysis revealed that "Protein processing in endoplasmic reticulum" (ko04141) was significantly enriched in dry 'Yuan 53646' seeds, suggesting that it may participate in protecting or repairing membranes. 15 DEGs, involved in water stress response, lipid body transport and membrane-bound vesicular transport, calcium ion binding and wound-induced proteins were identified as possible genes related to membrane integrity. Quantitative real-time PCR successfully validated the transcriptome analysis.

The transformation and migration of cadmium during chemical-looping combustion (CLC) and gasification (CLG) of the synthetic municipal solid waste (SMSW) was investigated in a tubular furnace. Both copper-based and iron-based oxygen carriers (OCs) can make elemental cadmium (Cd (g)) into cadmium oxide (CdO) at 850 degrees C, but their complete reduction products do not have this ability. Cadmium was distributed mainly in the bed material during CLC, but distributed mainly in the fly ash during CLG. After 2 min of reaction, approximately 90% of the cadmium in the bed material distributed in the OC particles, indicating that large amount of cadmium would volatilize from the SMSW particles and migrate to the OC particles at the initial stage of CLC and CLG. As the reducing gas generating later may restore CdO to Cd (g) again during CLG, the cadmium migrating to the OC particles was detached gradually. A two-step-transformation and migration mechanism for cadmium during CLC and CLG was proposed. After five successive cycles of the CLC process, the concentration of cadmium in the OC particles increased linearly from 7.1 mg/kg to 33.3 mg/kg with an average capture efficiency of 85%, while after just one cycle of the CLG process, the high concentration of the cadmium in the OC particles can be removed efficiently. Overall, the cadmium in MSW can be captured by CLC, while be removed by CLG. Therefore, the coupling of CLC and CLG processes may provide an innovative and efficient control, even recycling technology for the cadmium in MSW.

汞对人类和环境的危害巨大,而煤中汞的排放是人为汞排放的主要污染源,引起国际国内的广泛重视.基于煤中汞的赋存形态和分布,本文对煤燃烧、煤气化以及煤化学链燃烧/气化过程中的汞的排放进行了综述,对比了传统煤燃烧过程的燃烧前脱汞、燃烧中脱汞、燃烧后脱汞.作为新型的煤转化方式,煤化学链燃烧/气化具有能效高、污染物协同脱除等优势,对煤化学链转化过程中S、N、Hg等污染物的协同脱除以及基于化学链技术的汞脱除方法需要进一步研究.

Wheat is one of the most important staple food crops in many parts of the world. Nitrogen (N) is often considered to be the most important mineral nutrient element for crop growth and development. Nitrogen use efficiency (NUE) comprises nitrogen uptake efficiency (NUpE) and nitrogen utilization efficiency (NUtE). We constructed a high-density genetic map using a set of 184 recombinant inbred lines (RILs) derived from the cross ‘Tainong 18 × Linmai 6’ (TL-RILs). In this study, 14 seedling traits and 17 maturity traits related to NUE and agronomic traits of wheat were investigated using the TL-RILs under hydroponic culture trials with high N (HN), moderate N (MN) and low N (LN) levels in two time frames, and under field trials with HN and LN levels in two growing seasons. A total of 121 and 130 quantitative trait loci (QTLs) we detected at seedling and maturity stages, respectively. Of these, 47 relatively high-frequency QTLs (RHF-QTLs) and 16 QTL clusters were found. The most important cluster, C9, included morphological, biomass, yield, NUpE and NUtE traits at the same time. The contributions for most QTLs were high, with the highest contribution of 30.00%. Seventeen RHF-QTLs were detected in this cluster, and it showed a favorable relationship between the RHF-QTLs for breeding programs. The markers in the region of cluster C9 should be valuable in marker-assisted selection (MAS). The sequence of DArT marker D-3940950 in the C9 region was identified to the RhtB1 gene with the similarity of 100% by BLAST against the Chinese Spring genome (IWGSCv1.0). The correlation analysis suggested that the morphological/biomass traits and eight yield traits can be considered as the primary morphological indexes for the evaluation of NUE instead of using element determinations, and the outcomes make it easy to identify NUE on a large scale.

Chemical looping gasification (CLG) is a cost-effective alternative to the traditional fossil conversion process. In this article, the effects of three different types of coal ash on Fe-based oxygen carrier in coal char CLG were investigated. The composition of coal ashes and the microstructure of Fe4Al6 oxygen carrier were characterized by SEM-EDS, XRD and BET. The effects of different components of coal ash (SiO2, CaO, and K2O) were examined, and their effect mechanisms were analyzed. The findings suggested that the effect of coal ash on Fe4Al6 oxygen carrier could be divided into three aspects: (i) inhibition effect by forming low-melting-point compounds; (ii) enhancement effect through catalysis or formation of specific structure; and (iii) neutral effect by integrating with oxygen carrier. In addition, the formation of low-melting-point compounds, which is mainly due to SiO2 and CaO, was found to cause sinter and agglomeration of oxygen carrier. Moreover, potassium salts were found to either act as catalysts or cause the formation of K-Fe-O compounds; they promoted the release of lattice oxygen from oxygen carrier while enhanced oxygen carrier's stability. The findings suggested that coal ash containing high content of K2O and Fe2O3 could enhance the performance of oxygen carrier during CLG.

转录因子是基因表达调控过程中的重要调节因子.为更好地了解蔷薇科植物苹果转录因子所编码的基因家族,利用苹果基因组数据进行转录因子筛选鉴定和系统预测,并与桃和草莓2个蔷薇科物种进行分析比较.结果表明:在苹果、桃、草莓中分别鉴定到3 039、1 527、1 506个转录因子成员,可分为58个转录因子家族;基因染色体定位显示预测的转录因子以不同密度分布在所有染色体上;所有的转录因子都具有类似的GO分析结果和亚细胞定位预测信息;随机选择了与拟南芥MYB转录因子同源性较高的苹果基因进行了干旱胁迫处理下的表达量检测,值得注意的是,有6个基因经过PEG处理后在平邑甜茶和T337苹果品种中的表达量具有相似的变化趋势.该研究系统分析鉴定苹果全基因组中的所有转录因子基因家族,为今后深入了解蔷薇科植物转录因子的分类和基因功能研究提供了一定的参考依据.

CaSO4 is considered to be a potential oxygen carrier for chemical-looping combustion (CLC) due to its cheapness and high oxygen transport capacity. To improve the physicochemical stability of the CaSO4 oxygen carrier, CaSO4 composite oxygen carriers supported with clay, cement, and ash separately were prepared. It was found that the attrition resistance of the CaSO4 oxygen carrier composed of clay and cement improved due to the bond action of clay and cement. The reactivity of the composite oxygen carrier with coal was investigated in a thermogravimetric analyser (TGA) and fluidised bed. Sulphurous gas products were analysed by mass spectrometry (TG-MS) and gas chromatography (GC). Based on the catalysis of the active components in clay, cement and ash, the reaction rate of CaSO4 with coal was improved by the active materials. However, the side reaction generating the sulphurous gas was severe in both the reduction and oxidation stages, especially when using steam as the gasifying agent. To enhance the regeneration, the CaSO4/clay composite oxygen carrier was upgraded by adding CaO. It was demonstrated that SO2 release can be restrained in both the reduction and oxidation stages when the mass ratio of CaO to the CaSO4/clay composite oxygen carrier was higher than 1. At this point, the corresponding oxygen transport capacity was about 14.1 wt%.

生物农药开发前景广阔,乳浆大戟作为一种中草药,分布广、资源丰富,可利用其自身的毒性开发生物农药.以75％乙醇加热萃取法提取乳浆大戟中的活性成分,进行了杀虫抑菌生物活性试验,为乳浆大戟开发为新型生物农药提供科学依据.试验结果表明:提取物对果蝇及桃蚜具有良好的毒杀活性,提取物对果蝇的半致死量LC5o为75.51 mg/mL,果蝇死亡率与提取物浓度呈正相关,对桃蚜毒性的半致死量LC50为9.35mg/mL,当提取物浓度为50 mg/mL时对桃蚜的校正死亡率为85.59％;提取物对大肠杆菌、金黄色葡萄球菌以及枯草芽孢杆菌均有一定的抑菌作用,其中对枯草芽孢杆菌抑制作用较强,最大抑菌圈直径为1.53 cm;25mg/mL的提取物对玉米大斑病菌落扩展有明显抑制作用,抑菌率45.28％,对盆栽玉米苗大斑病的防治效果为36.63％.