玉米雄穗检测是玉米种植和育种农艺管理中必不可少的技术，可应用于产量估算、生长监测、智能采摘、病害检测等方面。然而，田间的玉米雄穗普遍存在遮挡现象，不同生长阶段的雄穗大小和形态颜色也不尽相同。针对这些问题，本文提出了SEYOLOX-tiny模型，可以更精准、更鲁棒地识别田间的玉米雄穗。通过无人机构建了丰富的玉米雄穗图像数据集，在保证图像质量和图像采集效率的同时兼顾不同时期的玉米雄穗的图像多样性。另外，YOLOX嵌入注意力机制，在关键特征的提取时，能有效抑制不利因素（遮挡、重叠）的噪声，有助于应对农田多变复杂的环境。实验结果显示，改进的识别算法SEYOLOX-tiny平均检测精度达到95.0%；相较于原始模型的mAP_@0.5、mAP_@0.5-0.95、mAP_{@0.5-0.95（面积=小）}和mAP_{@0.5-0.95（面积=中）}提升1.5、1.8、5.3和1.7个百分点。因此，本文提出的方法可以满足玉米穗检测视觉系统中所需要的精度和鲁棒性。

马铃薯是中国北方主要的粮食作物之一。然而，降水量少且年际波动大严重威胁着北方雨养马铃薯的高产和稳产。在水分限制条件下，优化水分管理措施可有效提升马铃薯的产量和水分利用效率，从而能保证粮食安全。但当前较少研究定量了不同水分管理措施对中国北方马铃薯产量和水分利用效率的贡献。本文基于多源大田试验数据和作物模型，使用Meta分析方法定量了中国北方大兴安岭区、燕山丘陵区、阴山北麓区和黄土高原区马铃薯的潜在、灌溉和雨养产量及其水分利用效率。结果表明，APSIM-Potato模型模拟的马铃薯潜在干重产量在燕山丘陵最高（12.4 t ha^-1），其次为阴山北麓（11.4 t ha^-1）、大兴安岭（11.2 t ha^-1）、和黄土高原（10.7 t ha^-1）。大兴安岭、燕山丘陵、阴山北麓和黄土高原实测的雨养马铃薯干重产量分别占各区潜在产量的61、30、28和24%。潜在条件下燕山丘陵马铃薯的水分利用效率最高，其次为大兴安岭、阴山北麓和黄土高原，对应的水分利用效率分别为2.2、2.1、1.9和1.9 kg m^-3。在北方马铃薯种植区，沟垄种植的马铃薯产量和水分利用效率可较平作提升8-49%和2-36%，而沟垄种植搭配覆膜的马铃薯产量和水分利用效率可较平作提升35-89%和7-57%。在水资源有限的马铃薯种植区，通过沟垄种植、覆膜和补灌相结合的水分管理方式能协同提高马铃薯的产量和水分利用效率。

染色质可及性在基因转录调控中起着至关重要作用。然而，染色质可及性的调控机制，及其调控玉米关键基因表达和籽粒发育的机制尚不清楚。本研究中，我们分离了一个玉米籽粒突变体，将其命名为dek219，该突变体表现为粉质胚乳和胚停止发育。Dek219编码DICER-LIKE1 (DCL1)蛋白，是一种miRNA生物发生的必需酶。Dek219功能缺失导致大多数miRNAs和组蛋白基因的表达水平显著降低。进一步研究表明，热激转录因子Hsf17-Zm00001d016571模块可能是影响组蛋白基因表达的因素之一。转座酶可及染色质测序分析(ATAC-seq)表明，与野生型(WT)相比，dek219的染色质可及性发生了改变，这可能调控了籽粒发育中关键基因的表达。通过分析WT和dek219之间的差异表达基因(DEGs)和差异可及染色质区域(ACRs)，我们鉴定到119个受染色质可及性调控的候选基因，包括已报道的玉米籽粒发育关键基因。综上所述，这些结果表明Dek219影响染色质可及性和关键基因的表达，是玉米籽粒发育所必需的。

During the attack of a pathogen, a variety of defense-associated proteins are released by the host plant in the apoplast to impede the perceived attack.  This study utilized the mass spectrometry (LC-MS/MS) and label-free quantification method to analyze the apoplastic fluid (APF) from maize stalk and identified the proteins responsive to the Fusarium verticillioides infection.  We have identified 742 proteins, and among these, 119 proteins were differentially accumulated (DAPs), i.e., 35 up-regulated, 18 down-regulated, and 66 proteins were only induced by the pathogen infection.  The differentially accumulated proteins were analyzed for their Gene Ontology (GO) and Kyoto Encyclopedia of Gene and Genomes (KEGG) pathway enrichment.  The highly enriched Biological Process (BP) term was the L-serine biosynthesis process, whereas the most enriched Molecular Function (MF) term was the cysteine-type endopeptidase inhibitor activity.  It was also found that the pathways related to the biosynthesis of amino acid, biosynthesis of secondary metabolites, protein processing in the endoplasmic reticulum, and carbohydrate metabolic pathways were significantly enriched.  Moreover, 61 out of 119 differentially accumulated proteins were predicted as secretory proteins.  The secretory pathways analysis showed that a greater number of proteins were secreted through the conventional secretion system compared to the unconventional secretion system.  The identified secreted proteins were related to a variety of pathways in defense responses including cell redox homeostasis, cell wall modification, signal transduction, carbohydrate metabolism, binding proteins (metal ion binding, RNA binding and heme-binding), maintenance and stabilization of other proteins, indicating a complex response from the plant to the fungal infection.  Our data suggested that a number of host proteins belonging to various pathways have been modulated in the apoplastic region.

免耕和秸秆还田均影响土壤有机碳含量和组分。然而，免耕和秸秆还田对土壤有机碳库变化的影响有待进一步研究。本研究选择华北平原11年长期定位试验，试验主处理为免耕(NT)和常规耕作(CT)，副处理为秸秆不还田(S0)、仅小麦秸秆还田(S1)和小麦玉米秸秆均还田(S2)，揭示耕作和秸秆还田对土壤有机碳数量和质量的影响。分析不同管理模式下土壤有机碳及其不稳定性组分（颗粒有机碳、高锰酸钾氧化性有机碳、微生物量碳和可溶性有机碳）含量，利用荧光光谱结合平行因子分析可溶性有机碳组成，采用¹³C核磁共振技术分析土壤有机碳化学结构。结果表明，秸秆还田显著增加了0-20 cm土层土壤有机碳含量和储量，但免耕对其仅起到层化作用，即与常规耕作相比，免耕增加了0-10 cm土层有机碳含量和储量，却降低了10-20 cm土层有机碳含量和储量，这种现象在小麦玉米秸秆均还田条件下(S2)条件下更加明显。不稳定性有机碳组分变化趋势与土壤有机碳相似，其中颗粒有机碳和高锰酸钾氧化性有机碳对秸秆还田较为敏感，而前者对耕作更为敏感。可溶性有机碳的六个荧光组分主要包括腐殖质类物质和少量的富里酸类物质和色氨酸。秸秆还田显著降低了荧光指数(FI)和自生源指数(BIX)，但增加了腐殖化指数(HIX)。在小麦玉米均还田条件下(S2)，免耕显著增加了上层HIX和下层BIX及FI。土壤有机碳化学结构表现为氧烷基碳>烷基碳>芳香碳>羧基碳。综上所述，在小麦和玉米秸秆均还田条件下，免耕增加了上层土壤有机碳含量及其不稳定性有机碳组分、可溶性有机碳的腐殖化程度和下层微生物驱动的可溶性有机碳。小麦玉米秸秆均还田是增加耕层土壤有机碳有效管理措施，免耕对上层和下层土壤有机碳层的差异变化可能对碳固持具有长期的影响。

本文研究不同采收时间（间隔1-2周）对赣南脐橙果汁的化学成分及其抗氧化能力的影响。研究结果表明，随着果实逐渐成熟，果汁中可溶性固形物 (TSS)、总酚 (TPC)、总黄酮（TFC）、蔗糖以及橙皮苷含量均逐渐增加，在成熟后期阶段略有下降。可滴定酸 (TA)、维生素C (V_C) 和柠檬苦素的含量在整个成熟期均呈下降趋势。果糖、葡萄糖以及芸香柚皮苷含量在整个采收期均有波动，没有明确的上升或下降趋势。运用三种体外抗氧化筛选平台（DPPH, FRAP, ABTS）对果汁的抗氧化活性进行评价，结果表明采收时间对赣南脐橙果汁体外抗氧化能力无显著性影响 (p>0.01)。在此基础上，本文运用主成分分析和皮尔逊相关性分析对不同采收期赣南脐橙果汁的化学成分及抗氧化能力进行了归类和相关性分析。本文首次深入系统的研究了采收时间对赣南脐橙果汁的化学成分及抗氧化能力的影响，研究成果有望为赣南脐橙品质评价提供重要科学依据。同时，我们的研究结果表明，在成熟后期采摘的赣南脐橙果汁不仅柠檬苦素含量低，而且具有很好的抗氧化能力和很高的黄酮类化合物含量，非常适合用于果汁加工。

试验研究了温度和太阳辐射对水稻产量的影响，旨在明确淮河下游水稻高产形成对温度和太阳辐射的需求。试验于2017-2018年以2个中熟中粳和4个迟熟中粳为材料，设置5月10日、5月17日、5月24日、5月31日、6月7日、6月14日和6月21日7个播种期。随着播期的推迟，水稻全生育期天数呈缩短的趋势，主要表现为播种至抽穗期天数的缩短。水稻全生育期有效积温、日平均温度、累积辐射和日均辐射均随播期推迟而减少。与T1播期相比，T2，T3，T4，T5，T6和T7播期分别减产0.12-0.35，0.45-0.89，0.74-1.56，1.41-2.24，2.16-2.90和2.69-3.64 t hm^-2。水稻产量与不同生育阶段有效积温呈极显著正相关。温度是影响优质食味水稻在沿淮下游地区形成高产的主要气象因子，当中熟中粳和迟熟中粳获得相对高产时，播种至抽穗期平均温度范围分别为25.8-27.0°C和26.6-27.1°C，抽穗至成熟期分别为20.3-23.3°C和20.3-22.1°C。中熟中粳和迟熟中粳在沿淮下游地区的最佳播期分别为5月15-31日和5月15-18日。

To date, little attention has been paid to the effects of leaf source reduction on photosynthetic matter production, root function and post-silking N uptake characteristics at different planting densities. In a 2-year field experiment, Xianyu 335, a widely released hybrid in China, was planted at 60 000 plants ha^–1 (conventional planting density, CD) and 90 000 plants ha^–1 (high planting density, HD), respectively. Until all the filaments protruded from the ear, at which point the plants were subjected to the removal of 1/2 (T1), 1/3 (T2) and 1/4 (T3) each leaf length per plant, no leaf removal served as the control (CK). We evaluated the leaf source reduction on canopy photosynthetic matter production and N accumulation of different planting densities. Under CD, decreasing leaf source markedly decreased photosynthetic rate (P_n), effective quantum yield of photosystem II (ΦPSII) and the maximal efficiency of photosystem II photochemistry (F_v/F_m) at grain filling stage, reduced post-silking dry matter accumulation, harvest index (HI), and the yield. Compared with the CK, the 2-year average yields of T1, T2 and T3 treatments decreased by 35.4, 23.8 and 8.3%, respectively. Meanwhile, decreasing leaf source reduced the root bleeding sap intensity, the content of soluble sugar in the bleeding sap, post-silking N uptake, and N accumulation in grain. The grain N accumulation in T1, T2 and T3 decreased by 26.7, 16.5 and 12.8% compared with CK, respectively. Under HD, compared to other treatments, excising T3 markedly improved the leaf P_n, ΦPSII and F_v/F_m at late-grain filling stage, increased the post-silking dry matter accumulation, HI and the grain yield. The yield of T3 was 9.2, 35.7 and 20.1% higher than that of CK, T1 and T2 on average, respectively. The T3 treatment also increased the root bleeding sap intensity, the content of soluble sugar in the bleeding sap and post-silking N uptake and N accumulation in grain. Compared with CK, T1 and T2 treatments, the grain N accumulation in T3 increased by 13.1, 40.9 and 25.2% on average, respectively. In addition, under the same source reduction treatment, the maize yield of HD was significantly higher than that of CD. Therefore, planting density should be increased in maize production for higher grain yield. Under HD, moderate decreasing leaf source improved photosynthetic performance and increased the post-silking dry matter accumulation and HI, and thus the grain yield. In addition, the improvement of photosynthetic performance improved the root function and promoted post-silking N uptake, which led to the increase of N accumulation in grain.

Azospirillum brasilense与Pseudomonas fluorescens是应用广泛的植物根际促生菌。目前Azospirillum brasilense与Pseudomonas fluorescens对稻田土壤氮循环和水稻生长发育的影响尚不清楚。本研究通过两年田间试验（2016-2017）解析了Azospirillum brasilense与Pseudomonas fluorescens对水稻根际土壤氮素转化和供氮能力的影响，明确了Azospirillum brasilense与Pseudomonas fluorescens在稻田肥料减施增效中的作用。微生物接种包括4个处理，分别为生理盐水接种（对照，M₀），水稻幼苗接种Azospirillum brasilense（M_b），水稻幼苗接种Pseudomonas fluorescens（M_p），水稻幼苗接种Azospirillum brasilense与Pseudomonas fluorescens的混合物（M_bp）。氮肥施用水平包括4个处理，分别为0 kg N hm^-2（N₀）)，90 kg N hm^-2（N₉₀），180 kg N hm^-2（N₁₈₀），270 kg N hm^-2 （N₂₇₀）。结果表明，与M₀相比，M_bp与M_p处理显著增强了水稻根际土壤氨化作用强度，高氮条件下提升作用更显著。与M₀相比，M_bp与M_b处理显著增强了水稻根际土壤固氮酶活性，低氮条件下提升作用更显著。接种用的Azospirillum brasilense与Pseudomonas fluorescens不参与水稻根际土壤的硝化和反硝化过程。根际促生菌与氮肥的交互作用对土壤呼吸速率与微生物量氮有显著影响。在M_bp处理中，N₉₀、N₁₈₀、N₂₇₀处理的土壤供氮能力与水稻产量无显著差异。水稻幼苗接种Azospirillum brasilense与Pseudomonas fluorescens的混合物，可将该地区氮肥施用量降至90 kg N hm^-2。

As a short-day plant species, maize requires an optimal photoperiod for inducing reproductive growth. However, there is a lack of information regarding photoperiod-induced changes in maize mRNA and protein levels. In this study, a photoperiod-insensitive maize inbred line and its near isogenic photoperiod-sensitive line were used. By integrating RNAbased transcriptomic and iTRAQ LC-MS/MS-based proteomic approaches, we generated a comprehensive inventory of the transcripts and proteins with altered abundances in response to a long photoperiod (LP) during growth stage transitions. We detected 22 000 transcripts in RNA-sequence runs and 5 259 proteins from an iTRAQ-based analysis. A weak correlation between mRNA- and protein-level changes was observed, suggesting the LP-induced transition between maize growth stages is largely regulated post-transcriptionally. Differentially expressed genes influenced by LP conditions were associated with several regulatory processes in both maize inbred lines, especially phosphate ion transport and the circadian rhythm. Additionally, 31 transcripts and six proteins related to photoperiodic flowering in maize were identified by comparing transcriptomic and proteomic data. This transcriptomic and proteomic analysis represents the first comprehensive and comparative study of gene/protein-level changes occurring in photoperiod-sensitive and -insensitive maize inbred lines

In this paper, the influence of drought hardening on the growth, development, resistance physiology, leaf microstructure and stomatal behavior of potato seedlings under drought stress was studied, and the mechanism of drought hardening improvement of potato seedling drought resistance was elucidated.  We found that drought stress had several adverse effects on potato seedlings, yet drought hardening alleviated the decrease in relative water content (RWC), net photosynthetic rate (P_n) and chlorophyll content and inhibited the increase in relative electric conductivity and malondialdehyde (MDA) content.  Compared with contrast seedlings, drought-hardened seedlings also had enhanced root vigor, increased antioxidant enzyme activity and higher levels of abscisic acid (ABA), proline (Pro), soluble sugars and polyamines (PAs) under drought stress.  In addition, the stomatal density of potato seedling leaves increased significantly, while the leaf area, stomatal size and stomatal aperture decreased with drought hardening treatment.  These changes led to reduced leaf transpiration rate (T_r) and improved water utilization efficiency (WUE).  The changes in leaf microstructure also had a positive effect on the drought resistance of the drought-hardened potato seedlings. So it can be concluded that through increasing the content of some endogenous hormones, osmotic regulatory substances and the activities of antioxidant enzymes, the resistance physiology of drought-hardened potato seedlings was enhanced. 

Rice (Oryza sativa L.) is highly susceptible to the rhizosphere salinity than other cereals.  High sensitivity has been observed, mainly at vegetative and reproductive stages in rice.  It is the duty of plant physiologists to comprehend the growth, development, and physiological processes of rice plants under stress.  This paper includes the overview of rice growth and developmental processes influenced by salt stress and the regulation pathways involved in these processes.  It also includes the promising salt tolerance strategies, i.e., genetic modification techniques, agronomic practices to improve rice growth, yield, and role of phytohormones and their management, especially inhibition of ethylene biosynthesis by using inhibitors 1-methylcyclopropene (1-MCP).  Rice cultivation may be a first choice for improvement of salt tolerance through plant growth regulators and improved cultivation techniques.  This study will significantly improve the understanding toward low rice grain yield and poor rice resistance under salt stress and will also stream scientific knowledge for effective utilization of salt affected soils by using different regulating ways.  

    An optimum heading date is essential for sustainable crop productivity and ensuring high yields. In the present study, F_2:3 populations were generated by crossing an early-heading accession, Y2280, with a late-heading accession, Y2282. The heading dates of the F₂ and F₃ populations were investigated in a field study. Using publicly available simple sequence repeat (SSR) markers, the early heading date gene HdAey2280 was mapped onto Aegilops tauschii chromosome 7DS between the flanking markers wmc438 and barc126 at distances of 15 and 9.1 cM, respectively. Further analysis indicated that HdAey2280 is a novel heading date gene. New SSR markers were developed based on the Ae. tauschii draft genome sequence, resulting in four new markers that were linked to the heading date gene HdAey2280. The closest distance of these markers was 1.9 cM away from the gene. The results collected in this study will serve as a framework for map-based cloning and marker-assisted selection in wheat breeding programs in the future.

Macroscopic grasp of agricultural carbon emissions status, spatial-temporal characteristics as well as driving factors are the basic premise in further research on China’s agricultural carbon emissions. Based on 23 kinds of major carbon emission sources including agricultural materials inputs, paddy field, soil and livestock breeding, this paper firstly calculated agricultural carbon emissions from 1995 to 2010, as well as 31 provinces and cities in 2010 in China. We then made a decomposed analysis to the driving factors of carbon emissions with logarithmic mean Divisia index (LMDI) model. The results show: (1) The amount of agricultural carbon emissions is 291.1691 million t in 2010. Compared with 249.5239 million t in 1995, it increased by 16.69%, in which, agricultural materials inputs, paddy field, soil, enteric fermentation, and manure management accounted for 33.59, 22.03, 7.46, 17.53 and 19.39% of total agricultural carbon emissions, respectively. Although the amount exist ups and downs, it shows an overall trend of cyclical rise; (2) There is an obvious difference among regions: the amount of agricultural carbon emissions from top ten zones account for 56.68%, while 9.84 % from last 10 zones. The traditional agricultural provinces, especially the major crop production areas are the main source regions. Based on the differences of carbon emission rations, 31 provinces and cities are divided into five types, namely agricultural materials dominant type, paddy field dominant type, enteric fermentation dominant type, composite factors dominant type and balanced type. The agricultural carbon emissions intensity in west of China is the highest, followed by the central region, and the east zone is the lowest; (3) Compared with 1995, efficiency, labor and structure factors cut down carbon emissions by 65.78, 27.51 and 3.19%, respectively; while economy factor increase carbon emissions by 113.16%.

The objective of this study was to determine the morphology mechanism of nitrogen (N) fertilizer rates and ratio on lodging resistance through analying its effects among lodging index (LI), lodging-related morphological traits and physical strength in basal internodes by comparing japonica and indica super rice cultivars. Field experiments, with three nitrogen levels (0, 150 and 300 kg ha-1) and two ratios of basal to topdressing (8:2 and 5:5) with two super rice cultivars (Yliangyou 2 and Wuyunjing 23), were conducted in the Baolin Farm, Danyang Country, Jiangsu Province, China, in 2011 and 2012. Effects of N fertilizer rates and ratios on morphology of whole plant, morphology traits in basal internodes and culm’s physical strength parameters were investigated at 20 d after full heading stage. LI of Yliangyou 2 was significant greater than that of Wuyunjing 23 due to larger bending moment by whole plant (WP) with higher plant height and gravity center height. With higher volume of N fertilizer, LI of two super rice cultivars was increased conspicuously. However, no significant effect was detected with increase of panicle fertilizer ratio. The size of breaking strength (M) in basal internodes was the key factor determining LI among N fertilizer treatments. Correlation analysis revealed that M value was positively related bending stress (BS) of Wuyunjing 23 and section modulus (Z) of Yliangyou 2, respectively. The higher N fertilizer levels induced reduction of BS of Wuyunjing 23 due to weak culm and leaf sheath plumpness status and reduced Z of Yliangyou 2 owning to small diameter and culm wall thickness, consequently, influencing their M indirectly. These results suggested that breaking strength was the key factor influencing LI with increase of N fertilizer levels. However, the lodging-related morphology mechanism was different with genotypes. Culm wall thickness and diameter in basal internodes of indica super rice and culm and leaf sheath plumpness status of japonica super rice influenced breaking strength, as well as lodging index, respectively.

Jojoba (Simmondsia chinensis) is mainly distributed in desert, and the molecular mechanisms of jojoba in response to abiotic stress still remain elusive. In this paper, we cloned and characterized a SOD gene from jojoba named as ScMnSOD, and introduced into Arabidopsis to investigate its functions of responding to drought stress. The transgenic Arabidopsis showed an improvement in drought tolerance. Moreover, under a water deficit condition, the accumulation of reactive oxygen species (ROS) was remarkably decreased in the transgenic lines compared to the WT. Furthermore, the ScMnSOD promoter was cloned to the 5´-upstream of GUS coding region in a binary vector, and introduced into Arabidopsis. And results showed that ScMnSOD expression can be induced by drought, salt, ABA, and low temperature. In conclusion, ScMnSOD plays an important role in drought tolerance which is, at least partially, attributed to its role in ROS detoxification.

Supercritical carbon dioxide (SC-CO2) extraction was employed to extract oil from Nigella glandulifera Freyn seed in this study. Response surface methodology (RSM) was applied to evaluate the effects of the process parameters (pressure, temperature, and CO2 flow rate) on oil yield of N. glandulifera seed. A Box-Behnken design was used to optimize the extraction parameters. The analysis of variance indicated that the linear coefficients of pressure and CO2 flow rate, the quadratic term coefficients of pressure and temperature and the interactions between pressure and temperature, as well as temperature and CO2 flow rate, had significant effects on the oil yield (P<0.05). The optimal conditions to obtain the maximum oil yield from N. glandulifera seed were pressure 30.84 MPa, temperature 40.57°C, and CO2 flow rate 22.00 L h-1. Under these optimal conditions, the yield of oil was predicted to be 38.19%. The validation experiment results agreed with the predicted values. The fatty acid composition of N. glandulifera seed oil extracted using SC-CO2 was compared with that of oil obtained by Soxhlet method. The results showed that the fatty acid compositions of oil extracted by the two methods were similar. Identification of oil compounds with gas chromatography-mass spectrometry (GC-MS) showed that the contents of unsaturated fatty acids linoleic acid (48.30%), oleic acid (22.28%) and saturated fatty acids palmitic acid (16.65%), stearic acid (4.17%) were the most abundant fatty acids in seed oil from N. glandulifera.