In response to the current problems of low production efficiency, discontinuous batches and difficult quality control in industrialized dish stir-frying equipment, based on the research of the influence of multi-parameter coupling of cooking time, power and speed on cooking quality, a drum-type industrialized continuous stirfrying equipment suitable for Chinese-style meat dish stir-frying is developed and its performance is verified. The stir-frying process is simulated using EDEM, and the stirring effect and stir-frying time corresponding to different scraper angles are compared. The results show that the stirring effect is the optimal when the scraper angle is 22.5 degrees, and the stir-frying time is the shortest when the angle is 45 degrees. Taking pork tenderloin as the research object and the comprehensive quality of stir-frying as the optimization index, orthogonal experiments and response surface analysis are conducted. The experimental results demonstrate that under optimal processing conditions (specifically a scraper angle of 22.5 degrees, electromagnetic power of 29.2 kW, and stirring speed of 29.6 rpm), the comprehensive quality of pork tenderloin slices achieves its maximum value. The verification experiments indicate that the error between the experimental values and the predicted values is less than 5 %. Comparative experiments show that this equipment's stir-fried pork tenderloin comprehensive quality is 54 % of traditional techniques, but its production efficiency is 7 % higher than that of commercial stir-frying equipment of the same specification. It has improved the processing efficiency while maintaining a certain quality. The development of this equipment provides a new idea for the continuous processing of Chinese cuisine.

Ice crystallization has been the main cause of the deterioration of frozen meat quality, because ice crystal expansion causes mechanical damage to the muscle tissue. Thus, in this study, an innovative non-crystal freezing (NCF) technology, which can achieve non-freezing at temperatures below the ice nucleation point (-4.5 °C for yak), was proposed, and corresponding equipment was designed to prolong the shelf life and increase the logistics distance of yak meat. The non-frozen stability and quality of yak meat with NCF were investigated and compared with those of traditional sub-frozen (-4.5 °C) and chilled (4 °C) yak meat. Results of thermal imaging and temperature curves indicate that ice nucleation and phase transition were observed in the -4.5 °C samples during 1-3 days, whereas the icing phenomenon was not found in the NCF samples during the entire 28-day storage period. The microstructure of the NCF samples was differed from that of the -4.5 °C samples, which avoided ice-induced freezing damage and maintained the original integrity. Compared with the -4.5 °C and 4 °C samples, the weight loss of the NCF samples was reduced by 5.33 %-6.94 % and 1.42 %-3.16 %, respectively. Microbial analysis and physicochemical results indicate that compared with 4 °C treatment, NCF extends the shelf life of yak meat by at least twice. NCF breaks down the line between chilling and freezing, combining advantages of low temperature and a non-freezing state, which makes the long-term storage and long-distance, cross-regional logistics of fresh yak meat possible.

In this study, a specialized experimental device integrating infrared thermal imaging, real-visual photography, and a time-temperature data collector was designed to investigate the effects of alternating electric field (AEF) assisted freezing on the temperature histories and freezing parameters in different layers of beef as well as the freezing damage and myowater loss. The findings revealed distinct differences in the freezing curves (e.g., slope) and parameters (e.g., Tnuc, TF, tpt and Fmiz) between the surface, middle, and inner layers of beef cubes under both AEF and traditional freezing conditions. AEF treatment regulated the freezing curves and key parameters of middle and surface layers, influencing ice crystallization. The equivalent ice areas for the surface, middle, and inner samples under AEF treatment were 8.16, 14.40, and 20.56%, respectively, significantly lower than those in traditional freezing (15.87, 24.60, and 28.8%). Compared to traditional freezing, AEF-assisted freezing decreased myofibrillar fragmentation index (MFI) of beef muscle, preserving its texture integrity. AEF treatment inhibited water migration and reduced water-holding capacity (WHC) loss. In conclusion, AEF-assisted freezing changed ice formation characteristics and alleviated freezing damage by regulating the freezing curve traits and parameters.

The study was designed to investigate the mechanism of Riboflavin (RF)-mediated UVA photosensitive oxidation on beef myofibrillar proteins (MP) oxidized at different storage times. To elucidate the direct relationship between RF and protein oxidation, the mechanism of action was analyzed in terms of amino acid and side chain residues, protein structure, and protein oxidative metabolism. Oxidation of MP resulted in significant changes in the levels of carbonyls, sulfhydryls, Lysine, Arginine, Threonin, and Histidine. The oxidized MP secondary structure was changed, fluorescence intensity decreased, and surface hydrophobicity increased. Metabolomics results revealed that RF-mediated UVA photosensitized oxidation is primarily mediated by Riboflavin metabolism and co-regulated with Phenylalanine metabolism. Moreover, with the increase of frozen storage time, Arginine and proline metabolism was inhibited, and the contents of creatine were significantly reduced, which exacerbated MP oxidative damage. The results provide a theoretical basis for unraveling the mechanism of RF-mediated UVA photosensitive oxidation of MP.

In the field of intelligent meat processing, the application of 3D laser scanning technology for identifying meat contours is essential for the accurate estimation of meat volume and quantitative slicing. In this study, based on 3D laser scanning technology, a contour adaptive shaping unit was developed to address the issue of scanning irregular meat contours and improve the scanning range and volume estimation accuracy. Moreover, we developed software for contour visualization imaging and volume estimation of raw meat using Halcon and Visual C# to optimize the scanning imaging and volume estimation of pork belly, hind shank, and pork loin. The results showed that the optimal shaping angles for chilled and frozen pork (loin, hind shank, and belly) were 60(degrees), 30(degrees), and 30(degrees), respectively, with a scanning accuracy of >= 90 % and an average increase of 3 %. After shaping, the volume forms of the three types of raw meat remained stable for 12, 9, and 6 s in the chilled and frozen state. The corresponding coefficients of variation (CV) of imaging accuracy were 0.77 %, 1.16 %, and 0.54 %, respectively, with high stability and consistency of the imaging accuracy. In addition, the pork color and the transfer speed did not significantly affect the imaging performance of the adaptive shaping system (p > 0.05). The results demonstrated that the adaptive contour shaping system exhibited superior optimization capabilities in raw meat imaging, which provided the technical basis for the subsequent research and development pertaining to adaptive quantitative slicing devices for raw meat of various specifications.

A soft texture in the interior with a crispy exterior is essential for deep-fried batter-coated meat strips (BCMSs). This study investigated the effects of carboxymethyl cellulose (CMC) on the batter properties and gel structure of wheat starch-flour blends. Various visual techniques, such as scanning electron microscopy (SEM), threedimensional magnetic resonance imaging (MRI), and infrared thermography, were employed to analyze the transfer of water/oil/heat between the medium, crust, and core meat to reveal the effects of changes in gel properties on the texture of deep-fried BCMSs. As the content of CMC increased, the batter viscosity initially remained unchanged and then increased. Results of the coating pickup and rheological tests showed that the CMC-0.75 % had the thickest coating and the poorest gel stability, which resulted in thick crust gel fracture, forming large chambers. According to the MRI and infrared thermal imaging results, large chambers facilitate the transfer of heat and oil to the core meat, thus enhancing crust crispness but decreasing meat tenderness. Comparatively, 0.5 % CMC improved the integrity and viscoelasticity of the crust gel network. The complete gel network inhibited the unfolding and reaggregation of muscle proteins caused by oil and heat transfer, which mitigated the degree of meat protein denaturation, thus protecting tenderness. Meanwhile, delaying protein denaturation reduced water migration from the meat to the crust and improved crispness. Thus, a moderate addition of 0.5 % CMC ensured a soft interior texture with a crispy exterior for fried BCMSs.

Prepared dishes, as a technological extension of pre-conditioned foods and representative products of the central kitchen, are becoming a major part of people's daily diets. However, the problem of dish quality deterioration owing to freezing in the frozen supply chain has not yet been addressed, and freezing quality enhancement techniques are lacking. Herein, special equipment was used to investigate effects of ultrasound-assisted immersion freezing (UIF) on the quality of the prepared dish (braised beef with potato) and compare it with immersion freezing (IF) and conventional air freezing (AF). Results indicated that UIF effectively shortened the freezing time and improved the freezing rate of the dish. A suitable intensity of UIF treatment (150 W) improved dish quality, and high-intensity UIF treatments (300 and 450 W) caused tissue structure destruction and decreased quality. The hardness of beef and potatoes treated with UIF-150 was significantly higher than that of other treatments (P < 0.05). Scanning electron microscopy demonstrated that UIF-150 reduced the size of ice crystals and maintained the structural integrity of beef and potatoes. Porosity values of beef were 6.91 %, 2.66 %, 2.09 %, 4.30 % and 6.94 % in the AF, IF, UIF-150, UIF-300 and UIF-450 groups, respectively, and the trend of porosity in potatoes was similar to that of beef. Meanwhile, the contents of volatile flavour components in the dishes were remarkably decreased after freezing treatments, and UIF treatment could promote the retention of volatile flavour components. Results of this study provided a reference for the application of UIF technology in the frozen quality enhancement of prepared dishes and their industrialisation.

To explore the flavor changes in specialty chicken meat after stewing, gas chromatography-olfactometry mass spectrometry (GC-O-MS) and gas chromatography ion mobility spectroscopy (GC-IMS) were used to analyze the flavor compound differences among Yellow feather chicken (YC), Lohmann powder chicken (LC), and Jianmen native chicken (JC) after stewing. Results indicated that LC had high shear force and hardness, while JC had lower protein content than YC. Regarding taste compounds, LC had higher contents of umami amino acids and AMP, whereas JC had more sweet amino acids. 13 key aroma compounds were identified by GC-O-MS, like hexanal gives JC a grassy flavor, while dimethyl disulfide affecting only LC's overall flavor. The results were further visualized using GC-IMS, indicating that the total concentration of volatile compounds in LC and JC was higher than in YC. Overall, LC and JC had excellent flavor performance than YC after stewing, with LC showing particularly prominent umami.

To address the issues of difficulty in quantifying the skills involved in cooking process of chefs and the unclear formation mechanism for dish quality, this study designed a multi-dimensional information sensing platform using infrared thermal camera (IR) and a nine-axis inertial measurement unit (IMU). This platform can achieve real-time collection of the chef's stir-frying frequency and the degree of uniform heating of ingredients. The stirfrying frequency was analyzed in conjunction with the power spectral density function, while the Composite Uniformity Index (CUI) was proposed based on the temperature field distribution to achieve a digital characterization of the heating uniformity of the ingredients. The results showed that higher stir-frying frequencies improved heating uniformity and accelerated protein denaturation but increased moisture loss, making the meat firmer. Moreover, we found that the stir-frying frequency stabilizes at 2 Hz and maintains the best quality of the dish. Notably, higher stir-frying frequencies correlated with increased production of volatile compounds, including particularly 3-methylbutanal and 3-hydroxy-2-butanone, and enhanced decomposition of esters and degradation of 1-pentanol. This study elucidates the role of heating uniformity in shaping meat texture and flavor by analyzing the stir-frying frequency, providing a theoretical foundation and technical support for the standardization of stir-frying processes.

Meat quality (MQ) is unstable during cold chain logistics (CCL). Different technologies have been developed to enhance MQ during the CCL process, while most of them cannot cover all the links of the cold chain because of complex environment (especially transportation and distribution), compatibility issues, and their single effect. Electric fields (EFs) have been explored as a novel treatment for different food processing. The effects and potential advantages of EFs for biological cryopreservation have been reported in many publications and some commercial applications in CCL have been realized. However, there is still a lack of a systematic review on the effects of EFs on their quality attributes in meat and its applications in CCL. In this review, the potential mechanisms of EFs on meat physicochemical properties (heat and mass transfer and ice formation and melting) and MQ attributes during different CCL links (freezing, thawing, and refrigeration processes) were summarized. The current applications and limitations of EFs for cryopreserving meat were also discussed. Although high intensity EFs have some detrimental effects on the quality attributes in meat due to electroporation and electro-breakdown effect, EFs present good applicability opportunities in most CCL scenes that have been realized in some commercial applications. Future studies should focus on the biochemical reactions of meat to the different EFs parameters, and break the limitations on equipment, so as to make EFs techniques closer to usability in the production environment and realize cost-effective large-scale application of EFs on CCL.

In this study, the physicochemical properties of potato starch from different varieties were investigated. Furthermore, the relationships among gelatinization, retrogradation behavior, and impedance characteristics of potato starch gels were evaluated by texture analysis, low-field nuclear magnetic resonance spectroscopy, and electrical impedance spectroscopy. The results indicated amylose content was positively correlated with setback viscosity, and negatively correlated with To and ΔH. In addition, impedance values of potato starch gels differed in a frequency-dependent manner. Notably, higher frequencies resulted in low diffusion of ions in prepared gels, which combined with the concentration of mobile ions in free water, led to a gradual decrease in impedance module. Compared with phase values, impedance module showed high correlation with gelatinization parameters (To, Tp, and Tc) and viscosity parameters (peak temperature and setback viscosity), more notably at frequencies below 100 Hz. In this context, the electric current flowed through mobile ions that interacted with bound water attached to the starch molecules at lower voltage frequencies, and were repressed by the formation of an ordered and compact gel network during retrogradation. Collectively, these results indicate that impedance spectroscopy can be potentially used as an efficient and reliable method to predict gelatinization and retrogradation behavior of potato starch.

水稻油菜轮作制度是华中地区最具代表性的耕作制度,但水稻收获后的秸秆清理和还田效果会影响后续油菜的播种和收获.利用微生物降解秸秆是解决这一问题的有效途径之一.前期研究发现,粗糙脉孢菌接种至水稻秸秆,培养48 h时秸秆有明显降解现象,因此,本研究通过转录组测序技术研究分析比较接种在PDA培养基上和接种在水稻秸秆上培养48 h时粗糙脉孢菌的差异表达基因,以探讨其降解机理.结果表明,两者间共存在3329个显著差异表达基因,GO(gene ontology)功能注释分析发现,这些基因主要富集在生物过程类,表达差异较大的基因主要参于核苷酸代谢、蛋白质代谢及与内膜系统;KEGG(Kyoto Encyclopedia of Genes and Genomes)通路富集分析发现,这些差异表达基因的功能主要涉及半乳糖代谢、果糖和甘露糖代谢、氧化磷酸化、次生代谢产物的生物合成和核糖体,在这些代谢途径中筛选到的与降解秸秆相关的酶系多数为上调表达.在这些代谢途径中,推测粗糙脉孢菌主要通过半乳糖代谢、果糖和甘露糖代谢来降解水稻秸秆.以上研究可为更高效地利用粗糙脉孢菌降解秸秆提供新的理论依据和一定的技术支持.

To clarify the application potential of Neurospora crassa NC-3 strain on rice straw returning, a combination of indoor simulation and pot experiment were conducted to investigate the effects of NC-3 strain on degradation, cellulose, hemicellulosic, lignin, total phenolic acid content of rice straw, germination rate and seedling rate of rapeseed.The results showed that NC-3 strain could rapidly colonize on sterilized rice straw（full of mycelia and spores at 72 h）.Compared with the sterile water, the degradation rate of rice straw in NC-3 strain was increased by 2.3,7.3 and 3.2 percentage points at 7,14 and 21 days, respectively.The contents of cellulose, lignin and total phenolic acid decreased with NC-3 strain by 2.0,10.7,10.4 percentage points, 0.7,0.9,1.3 percentage points and 7.6%,6.9%,6.4%,respectively.The degradation effect of NC-3 strain on cellulose, lignin and total phenolic acid of rice straw mainly occurred in the first two weeks（0—14 days）of straw, and the degradation effect on hemicellulose gradually increased after 14 days of culture.Addition of rice straw significantly reduced the germination rate and seedling rate of rapeseed, and with the increase of straw dosage, the inhibition effect was enhanced, but NC-3 strain could significantly increase the germination rate and seedling rate of rapeseed（3.3 and 9.7 percentage points higher than sterile water in petri dish test, respectively）.In summary, NC-3 strain could effectively accelerate the degradation of rice straw and the transformation of phenolic acids, and effectively improve the germination rate and seedling formation rate of rapeseed.

The distribution of the flow field, the input energy of the twin-screw, and the dissipated energy on the fluid during the twin-screw extrusion process were calculated by the POLYFLOW software to establish the relationship between the rheological parameters of starch fluid and tensile properties of the final extrudate. The results demonstrated that the pressure difference, the input energy of the twin-screw, and the dissipated energy on the fluid were directly proportional to the zero-shear viscosity (eta(0)), reduced with the raise of the relaxation time constant (lambda) and raised with the raise of the power-law index (n). When the moisture content of starch fluid raised, the eta(0) value reduced, whereas the lambda value and n value increased. The pressure difference, the input energy of the twin-screw, and the dissipated energy on the fluid decreased, reducing the maximum tensile force of the final extrudate. Through numerical simulation and experimental verification, it was found that the changes of eta(0) value, lambda value, and n value restricted each other on the tensile properties of final extrudate. Based on the numerical simulation, the tensile properties of the final extrudate could be predicted through rheological parameters of starch fluid.

SummaryThe present study sought to investigate the rheological properties of wheat starch‐gluten (WS‐G) and potato starch‐gluten (PS‐G) model doughs with different gluten fractions to elucidate the effectiveness of using model dough to predict wheat dough properties. The highest linear viscoelastic region, frequency dependence, maximum creep compliance and the lowest viscoelastic modulus and zero shear viscosity were observed in the wheat dough, followed by WS‐G and PS‐G model doughs. PS exerted a more significant damage effect on the gluten network while WS shared a tight integration with gluten protein, forming a more stable dough structure. The viscoelasticity of the model doughs shared a close association with the wheat dough under increased gluten fraction, while the frequency dependence of the model doughs showed no trend towards wheat dough. Therefore, starch‐gluten model dough could not fully stimulate the functionality of wheat dough irrespective of its gluten fraction.

为提高抗寒性,促进油菜种子发芽及幼苗生长,以甘蓝型油菜品种中油杂19为材料,研究外源海藻糖浸种对低温胁迫下油菜种子萌发及幼苗生长的影响,阐明外源海藻糖浸种的寒害缓解作用.结果表明,在低温处理下(10℃),油菜种子萌发受到抑制,发芽势、发芽率、发芽指数及活力指数均显著下降,平均发芽时间显著延长;种子萌发过程中异柠檬酸裂解酶活性显著降低,可溶性糖和可溶性蛋白消耗显著降低,脯氨酸含量增加缓慢;油菜幼苗苗长、主根长及干鲜重均显著降低.而外源海藻糖浸种可以显著提高低温胁迫下油菜种子萌发速率及根系发育,促进幼苗生长,其中以10 mmol/L的海藻糖浸种处理效果最好.10 mmol/L海藻糖浸种可以促进油菜种子可溶性蛋白和可溶性糖的消耗,增加脯氨酸积累,提高异柠檬酸裂解酶的活性,使种子发芽率和发芽势分别提高19.4％和61.8％,平均发芽时间缩短21.7％;同时也可以促进幼苗根系生长,增加养分含量,提高油菜幼苗鲜重.相关分析发现浸种24 h后,可溶性糖和蛋白及脯氨酸含量与各项发芽指标显著相关.综上认为,10 mmol/L海藻糖浸种24 h,可通过促进种子能量代谢和渗透调节,缓解低温对种子萌发的抑制作用,促进油菜生产,提升其抗寒能力.

将不同比例的马铃薯泥(MP)、α-淀粉酶酶解马铃薯泥(α-AMP)和β-淀粉酶酶解马铃薯泥(β-AMP)分别与小麦粉复配制作馕,对比分析了不同类型马铃薯泥对馕质构和风味的影响.结果表明,随着MP或α-AMP添加量增加,馕内部的气孔逐渐减少,其质构品质变差;而添加β-AMP的馕内部保留了均匀气孔,添加10％或15％β-AMP的馕具有良好的回复性和弹性.添加MP或α-AMP导致馕中葡萄糖含量增加,果糖和蔗糖含量降低;而添加β-AMP可使馕中葡萄糖和果糖含量增加,蔗糖含量降低.同时添加β-AMP比α-AMP更加有利于保留馕中呈味氨基酸.添加β-AMP的馕与小麦馕风味差异显著,其中苯乙醛、辛醇、麦芽酚等新增挥发性化合物有助于形成马铃薯馕的特殊风味.

【Objective】Nitrogen (N) uptake efficiency is one of the important factors affecting crop N efficiency, investigating characteristics of efficient N uptake and transport was the purpose to provide the theoretical basis for improving N efficiency and yield of rapeseed (Brassica napus L.) varieties.【Method】To explore the mechanisms underlying high N uptake and transport in rapeseed, two rapeseed germplasms with contrasting N efficiency (N efficient germplasm ‘498’ and N inefficient germplasm ‘428’) were used in this study under normal N (9.5 mmol·L-1) and low N (0.475 mmol·L-1) conditions at three different growth stages (Phenological growth stages 12, 14 and 16) in hydroponic culture. At the same time, the 15N isotope tracer technique was applied to study the uptake and transport capacity of NO3− and NH4+. Additionally, the expression level of genes (BnNPFs, BnNRT2s and BnAMTs) related to N uptake and transport in rapeseed germplasms with contrasting N efficiency were further analyzed by real-time quantitative PCR (RT-qPCR).【Result】Rapeseed germplasm ‘498’ showed superior advantages in plant growth and root development under different N concentrations, and the root morphological indexes (main root length, total root length, root surface area, root volume and lateral root number), biomass, N accumulation and N uptake efficiency were all significantly greater than those of germplasm ‘428’. 15N isotope tracer test also showed that ‘498’ showed greater advantage in the uptake and accumulation of NO3- and NH4+, especially for NH4+, as indicated by the significant differences in the accumulation of 15NH4+ between two germplasms. The RT-qPCR analysis further found that under normal N conditions, the relative expressions of BnNPF6.3a, BnNRT2.1e, BnNPF7.2a, BnNPF7.2c, BnNPF6.2c, BnAMT1;2a, BnAMT1;3c, BnAMT1;4a, BnAMT2;1a and BnAMT2;1b (involved in the uptake and transport of NO3- and NH4+) was significantly higher in ‘498’ than that in ‘428’. While under low N stress, the relative expressions of BnNRT2.4a, BnNRT2.5a and BnNRT2.5b (involved in NO3- uptake and transport) was significantly lower in the root of ‘498’ than that of ‘428’, but the expression level of BnNPF7.3a and BnNPF6.2c (referred to NO3- transport and redistribution) was significantly higher in ‘498’ than that in ‘428’, as well as the expression level of BnAMT1;1a, BnAMT1;2a, BnAMT1;3c, BnAMT1;4a, BnAMT2;1a and BnAMT2;1b (involved in NH4+ uptake and transport).【Conclusion】Compared with N-inefficient germplasm ‘428’, N-efficient germplasm ‘498’ were superior in root length, root surface area (volume) and lateral root number, additionally with greater ability in N (especially NH4+) uptake and accumulation. Under normal N application conditions, the expression of genes involved in NO3- and NH4+ absorption and transport were relatively higher in ‘498’, while the relative expression of genes involved in the NO3- transport and redistribution as well as NH4+ absorption and transport were significantly higher in ‘498’ than that in ‘428’ under low N stress, illustrating the relative higher N uptake efficiency of ‘498’ possibly linked to the higher expressions of several BnNPFs sand BnAMTs.

为分析不同品种马铃薯淀粉组成与理化性质的差异,本研究以15个不同品种中薯系列马铃薯为原料提取淀粉,并对其组成和理化性质进行了检测及相关性分析.光学显微镜和扫描电镜结果表明,马铃薯淀粉颗粒的粒径分布范围广,颗粒形貌存在差异,小颗粒多为卵圆形,大颗粒多为椭圆形、拉长形以及不规则形.不同马铃薯淀粉的理化性质存在显著差异,其溶解度、膨润力范围分别为25.92％～28.74％,4.90～6.26 g·g-1;糊化初始温度(To)、峰值温度(Tp)、终止温度(Tc)、糊化焓值(ΔH)范围分别为61.44～65.55℃、64.49～68.69℃、67.87～72.54℃、7.21～13.49 J·g-1;峰值黏度、衰减值、回生值范围分别为2499.3～3220.4、514.0～2218.4、401.0～884.1 BU.相关性分析结果表明,马铃薯淀粉中磷含量与峰谷黏度呈显著正相关,与溶解度呈显著负相关;平均粒径D[4,3]与短程有序参数1045/1022 cm-1和1022/995 cm-1均呈显著正相关;To与峰值黏度呈显著负相关;糊化温度与峰值黏度和崩解值均呈显著负相关,与峰谷黏度、最终黏度和回生值均呈显著正相关.本研究结果可为中薯系列马铃薯淀粉在食品加工中的应用提供科学依据.

为探究氮高效的机制,研究油菜苗期碳氮代谢规律,以两个氮效率差异显著的油菜种质(氮高效种质A294和氮低效种质A364)为材料,通过设置正常(CK,9.5 mmol/L)和低氮(LN,0.475 mmol/L)两个处理,比较不同氮效率油菜在根系形态、氮吸收转运同化、光合碳代谢生理指标以及碳氮代谢相关基因表达等方面的差异.结果表明,氮高效的A294在低氮胁迫下根系发达,植株生物量和氮累积量显著高于A364,前者根系吸收及向地上部转运氮的能力较强,而氮同化关键酶硝酸还原酶和谷氨酰胺合成酶活性在两个种质间无显著差异;同时,A294叶片SPAD值、光合色素含量、净光合速率及磷酸蔗糖合酶基因BnaSPS的表达均更高.进一步分析发现,低氮胁迫下A294根系中硝酸盐转运蛋白基因BnaNPF7.3的表达显著高于A364,而BnaNPF7.2b在A364根系的表达则显著高于A294;此外,A364可溶性糖含量的根叶比及根系中蔗糖合酶基因BnaSUS表达高于A294,说明低氮胁迫下氮高效油菜A294可以将更多的营养元素(氮)分配至地上部,使叶片保持较高的光合速率,为生物体构建提供保障;而氮低效油菜种质A364则倾向于将有限的营养元素(氮)分配在根系并维持其生长发育,同时其根系可溶性糖消耗占比高于A294,导致其根冠比高于A294.由此认为,油菜在响应外界氮缺乏胁迫时,氮素与能量物质(可溶性糖)的分配与消耗差异会影响叶片碳代谢(光合作用、蔗糖合成)速率,最终导致油菜苗期氮效率的差异.