Packing density regulates the microenvironment of tobacco (Nicotiana tabacum L.) fermentation and may thereby influence microbial activity and product quality. However, its effects on microbial community assembly and quality formation remain poorly understood. This study aimed to clarify how packing density affects flue-cured tobacco quality by shaping microbial communities, functional potential, and ecological interactions. Here, we investigated the effects of three packing densities (60%, 70%, and 80%) on chemical components, aroma compounds, microbial community structure, functional potential, co-occurrence networks, and assembly mechanisms of flue-cured tobacco (cv. Piaohe No. 2) after 10 days of fermentation. Moderate density (70%) achieved the most balanced chemical profile, with appropriate nicotine retention, potassium/chlorine ratio, and sugar/nicotine balance. T70 also exhibited the highest levels of total esters, total ketones, and β-ionone, key contributors to fruity, floral, and woody aromas. Microbial analysis revealed that T70 supported the highest diversity and was characterized by the enrichment of aroma-related bacterial taxa, including Bacillus and lactic acid bacteria, as well as the fungal genus Pichia. In contrast, T60 favored aerobic nicotine degraders, whereas T80 selected for obligate anaerobes associated with off-odor production. Functional predictions and network analysis showed that T70 upregulated fatty acid and carotenoid biosynthesis pathways and exhibited the highest modularity, indicating a compartmentalized, functionally complementary community. Neutral model fitting revealed increasing stochasticity with density, with T70 displaying a mixed assembly regime. Collectively, our findings show that packing density influences tobacco quality by regulating microbial community composition, functional potential, network interactions, and assembly processes. These results provide a scientific basis for optimizing packing density in tobacco processing.

[目的]研究γ-聚谷氨酸(γ-PGA)对烤烟根系发育及烟叶产量和品质的影响,为其在烤烟生产中的合理应用提供理论依据.[方法]在河南卢氏县和洛宁县进行大田试验,设置在移栽时(T1)、团棵期(T2)、移栽时十团棵期(T3)浇灌γ-PGA原液(用量15 L/hm2)200倍稀释液,以浇灌等量清水的处理为对照(CK),于移栽后30和60 d测定0～10,10～20 cm 土层土壤的含水率,于移栽后30,60和90 d测定根系体积和活力,于烤烟圆顶期测定烟株农艺性状及根、茎、叶干物质质量,在烟叶收获烘烤后测定其经济性状和化学成分,分析各处理土壤水分以及烤烟根系发育、干物质积累及烟叶产量和品质的差异.[结果]浇灌γ-PGA处理能显著提高0～20 cm 土层土壤含水率,以T3处理效果最好.与CK相比,施用γ-PGA显著提高了烤烟根系体积和生育前中期烟株的根系活力,在移栽后60 d,T1、T2、T3处理烤烟根系体积较CK增幅分别为39.15％～43.64％,47.38％～73.64％和62.92％～93.41％,根系活力增幅分别为39.01％～39.98％,36.33％～46.32％和51.72％～54.98％.施用γ-PGA显著增加了烟株全株干物质积累量,提高了烤后烟叶的产量、产值、上等烟比例和还原糖含量、糖碱比、钾氯比,改善了烤烟化学成分的协调性,且均以T3处理效果最好,其全株干物质积累量、产量、产值、上等烟比例较CK分别提高了 25.20％～46.60％,13.49％～20.79％,27.83％～31.89％和8.14％～12.72％.[结论]在豫西烟区于移栽时、团棵期2次浇灌γ-PGA溶液对烤烟促生增产提质效果最佳.

为明确气象因子对三门峡烤烟上部叶产量和品质的影响,确立优质上部叶形成的关键气象指标,为合理调节烤烟移栽期提供理论依据,以烤烟主栽品种云烟87为材料,于2020-2021年在灵宝进行大田试验,研究不同移栽期烤烟上部叶发育期间气象因子、产量及品质,解析气象因子与产量和品质的关系.结果表明,三门峡上部叶各生育阶段气象因子随移栽期推迟均发生明显的改变,以成熟期气象因子变幅最大.随移栽期推迟,上部叶产量、产值、上等烟比例和均价呈先增后减的趋势;还原糖含量、糖碱比先升后降,烟碱含量逐渐降低;烟叶香气质、香气量及感官质量总分呈先升高后降低的趋势;5月7日移栽处理烤烟上部叶经济性状和品质最佳.相关分析表明,上部叶各经济指标、还原糖含量、烟碱含量、糖碱比、香气质、香气量及感官质量总分均与其成熟期日均温呈显著或极显著正相关.各气象因子与上部叶香气质、香气量及感官质量总分关联度大小顺序依次为温度、日照时数、降雨量,其中以成熟期日均温关联度最大;当成熟期日均温在20.20～25.16℃时,上部叶香气质、香气量及整体感官质量较佳.

In order to find the optimal combination of nitrogen rate and number of retained leaves for the new flue-cured tobacco strain LY1306, and further improve the quality of tobacco leaves, this experiment adopted a two-factor split zone design. Nitrogen dosage（N） was the main zone and the number of retained leaves（L） was the secondary zone, and three levels were set（N: 22.5, 37.5, 52.5 kg/hm~2; number of retained leaves: 22, 24, 26 leaves per plant）. Their effects and their interaction on upper leaf area, key enzyme activities of carbon and nitrogen metabolism, photosynthetic characteristics, tobacco quality and economic characters of flue-cured tobacco leaves were studied. The results showed that the nitrogen application rate, the number of retained leaves and their interactions had significant effects on the upper leaf area, carbon and nitrogen metabolism enzyme activity, chlorophyll content and net photosynthetic rate of flue-cured tobacco. The reasonable combination of nitrogen application rate and the number of remained leaves was beneficial to the opening of the upper leaves of LY1306, and could maintain reasonable carbon and nitrogen metabolism intensity and photosynthetic rate during the ripening process. Under the three levels of leaf retention, tobacco yield, total nitrogen and nicotine contents were the highest under high nitrogen rate, while output value and potassium content were the highest under medium nitrogen rate. Under the three levels of nitrogen application, tobacco yield and total sugar and reducing sugar contents in upper leaves were the highest at high leaf retention level, while output value and proportion of fine tobacco were the highest at medium leaf retention level. The content of neutral aroma substances increased first and then decreased with the increase of nitrogen application rate and the number of retained leaves, and the highest value was found under the treatment with nitrogen application rate at 37.5 kg/hm~2 and 24 retained leaves per plant. In summary, the combination of 37.5 kg/hm~2 of nitrogen application rate and 24 retained leaves per plant could improve the grade structure of LY1306 flue-cured tobacco leaves, quality of upper leaves and economic benefits.

为探究钼、锌营养对烤烟生理特性及品质的影响,以烤烟品系LY1306为试验材料,采用大田试验,设置叶面喷施清水(CK)、0.1%钼酸铵溶液(T1)、0.2%硫酸锌溶液(T2)、0.1%钼酸铵溶液+0.2%硫酸锌溶液(T3)共4个处理,比较钼锌营养对烤烟叶片碳氮代谢关键酶活性、质体色素含量、光合性能、烤后烟叶化学成分及经济性状的影响.结果表明,与CK相比,T1、T2、T3处理均不同程度增强烤烟叶片发育过程中硝酸还原酶(nitrate reductase,NR)、谷氨酰胺合成酶(glutamine synthetase,GS)和蔗糖转化酶(sucrose invertase,INV)活性,提高烤烟净光合速率(net photosynthetic rate,Pn)及质体色素含量,促进烟叶干物质积累,并显著提高烟叶产量、产值、均价及上等烟比例;同时各处理还明显提高烤后烟叶总糖、还原糖和钾含量,提高烟叶糖碱比和钾氯比,改善烟叶化学成分的协调性;各项指标均以T3处理效果最佳.综上所述,钼锌配施最有利于提高烤烟碳氮代谢强度和光合性能,协调烟叶化学成分,改善烟叶品质,为钼锌营养在烤烟生产中的合理应用提供理论依据.

In order to clarify the effects of different types of potassium fertilizers on potassium content and quality of upper leaves of flue-cured tobacco, Yunyan 87 was selected as test variety, and field plot experiment was carried out. According to the types of potassium fertilizers, four treatments were set as no potassium application（CK）, and topdressing potassium sulfate（T1）, potassium fulvic acid（T2） and potassium citrate（T3）. The relationships between potassium content of tobacco leaves and soil available potassium content, carbon and nitrogen metabolism and chemical composition and quality of flue-cured tobacco under different treatments were analyzed. The results showed that compared with the conventional application of potassium sulfate, the effects of topdressing potassium fulvic acid or potassium citrate on the chemical compositions of cured tobacco leaves were as follows: increasing total sugar and reducing sugar contents, reducing nicotine and total nitrogen contents, significantly increasing potassium content of cured tobacco leaves by 12.39% and 20.35%, and increasing the total amount of neutral fragrance substances by 2.23% and 25.49%, respectively. Potassium fulvic acid had greater effects on the non-enzymatic brown degradation products and phenylalanine degradation products, while potassium citrate had a greater effect on the content of neophydiene. Compared with potassium sulfate treatment, the output value of flue-cured tobacco leaves under T2 and T3 treatments increased by 3.92% and 5.31%, respectively. Therefore, compared with topdressing potassium sulfate, potassium citrate treatment was more beneficial to increase potassium content and quality of flue-cured tobacco upper leaves.

为确立豫西地区适宜的上部叶成熟度,以主栽品种云烟87为材料,研究不同成熟度处理(M1、M2、M3、M4)的外观成熟特征与SPAD值,通过烤后烟物理特性、化学成分、中性致香物质含量、感官评吸并结合代谢组学分析,确定适宜豫西烟区的采收成熟标准.结果表明,随着成熟度的提高,烟叶的油分、身份、叶质重有所降低;低成熟度(M1和M2)顶1～3和顶4～6叶位的糖碱比、氮碱比、中性致香物质含量、感官质量评价较高.此时SPAD值在28～34范围内,田间成熟特征表现为叶面落黄程度为20％～50％、主脉2/3变白、支脉变亮、少量至有成熟斑、茸毛较少至部分脱落.代谢组筛选出苯丙氨酸、酪氨酸、莨菪亭、肉桂醛、芥子酸等香气前体物质在M1处理中含量较高,推测这些可能是优质上部烟叶中关键的代谢物.

探明水肥一体化技术对烤烟钾吸收及产质量的影响,为提高烟叶钾含量提供依据.以烤烟品种LY1306为试验材料,在田间采用单因素随机区组试验,设计空白对照(CK)、常规施肥(T1)和水肥一体化(T2)3个处理,对烤烟干物质积累、各部位钾素积累量和积累速率、烤后烟叶化学成分和经济性状进行比较研究.与CK、T1处理相比,T2处理的干物质积累量始终最高,干物质积累速率提高了70.03％、36.72％,最大干物质积累速率出现时间为53.370 d,较CK和T1处理提前了7.884 d和5.777 d;随生育期进程的推移,各部位钾素积累量呈明显的"S"形上升,处理间均表现为T2>T1>CK;T2处理各部位的钾平均积累速率、钾最大积累速率较CK和T1处理明显提高,最大钾积累速率出现时间整体上较CK和T1处理明显提前,且在烟草根系中表现最为明显,烟草根系中钾平均积累速率较CK明显提高64.67％,钾最大积累速率较CK和T1处理明显提高72.28％和33.72％,钾最大积累速率出现时间较CK和T1处理提前了7.28 d和8.78 d;T2处理各部位烤后烟叶钾含量、钾氯比均为最高,其中部叶钾含量较CK和T1处理显著提高了33.70％和20.59％,钾氯比较CK处理提高了31.60％;T2处理各经济性状指标均为最高,其中产值较CK显著提高了50.45％,较T1显著增加了9521.25元/hm2.水肥一体化技术能明显增加烟株的干物质积累,有效促进烤烟各部位钾素积累,协调烟叶各项化学成分,提高烤烟经济性状.

[目的]研究低钾胁迫抑制钙信号传导对植株幼苗叶片光合特性及钾吸收的影响,为缓解作物的低钾胁迫提供理论依据.[方法]以烟草品种K326为试验材料进行了室内水培试验.烟草幼苗先在营养液正常钾(K+?5?mmol/L)和缺钾(K+?0.15?mmol/L)营养液中生长8天,然后在营养液中分别施加钙通道有机阻断剂Vp、钙通道无机阻断剂LaCl3和钙离子螯合剂(EGTA)钙信号抑制剂,继续生长4天后取样,测定植株干鲜重、电导率、活性氧含量、叶片抗氧化酶活性、叶片光合特性等指标和植株地上、地下部钾素浓度及钾离子吸收相关基因表达量.[结果]1)不添加钙通道抑制剂或螯合剂条件下,低钾胁迫的烟株地上部和根系干重较常钾水平显著降低了59.29％、39.82％,鲜重显著降低了51.58％、48.19％,除水汽压饱和亏外的其余5项光合特性指标显著降低,植株地上部和根系钾含量分别显著降低了39.31％和77.05％,而叶中可溶性蛋白、相对电导率、过氧化氢含量则显著增加,NKT2、NtKC1、NtHAK1、NtHAK5基因的相对表达量分别增加了2.09、3.32、3.23、12.34倍.2)常钾水平下,3个钙抑制剂处理未明显影响地上部和根系干鲜重,而低钾水平下,钙抑制处理的地上部鲜重和干重显著高于无钙抑制剂对照.两个钾水平下,与各自对照相比,3个钙抑制剂处理的叶片相对电导率、活性氧积累量均显著增加,抗氧化酶SOD和POD活性、叶绿素含量显著减少,光合特性指标(除水汽压饱和亏外)明显降低.3)两个钾水平下,3个钙信号抑制剂处理的烟株地上部和根系钾含量均显著低于其对照,低钾胁迫下平均降低幅度分别达到25.54％和53.36％.低钾胁迫下,钾离子通道基因NKT2、NtKC1和转运蛋白基因NtHAK1、NtHAK5在根系中的相对表达量分别平均降低了60.60％、50.62％、38.61％、69.79％,钙通道相关基因NtCNGC1和NtCNGC11在根中的相对表达量分别平均降低了95.36％和87.04％.[结论]低钾胁迫明显影响烟株幼苗生长、光合作用及对钾素的吸收和积累.低钾水平下,外施钙通道抑制剂或螯合剂可进一步降低烟草叶片抗氧化酶活性,减弱烟株叶片光合作用,并抑制根中钾吸收相关基因的表达和烟株对钾素的吸收.

Salt stress can retard plant growth and reduce crop yields. Genes in the auxin-responsive Aux/IAA family play key roles in regulating plant growth and development. However, the molecular mechanisms of Aux/IAA proteins underlying growth regulation in response to salt stress remain unclear. In Nicotiana tabacum , we identified an AUX/IAA family gene, NtIAA26 , that exhibited significantly upregulated expression under salt stress. The NtIAA26-GFP fusion protein was located in the nucleus, suggesting that NtIAA26 functions as a transcriptional activator in tobacco. Notably, NtIAA26 overexpression substantially increased K + uptake, reduced Na + accumulation, enhanced antioxidant activity, and improved salt stress resistance in tobacco plants. Under salt stress, the expression levels of several K + transporter genes (e.g., NtHAK5 and NtHAK11 ) and antioxidant-related genes (e.g., NtSOD , NtPOD , NtAPX , and NtP5CS ) were higher in NtIAA26 overexpressing transgenic plants than in wild-type plants. Taken together, these findings provide novel insights into the functioning of NtIAA26 in the regulation of salt stress responses in tobacco and indicate that NtIAA26 may be a candidate for improving crop salt tolerance.

在教育部"双万计划"建设背景下,根据烟草学专业基础课程教学的实际情况和特点,课程组结合国内外著名高校优良做法,探索出一系列切实可行的核心课程教学方案.创新性地提出以学生为主体、需求为导向,结合生产实际经验积累+现代信息技术支持,边研究边实践,线上线下结合的课程教学体系,提高学生自主学习能力和专业创新能力,使学生从"我学会"到"我会学".为我国高等农林院校一流课程建设新模式提供实践经验,为栽培类专业课程教学提供理论依据与支撑.

为探索密封降氧对醇化环境及库存白肋烟品质的影响,以自然醇化42个月的湖北恩施成品白肋烟为材料,运用新型气调法,设置T1(1.5％～2％)和T2(7.5％～8％)2个低氧处理及1个常规处理CK,对其温、湿度及烟叶内在品质进行周期性对比.结果表明,与CK处理相比,T1和T2处理对温度影响不显著,但显著降低了相对湿度的变幅和变异系数.CK处理烟叶外观质量缓慢下降,而T1和T2处理则缓慢上升;T1、T2处理在12个月后,均显著提升了总糖含量,处理6个月后均显著提升了烟碱、钾、氯含量(除T1处理第12个月外);T1处理烟叶感官质量总分在周期内呈现缓慢上升趋势,T2处理呈现先上升后缓慢下降趋势,CK处理呈现短暂上升后快速下降趋势;其中T1处理显著降低了烟叶NNN、NAT含量及TSNAs总量,而T2、CK处理间无显著差异.两低氧气调处理均对库存白肋烟的品质提升具有一定效果,且以T1处理综合提升效果更优.

针对济源烟区干旱缺水的生态条件,开展不同类型保水材料对烟株生长及土壤蓄水保墒能力的影响研究,旨在筛选出适宜济源旱作烟区烟叶生长的保水材料.采用田间小区试验,以云烟87为供试材料,选择聚丙烯酸盐(PAA,T1)、聚丙烯酰胺(PAM,T2)、腐植酸(HA,T3)、γ-聚谷氨酸(γ-PGA,T4)4种保水材料,研究不同保水材料的保水效果及其对土壤水分含量、光合特性、烟株生长和产量形成的影响.结果表明,4种保水剂处理的烟叶叶面积增加比例达到2.93％～23.67％,显著高于对照;施用保水剂处理的T1、T2、T3、T4的光合速率分别比对照增加60.49％、23.54％、31.74％、12.77％;移栽后70 d,施用保水剂处理的干物质积累量增幅最大,达到22.33％～67.16％,且以T1(67.16％)、T2(64.76％)处理增加比例最高.保水剂处理的土壤含水量显著高于对照,以圆顶期20～30 cm土层的含水率增幅最高,达到10.44％～36.50％;4种保水剂处理的上等烟比例比对照增加3.57％～10.37％,产量及产值分别较对照增加3.31％～12.29％、3.71％～13.81％.施用保水剂对土壤蓄水保墒能力和烟株的生长具有良好的改善作用;施用聚丙烯酸盐及聚丙烯酰胺对土壤的促进效果最好,有利于烟株生长及其干物质积累.

Addition of biochar and straw has constituted an effective way to improve soil fertility in tobacco fields. However, little is known about the effects of these amendments on CH4 and N2O emissions and their potential microbial mechanisms. Here, we conducted an experiment in tobacco-planted soil using four treatments: mineral fertilizers only (F), biochar with mineral fertilizers (BF), wheat straw with mineral fertilizers (SF), and biochar + wheat straw with mineral fertilizers (BSF). Soil physical and chemical parameters, nitrous oxide (N2O) and methane (CH4) emissions, and the related microorganisms and functional genes (pmoA, mcrA, amoA, nirS, nirK, and nosZ) were analyzed. The results showed that biochar and straw addition significantly increased the uptake of CH4 by 34.2%, 9.3%, and 22.1%, respectively, and significantly increased the relative abundance of pmoA. Compared to the F treatment, the SF and BSF treatments significantly increased cumulative N2O emissions by 1.2- and 1.1-fold, respectively, while the BF treatment significantly decreased N2O emissions from the soil by almost 30%. Correspondingly, decreased relative abundance of amoA-ammonia-oxidizing archaea (AOA), nirS, nirK, and nosZ genes in response to biochar amendment were observed, whereas the relative abundance of amoA- ammonia-oxidizing bacteria (AOB) increased. Conversely, straw addition increased the relative abundance of amoA-AOA and nirS, nirK, and nosZ. Compared to SF, BSF significantly increased the relative abundance of nosZ and decreased the number of denitrifying bacteria. A structural equation model indicated that the important factors affecting N2O emissions were NH4+-N, NO3−-N, pH, and amoA-AOA and nirK genes, while the important factors affecting CH4 emissions were bulk density, pH, SMBC, and pmoA and mcrA genes. Biochar amendment could significantly reduce CH4 and N2O emissions by regulating functional microorganisms and soil physicochemical properties. By contrast, returning straw to the field would increase N2O emissions by increasing the relative abundance of denitrification-related genes.

Drought affects aromatic terpenoids biosynthesis in plant, but the associated regulatory mechanism is unknown. We investigated large-scale dynamic changes in trichomes, terpenoids, and transcriptomes in leaves of Nicotiana tabacum varieties K326 and Basma Xanthi with three replicates over five time-courses with or without drought treatment. We found drought affects trichome type, trichome density, and abundance of major terpenoids examined by gas chromatography-mass spectrometry analysis. Further RNA-Seq analysis revealed drought induced common and variety-specific expressional regulation on differentially expressed genes in terpenoid backbone and diterpenoid biosynthesis, including cembratrien-ol synthase gene, cytochrome P450 gene CYP71D16, and copalyl diphosphate synthase (CPS) gene. The correlation between these genes' expression and terpenoid abundance is positive under well-watered conditions but is variety specific under drought. A single mutation G to T, instead of two co-existed known mutations, in CPS exon 4 was identified in K326 where labdenediols were absent. Further full-length transcript comparison revealed splicing regulation in transcript CPS in both varieties. A truncated 3 '-end splicing of CPS transcripts may also contribute to the absence of labdenediols in K326. Thus, our results provide further understanding of the regulatory mechanism of diterpenoid biosynthesis under drought stress, which may guide crop breeding and farming.

全球气候变暖,土壤肥力下降,农业生产面临的问题日益严峻,如何保障粮食安全已成为人类可持续发展的重要课题之一.生物炭因其碳含量高、稳定性强的特殊性质,已成为多学科领域研究的热点,将其应用于农业领域也表现出巨大的潜力,可在减少温室气体排放的同时培育土壤碳库、改善土壤理化性质及生物学特性,进而提高作物产质量,取得较高的生态环境效益.本文在前人大量研究的基础上总结了生物炭在农业生产上的应用,系统归纳分析了生物炭固碳减排的作用机理及影响因素,提出了适用于农田土壤固碳减排的生物炭制备原料、制备温度、施用量,在未来发展方向上,需要进一步优化炭化技术、加强生物质炭性质与土壤类型互作对固碳减排的研究.

In order to investigate the response of soil respiration, soil microbial biomass carbon and nitrogen, and hydrothermal factors to the addition of biochar and straw, we used an LI-8100 soil carbon flux meter (LI-COR, Lincoln, USA) to study changes in soil respiration and microbial biomass under four treatments:conventional fertilization (CK), conventional fertilization +2.25t·hm-2 biochar-C (T1), conventional fertilizer +2.25t·hm-2 straw-C (T2), and conventional fertilizer +2.25t·hm-2 (biochar-C+straw-C), biochar-C:straw-C=1:1 (T3). The results showed that:① the addition of biochar and straw significantly increased the soil respiration rate and total CO2 emissions, with the largest increase in T3 and the smallest increase in T1. The effect of T1 on soil respiration was promoted in the early stage and later inhibited. ② The microbial biomass carbon and nitrogen and the number of functional bacterial colonies increased significantly with biochar and straw amendments. T1 had a significant promotion effect on nitrogen-fixing bacteria, while T2 had no significant effect on the number of fungi, and T3 showed a positive interaction effect. Soil respiration rates were significantly and positively related to soil microbial biomass carbon and nitrogen as well as to the number of bacteria and actinomycetes. ③ The 5 cm soil temperature of T3 significantly increased by 4.53%. The soil respiration rate and soil temperature showed a significant exponential correlation. To sum up, adding straw and biochar with equal carbon content can significantly increase the soil respiration rate and microbial biomass, and the interaction effect between biochar and straw is positive. Compared with that of the straw treatments, the application of biochar can reduce carbon mineralization to a certain extent, and the effect of carbon sequestration is better.

为提高蛟河晒红烟的抗逆性和烟叶品质,研究了叶面喷施壳寡糖与水杨酸对晒红烟抗氧化酶和防卫反应酶活性、病程相关蛋白基因表达量、田间发病情况、烟叶产量和质量的影响.结果表明,单独喷施壳寡糖、水杨酸溶液或两种溶液联合喷施均能提高烟叶过氧化物酶、超氧化物歧化酶、过氧化氢酶等抗氧化酶活性和苯丙氨酸解氨酶、几丁质酶、β-1,3-葡聚糖酶等防卫反应酶活性,增加病程相关蛋白基因PR-1、PR-2、NPR-1的表达量,其中单施水杨酸在喷洒后4d起作用,时效快但持久性较差;单施壳寡糖起效慢,但在一段时间内仍能保持高活性;壳寡糖与水杨酸联合喷施效果最优.与对照相比,可显著降低晒红烟田间发病率、提高烟叶产量,改善调制后烟叶中性香味物质含量等品质指标.

[背景和目的]盐胁迫会抑制作物的生长发育,从而影响作物的产量和品质.生长素/吲哚-3-乙酸(Aux/IAA)蛋白是响应生长素信号的关键因子,参与调控植物的生长发育和响应非生物胁迫.[方法]为了研究烟草生长素反应基因NtIAA17在烟草生长发育过程中的功能,以烟草K326为试验材料,通过克隆获得烟草NtIAA17基因,利用生物信息学分析其序列特征,qRT-PCR技术分析NtIAA17在烟草不同组织及盐胁迫处理0～12 h的表达模式,利用转基因技术获得过表达NtIAA17-OX(NtIAA17-overexpression)转基因烟草,对其进行响应盐胁迫的功能鉴定.[结果]NtIAA17基因片段为624 bp,编码207个氨基酸;相对分子质量为23.07 kD,理论等电点为8.24,该基因启动子区含有顺式作用元件与激素及胁迫相关;具有Aux/IAA家族蛋白的四个结构域(I-IV)和保守序列.NtIAA17基因与菠菜生长素抑制基因MoIAA13亲缘关系最近;亚细胞定位分析表明,NtIAA17蛋白是核定位蛋白.qRT-PCR结果表明,NtIAA17基因在茎和老叶中高表达,盐胁迫2 h时表达量最高.在盐胁迫条件下,NtIAA17-OX转基因烟草与野生型相比,生物量显著增加,脯氨酸含量积累增加,而MDA含量减少,抗氧化酶基因NtSOD、NtPOD表达量增加.[结论]NtIAA17基因可以响应盐胁迫信号,通过提高转基因烟草的抗氧化性来抵御盐胁迫带来的伤害,增加植株的生物量;本研究为后续耐盐胁迫分子育种提供候选基因和理论依据.

为探究适合河南烟区应用的水肥管理模式,促进烟株对养分的吸收,提高烟叶产量和品质,以中烟100为试验材料,通过大田试验,比较常规水肥管理模式(CK)、常规施肥+滴灌(T1)、优化施肥+滴灌(T2)三种管理模式下烤烟叶片生物学产量、烟叶三要素含量及积累量、烤后烟叶经济性状和品质性状的差异.结果 表明,与CK相比,T1处理烤烟叶片生物量提高了21.59％,烟叶N、P和K的积累量分别提高9.56％、54.78％和30.52％,烟叶产量、产值和上等烟比例分别提高6.45％、8.04％和30.48％;T2处理烤烟叶片生物量提高了33.36％,烟叶N、P、K的积累量分别提高了12.24％、98.75％、83.47％,烟叶产量、产值和上等烟比例分别提高了9.68％、15.05％、42.79％.T1和T2处理烤后烟叶的总糖、还原糖含量及糖碱比显著高于CK,烟叶氯含量显著降低,钾含量和钾氯比显著提高,烟叶的燃烧性均明显改善,感官质量提高,其中,T2处理烟叶化学成分协调性更好,其中部叶的香气、舒适度、甜度、杂气及刺激性分值及上部叶的香气、甜度、杂气分值明显高于CK.由此可见,优化施肥+滴灌模式适宜在河南省烟区推广应用,为河南烟区烟叶优质丰产的水肥管理模式奠定了科学依据.