Effects of Different Chemical Fertilizer Reduction Techniques on Flue-cured Tobacco Production

[Objectives]This study was conducted to find out the most suitable special formula fertilizer for flue-cured tobacco production in tobacco-growing areas of Zhaotong City,so as to provide a basis for scientific fertilization and reduced application of inorganic fertilizers with improved efficiency in tobacco production in Zhaotong City.[Methods]Different formulas of special base fertilizer and special topdressing for tobacco were designed by optimizing and adjusting the application amounts and proportions of nitrogen,phosphorus,potassium and medium trace elements in fertilizer formulas,and the formulas of special base fertilizer and special topdressing for flue-cured tobacco production were selected through a field plot experiment.[Results]The combination of special base fertilizer and special topdressing was conducive to the early growth and rapid growth of tobacco plants under the condition of reduced fertilizer application,and the treatment using organic-inorganic compound fertilizer as the special base fertilizer was the most obvious,with an average growth period of two days increased.Compared with conventional fertilization,the yield,output value,average price,proportion of superior tobacco and proportion of medium and superior tobacco increased in the organic-inorganic compound fertilizer treatment,with the yield increasing by 5.96%,the output value increasing by 17.08%,the average price increasing by 10.49%,the proportion of superior tobacco increasing by 4.63%,and the proportion of medium and superior tobacco increasing by 2.44%.It was concluded from indexes including growth period,agronomic traits,disease incidence and economic traits,the fertilization mode of organic-inorganic compound fertilizer with the addition of trace elements(boron,magnesium and zinc)applied as the base fertilizer and nitrogen and potassium topdressing was most efficient and economic.[Conclusions]This study provides a basis for scientific fertilization and reduced application of inorganic fertilizers with improved efficiency in tobacco production in Zhaotong City.

Com parison of Amino Acids in Root Exudates of Flue-cured Tobacco Varieties with Different Resistances against Black Shank

In order to explore the differences of amino acids in root exudates and plant tissues,we selected four flue-cured tobacco varieties [Yunyan 87(Ⅰ),K326( Ⅱ),NC102( Ⅲ),Hongda( Ⅳ) ]as the test materials and studied the components and mass fractions of amino acids in rhizosphere soil,non rhizosphere soil,roots and leaves via high performance capillary zone electrophoresis. Ten amino acids were detected out from four varieties,including histidine,lysine,tryptophan,phenylalanine,valine,threonine,proline,serine,alanine and glycine. The mass fractions of amino acids in leaves and roots were higher than those in rhizosphere soil and non rhizosphere soil. In rhizosphere soil and non-rhizosphere soil,the mass fractions of lysine,phenylalanine,threonine,proline and glycine in susceptible varieties( Ⅲ,Ⅳ) were higher than those in resistant varieties(Ⅰ,Ⅱ). In rhizosphere soil,the total amino acids successively were Ⅳ > Ⅲ >Ⅰ> Ⅱ,and in non rhizosphere soil were Ⅲ > Ⅳ >Ⅰ> Ⅱ. The total amino acids in roots of variety Ⅳ was the highest,up to 6 359. 195 μg / g. In leaves,the total amino acids in varietiesⅠand Ⅱ were higher than those in varieties Ⅲ and Ⅳ. The results indicated that amino acids could secrete to rhizosphere via root secretion,and the compositions and mass fractions of amino acids varied with flue-cured tobacco varieties,thus the secretion amount of susceptible varieties was higher than that of resistant varieties.

Effects of Applying Trace Clements on Yield and Quality of Flue-cured Tobacco Cuibi-1

[Objectives]To optimize the fertilization technology of flue-cured tobacco Cuibi-1.[Methods]From 2015 to 2016,the experiment of spraying Saikun multi-trace element water-soluble fertilizer was carried out.[Results]7 d and 14 d after transplanting tobacco seedlings,3750 mL/ha,300 times diluted Sakun multi-trace element aqueous solution was sprayed,the growth period of Cuibi-1 in the field was extended by 3-5 d.The incidence of mosaic disease at the rosette stage and granuville wilt at the foot leaf harvesting and curing stage decreased by 4.50-20.85 kg/ha,the yield increased by 67.8-68.7 kg/ha,the proportion of high-quality tobacco increased by 1.29-3.01 percentage points,and the output value increased by 2692.5-3441 yuan/ha,the sensory smoking quality has improved.[Conclusions]Increasing the application of multiple trace elements can increase the economic benefit and industrial use value of tobacco leaf production of Cuibi-1.

Effects of UV-B Radiation on the Activity of Antioxidants in Flue-cured Tobacco Leaves

[Objectives]This study was conducted to investigate the effects of UV-B radiation on the activity of main antioxidants in flue-cured tobacco.[Methods]The flue-cured tobacco variety Yunyan 87 was used as the test material for pot planting.Xuanwei County(1997 m)in Qujing Tobacco District,Yunnan was selected as the test point.Three levels of UV-B radiation was set to investigate the activity of PPO,SOD,POD and CAT and the contents of flavonoids and malondialdehyde during the development of the middle leaves of flue-cured tobacco in the same planting area by reducing the natural conditions by 75.04%(A1),70.01%(A2)and 30.02%(A3),respectively.[Results]Reducing UV-B radiation significantly increased the activity of tobacco SOD,POD and CAT,which showed that flue-cured tobacco in the low-latitude plateau area of Yunnan has adapted to the higher local UV-B radiation,and the flue-cured tobacco has formed a unique antioxidant enzyme system.The weakening of UV-B radiation treatment might partially change the antioxidant enzyme system of flue-cured tobacco,but there were no significant differences in the activity of antioxidant enzymes between different degrees of weakening UV-B radiation.The change trends of flavonoids and malondialdehyde in leaves at two different leaf positions were similar.The malondialdehyde content of treatment A1 was significantly higher than those of the CK,A2 and A3,and 70.01%-75.04% of UV-B radiation intensity might be the lower limit of Yunyan 87's adaptability to UV-B radiation.With the decrease of UV-B radiation,the sensitivity of flue-cured tobacco gradually decreased.[Conclusions]This study made a preliminary exploration for explaining the correlation of UV-B radiation and Yunnan flue-cured tobacco.

Effect of Different Boron Fertilizer Supply Patterns and Levels on Growth,Development and Quality of Flue-Cured Tobacco

Boron,one of the essential trace elements for normal growth and development of tobacco,has a great impact on the yield and quality of flue-cured tobacco. The objective of this study is to explore the best pattern and level of boron fertilizer supply of red soil in the Honghe tobacco area. In this study,the randomized block design was used to study different boron fertilizer supply methods and levels. The results showed that during transplanting,it was good to apply 1. 50 kg/ha Fertibor boron with pure boron content≥15%; at the resettling stage,it was good to spray 225 kg solution composed of 75 m L/ha Compo liquid boron with pure boron content≥130 g/L mixed with water onto leaves when night fell in a sunny day. The two fertilization methods had better effect than the basal application of boron fertilizer,and the resistance to pests and diseases or economic character of tobacco plants was better than under spraying treatment.

Effects of Spraying Plant Extract Mixture on Growth and Development and Diseases of Flue-cured Tobacco

[Objective]The paper was to study the effects of plant extract mixture on growth and development,photosynthetic indexes and disease control of flue-cured tobacco.[Method]Using field test method,a total of five treatments were designed in the test,including T1(control,conven-tional pesticide control),T2(conventional pesticide control+spraying plant extract mixture at 15 and 30 d post transplanting),T3(conventional pesticide control+spraying plant extract mixture at 15,30 and 45 d post transplanting),T4(conventional pesticide control+spraying plant extract mixture at 15,30,45 and 60 d post transplanting),and T5(conventional pesticide control+spraying plant extract mixture at 15,30,45,60 and 75 d post transplanting).In addition,flue-cured tobacco in treatments T2-T5 were sprayed with antiviral agent once at 30 d post transplanting,and sprayed with quality promoting agent at 30 and 75 d post transplanting,respectively.[Result]The agronomic traits and photosynthetic indexes of all treatments were improved by spraying plant extract mixture,and those in T5 treatment were the best.Spraying plant extract mixture had significant control effect on brown spot;the disease index in T5 treatment was the lowest,and the control effect was the best.The results showed that spraying plant extract mixture promoted the growth and development of flue-cured tobacco,reduced the disease index of brown spot,and improved the quality of tobacco leaves.[Conclusion]Spraying plant extract mixture has positive effect on growth and development and disease control of flue-cured tobacco.

Analysis of Employment Trend in Flue-Cured Tobacco Planting

Based on the investigation of the amount of labor used in each production link of flue-cured tobacco planting in Liuyang since 1989,and through the analysis of the changes of labor-related factors,it is concluded that the amount of labor used in tobacco planting in Liuyang experienced a significant increase and relatively stable stage in the early 1990s,and it has been declining continuously since the beginning of the 21st century;the change of flue-cured tobacco planting technology mode,as well as mechanized,large-scale and specialized production are the main factors that affect the change of the amount of labor used in flue-cured tobacco planting in Liuyang.Based on the method of changing the technical model to reduce amount of labor used,the types of labor used for planting of flue-cured tobacco can be divided into the following types:reducing the amount of labor by technical methods;reducing the amount of labor by making use of weather;reducing the amount of labor by using drugs;reducing the amount of labor used at the cost of reducing the technical implementation standards of a certain production link.The change of labor used in flue-cured tobacco planting is not only related to the cost and price factors,but also related to the profound social and economic background.In the future,reducing labor and cost is the trend of flue-cured tobacco production,and mechanization,large-scale and specialized production are the main development direction of flue-cured tobacco production,but under the condition that flue-cured tobacco production is still dominated by manual operation,maintaining a certain amount of labor is still the basis for maintaining high quality of flue-cured tobacco planting at present.

Development of Customized Production Machine for Flue-cured Tobacco Formula Nutritional Soil

On the basis of full investigation and repeated trials,nutritional soil composed of cake fertilizer,mushroom residue,cow dung and calcium magnesium phosphate fertilizer was determined as an alternative for traditional flue-cured tobacco fired ash soil.In accordance with the feed grinding,mixing and processing integrated principle,processing machine for flue-cured tobacco nutritional soil was developed.The clogging problem of mixing box was solved by improving grinding and stirring method of mixing system.Mechanized and large-scale production and commercialized supply of flue-cured tobacco nutritional soil was piloted to simplify the production process and reduce the production cost of nutritional soil for flue-cured tobacco and meet the needs of green development of tobacco production,thereby creating good social and economic benefits.

Risk Regionalization of Drought for Flue-cured Tobacco Planting in Qujing City Based on GIS

The risk regionalization of drought for flue-cured tobacco planting in Qujing City was studied to provide reference for drawing on advantages and avoiding disadvantages in flue-cured tobacco planting,disaster reduction,and disaster relief services.According to the production practice of flue-cured tobacco and local climate analysis,the risk of disaster-causing factors,sensitivity of disaster-breeding environment,vulnerability of carriers,and disaster prevention and reduction capability were analyzed and evaluated quantitatively.Secondly,starting from the formation mechanism of drought,a risk assessment model of the meteorological disaster was established by GIS technology.Finally,the risk assessment and regionalization of drought in the critical periods for drought-stricken flue-cured tobacco (transplanting period,root extending stage and vigorous growth period) in Qujing City were carried out.The results showed that in Qujing City,the risk areas of drought for flue-cured tobacco planting were divided into five grades in the transplanting period and six grades in the root extending stage and vigorous growth period.

Yield and Nicotine Content of Flue-Cured Tobacco as Affected by Soil Nitrogen Mineralization

Nitrogen(N)supply is the most important factor affecting yield and quality of flue-cured tobacco(FCT).A field experiment and an in situ incubation method were used to study the effects of soil N mineralization in the later stages of growth on yield and nicotine content of FCT in Fenggang and Jinsha,Guizhou Province.The yield and market value of FCT at Fenggang were much lower than those at Jinsha.However,the nicotine content of middle and upper leaves was much higher at Fenggang than at Jinsha when the same rate of fertilizer N was applied,which might be due to a higher N supply capacity at the Fenggang site.At later stages of growth(7-16 weeks after transplanting),the soil net N mineralization at Fenggang(56 kg N ha^(-1))was almost double that at Jinsha(30 kg N ha^(-1)).While soil NH_4-N and NO_3-N were almost exhausted by the plants or leached 5 weeks after transplanting,the N taken up at the later growth stages at Fenggang were mainly derived from soil N mineralization,which contributed to a high nicotine content in the upper leaves.The order of soil N contribution to N buildup in different leaves was:upper leaves>middle leaves>lower leaves.Thus,soil N mineralization at late growth stages was an important factor affecting N accumulation and therefore the nicotine content in the upper leaves.

Analysis on the Change of Soil pH in Tobacco Fields During the Cultivation of Flue-cured Tobacco

[Objectives] This study was conducted to understand soil p H changes during tobacco planting and its reasons. [Methods]Soil samples were collected from Jingdong,Jinggu and Zhenyuan tobacco-planting areas of Pu'er City before tobacco planting and during different growth stages of tobacco. [Results] Planting flue-cured tobacco changed the soil p H value. First,it was affected by the nicotine produced by the root system of tobacco plants. Second,it was affected by the type of soil. [Conclusions] This study has certain theoretical guiding significance for the cultivation management of flue-cured tobacco and the arrangement of ensuing crops.

Effects of Organic Fertilizers on Tobacco Growth and Heavy Metal Contents in Flue-cured Tobacco

Pb, Cd and As are main heavy metal elements in tobacco leaves in China. Through the application of organic fertilizers in the tobacco area of Pu'er City, the effects on tobacco growth and heavy metal contents were investigated. The results showed that the tobacco plants in the treatments applied with organic fertilizers as the base fertilizer grew at a lower rate and had relatively smaller stem girth and leaf number than the treatment applied with the compound fertilizer special for tobacco in early growth period, and the differences between various treatments were not significant. After applying the organic fertilizers, they had a positive effect in reducing heavy metal contents of flue-cured tobacco, and the effect of applying oil cake was better, followed by the treatment of chicken manure plus oil cake. The sole application of chicken manure had a certain effect on the control of Hg, As and Pb, but the Cd content increased. For the areas with high heavy metal levels, the selection of appropriate organic fertilizers has a practical significance to the reduction of heavy metal contents in tobacco leaves.

Canonical Correlation between the Leaf Quality Indicators of "Moderate Aroma" Flue-cured Tobacco

In order to find out the correlation between tobacco quality evaluation indicators in China's traditional " moderate aroma" tobaccoproducing areas and simplify the tobacco quality evaluation indicators,we evaluate the appearance quality and smoking quality of 143 flue-cured tobacco leaf samples in China's " moderate aroma" tobacco-producing areas,test the physical traits and chemical component,and analyze the canonical correlation between four quality evaluation indicators. The results show that there is significant or extremely significant canonical correlation between four evaluation indicators( tobacco smoking quality,chemical component,appearance quality and physical trait quality); the cumulative variance contribution rate of evaluation indicators is in the order of chemical component( 69. 17%) > appearance quality( 68. 76%) > physical traits( 64. 13%); appearance quality is most closely related to physical traits( 93. 84%). The individual indicators for tobacco quality evaluation make different contribution to the correlation between quality evaluation indicators. The chemical component evaluation indicators mainly include total sugar and ratio of total sugar to betaine; sensory taste indicators mainly include aroma volume,smoke concentration,irritation and softness degree; physical trait evaluation indicators mainly include leaf weight,leaf length and leaf density; appearance quality indicators mainly include leaf organizational structure,color,maturity and identity. Studies have shown that in the large-scale ecoregion,using canonical correlation analysis to simplify tobacco quality evaluation indicators is feasible.

Structure and Change of Costs for Flue-cured Tobacco Production:A Case Study of Liuyang Tobacco Growing Areas

On the basis of consulting related information and data,costs for flue-cured tobacco production were surveyed and analyzed with Liuyang tobacco growing areas as an example.Results showed that there is rise and fall in fertilizer cost for flue-cured tobacco production;change in pesticide and agricultural plastic film is little;other costs for flue-cured tobacco production rise rapidly in recent years.Besides,there is certain reduction in labor units per mu for flue-cured tobacco production;labor price has an annual growth rate of 15%-25%.The proportion of labor cost to total cost for flue-cured tobacco production is increasing,thus rise of labor cost is the major factor promoting rise of costs for flue-cured tobacco production.Through adjustment of purchasing price and various subsidies,the change of per mu yield is a decisive factor influencing benefits of flue-cured tobacco production.

Study on Climate Changes for Flue-Cured Tobacco Growth in Chenzhou City of Hunan Province

Chenzhou city is the most typical region of Nanling Hill Ecological Zone of flue-cured tobacco with of aroma style of burnt sweet and pure sweet in China and is the largest planting region of flue-cured tobacco in Hunan province. It is of significance to study the changes of climatic parameters with time because climate is the most important factor in determining the growth, yield and quality of flue-cured tobacco. In this study, the data of climatic parameters including cumulative sunshine hours(S), mean temperature (T) and cumulative precipitation (P)from 1952 to 2018 in Chenzhou were used to analyze their changes at the scales of year, whole field period and growing period of flue-cured tobacco. The results showed that at the scale of year, the cumulative S, mean T and cumulative P were ranged from 1029.0 h to 2072.1 h, from 17.1°C to 19.5°Cand from 897.1 mm to 2244.6 mm, with the means of 1449.7 h, 18.1°C and 1482.5 mm, respectively. At the scale of whole field period of flue-cured tobacco, the cumulative S, mean T and cumulative P were ranged from 298.1 h to 807.2 h, from 21.2°C to 23.9°C and from 416.7 mm to 1102.7 mm, with the means of 514.8 h, 22.3°C and 719.0 mm, respectively. At the scale of growing period of flue-cured tobacco, the annual cumulative S were ranged from 70.0 h to 257.2 h, from 77.3 h to 322.5 h and from 131.2 h to 300.3 h in the periods of rooting, flourishing and maturing with the means of 127.8 h, 190.4 h and 197.2 h, respectively. The mean temperatures were ranged from 14.2°C to 18.9°C, from 22.2°C to 26.1°C, and from 25.8°C to 29.6°C with the means of 16.4°C, 24.1°C and 28.0°C, respectively. The annual cumulative P were ranged from 69.9 mm to 553.9 mm, from 133.1 mm to 485.6 mm and from 46.4 mm to 356.8 mm in the periods of rooting, flourishing and maturing with the means of 262.5 mm, 299.9 mm and 153.9 mm, respectively. At the year scale, cumulative S annually decreased by 7.587 h, mean T annually increased by 0.02°C, while cumulative P changed irregularly with insignificantly increasing about by 0.184 mm annually. At the scale of whole field period of flue-cured tobacco, mean T annually increased by 0.0195°C, while both cumulative S and P changed irregularly with insignificantly decreasing by 1.64 h and 1.62 mm annually, respectively. At the scale of growing period of flue-cured tobacco, all climatic parameters changed irregularly except cumulative S in significant positive compound function in the maturing period. Meanwhile, the slight decreasing tendency of cumulative sunshine hours and the slight increasing tendency of cumulative precipitation are disadvantageous while the slight increasing tendency of cumulative precipitation in the maturing period is positive for the growth and quality of flue-cured tobacco.

Comparative Analysis on Chemical Components and Sensory Quality of Aging Flue-Cured Tobacco from Four Main Tobacco Areas of China

Complicated changes are happening during the aging process of flue-cured tobacco (FCT) and understanding of the changing components is of great significance in improving the quality,shortening aging time,and enhancing production and economic efficiency in tobacco industry.The aging samples of FCT from four main producing areas of China,i.e.,Yunnan,Sichuan,Hubei,and Dongbei,were used to study the changing rule of the components such as alkali,acid,and carbohydrate as well as the aroma and their relationship with sensory quality;and based on the correlation among the components and the sensory quality index,multivariable models were established to predict the aging quality.The results showed that the sensory quality of FCT increased steadily during the aging time,and at the same time,the acidic components (total organic acids,volatile acids) increased gradually,while the alkaline substances (nicotine,volatile alkali),carbohydrate (total sugars,reducing sugar) and pH values showed a downward trend.Correlation analysis found that the sensory quality and pH values were negatively correlated (P<0.05),while the sensory quality with total organic acids and aroma were positively correlated.The optimal model for predicting the quality of FCT was y=56.75-0.63x12+50.09x2-13.27x22,(y:sensory quality;x1:pH;x2:total organic acids).The average predicating error was 1.04% with maximum predicating error of 2.89% and the accuracy rate of above 97%.

Proteomics Identification of Differentially Expressed Proteins Relevant for Nicotine Synthesis in Flue-Cured Tobacco Roots Before and After Decapitation

Nicotine is a secondary substance synthesized in tobacco roots. In flue-cured tobacco planting,tobacco decapitation is an effective practice to promote nicotine biosynthesis by regulation of the redistribution of total nitrogen amounts. However,proteins relevant to nicotine synthesis in tobacco roots has not been identified and characterized yet. It is important to explore the regulation of nicotine biosynthesis in tobacco roots. To identify the proteins relevant to nicotine synthesis,the protein patterns in roots of flue-cured tobacco (cv. K326) before and after decapitation were analyzed. In the present study,the protein patterns in roots of flue-cured tobacco were analyzed by two-dimensional electrophoresis (2-DE),and the differentially-expressed spots were identified by matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS). Paired comparison of 2-DE maps revealed 26 spots of differentially-expressed proteins in roots before and after decapitation. Furthermore,nine differentially-expressed spots were identified. There were four proteins which were enzymes possibly involved in nicotine biosynthesis. In addition,the roles of the four enzymes in nicotine biosynthesis were discussed in a putative network. Our results would contribute to the understanding of the regulation pathway of nicotine biosynthesis and further to the molecular manipulation on the nicotine contents in flue-cured tobacco.

Relationship Between Hyperspectral Parameters and Physiological and Biochemical Indexes of Flue-Cured Tobacco Leaves

The experiment was set up for examining the physiological and biological indexes quickly and exactly, for obtaining information of tobacco-field fertilizing and tobacco growing. The ASD Field spec FR 2500 was used to measure spectra reflectance of flue-cured tobacco and the relationship between hyperspectral parameters and biochemical contents (total nitrogen, chlorophyll, carotenoid), and physiological indexes (fresh weight, dry weight, moisture content) of flue-cured tobacco leaves was studied by correlation and stepwise regression statistic methods at different nitrogen and potassium levels. The results indicated that the spectra curves of different treatments had obvious rules and great diversities. There were high correlations between different types of spectra parameters and ten physiological and biochemical indexes of flue-cured tobacco leaves. Hyperspectral characteristic variables of ten physiological and biochemical indexes were found through stepwise regression, and SDr/SDb was the characteristic variable closest to seven biochemical contents. Simultaneously, the R2 and regression coefficient of equations reached 0.05 significant level and the equations had good estimating effects through the examination of other samples. Accordingly, this study suggested that the ten physiological and biochemical indexes could be estimated quickly by the estimating models, at the same time nitrogen-potassium fertilization and growth condition of flue-cured tobacco could be inspected.

Characteristics of Potassium-Enriched, Flue-Cured Tobacco Genotype in Potassium Absorption, Accumulation, and In-Ward Potassium Currents of Root Cortex

This study was to investigate the main traits of potassium-enriched, flue-cured tobacco genotypes related to potassium absorption, accumulation, and in-ward potassium currents of the root cortex. Hydroponic methods, K+-depletion methods, and patch-clamp, whole-cell recordings were conducted to study the accumulation of dry matter and potassium in different organs, and to measure potassium absorption and dynamic and in-ward potassium currents in potassium-enriched, flue- cured tobacco genotypes. The average dry weights of leaves and whole plant of potassium-enriched, flue-cured tobacco genotype ND202 were 10.20, and 14.85 g, respectively, higher than JYH (8.50 and 13.11 g, respectively) and NC2326 (8.39 and 12.72 g, respectively), when potassium concentration in the solution ranged from 0.1 to 50 mmol L-1. Potassium accumulation in the leaves of ND202 was 18.6% higher than JYH and 34% higher than NC2326 when potassium concentration in the solution was superior to 0.5 mmol L-1. The Vmax (the maximum velocity) of ND202 was 118.11 μmol FW g-1 h-1, obviously higher than that of JYH (58.87 μmol FW g-1 h-1) and NC2326 (64.40 μmol FW g-1 h-1). In the in-ward potassium currents, the absolute value of current density (pA/pF) of ND202 was 60, higher than that of JYH (50) and NC2326 (40). Potassium concentration in leaves, Vmax, and in-ward potassium currents, could be used to screen potassium-enriched, flue-cured tobacco genotypes.

Screening of SSR Core Primers and Construction of Molecular ID for Flue-cured Tobacco Germplasm Resources in Hunan

[Objectives]This study was conducted to establish a reliable and unique molecular ID for flue-cured tobacco germplasm resources in Hunan Province,further improving the efficiency of germplasm collection and identification,and laying a solid material foundation for flue-cured tobacco breeding.[Methods]Twelve pairs of SSR primers with stable amplification and rich polymorphism were screened out from 816 pairs of SSR primers by a step-by-step screening method.As core primers of the SSR core primer library,the polymorphism of SSR primers was analyzed,the genetic relationship of 162 flue-cured tobacco germplasm resources was identified,and the molecular ID cards were constructed.[Results]The result of SSR primer polymorphism analysis showed that a total of 57 alleles were detected by 12 pairs of SSR primers in 165 tobacco germplasm resources,with an average of 4.75 alleles per pair of primers;the average diversity of SSR primers was 0.649;and the average value of Shannon's index was 1.235.The results of cluster analysis showed that 162 flue-cured tobacco germplasm resources were divided into five groups.The members of each group were divided based on genome information,which had nothing to do with their geographical origin.Meanwhile,12 pairs of SSR primers gave each flue-cured tobacco germplasm resource a unique molecular ID code.[Conclusions]From the above results,we can see that the 12 pairs of SSR primers obtained by screening have stable amplification polymorphism,and can serve as the primers of the core primer library,and can be used to construct the unique molecular ID of flue-cured tobacco germplasm resources.