湖南不同烟区烤烟烟碱含量差异的生态原因

于2007年在湖南省3个典型植烟生态区代表地(湘西北桑植县、湘中浏阳市、湘南永州市)分别同时进行大田本土栽培、客土与本土单独盆栽试验,检测烤烟K326收获期各处理中部烟叶杀青样品的烟碱含量,研究湖南不同烟区烤烟烟碱含量差异的主要生态原因.结果表明:湖南不同烟区大田本土正常栽培烤烟的平均烟碱含量存在显著差异,其中以桑植烟区所产烟叶烟碱含量最高,其次是浏阳烟区,永州烟区最低.盆栽试验结果表明,气候对湖南烟区烤烟烟碱含量有显著影响,土壤及其与气候的互作对湖南烟区烤烟烟碱含量的影响有限.气候、土壤及两者互作对湖南烟区烤烟烟碱含量变异的贡献率依次为60.0%、12.8%和27.2%.与湖南烟区烤烟烟碱含量关联度较大的主要亚生态因子依次为:成熟期的云量和伸根期的相对湿度、日照时数、昼夜温差、降雨量以及旺长期的平均气温.综合分析表明,气候是导致湖南烟区烤烟烟碱含量差异的主要生态因素.     

湖南烟区烤烟(Nicotiana tabacum L.)硼含量与土壤有效硼含量的关系

分析湖南烟区烤烟硼含量与土壤有效硼含量的关系,结果表明：（1）湖南烟叶硼含量偏低,平均为（21.72±12.98）mg/kg,变幅为9.22-89.04mg/kg,有88.89%的烟叶样本硼含量落在10.00-40.00mg/kg范围内;（2）湖南植烟土壤有效硼含量较低,平均为（0.25±0.23）mg/kg,变幅较大（0.07-1.28mg/kg）;有93.40%的土壤样本在不同程度上缺硼（≤0.40mg/kg）,另有4.51%的土样有效硼含量充足（〉1.0mg/kg）,满足优质烟叶生长发育正常的土样仅占2.09%;（3）烟叶硼含量与土壤有效硼含量呈极显著正相关（相关系数为0.745）,288个样品的烟叶硼含量（y^）与土壤有效硼含量（x）建立的回归方程为y^=11.47＋41.71x;（4）在土壤有效硼含量分组后,采用方差分析方法研究了烟叶化学成分的组间差异,表明烟碱、氮/碱、糖/碱的组间差异均达到1%的极显著水平,而总氮、总糖含量的组间差异不显著。     

不同种类镁肥对烤烟中微量元素含量和产质量的影响

针对福建武平烟区土壤酸化严重,土壤有效镁含量偏低导致烟叶镁含量低的问题,研究了3 种不同镁肥对土壤和烤后烟叶中微量元素含量以及烤烟产质量的影响。结果表明,施用不同镁肥后均能显著提高土壤交换镁的含量,但不同镁肥对提高土壤交换镁含量的时效不同。各处理土壤其它中微量元素含量以施用硫酸镁的土壤较高,施用氢氧化镁的土壤偏低。烤后烟叶的镁含量以氧化镁处理最高,其次为氢氧化镁。施用镁肥会影响烟叶其它中微量元素的含量,其中施用氢氧化镁会导致中上部烟叶钙铁含量轻度缺乏,而施用硫酸镁会导致烟叶中锌锰含量过高。各处理中以氧化镁处理烟叶化学成分含量最适宜,且经济性状最优。因此,在福建武平烟区建议施用氧化镁,既可以防止烤烟生育前期有效镁的淋失,又可以提高烟叶的产量和质量。     

氮肥形态和用量对藏东南地区烤烟产量和质量的影响

在藏东南地区进行了氮肥用量和形态对烤烟产量与质量影响的田间试验.结果表明,在施N量0～150kg·hm^-2范围内,施N量与烘烤后烟叶产量、产值、氧化钾及总N含量呈显著或极显著正相关,与上中等烟比例、还原糖含量则呈显著负相关,糖/碱比显著下降.氮肥用量75kg·hm^-2时,产量、质量最佳.无机氮肥对烤烟产量与质量的效应极显著优于有机氮肥.铵态氮、硝态氮、硝铵态氮肥处理间除上中等烟比例,其它各项指标仅略有差异,但均极显著优于酰胺态氮肥.铵态氮对烤烟产量与质量的影响略优于硝态氮,主要在于烟株吸收和同化过程的差异.     

湖南烤烟化学成分与土壤有机质含量的关系

以湖南烟区烤烟样品和对应的土壤样品为材料,研究了烤烟化学成分与土壤有机质含量的关系。结果表明,土壤有机质含量总体水平较高,平均为39.06g.kg-1±11.90g.kg-1;烤烟化学成分均存在着不同程度的变异,烟叶总氮和总钾含量较高,烟碱、总糖、氯和还原糖含量适宜;烤烟烟碱与土壤有机质含量的关系符合线性加平台模型,土壤有机质出现平台的转折点为36.25g.kg-1,与之对应的平台阶段的烟碱含量为3.00%;硝酸盐、亚硝酸盐含量随土壤有机质含量的增加而增加(P<0.01);石油醚提取物含量则有随土壤有机质含量的增加而减少的趋势;土壤有机质含量分组后,多重比较分析表明烟碱、总氮、硝酸盐、亚硝酸盐、石油醚提取物、钾、氯离子、总氮/烟碱、还原糖/烟碱、钾/氯在组间差异均达到5%的显著水平,而总糖和还原糖含量在组间差异不显著。     

藏东南地区植烟土壤环境研究

研究表明,土壤温度对藏东南地区烤烟产、质量具有关键影响.烟苗假植、适时垄栽、全程覆膜及非灌溉条件下中耕调控,增温保墒效果显著,烟株生长发育正常,烤烟土壤温度及水分生态适应性基本适宜.植烟土壤土质轻粗、土体疏松,有利于烟根烟碱合成和吸钾量的提高.pH6.2～7.3范围内,烤烟产、质量不受pH单一因子的影响.植烟土壤有效氮、磷(P2O57.1～12.2mg/kg)、钾严重失衡(14.6∶1∶13.6),充分发挥磷肥促进早发、加强生长、提前成熟的作用,对高海拔的藏东南地区烤烟优质适产具有特殊意义.     

模拟酸雨对不同土壤有机碳和作物秸秆分解的影响

为研究酸雨对不同pH值水稻土中有机碳分解的影响,选择酸性（pH 5.48）、碱性（pH 8.18）和中性（pH 6.70）水稻土（分别设置施用秸秆0、15 g·kg^-1土处理）在20 ℃条件下进行40 d的培养试验,各土壤组分别用pH值为6.0、4.5、3.0的模拟雨水将土壤含水量调为400 g·kg^-1(以风干土计).结果表明：秸秆、酸雨和土壤共同对土壤系统CO₂释放产生影响,秸秆的添加可显著提高土壤CO₂释放速率.培养期间,酸雨未显著影响土壤有机碳分解,但对土壤中作物秸秆的分解影响显著. pH 3.0酸雨处理下酸性和碱性土壤中秸秆40 d总分解量比pH 6.0处理高8%;酸雨抑制了中性水稻土中秸秆的分解,pH 3.0酸雨处理下秸秆40 d总分解量比pH 6.0处理低15%.pH 3.0酸雨处理下,酸性水稻土有机碳分解速率分别比中性和碱性水稻土高43%和50%（P<0.05）,秸秆在中性水稻土中分解量分别比其在酸性和碱性水稻土中低17%和16%（P<0.05）.     

不同生物有机肥对烤烟产质量及土壤养分的影响

为探明不同生物有机肥对广元烟区烤烟产质量和土壤养分的影响, 以云烟 87 为试验材料, 开展了不同生物有机肥施用田间试验研究。结果表明: (1)施用生物有机肥, 烤烟产量增加 1341.19—1499.06 kg·ha-1, 上等烟比率增加8.19%—10.88%, 产值最高增加 10838.62 元/ha, 显著地提高了烤烟上等烟比例和产值量(p<0.05); (2)施用生物肥烤烟钾素含量增加, 土壤养分增加, 蛋白酶活性增强; (3)采用供试细菌 SJ40、8GW11 和 C11 生产的生物有机肥效果优于接种放线菌生产的生物有机肥, 施用量以 1500 kg·ha-1 最佳。     

生物炭对植烟土壤微生态和烤烟生理的影响

生物炭是农林废弃物资源化利用的研究热点之一.通过田间试验,研究了烟杆炭不同施用量(0、1、10、50 t·hm^-2)对植烟土壤微生态和烤烟生理特性的影响.结果表明: 烤烟各时期土壤含水量均随生物炭用量增加而增加;在烤烟旺长阶段,50 t·hm^-2处理的土壤含水量显著高于其他处理.随着生物炭用量的增加,土壤总孔隙度和毛管孔隙度逐渐增加,细菌、放线菌、真菌的数量表现为先增后减的趋势,其中生物炭用量10 t·hm^-2处理下数值最大.土壤早期呼吸速率随生物炭用量的增加而增大,与对照相比,生物炭处理土壤呼吸速率增幅为7.9%～36.9%,生物炭高用量(50和10 t·hm^-2)与对照差异显著.生物炭提升了烤烟叶片水势,增加了叶片类胡萝卜素和叶绿素含量,显著增加了根系、地上部和总干质量.说明生物炭在改良植烟土壤微生态和调控烤烟生理特性等方面具有积极效应.     

钾肥用量及基追肥比例对烤烟干物质累积和钾素吸收动态的影响

采用田间小区试验研究了钾肥用量及基追肥比例对种植于红壤性水稻土上的烤烟干物质积累和钾素吸收动态的影响.结果表明,烤烟干物质累积高峰出现在烟株移栽后50～60 d,栽后30 d内以及80 d后累积较少.烤烟干物质累积总量随钾肥用量增加和追肥比例提高而增加.烟株含钾量在移栽后30～50 d最高,随后迅速降低,至成熟期仅为最高含钾量的一半.315 kg·hm^-2施钾处理在各生育期烟株平均含钾量均显著高于225 kg·hm^-2施钾处理.烟叶成熟时,225 kg·hm^-2施钾处理出现干物质累积负增长和钾素损失现象,而315 kg·hm^-2处理干物质累积和吸钾总量均呈持续增加趋势.成熟时基追肥比例为3∶7处理的烟株含钾量明显高于基追肥比例为5∶5和7∶3的处理.     

Identification,purification, and characterization of pathogenesis-related proteins from virus-infected Samsun NN tobacco leaves

Ten pH-3 soluble, low-molecular-weight pathogenesis-related proteins (PRs) were found to accumulate in leaves of tobacco cv. Samsun NN reacting hypersensitively to tobacco mosaic virus. Besides the previously characterized PRs 1a, 1b, 1c and 2, these proteins were provisionally designated N, O, P, Q, R, and S in order of decreasing electrophoretic mobility in native polyacrylamide gels. Two-dimensional gel electrophoresis indicated that the PRs consist of single polypeptides, except for R, which is composed of two components with slightly different molecular weights. Estimated molecular weights in SDS-containing gels were: PRs 1a and 1b 17 kD, 1c 16.5 kD, 2 31 kD, N 33 kD, O 35 kD, P 27 kD, Q 28 kD, R 13 and 15 kD, and S 25 kD. However, based on their elution from gel filtration columns and relative moblities in native gels of different acrylamide concentrations, P and Q appeared to have molecular weights similar to those of the PR 1 group. Upon chromatofocusing no additional components were resolved. The PRs were eluted between pH 7 and 4; except for R, their pIs, as judged from isoelectric focusing, appeared to lie in the range from pH 4 to 5.2. In the presence of 6 M urea PR 1a was split into two components, one of which was strongly retarded on gels, as were P and Q. None of the PRs was detected when gels were stained for glycoproteins.By combinations of gel filtration, DEAE-cellulose chromatography, and chromatofocusing, PRs 1a, 1b, 1c, 2 and N were purified, their amino acid compositions determined, and antisera raised against each of these components. By Western blotting, antisera against either PR 1a, 1b, or 1c reacted with each of the components of the PR 1 group, as well as with PR S. Similarly, the antisera against either PR 2 or N reacted with both 2 and N, as well as with O and R. On the basis of major similarities in molecular weight characteristics, amino acid compositions, and serological relationships, it is proposed to classify tobacco PRs into five groups: 1: PRs 1a, 1b, and 1c; 2: 2a (formerly 2), 2b (N), and 2c (O); 3: 3a (P), and 3b (Q); 4: 4a and 4b (the two components of R); and 5: PR 5 (S).     

Enantiomeric composition of nicotine in tobacco leaf,cigarette, smokeless tobacco,and e‐liquid by normal phase high‐performance liquid chromatography

Evaluating the source of nicotine in e‐liquid is a problem. Tobacco‐derived nicotine contains predominantly (S)‐(?)‐nicotine, whereas tobacco‐free nicotine products may not. Thus, we developed a new normal phase high‐performance liquid chromatography method to determinate the enantiomeric composition of nicotine in 10 kinds of flue‐cured tobacco, 3 kinds of burley, 1 kind of cigar tobacco, 2 kinds of oriental tobacco, 5 kinds of Virginia cigarette, 5 kinds of blend cigarette, 10 kinds of e‐liquid, and 4 kinds of smokeless tobacco. The amount of (R)‐(+)‐nicotine ranged from ~0.02% to ~0.76% of total nicotine. An e‐liquid sample had the highest level of (R)‐(+)‐nicotine. The extraction and purification processes used to obtain commercial (S)‐(?)‐nicotine from the tobacco do not decrease the amount of (R)‐(+)‐nicotine in tobacco. So the amount of (R)‐(+)‐nicotine in samples in our work were the same as tobacco samples.     

Spatial heterogeneity of available zinc, copper, and manganese in Xiangcheng tobacco planting fields, Henan province, China

Geostatistical methods were used in combina-tion with geographical information system (GIS) technol-ogy to analyze the spatial distribution characteristics of available zinc, copper, and manganese in the Xiangcheng tobacco planting fields, Henan province, China. Analysis of the isotropic variogram indicated that the Zn semivar-iogram was well described with the Gaussian model, with the distance of spatial dependence being 900.7 m; while the Mn semivariogram was well described with spherical models, with the distance of spatial dependence being 14 060 m; and, the Cu semivariogram was well described with exponential models, with the distance of spatial dependence being 27 860.7 m. Mn and Zn were strongly spatially dependent, with the C0/sill being 0.014 and 0.147 in this given region; while Cu was moderately spatially dependent, with the C0/sill being 0.3528. With the kriging analysis, the spatial distribution maps of contents of these three trace elements in the Xiangcheng tobacco planting regions was drawn with the Arcview software. It was found that the soils with higher content of Mn were mainly distributed in the high mountains of the southern part of the given regions, while the soils with higher content of Cu were mainly distributed in the south, decreasing from the south to the north. The soil with contents of Zn in the range of 0.76-1.33 mg/kg existed in the high mountains of the west and middle parts of the investigated regions, accounting for 76.11% of the whole area.     

有色膜遮光对烤烟生长和光合特性及其初烤品质的影响

以自然光为对照,采用红色、白色、蓝色、黄色4种有色薄膜于2010~2011年从团棵期开始对大田烤烟进行遮光处理,研究不同光质对烤烟生长、光合特性及初烤品质指标的影响。结果显示:(1)红膜处理最大叶长宽比最小、叶面积最大,黄膜处理则相反。(2)红、蓝膜处理烟叶净光合速率、气孔导度、蒸腾速率明显高于自然光处理,白、黄膜处理略高于对照或与对照持平,且遮膜处理前期红膜高于蓝膜处理,后期蓝膜高于红膜处理。(3)红、蓝膜处理有利于提高倒5叶SPAD值,黄膜处理则相反。(4)红膜处理显著降低了中部叶蛋白质、总氮含量和氮碱比,提高了施木克值,并显著提高了上部叶可溶性糖含量和氮碱比,降低了施木克值;蓝膜处理显著提高了中部叶烟碱和多酚含量,降低了可溶性糖含量、施木克值及氮碱比,并显著提高了上部叶蛋白质、总氮、烟碱和多酚含量,降低了施木克值,提高了氮碱比;黄膜处理显著降低了中上部叶蛋白质、总氮、烟碱和多酚含量,提高了上部叶施木克值、降低了氮碱比。研究表明,红、蓝膜处理更利于烟叶发育和光合特性的提高,初烤烟叶化学成分更协调,利于优质烟叶的形成。     

增施控释复合肥对烤烟叶片生理特性和氮、磷、钾含量的影响

采用盆栽试验,研究了施用控释复合肥对烤烟叶片生理特性和氮、磷、钾含量的影响。结果表明:增加控释复合肥的用量能显著提高烤烟叶片生育期的叶绿素、类胡萝卜素(团棵-打顶期)、抗坏血酸(ASA)含量(旺长-成熟期)、超氧化物歧化酶(SOD)活性(团棵-打顶期)和过氧化物酶(POD)活性(旺长-成熟期),同时,烤烟叶片氮、磷、钾含量也呈现上升趋势;相反,增施控释复合肥显著降低了烤烟叶片类胡萝卜素(成熟期)、丙二醛(MDA)、抗坏血酸(团棵期)、谷胱甘肽(GSH)含量(团棵-旺长期)和超氧阴离子自由基(O2·-)产生速率;增施控释复合肥不仅能提高烤烟的抗氧化能力,还能促进对氮、磷、钾营养元素的积累。     

Effects of tomato spotted wilt virus (TSWV) isolates, host plants, and temperature on survival, size, and development time of Frankliniella fusca

The effects of different isolates of the tomato spotted wilt tospovirus (TSWV), host plants, and temperatures on Frankliniella fusca (Hinds) (Thysanoptera: Thripidae), the most important vector of TSWV in North Carolina, were measured in the laboratory. Thrips were reared at either 18.3, 23.9, or 29.4 °C until adult eclosion on excised leaves of Datura stramonium L. or Emilia sonchifolia (L.). Plants were either infected with the TSWV isolates CFL or RG2, or left uninfected (control). The results revealed a positive relationship between larval survival and temperature, regardless of host plant or TSWV isolate. Both survival to adult and percentage transmission of TSWV by F. fusca were significantly affected by the interaction between host plant and TSWV isolate. The consequence of this interaction was that the cohort‐based percentage transmission from infected E. sonchifolia plants for CFL was 1.3‐fold greater than that of RG2, whereas the percentage transmission from infected D. stramonium plants for RG2 was twice that of CFL. Both host plant and TSWV isolates showed significant effects on thrips development time to adult and head capsule width of adult thrips, as well as on the incidence of thrips infection with TSWV. The infection status of these thrips was determined by ELISA for the NSs viral protein. Infected thrips reared on infected host foliage took longer to develop to adult and were smaller than non‐infected thrips which had also been reared on infected host foliage, demonstrating a direct effect of the TSWV on thrips. However, non‐infected thrips reared on non‐infected leaves took longer to develop than non‐infected thrips reared on infected leaves, suggesting an effect of the plant tissue on thrips. In addition, adult thrips reared on TSWV‐infected D. stramonium at 29.4 °C developed smaller head capsules than thrips developing on infected foliage at lower temperatures and on non‐infected leaves of D. stramonium or E. sonchifolia. Both TSWV isolates and host plants differentially affected females more than males. In conclusion, both the infection of thrips by TSWV and TSWV‐mediated changes in host plant quality were found to have significant biological effects on F. fusca.     

Stereoselective degradation of benalaxyl in tomato, tobacco, sugar beet, capsicum, and soil

The stereoselective degradation of the racemic benalaxyl in vegetables such as tomato, tobacco, sugar beet, capsicum, and the soil has been investigated. The two enantiomers of benalaxyl in the matrix were extracted by organic solvent and determined by validated chiral high-performance liquid chromatography with a cellulose-tris-(3, 5-dimethylphenylcarbamate)-based chiral column. Rac-benalaxyl was fortified into the soil and foliar applied to vegetables. The assay method was linear over a range of concentrations (0.5-50 microg ml(-1)) and the mean recoveries in all the samples were more than 70% for the two enantiomers. The limit of detection for both enantiomers was 0.05 microg g(-1). The results in soil showed that R-(-)-enantiomer dissipated faster than S-(+)-enantiomer and the stereoselectivity might be caused by microorganisms. In tomato, tobacco, sugar, beet, and capsicum plants, there was significantly stereoselective metabolism. The preferential absorption and degradation of S-(+)-enantiomer resulted an enrichment of the R-(-)-enantiomer residue in all the vegetables.     

Effect of NaCl on Biomass and Contents of Sugars, Proline and Proteins in Seedlings and Leaf Explants of Nicotiana tabacum Grown in vitro

Effects of NaCl on growth in vitro and contents of sugars, free proline and proteins in the seedlings and leaf explants of Nicotiana tabacum cv. Virginia were investigated. The fresh and dry mass of the seedlings decreased under salinity. These growth parameters in leaf explants decreased at 50 mM NaCl and increased up to 150 mM NaCl and then decreased at higher level of salinity. Free proline content in both seedlings and leaf explants increased and polysaccharide content decreased continuously with increasing of NaCl concentration. Reducing sugars, oligosaccharides, soluble sugars and total sugars contents in both seedlings and leaf explants decreased up to 150 mM NaCl and then increased at higher concentrations of NaCl.