This study was been conducted to determine chemical characteristics of soils in the major districts cultivating flue-cured tobacco plant. Also native soil productivities were measured by means of bioassay planting tobacco plant without fertilizer at 87 selected lolls through pot and field experiments. Inorganic nutrient in soils affecting the dry weight of tobacco leaves cultivated in the field were investigated. The results obtained are summarized as follows; 1. Among soil chemical characteristics, pH, $NO_3$-N, $NH_4$-N , $P_2O_5$, and Mg Influenced significantly the dry weight of tobacco loaves In pot experiment, whole In the field experiments, pH, $NO_3$-N, $NO_3$-N+$NH_4$-N, and Ca had influence. 2. Correlation coefficients between soil chemical characteristics and dry weight of tobacco leaves were higher in pot experiment than field. The results revealed that soil morphological characteristics might more close influence on dry weight of tobacco leaves than chemical characteristics. 3. For prediction of dry weight (Productivity) of tobacco leaves without fertilizer multiple regression analysis were introduced using troll chemical characteristics. A combination of pH, $NO_3$-N, and Ca was very reliable for prediction of productivity as equation. y=5.02+18.07$x_1$ +2.61$x_2$ +5.36$x_3$ R=0.444** Where $x_1$ : pH, $x_2$ : $NO_3$-N, $x_3$:Ca

Lines were developed from the two crosses, BY4 X NC 82 and BY 4 X BY 104, by bulk, backcross and anther-derived dihaploid methods of breeding , and their variations in major agronomic, chemical characters, heritability, and response to selection were compared. 1. The anther-derived dihaploid lines showed a greater genetic variability and heritability in characters investigated than the lines developed by the other two methods of breeding . However, those were Inferior In agronomic characters and yielded 15.4% less leaf tobacco than the lines developed by the bulk method. 2. The lines developed by bulk method were higher In the frequency of lines resistant to bacterial wilt and in the yield, but Its lines appeared later flowering. inferior leaf Quality, and higher total nitrogen contents than those developed by the backcross method of breeding. 3. In the population of the lines developed by the backcross method, bacterial wilt resistant lines were less frequent, but the lines with a good leaf quality were more frequent.

Effects of application time And rate of chlorine on the chlorine absorption and distribution at different stalk positions of the plants were Investigated in burley tobacco grown under the pot condition. Treatment consisted of 6 application times (from 2 weeks before transplanting to 8 weeks after transplanting with 2 weeks' interval) and 2 application rates (2g and 4g-KCl/pot) by 6X2 factorial experimental design. The tobacco plants took up the chlorine rapidly just after chlorine application, and the chlorine content of leaf was increased proportionally to the rate of chlorine application. The chlorine was accumulated when much in lower leaves when chlorine was applied early, while the chlorine accumulated much in upper leaves when chlorine was applied late. The chlorine content of leaf was negatively correlated to the degree of brightness, red color and yellow color of cured leaf. Significant Increases In cured leaf ratio, leaf thickness, leaf weight and weight Per unit leaf area of harvested leaf were obtained with increased chlorine application. When the chlorine was applied early, the leaf weight showed Increasing tendency.

This experiment was conducted to obtain basic information on breeding of flue-cured tabacco varieties . Nine cultivars and partial diallel set of 36 Fl hybrids were grown at Daegu Experiment Station, Korea Ginseng & Tobacco Research Institute in 1983. Partial dominance with high additive gene effect was observed for yield, leaves per plant , days to flower, leaf weight, nicotine and reducing sugar content. partial dominance with additive and dominant gene effect was observed for stalk height , leaf width midrib weight Overdominance with high dominant gene effect was observed for leaf length and midrib width. The directions of dominance were positive for yield, stalk height, leaf weight, leaf length, leaf width, midrib weight, midrib width and reducing sugar content, and the negative was days to flower. The estimates of effective genes were 1 for leaves per plant, 2 for stalk height, days to flower and leaf shape. 3 to 6 for leaf length, leaf width, leaf weight and midrib weight.

This study had been conducted to determine morphological characteristics of soil in the major districts cultivating flue-cured tobacco plant. Also native soil productivities were measured by means of bioassay planting tobacco plant without fertilizer at 87 selected soils through field experiment. Morphological characteristics of troll affecting the dry weight of tobacco leaves cultivated in the field were investigated Among soil morphological characteristics, topograpy, slope, topsoil depth, soil depth, and soil texture had influenced with high significant on the dry weight of tobacco leaves. For prediction of dry weight (productivity) of tobacco leaves without fertilizer , multiple regression analysis were introduced using soul morphological characteristics. A combination of topography, slope, topsoil depth, and soil texture was very reliable for prediction of productivity. The regression equation was y = -16.88 -14, 34$X_1$ +20.43$X_2$ +50.21$X_3$ -7.54$X_4$ +13.45$X_5$ R = $0.670^{**}$ Where $X_1$ : Topography $X_2$ : Slope $X_3$ : Topsoil Depth $X_4$ : Soil Depth $X_5$ : Soil Texture

황색종 잎담배의 성숙과 노쇠 (이식후 50일부터 106일까지 )에 따른 생엽중 전분, 전당, 니코틴 및 전질소의 함량 변화와 이들 성분간의 관계를 조사한바, 전분함량은 두 품종 모두 각 엽위에서 성숙함에 따라 증가하였으나 노쇠함에 따라 감소하였다. 전질소 함량은 성숙함에 따라 감소하였으나 니코틴 함량 은 점점 증가하였다. 전당 함량은 성숙함에 따라 감소하는 경향이었다. 전분 함량은 전질소 함량과는 부의 상관을 보였으나 니코틴 함량과는 정의 상관이 인정되었다. 전질소 함량과 니코틴 함량은 부의 상관이 인정되었다. 그러므로 수확기를 관행보다 5-7일 늦추는 것은 건엽에서 환원당과 니코틴의 비를 더 좋게 하는 방법일 것이다.

Nicotine, the main alkaloid of tobacco, showed different effect according to the enzyme. Among investigated enzymes, protease was inactivated remarkably by nicotine and the mode of inhibition was examined. $\alpha$-amylase and $\beta$-amylase were not affected, and cellulase and glucoamylase were inactivated partially when the concentration of it was over 1.0% , but protease was inhibited powerfully by nicotine The inhibition of protease by nicotine was performed almost in the initial stage of reaction, and was not so much affected by temperature, and was reversible. The inhibition type of protease by nicotine appeared as a Mixed-type inhibition.

$\alpha$, $\beta$-4.8.13-Duvatriene-1, 3-diols was identified as the major component of diterponoid extracted from Nicotiana Tabacum L. The isolated duvatriendiol was thermolyged at 300'c under a stream of nitrogen. The approximately 20 compounds were separated from the thermolyzates and the 9 compounds of them were identified with GC/MS. However, the thermolyzates identified in this study differed in distribution from the products under the condition of a different temperature or photooxidation.

The mutagenic activities of the pyrolyzates (300, 600, 750 and 85$0^{\circ}C$ ) of extracts from three saponeous expectorants (Platicodi Radix, Polygalae Radix and Asiasari Radix) and two nonalkaloidal antitussives (Lirionis Tuber and Codonopsis lanceolata Radix), medicinal plants, were studied in the Ames Salmonella/microsomes test system. The pyrolysates of Codonopsis lanceolata Radix and Asiasari Radix extracts at 85$0^{\circ}C$ were slightly mutagenic to tester strain TA98( frame shift ) and TA100(base-pair substitution) of Salmonella typhimurium, and the mutagens in these pyrolyzates required the metabolic activation by a liver microsomal fraction However, the extracts and pyrolyzates of all medicinal plants tasted except the above two results dud not show the significant increase in revertant colonies.

1. Under the current workroom conditions It is very difficult to control the moisture contents of raw materials in season of summer or winter. 2. The moisture absorption of the materials under the contributive conditions showed the efficiency of 65% in relative humidity and temperature of the currant workroom. 3, The results from this study, however , appeared the deviation of moisture content of the products by the order of 0.1% compared to the current deviation of 2.6~2.7%. 4. Equilibrium moisture contents of the tobacco was Inversely proportional to the temperature and directly related to the relative humidity of the workroom. 5. On the basis of the above results , the standard conditions of the workroom obtained from this study considering with the external temperature in winter could reduce energy by 17.4% through 38.4% .