This study was conducted to determine the time and methods of predicting tobacco yield, by studying the relationship of yield components to yield. 1. The relationship between each position in leaf dry weight and approached gradually each other and also correlation coefficient of top leaf was higher than that of lower leaf. The leaf dry weight per plant was highly correlated with leaf area from 16th leaf position on stalk. Leaf dry weight of each leaf position on stalk was highly correlated with leaf dry weight per plant at 14 to 16th leaf position. 2. The correlation coefficient between leaf dry weight and leaf area per plant was higher at the late growth stage than at the early growth stage, and higher between the near stages. Correlation coefficient between leaf dry weights was higher than that of leaf areas. 3. Flue-cured tobacco yield be estimated from leaf dry weight per plant at 50 to 55 days after transplanting. 4. Air-cured tobacco yield could be predicted from leaf dry weight per plant at 60 days after transplanting.

Several growth characteristics of two ornamental tobacco species, Nicotiana sanderae and N. affinis, were investigated in this study. Also effect of temperature and daylength on the flowering of the tobacco plants were evaluated to obtain basic information on breeding and cultivation. 1. The plants were great in high temperature-long day at the early stage and in low temperature-short day at the late stage of plant growth, for both Nicotana species. At the early growth stage the leaf length N. sanderae was great in high temperature-long day, and that of N. affinis was great in high temperature-short day period, while at the late stage of the plant growth the leaf lengths were more significantly effected by the temperature rather than daylength. Leaf width and leaf shape index were less sensitive to the conditions. 2. For both of the species, the total number of tobacco leaves not much influenced by the temperature and daylength. 3. There were no significant differences for budding and flowering period between the two species, both of which were sensitive to temperature and daylength with more influence by daylength than temperature. 4. Number of floral stalks, number of flower and flowering period were not much influenced by temperature and daylength; however, N. affinis had 2 more floral stalks, 31 more flowers, and 6 day longer flowering period than N. sanderae.

The experiment was conducted to obtain basic information on breeding of flue-cured tobacco varieties. Nine cultivars and partial diallel set of 36 F1 hybrides were grown at Taegu Experiment Station, Korea Ginseng & Tobacco Research Institute in 1983. Estimated heritability in the narrow-sense ranged from 66.21% to 94.12% for yield, leaves per plant, days to flower, leaf weight, leaf width, leaf shape, nicotine content and reducing sugar content, while that for stalk height, leaf length, midrib weight and midrib width ranged from 28.12% to 56.25%. The genotypic correlations were positive among yield, leaf weight, leaf length, leaf width, midrib weight and midrib width in the middle leaves, days to flower, nicotine content and reducing correlated with leaf length than leaf width. At the path coefficient analysis of the effect of leaf and midrib characters upon yield according to stalk position, leaf weight, leaf width and midrib width in the middle leaves, and leaf weight, and leaf width in the top leaves showed high direct effects.

Field experiment was conducted to find out the chemical characteristics of 12 Korean local varities, Local varities were compared with oriental, flue-cured and burley tobacco. Among tested varities, Hyangcho and Matskawa were desirable in respect of flavor, leaf color and texture. Hyangcho and Matskawa were higher in the content of nicotine and petroleum ether extract. Gajacho, Byeolcho and Kukjuo were higher in the content of reducing sugar, but lower nicotine, total nitrogen and petroleum ether extract. The nicotine and total nitrogen content of Kwangcho, Daruma and Catterton were lower than that of Br. 21. In the content of volatile organic acid which were major characteristic component of oriental tobacco, the Korean local varities were lower in the content of 3-methyl butanoic and 3-methyl pentanoic acid, but hirities, Hyangcho, Matskawa and Daruma were higher in the content of volatile organic acid. Korean local varities, especially small leaf group, were higher in the content of benzyl alcohol and furfural than any other type tobacco.

This study was conducted to obtain the breeding information for the leaf breakdown, and correlation coefficients between leaf breakdown and some agronomic characters in flue-cured tobacco at Taegu Experiment Station, Korea Ginseng & Tobacco Research Institute. NC 95 and NC 2326 were used as parents. The bulk method procedure was used from the F2 to the F4 generations, 54 plants were selected among F4, and 11 lines were selected among 54 F5 which based on high resistance to bacterial wilt compared with NC2326. The entries were composed of parents and 11 F6 advanced lines, and designed in randomized block with 3 replications. Plant seedlings were transplanted in 16 April. The number of breakdown leaf were investigated at flowering stage, 18 June. There were significant difference between NC 95 and NC 2326 for the number of breakdown leaf, number and weight of ground suckers, days to flower, yield and resistance to bacterial wilt, and similar results were appeared among lines. Estimated heritability in the broad-sense ranged from 59.3% to 87.4% for all characters. Most of genetic correlations were higher than phenotypic coefficients between characters. Number of breakdown leaf was positively correlated with days to flower, the number and weight of ground suckers, while it was negative to yield. One line among 11 had few breakdown leaf, low producted ground suckers and high resistance to bacterial wilt. Above results suggest that the number and weight of ground suckers can be use as a selection criterion for leaf breakdown even under the condition without leaf breakdown.

This Study was conducted to estimate the degree of dominance and gene frequency of some sueful characters in tobacco. The eight parents and a set of 28 crosses of F'1s was F'2s were used as materials, and planted on oriental's and burley cultivated system as randomized block designs, respectively. The observed characters were six agronomic characters which were plant height, number of leaves per plant, leaf length, leaf width, days to flowering and yield, and the data obtained from the experiment were analyzed from methods by Hayman's and Jinks. The results obtained are summarized as follows: 1. In Vr-Wr graphical analysis, number of leaves per plant, leaf length, days to flowering and yield were found to be inherited in partial dominance, and plant height was over dominance to be similar to complete dominance, but leaf width was inherited with partial dominance close to complete dominance. 2. In the gene frequency, two varieties Xanthi-Basma and KA 102, for days to flowering and yield had larger number of dominant genes as those were situated near the point of origen. 3. Additive effects of genes(D) were greater than dominance effects of Genes(H) for six agronomic characters except plant height, and mean degree of dominance over all loci was lower than 1 for days to flowering yield, leaf length and number of leaves per plant.

The study was conducted to obtain the genetic informations for some useful characters in tobacco breeding. The eight parents and a set of 28 crosses of F1's and F2's were used as materials, and planted on two different cultivated systems, i. e., oriental's and burley systems, during 1986-1988 at taegu Experiment Station, Korea Ginseng & Tobacco Research Institute. The observed characters were six agronomic characters which were plant height, number of leaves per plant, leaf length, leaf width, days to flowering, yield and five chemical components, nicotine, total nitrogen, protein nitrogen, total volatile base and pet, ether extract. The results obtaining are summarized as follows: 1. The higher heritabilities were found for days to flowering yield and nicotine in both generations, but values for number of leaves per plant, leaf length, total nitrogen and protein nitrogen were lower than other characters. 2. Genotypic correlation coefficients among all pairs of characters were slightly higher than the corresponding phenotypic correlations in F1's and F2's on two different cultivated systems. The relationship between leaf length and leaf width was the positive correlation, but that between number of leaves per plant and leaf width was negative. 3. From the genotypic correlations between yield and other characters, a conclusion that the yield was highly correlated with plant height, leaf length, leaf width and days to flowering was given. 4. Quality was positively correlated with number of leaves per plant and nicotine, but negatively with the other agronomic characters and chemical components.

This experiment was conducted to investigate the effect of growth medium in pots composed of upland soil(S), rice straw manure(M), carbonated rice hull(CRH), and their mixture on growth of tobacco cv. NC 82. The growth of shoot and root was vigorous in order of medium S+M+CRH>M>CRH>S. In M+S medium, root growth in the part of manure was superior to upland soil. But root growth of upland soil part in M+S plot was more vigorous than that in upland soil only. It is possibly due to be influenced by manure in M+S plot. Total length and weight of root, number of roots, and especially for development of adventitious root were closely related to shoot growth. Roots grown in upland soil part was brownish gray in color, while the roots in manure part was milky white. The milky white colored roots had longer life than others. It was concluded that root zone environments derived from several media in pots closely related to shoot growth and disease tolerance of tobacco plant.

Leucine and isoleucine were reacted with glucose in a propylene glycol solution and volatile compounds produced from these reaction were analysed by gas chromatography and mass spectrometry. A total of 24 compounds were identified in the leucine reaction volatiles and the major components were 2-isopropyl-5-methyl-2-hexenal, methylbutyraldehyde PGA, butyraldehyde PGA, 5-methylfur-fural, isopropylmethylhexenal PGA and 2-acetylpyrrole. From the isoleucing reaction volatiles, 20 compounds were identified and the major components were methylbutyraldehyde PGA, butyraldehyde PGA and 2-acetylpyrrole. The amino acids chosen for this study were considered as giving fruity and cocoa aroma when heated with glucose.

10. Three major factors, freeness, filler and blend ratio that exercised considerable influence on physical properties of cigarette papers were chosen for the sake of their optimization at this experiment. An optimization of those above factors in paper manufacturing was investigated using response surface analysis. Optimum beating degree for Kenaf, Flax and NBKP showed around 72。SR, 68。SR and 85 SR, respectively, in considering of five quality index such as porosity, tensile strength, stretch, whiteness and opacity. The best blending ration of reciprocal pulps treated under optimum beating degree were diversified and combination scope of the bast fiber (Kenaf, Flax) to the NBKP was range from 30% to 65% in case of the Kenaf, from 25 to 40% in Flax at the same receipe. The optimum range of calcium carbonate content revealed 25%~30% in Kenaf mixed NBKP and 24%~31% in Flax mixed NBKP.

Deoxyschizandrin, gomisin N, schizandrin, wuweizisu C, gomisin A and angeloylgomisin H were isolated from fruits of Schisandra chinensis BAILLON, and the lignan contents in shred and smoke of 'Balloon-Flower' cigarettes were quantitatively analyzed by capillary-GC(FID). The GC column was SPB-1 fused silica capillay (0.25mm id$\times$30m, Supelco) and the column oven temperature was programmed from 20$0^{\circ}C$ to 30$0^{\circ}C$ at the rate of 4$^{\circ}C$/min. In the shred of 'Balloon-Flower' cigarettes deoxyschizandrin. gomisin N, schizandrin, gomisin A and angeloylgomisin H were detected and schizandrein contets were the highest among them, 22.77$\mu\textrm{g}$/cig., gomisin N, schizandrin and gomisin A were 0.023, 0.054, 0.0849 and 0.167$\mu\textrm{g}$/cig. respectively, and angeloylgomisin H was not detected.

This experiment was carried out to select of heterokaryon based on the different buoyant densities of protoplasts. Protoplats were isolated from cultured cells (calli) of Nicotiana tobacum(cv. BY4) and from mesophyll cells of N. glauca. The two types of protoplats were fractionated by centrifugation in an iso-osmotic (770 mOs/kg. H2O) density gradients condition. Major difference in the buoyant density exists between two types of protoplasts isolated from different cells. The mesophyll protoplasts were fractionated in the higher gradient interphases than that of callus protoplasts. The two types of fractionated protoplasts were fused with 40% polyethylene glycol (PEG), and the protoplasts treated with PEG were separated by centrifugation in the same density gradients condition. The heterokaryons were fractionated in the intermediate density gradients.

Mold development on leaf tobacco(Flue-cured, var. NC 82) during the storage was examined according to the initial moisture content(MC) of the tobacco. The initial moisture content of the leaf tobacco was controlled as 12,14,16% after redrying. Those were packed in cardboard boxes and stored in a warehouse. Samples were taken monthly from June of 1988 through August of 1989 and were evaluated for mold development (colony count) and MC. The moisture content change in the leaf tobacco of 12, 14 and 16% initial MC was in the range of 11.1-13.3, 12.8-15.3 and 14.9-16.7% and the mean number of colonies from them were 1.4$\times$102, 1.0$\times$102, and 4.0$\times$102 colonies per gram of tobacco, respectively, however mold-damaged leaf tobacco other than the treatments was occasionally observed to have the colony number as high as 2.3$\times$105 colonies per gram of tobacco. In the meantime, the leaf tobacco was stored at 6 relative humidity levels at $25^{\circ}C$ in laboratory test. Leaf tobacco of 15.0-16.4% MC was maintained without the mold-damage after 80 days of storage whereas those of 19.9, 21.3, 25.5 and 27.1% MC became moldy after 50, 15, 11 and 6 days of storage, respectively.

The amino acid content and constitution of domestic flue-cured tobacco before and after the aging were investigated. The major amino acids of domestic flue -cured tobacco were histidine, serine, aspartic acid and proline and leucine, isoleucine and glycine were minority in them. Phenylalanine was the most changeable components through the aging. While the contents of tryptophan, sering and Proline which have herbaceous, harsh and bitter taste and aroma in smoke were reduced, tyrosine which adds smoothing and enhances smoke aroma was increased after the aging. The leaf tobacco aged at 4$0^{\circ}C$ for 30 days had a amino acid composition as good leaf tobacco storaged in natural condition for 2 years.