In order to improve the quality of flue cured tobacco leaves in bulk curing barns, by prolonging the baking time at the end of yellowing and color fixing stage, the appearance, interior and sensory quality of tobacco leaves were analyzed. The results show that, the chlorophyll and starch degradation rates of cured tobacco leaves of T1 and T2 were higher, and the appearance quality of the two treatments being 4.04 and 3.37 points higher than CK, the upper medium smoke being 23.85 and 17.69 percentage point higher than CK, and the sensory quality was better than T2. Extending the curing time at the end of yellowing stage was beneficial to improve the appearance quality of flue-cured tobacco and the degradation rate of macromolecular substances, and prolonging the curing time at the end of color fixing stage was beneficial to improve the sen-sory quality of flue-cured tobacco.

Field experiments were conducted in Longgang base,Guiyang to study the effects of different planting depth well cellar-type transplanting on the early growth and development of tobacco. Results showed that 35 d after transplanting, the treatments of tobacco growing point from 6 cm of well cellar mouth had the best agronomic traits with the highest biomass and root vigor, the best root development and the biggest comprehensive effect coefficient. The tobacco growing point from 6cm of well cellar mouth was most appropriate for well cellar-type transplanting planting depth, beneficial to early growth,root growth and dry matter accumulation of tobacco.

在贵州省烟草科学研究院贵阳龙岗基地，开展井窖式移栽烟苗根系不同覆土程度对烟株前期生长发育影响的试验。结果表明，移栽后35 d，根系全覆土的烟株农艺性状表现最好，地上部生物量、根系活力相对最高，根系发育较好；根系覆土1／3的烟株根系发育相对最好，根系抗逆性最强。井窖式移栽的烟苗根系采取全覆土方式较为适宜，有利于烟株前期地上部生长和干物质的积累。

In order to explore the changes of key enzymes in sucrose metabolism of flue-cured tobacco in different ecological regions,the key enzymes activity in sucrose metabolism of K326 flue-cured tobacco collected in key production period from different ecological regions was detected and analyzed.Results:the difference of AMS and SS in different ecological region and growth stage reached extremely significant level.The interaction of ecological region and growth stage had very significant influence on AMS,SPS and SS.

从贵州省毕节8个县市共采集正常及患病烟草根际土壤131份,用稀释涂布平板法及平板划线分离法从土样中分离、纯化出164株细菌菌株,在PDA平板上用平板对峙法初步筛选出18株对链格孢菌菌丝有抑制作用的菌株.用滤纸片扩散法进行复筛,结果显示1株菌株L3有明显的抑菌活性,其发酵液对链格孢菌的抑制直径约为17 mm.对该菌株进行了形态学和生理生化鉴定实验及16S rDNA序列分析,鉴定L3菌株为枯草芽孢杆菌(Bacillus sub-stilis).显微镜观察表明,L3能使菌丝畸变、断裂、顶端膨大、原生质凝集.

为探讨在高海拔区域植烟密度对红花大金元农艺经济性状、外观质量、化学成分和感官吸食品质的影响,采用田间试验的方法,在常规施肥的基础上开展了红花大金元不同种植密度试验.结果发现:当种植密度为86cm(窄行)～ 120 cm(宽行)×45 cm和87 cm(窄行)～120 cm(宽行)×40 cm(一垄双行)时,中上部烟叶的烟碱含量减低,烟叶内在化学成分的协调性提高,促进了烟株的田间生长发育,有利于提高烟叶的产量和产值；种植密度为115 cm× 60cm时,烟叶的上中等烟比例及均价较高；随种植密度的增加,上部烟叶的身份(厚度)降低,色度减弱.表明:种植密度与红花大金元烟叶产量呈正相关,宽窄行高密度处理有利于产量和经济性状的形成,种植密度对红花大金元中下部烟叶的化学成分影响较小,但密度增加有效降低上部叶烟碱含量.

Different plastic film mulching patterns were tested in tobacco cultivation to study the effect of different mulching patterns on microorganism quantity in tobacco soil for rational utilization of plastic film in tobacco cultivation.The results showed that the bacterium,fungus and actinomyces quantity in different treatments with double-row on single ridge was higher than treatments with single-row on single ridge.The plastic film mulching during total tobacco growth period had the inhibitory effect on growth of nitrobacteria,the promoting effect on growth of ammonifying bacteria at early growth stage of tobacco plants but the inhibitory effect on growth of ammonifying bacteria at later growth stage of tobacco plants.The film uncovering after 35d had certain promoting effect on growth of nitrobacteria and ammonifying bacteria.The plastic film mulching could obviously increase the content of nitrate nitrogen and ammonium nitrogen at middle growth stage of tobacco plants.

By the method of correlation analysis and factor analysis,total 27 tobacco samples from 9 tobacco-growing counties scattered in the administrative regions of Hubei Province were analyzed with data from 10 main chemical components in flue-cured tobacco leaves.A comprehensive evaluation was carried out by using the factor scores.The results indicated that the main chemical components in flue-cured tobacco leaves were highly positive-correlated with that of the others.The contribution rate of first-four characteristic roots was 91.400%,four main factors from the main chemical components in flue-cured tobacco leaves were obtained,namely the carbon nitrogen factor,combustion factor,Nit r/Nic factor and starch factor.Comprehensive analysis can be used in judging the quality of flue-cured tobacco according to the main chemical components in flue-cured tobacco leaves,and it will provide scientific reference to flue-cured tobacco industry usability.

Climate status of Enshi tobacco-growing areas at different altitudes of Hubei province was analyzed,and climate feasibility was comprehensively evaluated at different altitudes of Enshi tobacco-growing areas,and similarity analysis of climate conditions between Enshi tobacco-growing areas and high-quality tobacco-growing areas overseas was also conducted.The results indicated that: 1)Average temperature of every growth period and accumulated temperature of ≥10 ℃ decreased with the increasing of altitude,sunlight during field period and precipitation of every growth period increased with the increasing of altitude.Average temperature,precipitation,sunlight,accumulated temperature of ≥10 ℃ and frost-free period had significant difference among different altitudes of Enshi tobacco-growing areas.2)Climate feasibility indexes(CFI) decreased with the increasing of altitude,CFI was the largest(0.903) at high altitude areas,and CFI was the smallest(0.660) at low altitude areas,climate feasibility indexes had significant difference among different altitudes of Enshi tobacco-growing areas.3)The average similarity distance of the climate conditions at different altitudes was smallest between Enshi and Zimbabwe tobacco-growing areas,for 0.383,0.402,0.431,respectively.Similarity degree of the climate conditions was highest between low altitude areas of Enshi and high-quality tobacco-growing areas overseas,and lowest between high altitude areas of Enshi and high-quality tobacco-growing areas overseas.