Effects Of Altitudes On The Growth And Development And Quality Of Flue-cured Tobacco

On the basis of Hubei tobacco-growing regions,the status of climate and the quality of flue-cured tobacco there were analyzed.On the view of macroscopic,the physical properties, chemical composition,aroma matters and sensory quality of flue-cured tobacco were studied in different altitudes;on the view of microscopic,the effects of altitudes on microstructure and sub microstructure of flue-cured tobacco were analyzed.Main conclusions were as follows.(1) The climate of Hubei tobacco-growing areas had a long frost-free period,feasible temperature in fields,abundant precipitation,high accumulated temperature of≥10℃.However, discrepancies existed comparing with the quality tobacco regions aboard of the fields' sunlight. The nine climate factors of affecting the growth and development of flue-cured tobacco were conducted to multivariate cluster analysis,and the 22 counties were cluster into three areas.The first group contained Lichuan,Xianfeng and Wufeng with low average fields temperature,low active accumulated temperature of≥10℃,lack sunlight,short frost free periods and medium precipitation;The second group contained six counties,that were five counties of Enshi and Changyang of Yiyang with more precipitation and medium of other climate indexes;The third group contained thirteen planting tobacco counties with abundant average temperature and sunlight and active accumulated temperature and relative less precipitation.(2) Based on the climate vertical distribution discipline,climate condition of Enshi tobacco-growing areas could be classified into three groups at different altitudes areas,including lower altitude(＜800m),medium altitude(800～1200m),high altitude(＞1200m).On the basis of climate data of nine indexes at different altitudes of Enshi tobacco-growing areas,climate status and climate feasibility indexes at different altitudes were evaluated,similarity analysis of climate conditions between Enshi tobacco-growing areas and high-quality tobacco-growing areas overseas was analyzed.Frost-free period turned to shorter,average temperature and accumulated temperature of≥10℃turned to lower,sunlight and precipitation turn to more abundant along with increasing of altitudes.Average temperature,precipitation,sunlight,accumulated temperature of≥10℃and frost-free period during field period had significant difference among different altitudes.It showed that the significant trend of low altitude＞medium altitude＞high altitude except frost-free period between medium altitude and high altitude.CFI values at different altitudes showed that low altitude＞medium altitude＞high altitude,CFI had significant difference among different altitudes.The similarity of the climate conditions at different altitudes of Enshi tobacco-growing areas with overseas showed that low altitude>medium altitude>high altitude.(3) Systemic studies of histology and cytology were carried on to the growth and development different altitudes and the macroscopic and sub microscopic structures were examined.The results indicated that:positive relationship existed between root growths and aboveground.The growth and development of root and hacking in low altitude was in good condition,that of medium altitude was hampered affecting the stretch elongation of middle and lower leaves,and that of high altitude was doing well for mulching in early time with poor tip hacking.It was favorable for promoting the synthesis of aromatic substances(osmiophilic granules) by increased altitude reasonably.When the leaves were in optimum stage,the starch grain in cell began to degrade.With the increasing of altitude,the photosynthesis structure (chlorophyll body) had the trends of premature senility.The leaf cells was in meristems and growth and development stage before lengths of 15 centimeter and began to enter into function periods,the chloroplast started to accumulate starch grains and generated osmiophilic granules.While the leaf at the length of 40 centimeter,the black osmiophilic granules in chloroplast increased and endoplasmic reticulum was progressed near to the nucleus which surrounded with viscous filamentous grey osmiophilic substances generated from chloroplast and transported into vacuole formed into black osmiophilic matters again.The studies showed that the key to the quality of tobacco leaf forming was the process of development rather than mature phases.Change rules of thickness of palisade tissue and spongy parenchyma had the similar elementary disciplines.The cell density of palisade tissue had periodical changing law.With the leaf length increasing,the intercellular spaces augmented and before the length of 20 centimeter grew faster and then slowly.(4) Combing the demand characteristics of quality mountainous flue-cured tobacco of China Tobaco Hubei Industrial Corporation,the physical properties,chemical composition,aroma matters and sensory quality of flue-cured tobacco were studied in different altitudes in Enshi tobacco-growing areas.The results indicated that the physical properties were proper,the chemical compositions were harmony,the content of aromatic matters was abundant and the sensory quality was better.The organic acid content,neutral aromatic matters content,cembratriendid compounds content and products of browning reaction content of low and medium altitudes were analyzed, and the results showed that the total organic acid content,non volatile organic acid total content, saturated higher fatty acid and unsaturated higher fatty acid content demonstrated the trends of X2F>C3F>B2F of different gradings in the same elevation.The total organic acid content and non volatile organic acid total content of different gradings indicated the trends of medium altitude >low altitude;The neutral aromatic matters showed the trends of C3F>X2F>B2F in different altitudes;Cembratriendid compounds content had the same trends with the total organic acid content and non volatile organic acid total content indicating that increasing elevation could improve the content of cembratriendid compounds.And total products of browning reaction and total carotenoid degradation products content gave the trends of low altitude＞medium altitude.