烤烟品种云烟85烟叶的成熟度I.成熟度与叶片组织结构、叶色、化学成分的关系

Studies on leaf maturity of Yunyan 85, a variety of flue-cured tobacco I. Relationship between the maturity and the tissue, color and chemical compositions in leaves

对烤烟品种云烟 85品种的下二棚、腰叶、上二棚 3个部位的不同成熟度鲜叶进行解剖观察和叶绿素含量测定 ,并进行烘烤验证和烟叶化学成分分析 .结果表明 :烟株下二棚叶和腰叶采收的最适特征为叶片呈淡黄或黄多绿少、主脉全白发亮、支脉 1 /2至 2 /3变白、茸毛脱落较多以及叶尖叶缘稍枯 .上二棚叶采收最适特征为叶片全黄、主脉全白发亮、支脉 2 /3至全白、茸毛大部分脱落以及叶尖叶缘呈枯尖枯边 .各部位烟叶按该成熟度标准采收时 ,烟叶组织结构疏松 ,茸毛脱落较多 ,叶绿素含量下降 ,有利于烟叶的调制和烟叶品质的提高 ,烤后上等烟叶和上中等烟叶比例高 。

Mature fresh leaves from lower, middle and upper parts of the stalks of Yunyan 85, a variety of flue cured tobacco were dissected and oberved, and their chlorophyll content was determined. Then, those leaves were subjected to flue curing trial and chemical composition analysis. The optimal appearance of lower and middle leaves for picking was greenish or light yellow in colour, with the main veins completely white, 1/2 to 2/3 lateral veins turning white, a lot of tomenta falling off, and the rims and tips of leaves beginning to wither. Meanwhile, the optimal appearance of upper leaves for picking was yellow in colour, whith maim veins completely white, 2/3 to all of the lateral veins turning white, most of tomenta falling off, and the reins and tips of leaves having withered. When the leaves at different parts of the stalks were picked according to the normal appearance of maturity mentioned above, the tissues were loose, most of tomenta fell off, and chlorophyll content reduced, which was favourable for tobacco processing and quality improvement, such as the increasing of superior tobacco and proper ratios of chemical compositions.