为了在烟叶分级过程中准确把握烟叶的部位,选用曲靖地区K326品种的3个部位4个橘色等级共12个样品,分别对不同部位主脉的形态、单位长度的质量、颜色、力学性能等方面进行研究,采用图片和数据相结合的方法进行部位识别分析.结果表明:下部烟叶主脉闭合较直,叶面平坦,木质化程度较低,主脉较细、手感发软,主脉颜色浅黄或正黄,折断力小,主脉单位长度质量平均为0.066 g/cm,手感是“飘”的感觉.中部烟叶主脉半遮半露;叶面呈现油润状态;叶面皱褶,木质化程度较下部烟叶高,主脉粗细适中,主脉颜色深黄或浅棕褐色,折断力较大,主脉单位长度质量平均为0.104 g/cm,手感是“实”的感觉.上部烟叶主脉完全显露且主脉直,叶面皱褶有层叠,木质化程度高,主脉硬、较脆,主脉颜色黑色或黑褐色,折断力大,主脉单位长度质量平均为0.151 g/cm,手感是“沉”的感觉.“,”To accurately determine the stalk position of tobacco in leaf grading, 12 samples of four orange colors from three stalk positions of cv. K326 were selected from Qujing in Yunnan. Their shape, weight per unit length, color and mechanical property from the midribs of leaves were studied to identify different stalk positions by combining images with experimental data. The results showed that: lower leaves possessed straightly closed midribs, plain surface with low lignification degree and“floating”feel; their midribs were thin, soft, light yellow or yellow in color, and easy to break with the average weight per unit length of 0.066 g/cm. Middle leaves had half covered midribs, oily and wrinkled surface, a higher lignification degree and“real”feel; their midribs was moderate in thickness, deep yellow or light brown in color and harder to break with the average weight per unit length of 0.104 g/cm. Upper leaves possessed straight and completely revealed midribs, folded and wrinkled surface, with the highest lignification degree and“heavy”feel; their midribs were hard, brittle, black or dark brown in color and the hardest to break with the average weight per unit length of 0.151 g/cm.