Comparative Leaf Anatomy of Different Flue-cured Tobacco Varieties from Zimbabwe and Yunnan

Using the method of slides observation under microscope,this study was conduced to investigate the anatomical structure of the mature fresh leaves from upper,middle and lower stalk positions of four flue-cured tobacco cultivars from Zimbabwe KRK22,KRK23,KRK26,T29 and two varieties K326,Hongda cultivated in Yunnan.The results showed that the dissecting features of KRK26 from Zimbabwe had well-developed mesophyll cell,better arrangement,medium intercellular,leaf thickness,the thickness ratio of palisade to spongy was equal to cultivars of Yunnan.Compared with cultivars of Yunnan,the palisade cell size and cell number of KRK23,T29 were decreased and intercellular was increased,leaf thickness,and its thickness ratio of palisade to spongy and other anatomical parameters were lower.Although the leaf thickness and the thickness ratio of palisade to spongy of KRK22 were higher than cultivars of Yunnan,its intercellular was large,and leaf structure was looser,the palisade cell was disintegrated in the lower leaves.With the rising of the stalk positions,the palisade tissue thickness,the thickness ratio of palisade to spongy,the thickness ratio of palisade to leaf,palisade tissue cell density were increased,and the intercellular of spongy was decreased,the thickest leaf thickness was the upper leaves and thinnest thickness was the middle leaves.