Effects of Shading on Leaf Trichome Morphology and Structure and Secretions Content of Flue-Cured Tobacco

By utilizing optical microscopy and transmission electron microscopy,the density,morphology and structure of tobacco trichomes were studied under both shading and natural light.Results showed that,under natural light,the density of trichomes was greater and the number of trichome cells was more. The number of trichomes cells was stable.Its content of inclusion was plentiful and the outline of the cell was vague.Chlorophyll fluorescence was weak.The number of the dark osmiophilic particles was more.There were black sediments near the cell wall.But under the shaded condition,the density of trichomes was smaller,the number of trichomes cells was also stable.The cytoplasm was thin and the outline of trichome cell was clear.Chlorophyll fluorescence was strong while the structure of chloroplast was intact,in which grana thylakoid lamellae was clear and black osmiophilic particles were less.Using GC / MS to analyze the tobacco leaf extract under different light conditions,the content of duvatriene diol,main secretion of tobacco trichome under shaded condition was less than that under the natural light.It indicated that light intensity had significant effect on the development of tobacco leaves and secretion activities of glandular.