The Development Of Glandular Trichomes And Crystal Idioblasts Of Orient Tobacco And The Effect Of Environment On Them

This paper studied on the development of glandular trichomes and crystal idioblasts of oriental tobacco and the effect of environment on them in Yunnan and Xinjiang in addition to pot experiment in Henan Agriculture University during 2001-2002. The results were as follows:The glandular trichomes of oriental tobacco was principally classified by multicell-headed long stalk trichomes,monocell-headed long stalk trichomes and multicell-headed short stalk trichomes .Branched trichomes was hardly observed. Density of short trichomes and long ones and their ratio raised with the increasing of stalk position.The long trichomes had absolute superiority on the leaves,especially on the yonger leaves. The percentage on the lower surface was higher than that on the upper surface.The morphology development of trichomes of two types was studied. Initial cell of the trichomes generally developed into long ones. The primary long trichomes and short ones both issumed from the first and second leaf primordium about 100-200um.The differentiation cells bulging from protoderm developed into long trichomes or short ones in different mode of morphology formation. The long trichomes had longer stalk composed of 2-5 cells and one rod-liking gland head composed of l-8secretory cells. The short trichomes had shorter stalk composed of only one cell and one ball-liking gland head composed of 8-16secretory cells.The trichome density was highest when the leaves was 1 centimetre and appeared to descend gradually during the growth of leaves. The number of trichomes came to maxium when the leaves length was half of mature leaves,then decreased. The density and number of the long trichomes prevailed over short ones during the growth of the leaves though the forming velocity of short trichomes exceeded that of long ones. The trichome density of the leaves of three maturity varied by the leaf position. The trichome density varied by maturity ,leaf position and trichome types during leaf maturing. When the immature leaves turned into proper mature, the total trichome density on the uppeer and lower leaves decreased with obvious variation while no variation on the middle leaves. When the leaves appeared over mature ,only the total trichome density on the lower leaves obviously decreased.The secretion activities of two trichomes was observed. The long trichomes wereclosely related with the stage of leaf development .especially the mature stage.The secretion of gland cells grandually strengthened in the ver-matured leaves.and came to climax when the leaves were proper mature,then weakened when the leaves appeared over mature. A minority of trichomes delayed and had a little of gummy exudate in the fine-matured leaves,consequently secreting much during curing of the leaves.The short trichomes were obviously different from the long ones.The exudate observed in the long trichomes was hardly observed in the short trichomes during the growth ,mature and aging of the leaves.The cuticular constituents about 15 were analyzed by GC/MS,5 compounds were belonged to secretory products of the glandular trichomes and their degradations.The content of cembratriendiol was higher.The trichome density varied in different regions.Compared with Xinjiang,there were higher densities of multicell-headed long stalk trichomes,multicell-headed short stalk trichomes and total trichomes in Yunnan,and multicell-headed long stalk trichomes were especially significant.The effect of different-typed fertilizers on trichome density varied by trichome category and leaf position. The multicell-headed long stalk trichomes were obviously influenced,The monocell-headed long stalk trichomes were affected any the less,however, the short trichomes were hardly influenced.The trichome density in the upper and middle leaves were more influenced than that in the lower leaves.The application of organic fertilizers enhanced the denity of multicell-headed long stalk trichomes and total trichomes of the upper leaves while chemical fertilizers increased the denity of multicell-heade...