Observation and comparison of the Semen Sterculiae Lychnophera prepared by 3 kinds of scanning electron microscope methods
HUANG Yuan-jie;LI Wei-dong;MENG Chun-mei;CHENG Xiao-jing;MO Xiao-min;Life Sciences Institute,Guangxi Medical University;
Morphological characteristics of the Semen Sterculiae Lychnophera were examined by scanning electron microscope( SEM) by using three different preparation techniques of SEM samples including drying directly,conventional method and Osmium tetroxide solution fumigation dyeing after drying. The effect of three treatments above was also analyzed. The results showed that the surface of the thin and fragile outer seed coat had irregular wrinkles,abundant glandular scales and stomatas and a few non-glandular hairs. The epidermal cells were polygonal. The parenchyma cells of the thicker middle layer seed coat were cluster which were crosslinked with each other. The leathery belt,leathery sieve pores,spiral vessels and annular vessels were distributed among the parenchyma cells. The middle layer seed coat expanded remarkably after water absorption and was easy to break the outer seed coat.The parenchyma cells with thin wall were ranged within various sizes and were easier to be broken. The pits and pit membrane were clear. The thin and smooth inner seed coat was composed of hierarchical polygonal cells. Two pieces of endosperm were hypertrophic and cubic or short-rop shaped cells arranged neatly. Cells of the thin cotyledons were rectangular or polygonal,which were closely packed and with abundant stomatas among them. To a certain extent,conventional biological EM sample preparation reflected the ultrastructure of the Semen Sterculiae Lychnophera after water swelling. The imagesobtained were clear,but damage or loss of the structure occurred easily and thus affected the overall view. Drying the sample which was dyed by osmium tetroxide solution fumigation could keep better structure of the Semen Sterculiae Lychnophera and obtain high quality images at the same time. Combined with these two methods was beneficial to understand the characteristics of seed ultrastructure more comprehensively.