Mohamed-Yasseen, Yasseen .
Scanning and Transmission Electron Microscopic Observations on Ultrastructures of Onion Seed .
Scanning electron microscope (SEM) permits a depth of focus hundreds of times greater than the light microscope. SEM and transmission electron microscopy (TEM) studies were performed on onion seeds and seedlings to investigate short storability. Ten cultivars of onion seeds were used in this study and different methods of seed preparation were used for SEM studies. SEM observations of onion seed coat showed shrinkage and cracks which were more pronounced near the hilum area. Onion seeds have a large opened micropyle compared to seed size and fungal growth was obvious. Observations of cryofractured seeds showed the presence of embryo under the protruding part of the hilum while the cotyledon was immersed inside the endosperm. Root tip of seedlings resulted from aged seeds were observed using transmission electron microscopy and showed lipid coalescence and deterioration on plasma membrane. These observations suggested that cracks, seed coat shrinkage and position of embryo facilitate fungal infection and electrolyte leakage which lead to seed aging and lose of seedling vigor.
Log in to add this item to your schedule
1 - Genetic Engineering & Biotechnology Research Institute- University of , Plant Biotechnology, Sadat
Scanning Electron Microscopy.
Presentation Type: Poster:Posters for Sections
Location: Hall A/Convention Center
Date: Monday, August 2nd, 2010
Time: 5:30 PM