Abstract
During germination, orthodox seeds lose their ability to tolerate desiccation resembling recalcitrant seeds. This research aimed to investigate the cell changes during the re-induction of the desiccation tolerance (DT) in Sesbania virgata germinated seeds with 1, 3 and 5 mm long radicles. To re-establish DT, germinated seeds were incubated for 72 h in polyethylene glycol (PEG, -2.04 MPa) before dehydration in silica gel (at 10% moisture content) followed by rehydration. Cell viability was assessed through TUNEL test in dry radicles and transmission electron microscopy in both fresh and dry radicles. The positive-TUNEL confirmed the DNA degradation, through the green fluorescence of the cell nuclei from 5 mm radicle length and the ultra structural evaluations detected loss of cellular content integrity in 3 and 5 mm cell radicles that did not survive dehydration to 10%.
Index terms:
cell viability; transmission electron microscopy; TUNEL test