Abstract:
Pineapple wilt disease is a common occurrence in pineapple cultivations
in Sri Lanka. Reddening of leaves, twisting of their tips and wilting of
plants are the characteristic symptoms of this disorder. Clostero shaped virus
particles measuring about 1400-1800 nm x 12 nm and bacilliform virus
particles with dimensions of 133nm x 33 nm were observed in infected
samples of wilted pineapple plants under immuno electron microscopy.
Furthermore Australian made polyclonal antiserum gave a strong positive
colour reaction when tested with wilted pineapple isolates from Sri Lanka.
Pineapple slip suckers known to be infected with clostero and bacilliform
virus particles associated with mealy bug wilt of pineapple, were
heat treated in hot air and water bath at 400,45°,500,55° and 600 C temperatures
for varying time durations. Plant survical was drastically reduced at
600 C. A significant observation was that in both methods of treatment,
plants subjected to 55° C for 15 minutes, gave negative results during the
first month after heat treatment showing it has temporarily suppreseed the
virus in the tissues. However Enzyme linked immunosorbent assay, immunosero
electron microscopy and polymerase chain reaction methods demonstrated
that heat treatment does not elininate permanently, the two types of
virus particles present in wilted pineapple plants in Sri Lanka.
