Three isolates of Botryodiplodia theobromae isolated from mango,
peach and pear and one isolate of Ftisarium moniliforme isolated front
mango were tested in vitro B. theobromae and F. moniliforme had the
ability to produce many cell wall degrading enzymes in media containing
different carbon sources. Maximum activity of cellulase was recorded at pH
4.5 on media containing CMC.xylanandcellutoseasacarbonsources.lt
was also found that B. theobromae and F. moniliforme revealed a high
activity of xylanase in liquid media containing xylan, CMC, cellulose,
polygalacturonic acid and pectin at pH 4.5-6.8. It was shown also that B.
theobromae isolates and F. moniliforme could produce high quantities of
polygalacturonase (PG). The relationship between incubation periods and a
secretion of degrading enzymes cellulase, xylanase and PG in filtrates of
culture medium containing xylan as a carbon source at pH 4.5 was studied.
The degrading enzymes cellulase, xylanase and PG were determined in
infected mango fruits 5 days after inoculation with B theobromae and F
moniliforme isolates. It was found that B. theobromae isolated from mango
was the highest isolate in producing degrading enzymes at pH 4.5. The
relationship between the time and secretion of degrading enzymes in
infected mango fruits, inoculated with B. theobromae (mango isolate)
showed that the highest secretion of cellulase was after 2 days of inoculation
while secretion of xylanase and PG was after 4 days of inoculation. |
