Abstract:
The 'effect of ten crop species along with two different rooting media viz" coco dust
and soil on the root colonization ability of the fungal BCA Purpureocillium
lilacinum and its persistence in rhizosphere of the ten crop species along with the
presence or absence of nematode were evaluated through a test tube experiment in
laboratory and, a pot experiment in shade house. P. lilacinum resulted, in root
colonization in all of the crop species in varying percentage depending on the
rooting media and the crop species themselves. A constant 100% and an average of
45.30% root colonization were obtained in coco dust and in soil, respectively. In
soil, a maximum and a minimum root colonization was observed in cucumber
(67.17%) and chickpea (30.55%), respectively; whereas maize (55.50%), potato
(50%), brinjal (48.14%), cabbage (44.28%), rice (44.26%) and tomato (43.45%);
wheat (37%), soybean (32.07%) gave statistically similar result to cucumber and
chickpea, respectively. Population dynamics of the fungus showed no significant
difference between soil without crop species and soil from the root zone of majority
of the test crop species. Overall, 8 out of 10 crop species showed higher densities
compared to soil. Of them, 3 (maize, brinjal, soybean) showed significantly higher
CFU/g of soil whereas the-rest 5 (rice; wheat, potato; cucumber, chickpea) showed
insignificantly higher CFU/g of soil and conversely, 2 (tomato and cabbage) showed
significantly lower CFU/g of-soil in the rhizospbere compared to soil. Both the crop
species (in most cases) and the nematode population did not exert significant effect
whereas time was the factor to have an obvious effect on the population densities of
P. lilacinum. The reduction in CFU/g of soil compared to initial densities ranged
from 6.5% in brinjal to 14.'6% in cabbage, 9.8% in brinjal to 21.8% in cabbage, and
17.3% in maize to 32% intomato at 10, 20 and 30 DAI.
Description:
A Thesis
Submitted to the Faculty of Agriculture,
Sher-e-Bangla Agricultural University, Dhaka
in Partial fulfillment of the requirements
for the degree of
MASTER OF SCIENCE (MS)
IN
PLANT PATHOLOGY
