Abstract:
An experiment was carried out at Molecular Biology and Plant Virology Laboratory, under
the Department of Plant Pathology, Sher-e-Bangla Agricultural University, Dhaka-1207.
The study was designed to aid in further experiments and find out the suitable measures to
control rice blast pathogen. The study consisted of the isolation of rice blast pathogen from
the field sample for morphological study, the evaluation of 12 different selected solid
media to have a comparative analysis of their performance on morphological study of
Magnaporthe oryzae, the pathogenicity test through Koch’s postulates and evaluation of
efficacy of four latest chemicals against Magnaporthe oryzae. Diseased samples were
collected randomly from the severely rice blast infected field from Mymensingh and
Thakurgaon districts. The disease affected plant parts were collected and conveyed to the
laboratory for in-vitro experiments. The morphological study was done by observing two
isolates from the collected samples. It is evident that the disease was caused by
Magnaporthe oryzae as the isolates produced pyriform, 3 celled hyaline conidia which had
two septa. Among the 12 selected media PDA, CDA and PSA gave better performance in
terms of mycelial growth and PSA, PR
S
DA for sporulation. On the other hand, PA (Prune
agar) and SA (Starch agar) also gave good performance and these media can be a good
alternative for morphological study and isolation purpose. Among the four selected
fungicides, Amister top 325 SC and Blastin 75 WDG gave 100% mycelial growth
inhibition with 500 ppm, 1000 ppm and 1500 ppm doses against Magnaporthe oryzae invitro.
Besides,
Acibean
28
SC
and
Deconil
500
SC
had
lower
effect
on
rice
blast
pathogen
over
control.
