Abstract:
An experiment was conducted in the Molecular Phytobacteriology Laboratory of
Department of Plant Pathology at Sher-e-Bangla Agricultural University, Dhaka during
the period of May, 2018- October, 2018 to observe the prevalence of Ralstonia
solanacearum in stored potato tuber collected from Narayanganj District of Bangladesh
viz- Hazi Rahmatullah cold storage, Sahin cold storage and Ma cold storage. Ralstonia
solanacearum was isolated from collected potato tubers and it’s morphological,
biochemical and cultural features were studied. On NA medium, circular, mucoid,
convex, lucid coloured colonies of bacterium were formed. It produced highly fluidal,
slightly raised and creamy white colonies with light pink or pinkish red centre and
irregular margin after 48 hrs of incubation at 30
o
C on TTC medium. The bacterium was
gram negative, rod shaped and showed positive result in KOH solubility test, levan
production test, catalase test, oxidase test and pectolytic test. Incidence of Ralstonia
solanacearum is significantly influenced by temperature, relative humidity, ammonia
supply and O
2
supply & CO
removal. Incidence varied significantly from one cold
storage to another cold storage with increase of temperature. Maxmium incidence was
2
found in the month of October (26.21%) at temperature 4.44
ammonia supply 9 hours and O
2
supply & CO
2
o
C, relative humidity 90%,
removal 1hour at Ma cold storage. Lowest
incidence was found 12.42% in May at temperature 1.67
o
C, relative humidity 86%,
ammonia supply 13 hours and O
2
supply & CO
removal 1hour at Sahin cold storage. By
correlation regression analysis confirmed that Maximum incidence was occurred at
highest temperature (4.44
o
C).
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
IN
PLANT PATHOLOGY
