ABSTRACT
Background: A laboratory bioassay study was conducted to evaluate the in vitro pathogenicity of different isolates of B. bassiana, M. anisopliae
and L. lecanii, against the adults of black bean aphid.
Methods: The PCR-based method was used to identify the different isolates molecularly using sequence information from the ITS
region. The total genomic DNA of the 19 fungal isolates was recovered from aphid cadavers using CTAB. The amplified DNA using
QRT-PCR showed no significant differences in the ANOVA that tested mean cycle threshold (CT) values from the control. Postmolecular identification of the isolated entomopathogen was approved. The single discriminative concentration bioassay was carried
out to determine LT
50 values for each of twelve isolates to determine the most virulent for further studies.
Result: LT
50 values for B. bassiana, M. anisopliae and V. lecanii isolates varied from 110-113, 71-75 and 64-77h, respectively. B.
bassiana isolate BBK2, M. anisopliae isolate MAA2 and V. lecanii isolates VLJ2 were selected for further experiments based on their
discriminating concentration values. LC50 of BBA post-exposure to isolates of V. lecanii, M. anisopliae and B. bassiana was 46, 269
and 251 ppm, respectively. A significant difference in cumulative mortality was recorded between the three EPF. M. anisopliae showed
a higher significant cumulative mortality during the first and second days post-application. Then V. lecanii recorded higher significant
cumulative mortality from the third until the seventh-day post-application. V. lecanii showed higher virulence among the other
entomopathogenic isolates.
 

Title

Legume Research

Publisher

Agricultural Research Communication Centre

Publisher Country

India

Indexing

Thomson Reuters

Impact Factor

0.7

Publication Type

Both (Printed and Online)

Volume

45

Year

2022

Pages

1572-1579