Genotypic variations in response to various Bacillus thuringiensis endotoxin and strain formulations in the striped stemborer (Chilo suppressalis, Walker) (Lepidoptera : Pyralidae)

Date

4-1994

Degree

Bachelor of Science in Biology

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Cesar G. Demayo

Abstract

Variability in response of the striped stemborer populations to the different St endotoxins and strain formulations were investigated to determine if there exists genetic flexibility in the borers to adapt to the toxin. Different larval populations were treated with endotoxins Cry IAc, Cry IIA and Cry IC; and strains HD73, 261, 231, 105, 99, 92 and 83. Larval populations were evaluated based on the mortality and avoidance parameter. Lethal dosage and larval sensitivity to the toxin were the parameters utilized in determining genotypic variation. Results show population differences in response to . Likewise, segregation of genotypes could be observed, the extent of which is dependent on the nature of the toxin ed. Lethal dosage and toxin sensitivity also varied significantly between populations and the toxins used indicating that populations of the borer differ in their susceptibility to Be strains and endotoxins.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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