Karyotype analysis of the brain chromosomes of armyworm, Mythimna separata (walker) (Lepidoptera : Noctuidae)

Date

3-1990

Degree

Bachelor of Science in Biology

Major Course

Major in Cell Biology

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Adelina A. Barrion

Abstract

Modified air-drying technique using lacto-aceto-orcein staining was employed to observe the mitotic stages and dotemine the karyotype of the let instar larvae of M. separata, One hundred fifty prometaphease calls were observed and chromusome numbers ranged from 2n=13 to 2n=156 with its moth. at 2n=31, hence, utilized for karyotyping. Chromosome variation appeared to be a natural characteristic of M. seperata. Fragmentltion and fusion are suggested to be the mechanisms responsible for the occurrence of supernumerary chromosomes. The chromosomes of M. separata were holokinetie or has "diffused centromerae" since no specific centromere was observed and the whole chromosomes segregated without exhibiting differential repulsion. The structures of chromosomes varied from rod-like and spherical to ovoid shapes. The actual mean length ranged from 2.4.1. .38 mm to 5.6+ .63 me and relative lengths ranged from 0.018 to 0.045 mm. The mean mitotic index was 0.589.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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