Gamma Ray induction of translocations in the corn earworm, helicoverpa armigera (Hubner), (Lepidoptera: Noctuidae)

Issue Date

10-1997

Abstract

Male pupae (pharate adults) of the corn earworn, Helicoverpa armigera (Hubner), were subjected to 100 and 150 Grey (Gy) of gamma irradiation. Karyological analyses of the normal homogametic male prepipae revealed diploid genomic complement 2n = 62 (30 IIA + ZZ), small homomorphic chromosomes with mean relative length ranging from 0.022 to 0.044 and regular first meiotic behavior. The same were exhibited by the first generation progenies of the crosses between normal males and females. On the other hand, the progenies of matings involving normal females and 100 Gy or 150 Gy irradiated males possessed spermatocytes with heterozygous reciprocal translocations. These translocations appeared as chains and rings at diakinesis. At 100 Gy gamma radiation, the 900 spermatocytes of 30 first generation H. armigera exhibited 71.30% chain, 9.8 ring, 4.9% chain and ring and 14% normal; at 150 Gy gamma radiation, the spermatocytes showed 84.87% chain, 2.71% ring, 12.42% chain and ring and 1.67% normal. Thus, the inheritance of induced partial male sterility was inferred, translocations being markers of gametic infertility.

Source or Periodical Title

The Philippine Entomologist

ISSN

0048-3753

Volume

11

Issue

2

Page

109-117

Document Type

Article

Frequency

semi-annually

Physical Description

tables; illustrations

Language

English

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